# Could the Kriegsmarine IJN neutralize the US War Effort with a combined attack?



## Freebird (Jan 10, 2008)

If the Axis had made joint plans for an attack on the USA Allies, involving submarines, commandos and covert operations to begin at the same time as the Pearl Harbour attack, could it have succeeded?

*1.) The U-boat war*

Some facts to consider, it was not until 5 weeks after "Pearl harbor" that Adm. Donitz's operation "Drumbeat" began with the actions of just 5 *five* submarines off the US East coast, but these were responsible for huge losses. If the Germans had 25 - 30 boats on station at the time of Pearl Harbor, and the Japanese had stationed most of their 63 available long-range boats on the US West Coast or shipping routes, the Axis should have been able to destroy at least 3 or 4 times as much Allied shipping as they did. The Allies lost over 6 million tons in the first year, even losing double that number would have been devastating.

(Quotes from Wikipedia) 


> Each U-boat made routine signals on exiting the Bay of Biscay, which were picked up by the British and plotted in Rodger Winn's London Sub Tracking Room, cabled an early warning to the Royal Canadian Navy. Working on the slimmest of evidence, Winn correctly deduced the target area and passed a detailed warning to Admiral Ernest J. King in the USA of a "heavy concentration of U-boats off the North American seaboard". Rear-Admiral Frank Leighton of the US Combined Operations and Intelligence Center then informed the responsible area commanders, *but little or nothing was done*.
> 
> The primary target area was the "North Atlantic Coastal Frontier", commanded by Rear-Admiral Adolphus Andrews and covering the area from Maine to North Carolina. Andrews had practically no modern forces to work with: on the water he commanded seven Coast Guard cutters, four converted yachts, three 1919-vintage patrol boats, two gunboats dating to 1905, and four wooden submarine chasers. About 100 aircraft were available, but these were short-range models only suitable for training. As a consequence of the traditionally antagonistic relationship between the US Navy and the USAF, all larger aircraft remained under Air Force control, and in any case the Air Force was neither trained nor equipped for anti-submarine work.
> 
> ...



Considering the almost total lack of preparation, and the fact that it took 6 - 10 months for the Allies to respond with Convoys anti-sub measures (the first U-boat on the US East coast was not sunk until April), it's hard to see what would prevent the Axis from wiping out the majority of Allies shipping in the first year


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## Freebird (Jan 13, 2008)

There are several threads dealing with Submarines shipping, I'm going to combine some of the ideas together.

From "How not to use submarines"



Rich46yo said:


> Its interesting that with all the interest in the Pacific war , and the IJN, one reads and hears so little about the IJN submarine force. They started the war with the largest submarine force in the world both in numbers and diversity. Many of their boat designs were very large with incredible ranges, perfect for the Pacific. They had several terrific torpedo designs. One of which, the Long Lance, was the best torpedo in the war. But they also had a very good electric design.
> 
> While they had some early success the IJN boats just didn't do a whole lot in the war. The few American capitol ships they sunk and damaged just didn't mean much in the big picture as American shipbuilding Industry kicked in.
> 
> ...



From "Which submarine was the better one?"



Kurfürst said:


> Simple fact is that in 1942 alone the Kriegmarine sunk more enemy shipping than the USN subs in the entire war; another simple fact is that the Allies could *just* endure that because the immense shipbuilding capacity the US had.



From "Did the US save Europe?"



freebird said:


> Suppose the Japanese had destroyed the fuel storage at Pearl the maintainance facilities there too?
> 
> And if they had used their submarines to sink US shipping in the Pacific?





comiso90 said:


> If you are going to hypothesize that, you may as well throw in catching the carriers.
> 
> At the most, the war would have been prolonged. Japan never wanted to conquer the US. they wanted to pursue their Asian empire building w/o us butting in.
> 
> Industrial might would prevail in the end....



*Could the German U-boats IJN subs have sunk 2 or 3 times as much Allied shipping in 1941-1942? *

Does anybody have an argument why they couldn't?

If they did sink Allied merchants at 2 or 3 times historical values, how would the Allies react?


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## Soren (Jan 13, 2008)

My opinion is yes it could've succeeded. But Stalingrad had to be taken at some point and with it the USSR, to secure the resources necessary, but that wouldn't have been a problem once Stalingrad was conquered. 

Had the German troops been equipped with winterclothes then Stalingrad would've fallen quickly, and any Soviet attempt at a pincer movement would've been made completely impossible. As it was without the winterclothing 60% of army group center was off the frontline just trying to get through the winter, while the last 40% were fighting at Stalingrad against Soviet forces outnumbering them 10 to 1.

So give the German troops their winterclothing in 41 to 42, then the USSR would've been defeated swiftly.

As for the U-boat scenario, it is very plausible if the Japanese let themsselves be indoctrinated in German U-boat tactics.


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## Freebird (Jan 13, 2008)

Soren I'm not sure I can agree with you about the Germans winning at Stalingrad if they only had winter clothes, I think they need to be in a much better position vs. the UK US. Germany WOULD have to beat the USSR, thats for sure. But lets not jump ahead too fast, the situation on the ground would depend on what happens in the rest of the ETO. 

The British were at the point of cancelling operations in the Far East in 1943 due to the "British Import Crisis", from the 5 million UK tons lost in the first 15 months. If for example they lost 6 or 8 million tons in the first 6 months of the war, could they keep up supplies to the Desert Army? Not unless they have some other option. And if the US has lost 4 - 6 million tons by Nov 1942, they can't keep operations going in the Pacific do "Torch" as well. 

If the Germans were still in secure N. Africa, they could have 150,000 - 200,000 more troops in Russia. Now *this would make a huge difference at Stalingrad*.

Also, with the shipping situation going from "strained" in 1942 to "extreme crisis", would the Allies be able to send anything to Russia at all in 1942?


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## Freebird (Jan 13, 2008)

Soren said:


> As for the U-boat scenario, it is very plausible if the Japanese let themselves be indoctrinated in German U-boat tactics.



Ok I'll set out the scenario and see what people think.

*1.* The Japanese take Germany's advice, they send out all 63 of their subs to be ready the minute bombs drop at "Pearl Harbor", they target shipping at all of the major Allied ports in the Pacific Indian Ocean. 



Glider said:


> The IJN had the subs to create all sorts of problems for the US it was their approach to using them that was a missed oppertunity. They had the range to attack almost anywhere on the US West coast. This alone would have caused the US to spread their forces across half the Pacific, leaving weak spots.
> The Japanese also had enough submarines to launch co-odrinated attacks on convoys using similar wolf pack tactics. There is a lot of ocean between the US and the pacific bases and it could have been used to effect.
> A small point about the Japanese using submarines to resupply the army bases on the islands. The IJA had their own submarines for resupply, hard to believe but true.
> Also the Japanese subs could dive quite quickly the earlier ones were a little slow but considering their size it was quite good and the later ones were very handy.
> As for the diving depth, no submarines could match the Germans in this area so there is no shame in not matching them.





syscom3 said:


> As for IJN wolf packs, I would have a "team" of 3 or more boats stationed in the following area's to tie up US escorts:
> 
> Between *Hawaii* and The US Mainland
> 
> ...



Syscom in late 1941 there is not even really much need to use "wolf packs", which were developed by Donitz to try to mass attack and "overload" protected convoys.

The IJN should send 2 or 3 subs to lurk outside all of the major pacific ports, in the Fall of '41 *all of the merchant ships were unescorted in the Pacific/Indian Ocean, and ASW capabilitys were almost zero.*

Of the 63 Japanese Ocean-going subs they could send out,
3 subs to each of the following:

San Diego
San Fransisco
Los Angeles
Seattle
Sydney, Aus.
Pacific entrance to Panama Canal
Aden the approach to the Red Sea

And 2 subs to each of the following:

Hawaiian Islands
Portland, Or.
Brisbane, Aus.
Perth, Aus.
Melbourne, Aus.
Auckland, N.Z.
Wellington, N.Z.
Calcutta, In.
Bombay, In.
Karachi, Pak.
Mombassa/Zanzibar, Africa
Durban/Port Elizabeth, Africa
Cape Town, S.A.
Suva, Fiji
Batavia, Java
Borneo
New Caledonia
Rangoon, Burma
Ceylon
Singapore
Straights of Hormuz (Persian Gulf)


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## Freebird (Jan 13, 2008)

comiso90 said:


> If you are going to hypothesize that, you may as well throw in catching the carriers.



Why not, better to consider the "worst case scenario"

*2.* The Japanese attack "Pearl harbor" as they originally planned, which was if negotiations did not succeed, they planned to attack at the end of October. (Scary monsters come out on Halloween?  ) 

So they attack at the end of Oct, they catch all 3 US Pacific Carriers in port and sink them. Because Nagumo is not worried about the US carriers surprising him, he sends in a third, fourth fifth wave, destroying the Oil tanks, Sub base, repair shops, and destroys 24 destroyers 5 cruisers and badly damages the rest (5 DD 3 CA)

*3.* The Germans have been warned about the attack by the Japanese, so they have 40 - 50 U-boats waiting in the US West Coast Caribbean ports ready to commence operations. They have also bullied the Vichy French into allowing them the use of Martinique other ports for supply. 

*4. *Nazi Germany does not declare war on the America, and the US Congress adopts a "Pacific First" strategy, although they will still send some munitions supplies to the UK and Russia (if there are any ships to carry them on....) 

In this scenario I can't see the Allies losing any less than 7 - 10 million tons in the first 6 months, and another 4 - 8 in months 7 - 12. There are just too many unprotected ships, and it will take time to get them to safe ports or in convoys.


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## Soren (Jan 13, 2008)

Freebird,

With the last 60% of Army Group Center the Germans would've taken Stalingrad, there's no doubt about that, the 40% actually there already achieved to capture 90% of the city before winter set in. Now if the KM in addition to winterclothing being shipped by the OKW could occupy the USN with the help of the Japanese in Pacific then there would suddenly be a whole lot of men available in the east - atleast another 650,000 to 700,000.

With the USSR defeated the Germans could comfortably venture into a prolonged war in the pacific as-well, but isolating Britain would still be important if an invasion was to be considered. 

With unlimited resources as would be present with the capture of the USSR the Type XXI could be sent into service already by late 1943, and with that the Antlantic would've been secured. 

As to your worst case scenario, I agree. If the Germans alone had been warned by the Japanese of the attack at Pealr Harbour and placed 40 - 50 U-boats to hunt down sink the US carrier fleet emmidiately after the attack (In this case the IJN doesn't sink them) it would've spelled no less than a disaster for the USN. The Japanese would suddenly have complete naval air-superiority over the pacific. The addition of the German KM in the Pacific would've indeed been a nightmarish situation to be facing for US .


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## Glider (Jan 13, 2008)

Had the Germans and Japanese co operated and co ordinated their attack I have no doubt that they would have inflicted considerable losses to the allied vessels over and above the losses incurred.
However the allies would have responded differently and introduced convoys much sooner than they did off the USA coast. Losses of that size would have put ASW at the top of the Allied priority list.
Could the Japanese and Germans sustained that type of attack. Probably yes but at a reduced rate, could they have won? probably not given the technical resources available to both sides.

I am afraid that the Type XXI could not have been introduced into into service during 1943, the preliminary design wasn't finished until mid 1943. Interestingly the Japanese were ahead of the Germans in this area with a prototype high speed underwater submarine based on a significant increase in in battery power and streamlining in operation in 1939. Fortunately for the allies, the Japanese didn't follow this up until late 1944. So if anyone could have had a true submarine in 1943, it would have been the Japanese.


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## Freebird (Jan 13, 2008)

Glider said:


> Had the Germans and Japanese co operated and co ordinated their attack I have no doubt that they would have inflicted considerable losses to the allied vessels over and above the losses incurred.
> However the allies would have responded differently and introduced convoys much sooner than they did off the USA coast.



Glider the problem is that the British were hard pressed to keep the convoy escorts in the North Atlantic in 1942, the USA had very little available to help with this job, they could not introduce convoys even if they wanted to. Remember it takes not only ships, (DD, DE, sloops etc) but they needed ASW equipment (Sonar, Hedgehog) and trained crew. Even after Adm. King finally agreed to put in convoys, it still took a few more months to put it all in place. And we are only talking US East Coast Caribbean here. Imagine if the Allies had to do this on the US West coast, the S. Pacific, Indian Ocean, African, Australian ports as well. The alternative is that all the ships would be stuck in port because there is no escort available. (which is what actually happened in summer 1942 on the US East coast)



Glider said:


> Losses of that size would have put ASW at the top of the Allied priority list.
> Could the Japanese and Germans sustained that type of attack. Probably yes but at a reduced rate, could they have won? probably not given the technical resources available to both sides.



For example if the last two months of 1941 the Allies lose 4 - 5 million tons worldwide. In January the Allied governments go into crisis mode, but what can they do? The US must continue to supply Hawaii, Australia the outposts at Midway, American Samoa, Tonga, NZ, etc. The British must continue to send supplies to Egypt, Malta, India, Burma, Malaya, Australia others. The US UK might lose another 4 - 5 million tons in the first quarter of 1942.

The "British Import Crisis" in March 1943 resulted after the British lost 5.1 million tons in the first 15 months after Pearl Harbour, but they built only 2.2 million tons in that time. Nevertheless, losing less than 3 million net put us into crisis mode

HyperWar: British War Economy [Chapter XIV]

British Import Crisis

I'm afraid that the loss of so much tonnage would mean abandoning the Far East (Malaya Burma), or Egypt, or even both. With the USA losing so much of its fleet, it would be in no position to help out, as it did historically in 1943


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## Soren (Jan 13, 2008)

Glider,

Regarding the Type XXI, it could like I said have been sent into service by late 1943 to early 1944. As it was the boat was already being constructed in 1943.



> Probably yes but at a reduced rate, could they have won? probably not given the technical resources available to both sides.



Technical resources ? Like what ?

I strongly believe they could've won the Pacific, esp. with the Japanese employing German U-boat tactics, and with the help of the KM U-boats the USN wouldn't stand much chance. There'd litterally be swarming with subs in the Pacific and the IJN would make sure the airspace was clear.

Also I think that a close co-operation in the Pacific would've lead to larger exchanges of technology between the two nations, something which would've undoubtedly been of large benefit to Japan. If the Japanese had started building AFV's a/c like the Germans it would've been all over for the Allies.


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## plan_D (Jan 13, 2008)

Would the German U-boats be supplied from Japanese bases or German ones? The trip to the Pacific from Brest is a long way; I see the only option being Japanese supply bases in the Pacific. If that's the case, would the Japanese be able to keep those bases supplied from Japan - after all, the supply situation would cause greater demand as they would now have two submarine fleets in operation. 
I'm certainly no expert on the Pacific submarine war, but weren't the Japanese submarines in the fleet? When the fleet wasn't in operations, nor were the submarines - correct? If that's so, which it may not be, wouldn't the Japanese supply situation be worsened if they took up the (excellent) submarine wolfpack tactics of the Germans?

Soren, I don't believe the Japanese would have done any good with Panthers or Tigers. The only real benefits would be the Pz.kpfw III, Pz.Kpfw IV, Sd.Kfz 251 and possibly a few SPGs. The war in the Pacific wasn't really an armour war, more infantry. The only real benefit in aircraft design (in my opinion) would be a small number of Bf 109s for home defence, German aircraft range was too short for Pacific and CBI operations.


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## syscom3 (Jan 13, 2008)

Why would Japan want to build mechanized forces?

They were short of oil, short of high quality armor steel and short of shipping to keep things running.

And then where were you going to use them?

While the concept of having IJN U-Boats run amok in the Pacific is interesting, remember the following:

1) The Pacific is a huge place in which to route convoys.
2) The IJN never did have the forward bases in which to sustain operations. Look at the distance from Truk and Eniwetok to the west coast of America. Just getting from their bases to there would take a combined month or two off of their missions. (Similar to the USN sorties from Midway to the Japanese home Islands). And the facilities at these bases was never more than enough to do simple repairs and outfitting.
3) The IJN sub force was always prone to being located and sunk. Once the escorts had radar, the subs would be having a tough time to attack with impunity.
4) Dont underestimate the ability of the IJN command structure to muck things up.


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## plan_D (Jan 13, 2008)

I think the Japanese would have benefited from the German Pz.Kpfw III and IV at the very least; I recognise that most of the PTO and CBI was fought in jungle conditions but there was armoured conflict. The presence of effective armour would have been most felt in China. 

I'm pretty sure that we're all aware of the Japanese Tiger and Panther - a silly idea in my opinion, far too big for the enclosed spaces the Japanese Army would be fighting in.


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## Freebird (Jan 13, 2008)

plan_D said:


> Would the German U-boats be supplied from Japanese bases or German ones? The trip to the Pacific from Brest is a long way; I see the only option being Japanese supply bases in the Pacific. If that's the case, would the Japanese be able to keep those bases supplied from Japan - after all, the supply situation would cause greater demand as they would now have two submarine fleets in operation.



Plan D, the Japanese had the longest and biggest submarines of anyone, including the Germans, so they could operate anywhere in the Pacific or Indian Ocean from Rabaul, Truk, Singapore or even right from Japan. The Germans would operate where they did historicaly, except that they would be in place off the US ports right after the Pearl Harbor attack, instead of waiting 5 weeks to go into action. The Germans aslo re-fueled somewhat chandestinly from the Canary Islands, Azores and maybe also the French ports in the Caribbean Africa. 



> I'm certainly no expert on the Pacific submarine war, but weren't the Japanese submarines in the fleet? When the fleet wasn't in operations, nor were the submarines - correct? If that's so, which it may not be, wouldn't the Japanese supply situation be worsened if they took up the (excellent) submarine wolfpack tactics of the Germans?



The IJN submarines were very poorly used, (see quotes from Rich Glider) they were mostly "fleet aux. boats" waiting for weeks to try to hit a US Carrier, or carrying supplies. What the Japanese didn't realize is it's easier to put an Allied task force out of action by cutting off its supplies than trying to sink carriers. 

P D, I think the Axis strategy would be to choke off the supplies going to Egypt, Burma India, and then they would conquer all of Asia


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## plan_D (Jan 13, 2008)

Even with the long range of the Japanese submarine, it would be ideal to have a forward operating base to reduce the turnaround time after every operation. After all, long range doesn't reduce travel time - moving from Hawaii to Japan, or even Rabaul takes some time. How large was the Japanese submarine fleet in comparison the German fleet ? It's a difficult task maintaining a blockade, the question is whether the Japanese and Germans would have enough to maintain a constant blockade all year on every route throughout the Allied terrorities. 

I was going by Soren's idea of Germans operating in the Pacific. The U-boats historical bases of operations wouldn't be good enough for such an adventure. They would have to operate from bases in the Pacific - which would increase the pressure on the Japanese supply system.
And as I said before, if the Japanese are using their submarines like the Germans - then their supply demand would be larger thus stretching Japanese supplies even more.


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## Freebird (Jan 13, 2008)

syscom3 said:


> Why would Japan want to build mechanized forces?
> 
> They were short of oil, short of high quality armor steel and short of shipping to keep things running.
> 
> ...



They would mainly wait in harbour approaches, around major ports like Sydney, Calcutta, Auckland, Melbourne, Durban, Batavia, Bombay etc.


> 2) The IJN never did have the forward bases in which to sustain operations. Look at the distance from Truk and Eniwetok to the west coast of America. Just getting from their bases to there would take a combined month or two off of their missions. (Similar to the USN sorties from Midway to the Japanese home Islands). And the facilities at these bases was never more than enough to do simple repairs and outfitting.



Syscom, once the Japanese have Singapore (Magnificent base kindly built equipped by the British taxpayer!  ) It is centrally located to threaten Burma, India, Java, Australia. The Japanese also had a plan to buils a sub base in Madegascar.



> 3) The IJN sub force was always prone to being located and sunk. Once the escorts had radar, the subs would be having a tough time to attack with impunity.



The US Britain have their hands full in the Atlantic US West Coast, it would take 8 - 12 months* minimum* to institute convoys strong ASW in Australia Indian Ocean. 


> 4) Dont underestimate the ability of the IJN command structure to muck things up.



Thats the only thing that might save us....


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## Freebird (Jan 13, 2008)

plan_D said:


> Even with the long range of the Japanese submarine, it would be ideal to have a forward operating base to reduce the turnaround time after every operation. After all, long range doesn't reduce travel time - moving from Hawaii to Japan, or even Rabaul takes some time. How large was the Japanese submarine fleet in comparison the German fleet?


 
In the fall of 1941, (Pearl Harbour) the Japanese have 63 long range boats, the Germans had about 100



> It's a difficult task maintaining a blockade, the question is whether the Japanese and Germans would have enough to maintain a constant blockade all year on every route throughout the Allied terrorities.



Actually, its harder on the Allies. In 1942 the Axis have submarines patrolling the weakly defended Pacific Indian ports, sinking targets of oppertunity. Meanwhile the Allied cargo fleets are stuck in port, because of a lack of escorts.



> I was going by Soren's idea of Germans operating in the Pacific. The U-boats historical bases of operations wouldn't be good enough for such an adventure. They would have to operate from bases in the Pacific - which would increase the pressure on the Japanese supply system.
> And as I said before, if the Japanese are using their submarines like the Germans - then their supply demand would be larger thus stretching Japanese supplies even more.



Plan D, I think when Soren said "with the help of the KM" he meant that with the U-boats tying up the very limited Allied escort ASW resources in 1942, the Japanese would have an easier time. (at least that's what he SHOULD have meant!) The Germans would not be able to get very far out of the Atlantic, there are enough targets already!


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## Soren (Jan 13, 2008)

The KM subs wouldn't stray far from the Atlantic for any lon period of time as long as the USSR still existed, however with the USSR defeated the KM could comfortably engage in a prolonged war in the Pacific. In Freebird's scenario it is my understanding that the KM U-boats would only be there to sink the USN carrier fleet and any remaining ships after the Pearl Harbour attack, and then the IJN subs would take over employing German wolfpack tactics. 

Now that having been said, it would've meanwhile been a whole lot easier for the German U-boats in Atlantic, with the US being unable to send many merchant ships and the British having to haul it nearly all alone. Isolating Britain wouldn't have been too hard in this case. What this means is that the Germans could send subs to the Pacific to help out the IJN, ofcourse utilizing the same refueling locations. And then ofcourse there was the milk cows, the Japanese would've undoubtedly have some huge milk cows with the task of refueling submarine force. 

Hope that cleared up what I meant.


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## Freebird (Jan 14, 2008)

Soren said:


> The KM subs wouldn't stray far from the Atlantic for any logn period of time as long as the USSR still existed, however with the USSR defeated the KM could comfortably engage in a prolonged war in the Pacific.


 Soren I don't think the KM boats with the shorter range would get into the Pacific, obviously it would be almost impossible to sneak through the Panama Canal. If they were to stray outside the Atlantic it would probably be only if the KM IJN have a base in the Indian Ocean (Madagascar). 



> In Freebird's scenario it is my understanding that the KM U-boats would only be there to sink the USN carrier fleet and any remaining ships after the Pearl Harbour attack, and then the IJN subs would take over employing German wolfpack tactics.



No actually I think the KM U-boats would be lucky if they could hit even 1 Carrier. The 3 Pacific US carriers were lost at "Pearl" the US would bring 3 or maybe even all 4 remaining carriers into the Pacific. The U-boats would be taking advantage of the 6 months+ of disorganization on the Atlantic Caribbean coasts to destroy as much shipping as possible.



> Now that having been said, it would've meanwhile been a whole lot easier for the German U-boats in Atlantic, with the US being unable to send many merchant ships and the British having to haul it nearly all alone. Isolating Britain wouldn't have been too hard in this case.



Britain would not have been isolated, what is most likely is that Royal Navy would continue to run heavily escorted convoys to the UK, which the U-boats could not seriously impede. However this would be at the cost of the war effort in Egypt, Australia the Far East.



> What this means is that the Germans could send subs to the Pacific to help out the IJN, ofcourse utilizing the same refueling locations. And then ofcourse there was the milk cows, the Japanese would've undoubtedly have some huge milk cows with the task of refueling submarine force.
> Hope that cleared up what I meant.



I think the Germans WOULD re-build their supply-subs, but as I said earlier they wouldn't operate in the Pacific. As the North Atlantic became more protected they would look for targets in the South Atlantic, and make an occasional massed "wolf-pack" attack on a Halifax-Liverpool convoy, attempting to overwhelm the escorts. This would prevent the Royal Navy from pulling escorts from the N. Atlantic route and sending them to the Indian Ocean or Pacific. Again, this is basically what really happened, except that the Japanese never took advantage of it.


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## Freebird (Jan 14, 2008)

Glider said:


> Had the Germans and Japanese co operated and co ordinated their attack I have no doubt that they would have inflicted considerable losses to the allied vessels over and above the losses incurred.
> However the allies would have responded differently and introduced convoys much sooner than they did off the USA coast. Losses of that size would have put ASW at the top of the Allied priority list.





renrich said:


> The outcome of the war at least at one point largely hinged on the "Battle of the Atlantic" To me the "Battle of the Atlantic" now seems to fall into the same category as the BOB, not quite as close run as previously thought.



Here is the problem that the British face. They can aviod heavy losses by running well protected convoys, but with the limited ASW available most non-Atlantic shipping did not have much protection, if any.

Suppose for example that in the first 3 months of the war the IJN KM sink 2 million tons average per month. in months 4 5 they sink 1.5 million/month, and in month 6 this falls to 1.25 million.

After 6 months the Allies have lost 10.25 million tons, which might break down as 3.75 US 6.5 British (million tons lost). Of the British losses probably 1.75 million would be tankers, and 4.75 million would be "Dry cargo".

In the fall of 1941 the British have 15.5 million tons "Dry Cargo" capacity, + 5 million tons of tankers. The Shipping board statistics report that normally 10% of the total is unavailable at any one time, due to breakdowns, repairs, or in drydock fixing battle damage. (many were hit by torpedoes but didn't sink)

Of the 14 million available "Dry Cargo", the British fleets are shown on the map below. Every single fleet is strained and short of tonnage, there is no "Reserve" available. Most of the shipping runs in complicated routes, so it is very difficult to transfer quickly. For example, a (South Atlantic) ship leaves Britain with war supplies for West Africa and South Africa. In W. Africa it unloads some cargo, and loads additional raw materials for S. Africa. In S. Africa it unloads and then loads coal bound for Argentina. In Argentina it unloads the coal and then re-loads with bales of meat grain for the Caribbean. In Jamaica or Trinidad it unloads, then re-loads at Georgetown (Guiana) with cargo of Bauxite for Britain. The outbound ships of the Indian Ocean fleet are fully loaded with war supplies for Egypt, Malaya, India Australia, they then reload with meat from Australia, or raw materials from India, Malaya Africa. (Tin, Rubber, Bauxite etc.). The Australian fleet loads food for India Africa, and returns with goods raw materials for the domestic factories. The Pacific fleet supplies not only NZ, but also Fiji, Tonga, Tahiti New Caledonia. The Med fleet is used to supply Malta, Cyprus Tobruk, is also used by the Military for operations.


*Here is the problem: Where can the British subtract the 4.75 million tons without severe consequences in operations?* Unless they have some other option available (such as a Trans-Africa rail link) they would probably lose Egypt India


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## Glider (Jan 14, 2008)

freebird said:


> Glider the problem is that the British were hard pressed to keep the convoy escorts in the North Atlantic in 1942, the USA had very little available to help with this job, they could not introduce convoys even if they wanted to. Remember it takes not only ships, (DD, DE, sloops etc) but they needed ASW equipment (Sonar, Hedgehog) and trained crew. Even after Adm. King finally agreed to put in convoys, it still took a few more months to put it all in place. And we are only talking US East Coast Caribbean here. Imagine if the Allies had to do this on the US West coast, the S. Pacific, Indian Ocean, African, Australian ports as well. The alternative is that all the ships would be stuck in port because there is no escort available. (which is what actually happened in summer 1942 on the US East coast)
> 
> 
> 
> ...



I don't disagree with this and have no doubt that we might have had to give up the far east. The Med no. However in the long run the allies would have won due to their increased production. The USA could have and I believe would have put convoys at the top of their priority. The USN had a large number of destroyers that were used exclusively for 'Fleet' operations and I believe would have been used for convoys.


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## Glider (Jan 14, 2008)

Soren said:


> Glider,
> 
> Regarding the Type XXI, it could like I said have been sent into service by late 1943 to early 1944. As it was the boat was already being constructed in 1943.


I am sorry but it couldn't have been in service that fast. The design was completed in June 1943 and authorisation to proceed given on August 1943. Production went straight away without a prototype and it couldn't have gone ahead any faster. The minimum planned building time was 6 months and obviously the building yards need to time to prepare and the first Type XXI was commissioned in June 1944.



> Technical resources ? Like what ?



The ASW technology available to the Allies and their production ability.



> I strongly believe they could've won the Pacific, esp. with the Japanese employing German U-boat tactics, and with the help of the KM U-boats the USN wouldn't stand much chance. There'd litterally be swarming with subs in the Pacific and the IJN would make sure the airspace was clear.


For every sub on station at least another four are in support, one on the way to the station, one on the way back from the station, one being maintained and another being worked up. The headline numbers should take this into account 



> Also I think that a close co-operation in the Pacific would've lead to larger exchanges of technology between the two nations, something which would've undoubtedly been of large benefit to Japan. If the Japanese had started building AFV's a/c like the Germans it would've been all over for the Allies.



There is no doubt that the axis forces would have caused significant additional losses if they had co operated. Would they have won? who knows


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## renrich (Jan 14, 2008)

To begin with the Japanese doctrine with subs was that they were to operate with the fleet not to sink merchant ships. There were a number of I boats outside of Pearl Harbor during the sneak attack and they sank nothing. If the IJN had 63 ocean going subs it is preposterous to think they could all be on station at once. Probably less than half if every sub they had was taken away from the fleet. The Jap admirals were not about to turn loose of their subs. However, to think that 30 or so subs could have a significant impact on shipping in the Pacific seems implausible. To begin with, the merchant shipping in the Pacific was never as profuse as in the Atlantic and spread over a much larger area. The amount of time an I boat could stay on station off the US west coast would be severely limited because of the distance involved. The U-boat threat was pretty much over with by mid 1942 anyway. Doenitz by concentrating his boats off the American coast in early 1942 may have resulted in a lot of easy sinkings but it gave an invaluable relief to the North Atlantic convoys and from that time on the issue was never in doubt. Once the US was in the war, the issue as far as who would win was settled. It was just a matter of how long before it was over.


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## Freebird (Jan 15, 2008)

renrich said:


> To begin with the Japanese doctrine with subs was that they were to operate with the fleet not to sink merchant ships. There were a number of I boats outside of Pearl Harbor during the sneak attack and they sank nothing. If the IJN had 63 ocean going subs it is preposterous to think they could all be on station at once. The Jap admirals were not about to turn loose of their subs.



Well I said as part of the scenario "what if" the IJN had taken Germany's advice and used their subs against shipping. So the Admirals would be told to do so whether they agreed or not. 

They could certainly have all of their boats ready on station outside Allied ports right after "Pearl". After the first patrol they could probably keep half of their subs on station at any one time.



> *However, to think that 30 or so subs could have a significant impact on shipping in the Pacific seems implausible*. To begin with, the merchant shipping in the Pacific was never as profuse as in the Atlantic and spread over a much larger area.



Why implausible? The Germans created havoc on the US East coast with no more than a dozen or two boats. The shipping routes all converge on the harbours, where there will be more than enough targets. 



> he amount of time an I boat could stay on station off the US west coast would be severely limited because of the distance involved.



The distance from Tarawa Marshall Islands to San Fransisco or Los Angeles is about 4,000 miles, compared to the 4,500 miles that German U-boats traveled to attack shipping in the Caribbean or US Gulf Coast, and the Japanese boats had longer range than the Germans



> The U-boat threat was pretty much over with by mid 1942 anyway.


Actually the worst period for the Allies was from May-Nov 1942 when the German Italian subs sank an average of 600,000 tons/month



> Once the US was in the war, the issue as far as who would win was settled. It was just a matter of how long before it was over.



Pehaps, but not guaranteed. If the Axis had seriously disrupted shipments to Russia won in N. Africa, Germany had a chance of beating the Soviets. Also if the Axis had prevented the British from defending Burma, India Persia the whole course of the war could be different.


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## Hunter368 (Jan 15, 2008)

renrich said:


> Once the US was in the war, the issue as far as who would win was settled. It was just a matter of how long before it was over.



Can't agree with that comment.


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## syscom3 (Jan 15, 2008)

Hunter368 said:


> Can't agree with that comment.



I'd say once the US had the atomic bomb, it was only a question on who was going to get nuked first.

In 1944, the US had the industrial and logistics capabilities to do pretty much what it wanted to do (except for a direct invasion of Europe, where the Brits would be needed).


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## Freebird (Jan 15, 2008)

*I have questions about the US strategy,* for Renrich Syscom (or anyone else). 

*Suppose that the Japanese had captured or occupied Tahiti, Cook Islands American Samoa right after "Pearl Harbour" at the same time as they occupied Tarawa.* {area on map "Possible Japanese Expansion"} Would the U.S. still support the "ABDA" plan, to try to prevent Japan from taking Java, Sumatra New Guinea? Or would they concentrate everything on the Western Pacific Hawaii/Tahiti axis? 

Assume that the USA is pursuing a "Pacific First" policy, so they have all 4 remaining fleet carriers available in the Pacific. The British could contribute 2 fleet carriers to "ABDA", + adequate supporting elements (BB's, DD's, CA's etc)

Do you think it would be best to attack the Japanese perimiter from 2 directions, (SW NE) to split the defence, or to concentrate all in one group?

{see map}


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## Hunter368 (Jan 15, 2008)

syscom3 said:


> I'd say once the US had the atomic bomb, it was only a question on who was going to get nuked first.
> 
> In 1944, the US had the industrial and logistics capabilities to do pretty much what it wanted to do (except for a direct invasion of Europe, where the Brits would be needed).




I would agree with the nuke comment, but when they entered the war in 41 they did not have a nuke. So to "assume" the war was over just b/c USA had entered the war is not a fair statement. Not to mention it was a race to see who made the first nuke, just happen to be the USA.

The second part of your comment:

I would agree that they had more industrial power then any single nation had, but that does not make them the winner in any war, not to mention WW2. As I am sure you would agree. The next comment I would say is that, while the USA had the biggest industrial base, but did they have the will to fight and lose millions of dead (if other Allied powers did not do the dirty ground work) or did the American people of the will to nuke and kill millions of innocent people (none soldiers)?

It's one thing to say I could kill you, it's another if you actually have the will to drop the bomb......over and over and over again killing millions.

But I could also be just reading into your last comment too far, perhaps your comment that "they could do just about anything they wanted" was too general and I read more into it then you meant. If so ignore the last 75% of this post.


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## syscom3 (Jan 15, 2008)

Hunter368 said:


> I would agree with the nuke comment, but when they entered the war in 41 they did not have a nuke. So to "assume" the war was over just b/c USA had entered the war is not a fair statement. Not to mention it was a race to see who made the first nuke, just happen to be the USA.
> 
> The second part of your comment:
> 
> ...



In 1944, the USN and AAF was so overwhelmingly dominat in the Pacific, that the Japanese were just being swept aside with minimal effort (as compared to the casualties taken in battles with the Germans). 

There was nothing the IJN and IJA could do to stop the US war machine in 1944, even if they had a fully intact navy as they had at the start of the war.

As for killing "innocent" people with a nuke? No problem. We had no compunture to do it on the Japanese, and no problem doing it to the Germans.


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## Hunter368 (Jan 15, 2008)

syscom3 said:


> In 1944, the USN and AAF was so overwhelmingly dominat in the Pacific, that the Japanese were just being swept aside with minimal effort (as compared to the casualties taken in battles with the Germans).
> 
> There was nothing the IJN and IJA could do to stop the US war machine in 1944, even if they had a fully intact navy as they had at the start of the war.
> 
> As for killing "innocent" people with a nuke? No problem. We had no compunture to do it on the Japanese, and no problem doing it to the Germans.



Agree in 44 USA did have "little problems" with Japanese.

USA did not kill millions in Japan and they looked at the Japanese as almost less then human......nuking them was not as hard. But I still question would of the American people killed millions of Japanese.

But agree defeating Japanese does not mean you would of won the war. Not to mention if things would of happened just a little different the war might of ended very differently. What I am saying is, just b/c USA entered the war in 41 does not make it a lock for the Allies to win. It just helped a great deal.

The war in ETO was different then the PTO......it was more civilized then PTO. Not so sure American people would of been so quick nuking German, Italian, Russian, etc cities. Many Americans had strong ties to families in Europe, not sure they would quick to nuke them one after the other. That makes getting dirty and fighting on the ground.......again America has never had strong will to take heavy causalities in war.

Would she of been willing take so many causalities (on the level as Germany or Russia) to win the war? Or would of she instead sued for peace getting the best agreement she could. I think she would of sued for peace and would of gotten fairly good agreement in her favor instead of suffering causalities in the millions.


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## syscom3 (Jan 15, 2008)

Hunter368 said:


> ......it was more civilized then PTO. Not so sure American people would of been so quick nuking German, Italian, Russian, etc cities. Many Americans had strong ties to families in Europe, not sure they would quick to nuke them one after the other. That makes getting dirty and fighting on the ground.......again America has never had strong will to take heavy causalities in war.
> 
> Would she of been willing take so many causalities (on the level as Germany or Russia) to win the war? Or would of she instead sued for peace getting the best agreement she could. I think she would of sued for peace and would of gotten fairly good agreement in her favor instead of suffering causalities in the millions.



There was very little "love" for the Germans in those years. Given the choice between taking lots of allied casualties and inflicting punishment on the Germans that would have forced them to surrender, then the US people would have supported it completely.

As for civilized? I dont think so. Only difference between the war in the two theaters, was surrendering was an option in which you could be reasonably sure you wouldnt be executed on the spot.


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## syscom3 (Jan 15, 2008)

We were reading the japanese messages sent back and forth to the subs, so the ones on station would eventually be found and sunk.

If this scenario were to have actually have happened, the IJN sub force would had a spectacular but short career.


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## Freebird (Jan 15, 2008)

syscom3 said:


> We were reading the japanese messages sent back and forth to the subs, so the ones on station would eventually be found and sunk.
> 
> If this scenario were to have actually have happened, the IJN sub force would had a spectacular but *short career.*


 ??

We were reading the German transmissions too for all the good it did in early '42.

The USN had U-boats off the East Coast but could not sink any until April 1942. They did not institute convoys until May/June '42, because of a lack of escorts capable of ASW, and finally began ASW operations with the help of experienced Royal Navy ASW corvettes. *How would the US deal with sinkings on the US West Coast when they were unable to deal with it on the East Coast?* I don't doubt that the US would sink some Japanese subs, but very few in the first 6 months or so, meanwhile the shipping would have taken a heavy hit. 

And you are correct, by 1944 the US production will be huge. The question would be could the Japanese buy enough time in '42-'43 to consolidate gains.
When you talk about the massive US shipbuilding, remember that at maximum capacity it can build about 1.1 million tons/month. *Even so the US was short on shipping capacity right up until 1945.* So losing an extra 4 - 6 million tons in 1942 will have an impact for the next two years.


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## syscom3 (Jan 16, 2008)

The first warship sunk by a US sub in WW2 was a Japanese sub ambushed near Midway.

The USN intel people deduced its projected location because the IJN was too "chatty".

Theres no reason to believe that things would have been different in your scenario.


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## plan_D (Jan 16, 2008)

It is certainly an interesting scenario, and there definately would be increased losses of merchant shipping. As I said before though, it is a hard job to maintain a constant blockade - it always has been. The Allies would have a tough time at first but the German and Japanese boats would be sunk and that would mean that Germany and Japan would have to maintain production of their boats to keep pressure. Would Japan be able to maintain a submarine fleet like Germany did ? 

If there was a serious loss of merchant shipping through the Indian Ocean the British could have abandoned Burma in '41 (like they did) and hold up in India without reinforcement as the Japanese did not have the supply line to attack India with any real force. In the emergency the British would have to rely on Indian industry and manpower (which was producing arms and soldiers albeit of lesser quality). 
Without sending reinforcements to the Far East the 8th Army would have taken North Africa before Rommel arrived, they came close in reality but they took men away for Greece then again for the Far East. 

It's too easy to say what they could have done, or should have done. We'll never know what they would have done. But for me I would have not reinforced the Far East and ordered a general retreat behind the Indian border and aimed to take North Africa before the Germans were involved. That would have forced the Vichy French in N.Africa to collapse, and the Germans would have to attempt a forced landing in Africa - something they would not look forward to doing. As the Japanese would not have to supply in Burma to attack India they would be held to stalemate. And once the war on the Eastern Front was fully underway it could free up British troops in N.Africa - but it would have the effect of giving the Germans a reserve of 300,000 men for Russia, which they lost in Tunisia.


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## Freebird (Jan 17, 2008)

plan_D said:


> It is certainly an interesting scenario,



Thanks  



> and there definately would be increased losses of merchant shipping. As I said before though, it is a hard job to maintain a constant blockade - it always has been. The Allies would have a tough time at first but the German and Japanese boats would be sunk and that would mean that Germany and Japan would have to maintain production of their boats to keep pressure. Would Japan be able to maintain a submarine fleet like Germany did ?



Unfortunatley the extra work is mostly with the surface fleet. For example, 6 - 8 or so Japanese subs spread out from Cape Town - Aden (Red Sea entrance) on the East coast of Africa along the Egypt India supply route would face very little ASW opposition. After a few dozen sinkings, the British would have to institute convoys with whatever DD's CL's they could scrape up. Even if there were a couple of weeks when the Japanese subs are absent (returning to re-supply) the Royal Navy will still have to run the convoys because they can't be sure where the subs are. 

I think the Japanese could have concentrated on building subs, instead of wasting time with mini-subs, hybrid BB/CV's or other projects.



> If there was a serious loss of merchant shipping through the Indian Ocean the British could have abandoned Burma in '41 (like they did) and hold up in India without reinforcement as the Japanese did not have the supply line to attack India with any real force. In the emergency the British would have to rely on Indian industry and manpower (which was producing arms and soldiers albeit of lesser quality).



I agree with you to some extent, I might try to stiffen up Singapore if possible, but if it fell I agree its best not to stay in Burma. Of course there was pressure from the US for an offensive to re-gain acess to the Burma Road. The Burma front was such a drain on resources manpower, especially from disease.



> It's too easy to say what they could have done, or should have done. We'll never know what they would have done. But for me I would have not reinforced the Far East and ordered a general retreat behind the Indian border and aimed to take North Africa before the Germans were involved.



The Rommel Africa Korps are in Africa from Feb of 1941. However the offensive "Crusader" occurs from mid Nov - early Dec 1941, leaving the British in control of the eastern half of Libya and Rommel retreating due to lack of fuel supplies. The British have about 6 weeks before Rommel has built up to attack again. This would be the time to push the Axis back to Tripoli, except they lost their re-inforcements to Malaya/Burma as you said. 

The real concern is to prevent the Japanese from isolating Australia India. At the time a Japanese invasion of Australia was feared a real possibility, especially in Canberra, even though it was not seriously considered in Tokyo.

*What do you think of a combined US/UK Naval offensive against the Japanese? *As it was the Allies outnumbered them, but though poor planning we allowed Japan to sink our ships in small groups. 

*The Japanese Navy* in Nov 1941 is 
*6 CV's*,
*4 or 5 CVE's*,
*6 BB's* (2 modern Nagato's, 4 older Ise Fuso class) 
*4 BC's* (older Kongo's),
*18 CA's *
*20 CL's*
*84 DD's*

After Pearl Harbour, (assuming that the US loses 3 carriers, are pursuing King's idea "Pacific first") *The US Navy* is:

*4 CV 
2 CVE
10 BB's *{2 modern N.Carolina class + 8 older Penn, N.M., N.Y., Ark. class}
*18 CA's
19 CL's
140 DD's* (70 fairly modern + 70 older "flush deck")

*The British* (with Aust. Dutch) had available for the Far East
*2 CV's* (Indomitable Formidable)
*1 CVE* (Hermes)
*6 BB's* (2 modern + 4 "Royal Sovereign class)
*7 CA's
20 CL's
30 DD's*

So the Allies could put up a force about 150% of the Japanese, except for carriers in which they were about equal. (the Japanese CVE's were not available for fleet actions for the first few months, they were supporting
operations in South China Sea transporting aircraft)

If the Allies had had better strategy could they have done better with "ABDA"? 



syscom3 said:


> *1st: The sea lanes to Australia were vital and had to be defended at all cost*.
> 2nd: Preserve the carrier forces to defend Hawaii and go on attack as an opportunity arose.
> 3rd: Contain the Japanese forces at Rabaul
> 4th: As heavy bombers become available to the AAF, begin systematically attacking the oil refineries of the NEI.
> ...



Consider if the Japanese had advanced to the SE right after "Pearl Harbour" to occupy Samoa Tahiti *{see my map in post #27}*, and cut off Australia's supply line from America, how will the US react? Would it be better to combine all the Allied assets? Or have one fleet advance from Hawaii and another from Australia?


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## plan_D (Jan 17, 2008)

The Royal Navy and USN would have to be able to work together to keep India and Australia alive; in the event of losing Singapore the most important areas of the time [in the Far East] are Australia and India. The question would really be a matter of command - would the U.S be able to provide someone who able to work with the British and the same applies to the U.K, only vice versa.


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## renrich (Jan 17, 2008)

It is inconcievable that the US would have pursued a Japan first strategy but if they had they would have been impelled to try to relieve the PI. I believe they already had a plan for that, Plan Orange. That plan would have had to be revisited after Pearl Harbor(thank goodness) Actually Yammamoto did us a huge favor by attacking PH. He put paid to the primacy of the BBs, demonstrated the efficacy of the CV and of course aroused the US. Never underestimate the ferocity of the English speaking peoples, especially the US, once they are aroused.


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## renrich (Jan 17, 2008)

i before e except after c. Inconceivable!


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## Freebird (Jan 18, 2008)

plan_D said:


> The Royal Navy and USN would have to be able to work together to keep India and Australia alive; in the event of losing Singapore the most important areas of the time [in the Far East] are Australia and India.



Agreed, if the US follows MacArthur's plan to attack northwards from Australia it would work. I think it would have been more effective than the raids done in early '42 in countering Japanese moves. It's ususally best to defend what you already have.



plan_D said:


> But for me I would have not reinforced the Far East and ordered a general retreat behind the Indian border and aimed to take North Africa



I would assume in this scenario that the British have completed the rail link to across Africa, otherwise they would probably lose Egypt in early '42. As it was the British were pushed back from Jan - May '42, if they weren't getting supplies (because of Japanese subs in East Africa) I don't think they could have stopped Rommel before he reached the Canal. He had the fuel supplies to do it in early '42 because the Luftwaffe had almost neutralized Malta. When the spring offensive began in Russia in 1942, the LW was withdrawn from the Med, and so the RAF from Malta began to seriously interfere with Rommels supply.


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## Freebird (Jan 18, 2008)

renrich said:


> It is inconcievable that the US would have pursued a Japan first strategy but if they had they would have been impelled to try to relieve the PI. I believe they already had a plan for that, Plan Orange. That plan would have had to be revisited after Pearl Harbor(thank goodness) Actually Yammamoto did us a huge favor by attacking PH. He put paid to the primacy of the BBs, demonstrated the efficacy of the CV and of course aroused the US. Never underestimate the ferocity of the English speaking peoples, especially the US, once they are aroused.





renrich said:


> i before e except after c. Inconceivable!



*?? Was that HMS Inconceivable? Must have been planned as the 7th Illustrious class...*  

Why do you think that the US would not persue "Pacific First"? Syscom has speculated that if Germany had not declared war then Adm. King's plans might have been adopted. The "Pacific First" still assumes that the US will supply aid to Britain Russia. I think it would involve a more realistic assesment, that the US would not be able to field a sizable ground army for about another year, but that with naval assets could counter the Japanese right away. Plan Orange actually was for a cross-Pacific attack, through Guam the Marshalls, favoured by King. This is what the Japanese most likely expected. MacArthur disagreed, he wanted to atack up through New Guinea the Philippines. *In my scenario, the Japanese sinking of the US carriers the occupation of Samoa Tahiti presents an immediate problem as it cuts off Australia from the US.* 

I think MacArthurs strategy would be best, if the US could keep the main Japanese force (Nagumo's) in the North Pacific, the British fleet + the US "South Pacific" force would try to surprise the Japanese, converging in the Java Sea. Basically this would be the battle of "Java Sea" except with CV + BB as well. The US would be outnumbered in carriers at Midway/Hawaii, so would have to rely on the help of island based P-40's. The objective would be to prevent Nagumo from assisting Inouye's 4th Fleet. I would include all of the British units that were based in the Indian Ocean in Nov/Dec '41, (CV's Indomitable, Illustrious, Formidable, + BB's Prince of Wales, 4 Revenge class) except that I would send HMS Rodney instead of Repulse. Since the US UK have better intelligence than Japan we would hope to catch them unprepared, since they would be expecting the main thrust from Hawaii. Interesting, since the CV's were sunk at Pearl as well, the US is back to using its BB's. 

*I think the US UK should try to eliminate the Japanese Navy in New Guinea Java Sea, while Nagumo is held at Midway.* 

Unless the US has a different plan?


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## SeaSkua (Jan 19, 2008)

Could the ROYAL NAVY send that big a fleet to face Japan? What would they have left to face the German Italian Navy?


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## syscom3 (Jan 20, 2008)

Freebird, you're underestimating the logistics the IJN would need for deep strikes into the Central Pacific. While Truk could be the focus of your operations, it was still a forward base, not a shipyard able to perform repairs and overhauls.

As history showed, the strikes against Midway and Pearl Harbor stretched the IJN fleet train to the limits.

Now if it were operations against the allies in the Indian ocean that were to be performed, its conceivable. Simply because the naval oil sources were not to far from their fleet anchorages.

One thing you should also keep in mind, was the normal attrition rates for reasons other than combat, was taking a toll on the fleet aircrews. After several months of battle, the IJN needed a pause in the action to regroup, refit and rearm.

Also, the IJN carriers were considerably smaller than the US carriers. I don't know the exact figures off the top of my head, but the fleet carriers only carried 70% capacity of the USN types. And their smaller carriers were carrying only as many as 2 dozen or so.

Just saying that a small carrier is going to be the core of your strike force would be a recipe for disaster. Not enough fighters for protection, and not enough bombers to be usefull on the attack.


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## Freebird (Jan 21, 2008)

I agree with most of your points.



syscom3 said:


> Freebird, you're underestimating the logistics the IJN would need for deep strikes into the Central Pacific. While Truk could be the focus of your operations, it was still a forward base, not a shipyard able to perform repairs and overhauls.



correct, I would think that they would use Truk only to take on fuel supplies.



> As history showed, the strikes against Midway and Pearl Harbor stretched the IJN fleet train to the limits.
> 
> Now if it were operations against the allies in the Indian ocean that were to be performed, its conceivable. Simply because the naval oil sources were not to far from their fleet anchorages.



I agree I also think that the Japanese subs would be far more detrimental to the British supply line through the Indian Ocean. I would imagine that the Japanese would have no more than a dozen or so boats on the US West Coast, but as we have seen they can do significant damage to unprotected shipping. And although convoys escorts (when finally introduced) will prevent some losses, convoys typically cost between 15 - 20% reduction in capacity, due to the time lost assembling the convoy, all ships travelling at the speed of the slowest etc.



> One thing you should also keep in mind, was the normal attrition rates for reasons other than combat, was taking a toll on the fleet aircrews. After several months of battle, the IJN needed a pause in the action to regroup, refit and rearm.
> 
> Also, the IJN carriers were considerably smaller than the US carriers. I don't know the exact figures off the top of my head, but the fleet carriers only carried 70% capacity of the USN types. And their smaller carriers were carrying only as many as 2 dozen or so.



Their capacity was slightly less but comparable to US capacity.

Yorktown class A/C capacity: 90
Lexington 90
Ranger 86
Wasp 84

Kaga/Akagi 90
Shokaku/Zuikaku 84
Soryu/Hiryu 73
Ryujo 37
Zuiho 30
Taiyo 27
Hosho 21



> Just saying that a small carrier is going to be the core of your strike force would be a recipe for disaster. Not enough fighters for protection, and not enough bombers to be usefull on the attack.



All 6 major Japanese carriers were at Pearl. I would think that they would use the minor carriers as support for operations where very little air opposition, if any, was expected, such as in Samoa or Tahiti. The defenders would have a dozen or two aircraft at most, and probably all would be destroyed on the ground. They would also probably group 2 light carriers together, giving a combined airgroup of about 60, adequate enough for operations against weaker targets.

Again getting back to strategy, a possible effect of the sub offensive on the US is to disrupt shipping delay operations in the Pacific. This would help Japan consolidate gains, especially in the East Indies Indian Ocean. However the effect on Britain would be devastating. Unless the British find another way to supply their N. African India fronts, they could end up losing both. It is a terrible position for the British to be in, because every ship sunk in East Africa, (Durban - Red Sea) means that another replacement ship would not arrive for minimum 2 months. (4+ month round trip Liverpool - Alexandria)


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## renrich (Jan 21, 2008)

I must be missing something here. Are we saying that the US carriers were sunk at PH also?


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## syscom3 (Jan 22, 2008)

Freebird, the aircraft capacity of the Japanese carriers you quoted, is of the design specs from the mid 1930's. The actual capacity of the carriers in 1942 (with larger sized aircraft as compared to the mid 30's) at Midway were:
Kaga: 72, Soryu: 57, Hiryu: 59, Akagi: 63. Light Carriers were : Zuiho: 18, Ryujo: 30, Junyo: 33.

As for your submarines, while its probable that they could have all 60 or so subs active at the start, maintaining full strength over a period of months would be very hard to do. even 2/3rds strength only leaves you with 40 or so subs, covering an immense area of the world. And that doesn't account for force reductions due to ships being damaged, sunk or in transit.

Saying you will put your subs near the major ports leaves you vulnerable to counter attack by ASW. Even if your subs are not sunk outright by ASW attack, just being forced away from a ship or convoy is success.

As for attacking deep into the central pacific, just what would you really accomplish? You have to do lasting and irrepairable damage to knock Samoa, Playmra, Johnston or Fiji out of the war. And that takes lots of aircraft and multiple raids. In addition, Your carriers would need to be massed into a task force to accomplish anything of military value, thus putting a strain on the fleet supply.

And as events proved in Guadalcanal and New Guinea, the P39's and P40's (that the AAF had available in Hawaii and the line islands in 1942) were adequate against IJN aircraft at the low altitudes, where they would have to fight. Attrition would cripple your air groups in a hurry.


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## Freebird (Jan 22, 2008)

renrich said:


> I must be missing something here. Are we saying that the US carriers were sunk at PH also?



Yes, I put a hypothetical forward if the US had lost 3 carriers at Pearl. 



syscom3 said:


> Freebird, the aircraft capacity of the Japanese carriers you quoted, is of the design specs from the mid 1930's. The actual capacity of the carriers in 1942 (with larger sized aircraft as compared to the mid 30's) at Midway were:
> Kaga: 72, Soryu: 57, Hiryu: 59, Akagi: 63. Light Carriers were : Zuiho: 18, Ryujo: 30, Junyo: 33.



Where did you get your figures from? 

I used HazeGray, almost all of the figures listed were from 1939-1940, not mid 30's.

World Aircraft Carriers List: Japanese Aircraft Carriers

Both of the *Shokaku* class are listed as 84 aircraft (max), both completed in 1941.

Both *Kaga Akagi *had an initial capacity of 60, with 90 or 91 aircraft max after reconstruction, Kaga's reconstruction completed in 1935, Akagi's in the Sept of '38. 

*Soryu Hiryu* are listed as 71 73 aircraft max, with Soryu first in commision beginning 1938, Hiryu completed summer 1939. 

*Zuiho Shoho* are listed as carrying 30 aircraft, with Zuiho in service Dec 1940, Shoho Jan '42. 

So all of the stats are Fall '38 or later, except for the Kaga. The Nakajima "Kate" B5N1 was in service on Japanese carriers starting 1937-1938, while before the "Val" D3A (47' wingspan, 33.5' length) they used the B4Y1 (50' x 33') and the Aichi D1A (37' x 30.5') but the D1A was a biplane, I don't think it had folding wings.

In any event, the 6 carriers were more than enought to do the job at Pearl.



> As for your submarines, while its probable that they could have all 60 or so subs active at the start, maintaining full strength over a period of months would be very hard to do. even 2/3rds strength only leaves you with 40 or so subs, covering an immense area of the world. And that doesn't account for force reductions due to ships being damaged, sunk or in transit.



*I agree, the Japanese would have to put building subs as a priority*, to replace losses after the first few months. It does not take very many subs sinkings to force the Allies into a much more cautious shipping policy in the Pacific, which will hamper the Sout Pacific build-up.



> Saying you will put your subs near the major ports leaves you vulnerable to counter attack by ASW. Even if your subs are not sunk outright by ASW attack, just being forced away from a ship or convoy is success.



Yes you are correct, but the ASW capability in the first 4 - 6 months is negligable, even after that it is very limited for the first year or so. The German U-boats used this tactic to lurk outside US East coast ports, yet the none were sunk off the US East Coast until April 1942, and the convoys were not instituted until May, where in the Atlantic the US had some very effective assistance of well trained British/Canadian ASW crews. US Naval Command had some expectation that they would have to defend against U-boats (in the lead up to war 1940-1941), whereas there was virtually no preparation in the Pacific against Japanese subs.



> *As for attacking deep into the central pacific, just what would you really accomplish?* You have to do lasting and irrepairable damage to knock Samoa, Playmra, Johnston or Fiji out of the war. And that takes lots of aircraft and multiple raids. In addition, Your carriers would need to be massed into a task force to accomplish anything of military value, thus putting a strain on the fleet supply.



I'm not contemplating raids, I think the Japanese could occupy Samoa outright, and establish a squadron or two there. In the fall of 1941 it is defended by a single US Marine defence battalion. I don't think they would attack Fiji, it is a little more strongly defended. The US would still have troops on Johnson Palmyra.

*The point would be to have the US waste months building up to re-occupy Samoa, and to use scarce troop assets to re-inforce US bases* in Johnson, Palmyra, Christmas, Midway island etc. The Free French garrison in Tahiti is poorly equipped, I think the Japanese would then only use the air naval bases, while allowing/helping the Vichy French to re-occupy and defend Tahiti. Remember that the Vichy Army offered minimal if any resistance to Axis forces, yet they stubbornly fought against the Allies in every instance when the Allies attempted to occupy Vichy territory, even when defending against heavy odds. (Morocco, Algeria, Syria, Madegascar, Dakar)



> And as events proved in Guadalcanal and New Guinea, the P39's and P40's (that the AAF had available in Hawaii and the line islands in 1942) were adequate against IJN aircraft at the low altitudes, where they would have to fight. Attrition would cripple your air groups in a hurry.



*It would take many months for the US to be able to bring planes troops supplies to the forward bases to be able to offer resistance.* For example, the delays to re-take Samoa re-establish communications would seriously hamper US Australian resistance in the Solomons N. Guinea. With the greater threat from Japanese subs, it would also take a few or many extra months to arrange convoys to bring the vital supplies forward.


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## syscom3 (Jan 22, 2008)

> Where did you get your figures from?



From the book "Shattered Sword". The author made use of IJN documents to prove the actual AC stowage was far less than stated figures. The numbers I listed where the figures the carriers had during the Midway operation. The Shokaku and Zuikaku also had a capacity of 70 or so aircraft. 

Shattered Sword: The Untold Story of the Battle of Midway




> I agree, the Japanese would have to put building subs as a priority[/B], to replace losses after the first few months. It does not take very many subs sinkings to force the Allies into a much more cautious shipping policy in the Pacific, which will hamper the South Pacific build-up.



Slow it down in the SW Pacific, but not stop a moderate buildup in the Central Pacific from Hawaii to Samoa.



> I'm not contemplating raids, I think the Japanese could occupy Samoa outright, and establish a squadron or two there. In the fall of 1941 it is defended by a single US Marine defence battalion. I don't think they would attack Fiji, it is a little more strongly defended. The US would still have troops on Johnson Palmyra.



The IJN never had the amphib capability to strike out at long distances. Even if they achieved success's in the Port Moresby invasion, they still couldn't do anything past the Solomon Islands untill fall 1942. In which time, they would be challenged by better equipped allied units which would stop them on the spot.



> The point would be to have the US waste months building up to re-occupy Samoa, and to use scarce troop assets to re-inforce US bases in Johnson, Palmyra, Christmas, Midway island etc. The Free French garrison in Tahiti is poorly equipped, I think the Japanese would then only use the air naval bases, while allowing/helping the Vichy French to re-occupy and defend Tahiti.



Why do you suppose Samoa would fall so quickly? The Wake invasion in 1941 was nearly a disaster for the IJN. In 1/2 year, the US would have gotten enough troops and aircraft to Samoa and surrounding islands to make a hypothetical Japanese attack or invasion a debacle for them. And stop wasting time about French Polynesia. It had no military value and it was way to far away to be invaded let alone supplied by Japan



> It would take many months for the US to be able to bring planes troops supplies to the forward bases to be able to offer resistance.[/B] For example, the delays to re-take Samoa re-establish communications would seriously hamper US Australian resistance in the Solomons N. Guinea. With the greater threat from Japanese subs, it would also take a few or many extra months to arrange convoys to bring the vital supplies forward.



Why would it take "many months"? The US would still have Pearl as a forward shipyard and base even if the oil tanks were wrecked. Offensive operations deep into the SW pacific could be curtailed, but aggressive patrolling from pearl could still be accomplished. Samoa or Fiji couldn't be threatened untill late 1942 at the minimum. And thats plenty of time to fortify them. 

You place far to much credence on Japanese amphib capability (against a defended beach), which usually was dismal even under the best of circumstances.

As for air power, there were several BG's and FG's available to be sent to the various islands to block the Japanese. All Japanese airpower would have to be used from their carriers, all of which all were shown to be vulnerable to allied fighters.


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## Freebird (Jan 25, 2008)

syscom3 said:


> Slow it down {the buildup} in the SW Pacific, but not stop a moderate buildup in the Central Pacific from Hawaii to Samoa.



If the US had lost the carriers at "Pearl" and had the Navy shipyards, bases fuel supplies destroyed, they would have to use the Naval assets brought from the Atlantic to escort vital supplies to Hawaii for re-building re-inforcing the island. Next on the list of priorities would be Midway, Wake, Palmyra, Johnson. Samoa could probably not be helped, any more than Guam.



> The IJN never had the amphib capability to strike out at long distances.



WHAT??? Never had amphibious capability? Then how did they capture Wake Island? What was the land force preparing to do at Midway other than a long-distance amphibious operation? 



> Even if they achieved success's in the Port Moresby invasion, they still couldn't do anything past the Solomon Islands untill fall 1942.



Sorry this is wrong too. What do you mean they couldn't do anything past the Solomons until fall 1942? This is not correct, the Japanese occupied the Gilbert Ellice Islands (including Tarawa) in late 1941 early 1942 - these are over 1,000 miles EAST of Guadalcanal in the Solomons. The Japanese could certainly attack Samoa at the same time as Pearl Harbour. It would also be easier than attacking Wake because they could bring troops for a surprise attack directly into the port, just as the Germans did in Norway. 



> In which time, they would be challenged by better equipped allied units which would stop them on the spot.



What units? The US is short of troops as war breaks out, they will have to use them to protect Hawaii Midway. Another problem would be the shortage of DD cruisers to support operations. 



> Why do you suppose Samoa would fall so quickly? The Wake invasion in 1941 was nearly a disaster for the IJN. In 1/2 year, the US would have gotten enough troops and aircraft to Samoa and surrounding islands to make a hypothetical Japanese attack or invasion a debacle for them.



You don't have 6 months, the Japanese can land in Samoa on day 1. I would expect the battle for Samoa to be similar to Guam, not like Wake. The advantage Wake had (unlike Guam or Samoa) is that Wake was so small there is no place to land except under fire, it's uninhabited so its impossible for a ship making a sneak attack to posing as civilian transport Also the danger of civilian casualties would push the defenders to surrender. (which is what happened on Guam)

HyperWar: History of USMC Operations in WWII, Vol. I: Part II, Chapter 2



> And stop wasting time about French Polynesia. *It had no military value* and it was way to far away to be invaded let alone supplied by Japan



No military value??? If the US doesn't have Samoa the supply line to Australia will run through Tahiti. I would think that would be of considerable value.



> Why would it take "many months"? The US would still have Pearl as a forward shipyard and base even if the oil tanks were wrecked.



The Shipyard repair facilities are destroyed along with the sub base oil tanks.



> Offensive operations deep into the SW pacific could be curtailed, but aggressive patrolling from pearl could still be accomplished. *Samoa or Fiji couldn't be threatened untill late 1942 at the minimum.* And thats plenty of time to fortify them.



*?? What do you base this on?* What is going to stop them? Remember that it wil take a couple of weeks at least for the US to bring carriers support from the Atlantic. The Japanese have naval ground assets that could be used on day 1.



> You place far to much credence on Japanese amphib capability (against a defended beach), which usually was dismal even under the best of circumstances.



Samoa is too large (76 sq. miles) to cover all the beach fronts, *there is only 1 battalion defending!! *Wake was a different story because it was so small (2.5 sq. miles, and the defenders were prepared waiting



> As for air power, there were several BG's and FG's available to be sent to the various islands to block the Japanese. All Japanese airpower would have to be used from their carriers, all of which all were shown to be vulnerable to allied fighters.




In the first few months the US will be primarily concerned with strengthening the defence of Hawaii, the West Coast the nearby bases, Johnson, Palmyra Midway, they won't be able to build up in the South Pacific

The US doesn't have 6 months to prepare a defence of Samoa. The US is very short on troopships, and the sub attacks on shipping will severly curtail movement of supplies. The first priority will be bases close to Hawaii, it will be a many months before they have any capability to re-inforce Samoa. The Chiefs would probably concede Samoa, just as they did Guam. 


It would take many months because you can't bring troops supplies without shipping. After a few months of heavy shipping losses on the West Coast the US Navy would probably do exactly what they did on the East Coast in the summer of 1942, stop sailings and keep the ships in port because they can't protect them. You can't even begin to think about moving troops, supplies air power to forward bases if you can't safely move shipping.


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## Glider (Jan 25, 2008)

freebird said:


> If the US had lost the carriers at "Pearl" and had the Navy shipyards, bases fuel supplies destroyed, they would have to use the Naval assets brought from the Atlantic to escort vital supplies to Hawaii for re-building re-inforcing the island. Next on the list of priorities would be Midway, Wake, Palmyra, Johnson. Samoa could probably not be helped, any more than Guam.



I think that you are relying on a level of damage that was beyond the ability of the IJN to inflict. 
As an example, Malta as we all know was pounded on a vast scale over a period of months, using land based bombers that carried a much larger load than the naval bombers could carry. But the dockyard was still able to function to a limited degree, the subs could still operate for the vast majority of the time, the airfields could still operate and the fuel tanks remained in operation. 




> WHAT??? Never had amphibious capability? Then how did they capture Wake Island? What was the land force preparing to do at Midway other than a long-distance amphibious operation?


The IJN ability to land troops was very limited and a weak spot with few ships. They could and did have some probably for one landing but they couldn't be everywhere. A serious opposition would wreck havoc with their landing forces


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## Freebird (Jan 25, 2008)

Glider said:


> I think that you are relying on a level of damage that was beyond the ability of the IJN to inflict.
> As an example, Malta as we all know was pounded on a vast scale over a period of months, using land based bombers that carried a much larger load than the naval bombers could carry. But the dockyard was still able to function to a limited degree, the subs could still operate for the vast majority of the time, the airfields could still operate and the fuel tanks remained in operation.



Glider the facilities at Malta were hardened to withstand bombing, the ones at Pearl were not. I am hypothesizing if the 3 US Pacific carriers had been caught at Pearl, and the Japanese re-armed re-fueled their aircraft for a "third wave", possible fourth. This was advocated by Genda Fuchida, as the latter reported "many targets remain, shipyards, maintainance facilities, oil tanks, fleet units (DD, CL, CA's).". The first wave returned to the carriers at 10 am, and could have returned as the third wave. Since the carriers would have been out of the way, the Japanese fleet was not in danger.

Pearl Harbor - The Approach- Imperial War Museum

It is possible that some of the targets would be repairable, but the damage would at least require months of work to fix



> The IJN ability to land troops was very limited and a weak spot with few ships. They could and did have some probably for one landing but they couldn't be everywhere. A serious opposition would wreck havoc with their landing forces



Yes you are correct in this. The Japanese had some examples to work with, (besides "Taranto" obviously!) The result of the German surprise landings in Bergen, Trondheim, etc. in Norway done with troops hidden in civilian ships was very successful with few casualties, even though the Norweigans had been warned that an attack was likely.

On the other hand, an amphibious attack with navy units against prepared defence (ie. Crete, Oslo) was very costly. I would expect the Japanese to use the "Trojan horse" formula wherever possible, taking as many as possible targets right away, before defence is organized. Of course this is not possible at Wake, because it is not a civilian port, so the defenders assume that any approaching ship is hostile. 

In any event, they could have used the troops to land in Samoa instead of Guam. After the air raid to destroy the US aircraft, the defenders in Guam cannot go anywhere cannot be re-inforced. They could be dealt with later after more important targets are secure


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## Glider (Jan 25, 2008)

freebird said:


> Glider the facilities at Malta were hardened to withstand bombing, the ones at Pearl were not. I am hypothesizing if the 3 US Pacific carriers had been caught at Pearl, and the Japanese re-armed re-fueled their aircraft for a "third wave", possible fourth. This was advocated by Genda Fuchida, as the latter reported "many targets remain, shipyards, maintainance facilities, oil tanks, fleet units (DD, CL, CA's).". The first wave returned to the carriers at 10 am, and could have returned as the third wave. Since the carriers would have been out of the way, the Japanese fleet was not in danger.



I still don't think you understand the scale of the attack that Malta had to put up with but first the other facilities. The Harbour cannot be and wasn't hardened, neither were most of the fuel supplies. The airfields were but only to a point, all major maintanence and repairs were off the airfield (a lot of it done in a bus garage).
There was one period ( I do hope I remember this right) where on average 30 tons of bombs, fell on EACH airfield, every day, for three months. This is in addition to all the other targets, we are talking of many thousands of tons of bombs. Despite all this, everything was kept running to some degree. The IJN could have stayed until they dropped every bomb they had, used every drop of fuel and still couldn't come close to this. 

The USA bases on Pearl were large and able to help each other. Army bases had sophisticated workshops able to assist and the engineers to do it. Aircraft can be quickly flown in and these would be the key.

It would be to big a nut to crack for the Japanese.


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## Freebird (Jan 25, 2008)

Glider said:


> I still don't think you understand the scale of the attack that Malta had to put up with.



Actually I do, it was an incredible ordeal. Just reading the history of the "Ohio" in Pedestal shows the lengths the British would go to keep the place going. Somebody should give the island a medal or something.  



> the other facilities. The Harbour cannot be and wasn't hardened, neither were most of the fuel supplies. The airfields were but only to a point, all major maintanence and repairs were off the airfield (a lot of it done in a bus garage).



I should clarify "hardened" meaning that everything possible done to prepare for air attack. The RAF on Malta used every trick in the book, from the bus garage as you mentioned, to camoflaging fuel tanks, the sub base and other facilities. The difference between areas in active combat (like the UK Malta) with other places that are in a peace time mode is like night and day.



> The USA bases on Pearl were large and able to help each other. Army bases had sophisticated workshops able to assist and the engineers to do it.
> 
> It would be too big a nut to crack for the Japanese.



I'm not contemplating a total destruction of the Pearl facilities, but considerable damage would be done, which would require more supplies brought by the overstreached shipping assets. The follow-on attacks on Pearl could have taken out the fuel tanks, the maintainance shops for the fleet, the cruisers destroyers, and probably the sub base as well.


> Aircraft can be quickly flown in and these would be the key.



The problem is that with 3 carriers knocked out, the US would have to use 1 or 2 to ferry aircraft to Hawaii, Midway the other forward bases, which would reduce the number available for the fleet. Any counter-attack by the US on the Japanese would require a large build up of supplies supporting elements, if the limited shipping is busy bringing fuel to replace that lost in the tanks, supplies tools to replace those destroyed it means less is available to supply Australia and for the offensives. With an aggressive sub offensive on both coasts finding enough escorts to bring supplies to the South Pacific at the same time would be tough, especially as they are needed to accompany the carriers capital ships


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## syscom3 (Jan 30, 2008)

Freebird, youre giving the IJn far to much credit for being able to destroy Pearl Harbor and then conquor most of the Pacific Ocean in short order.

Consider the following:
1) While the IJN could damage the naval base, it could hardly be considered to have the capability of destroying it. There werent enough aircraft, and the dive bombers only could carry a 500 pound bomb.

2) "American anti-aircraft performance had improved considerably during the second strike, and two-thirds of Japan's losses were incurred during the second wave. Nagumo felt if he launched a third strike, he would be risking three-quarters of the Combined Fleet's strength to wipe out the remaining targets (which included the facilities) while suffering higher aircraft losses" .... plus not every fighter and fighter pilot had been knocked out. The time between a 2nd and 3rd strike would have meant the US could put together enough aircraft to inflict damage on the Jpanese 3rd strike.

3) "A third wave attack would have required substantial preparation and turn-around time, and would have meant returning planes would have faced night landings. At the time, no Navy had developed night carrier techniques, so this was a substantial risk. The task force's fuel situation did not permit him to remain in waters north of Pearl Harbor much longer since he was at the very limits of logistical support. To do so risked running unacceptably low on fuel, perhaps even having to abandon destroyers en route home"

4) The USN had the resources to rebuild the damaged oil bunkers and refill them within a few months, irregardless of IJN subs.

5) The Japanese light carriers were an odd bunch, and really could not be classified as fleet carriers. The Zuiho and the Ryujo are a case in point. One had elevators to small to handle the val dive bombers, the other didnt have enough speed to allow a fully armed torpedo bomber to take off in light winds. Consider them escort carriers to cover convoys, and not capable for offensive action.

6) The Japanese had to secure the Philipines, Malaya (and Burma),the NEI and Eastern Indian ocean prior to nay offensive action into the SW Pacific.

7) The USN was fully capable of reinforcing Samoa, Fiji and the New Hebrides with enough ground and air units to make a Japanese invasion very costly. 

8 ) The fact B17's were present meant the IJN had to move very cautiously outside of their protected area's of the Marshalls and Gilberts.

9) Even if the three carriers at pearl were caught and knocked out of action, the other three carriers would provide plenty of offensive capabilities to blunt or push back any Japanese advances in the central Pacific.


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## Soren (Feb 1, 2008)

Syscom3,

Freebird is not giving the IJN too much credit at all, you're just giving it too little. As it was the IJN from 41 -42 had the upper hand in capability, it wasn't untill 1943 after repeated setbacks caused by poor tactics decisions that the IJN lost its upper hand. So in Freebird's scenario the IJN has lots of chances to significantly alter the historic chain of events.


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## Freebird (Feb 3, 2008)

syscom3 said:


> Freebird, youre giving the IJn far to much credit for being able to destroy Pearl Harbor and then conquor most of the Pacific Ocean in short order.
> 
> Consider the following:
> 1) While the IJN could damage the naval base, it could hardly be considered to have the capability of destroying it. There werent enough aircraft, and the dive bombers only could carry a 500 pound bomb.
> ...



Syscom, the problem was that they Japanese waited until early afternoon for the search planes to try to find the carriers, if they had been in Pearl that morning the Japanese could have re-armed the first wave as soon as it landed at 10 am, and sent the third wave before the second returned at noon. And while I agree that the "Third wave" might suffer 25 or more planes lost, it would still be worth it. 

I think it could work, but I'm not an expert on aircraft so I'll post a poll to see what opinions are.



> 4) The USN had the resources to rebuild the damaged oil bunkers and refill them within a few months, irregardless of IJN subs.
> 
> 5) The Japanese light carriers were an odd bunch, and really could not be classified as fleet carriers. The Zuiho and the Ryujo are a case in point. One had elevators to small to handle the val dive bombers, the other didnt have enough speed to allow a fully armed torpedo bomber to take off in light winds. Consider them escort carriers to cover convoys, and not capable for offensive action.



The US certainly would have to rebuild the tanks repair shops, but the US (and British) were very short on shipping resources, so your re-supply would reduce the amount available to build up in Australia, NZ, etc. The increased Axis sub activity would also mean that your re-supply tankers would have to be escorted, futher draining US naval assets at a time when they are critically short. 

Your point about the light carriers is not quite correct, because they *did *conduct support operations. I didn't contemplate the light carriers for major fleet operations, but for supporting operations in outlying areas, which they did historically. Zuiho Ryujo performed support operations in the Solomons, China Sea Indian Oceans. Which carrier did you think was too slow? The Ryujo is listed as capable of 29 knots, Zuiho 28.


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## Freebird (Feb 24, 2008)

Soren said:


> Syscom3,
> 
> Freebird is not giving the IJN too much credit at all, you're just giving it too little. As it was the IJN from 41 -42 had the upper hand in capability, it *wasn't until 1943 after repeated setbacks caused by poor tactics decisions that the IJN lost its upper hand.* So in Freebird's scenario the IJN has lots of chances to significantly alter the historic chain of events.






syscom3 said:


> Freebird, youre giving the IJn far to much credit for being able to destroy Pearl Harbor and then conquor most of the Pacific Ocean in short order.
> 
> Consider the following:
> 
> 4) The USN had the resources to rebuild the damaged oil bunkers and refill them within a few months, irregardless of IJN subs.



*What do you mean irregardless of subs?* Will they just keep sending tankers unprotected until some get through? The US does not have enough escorts to bring tankers and support the carriers in 1942. If you mean that they send the Navy to escort oil tankers that would preclude action in the South Pacific 



syscom3 said:


> 6) The Japanese had to secure the Philipines, Malaya (and Burma),the NEI and Eastern Indian ocean prior to any offensive action into the SW Pacific.



What possible connection is there between the IJA campaign in Burma and the IJN fleet activities in the South Pacific? 



syscom3 said:


> 7) The USN was fully capable of reinforcing Samoa, Fiji and the New Hebrides with enough ground and air units to make a Japanese invasion very costly.



Actually no, they were not capable at all. 

*Quoted - Dwight Eisenhower, Crusade in Europe*


> "Sunday Dec 14, 1941. The Navy informed Gen. Marshall that the *US Pacific fleet would be unable for SOME MONTHS to participate in offensive actions.* The Navy's carriers remained intact but supporting vessels for the carriers were so few in number that great restrictions would have to be placed upon their operation"



You are basing what they "could have done" on 20/20 hindsight on the exact capabilities of the Japanese. At the time there was no way of knowing what the japanese would do, so caution defense of the USA proper was the #1 concern, not operations in some far-away Pacific location



syscom3 said:


> 8 ) The fact B17's were present meant the IJN had to move very cautiously outside of their protected area's of the Marshalls and Gilberts.



Without US carriers to provide any fighter escort the Japanese won't be that concerned about B-17s



syscom3 said:


> 9) Even if the three carriers at pearl were caught and knocked out of action, the other three carriers would provide plenty of offensive capabilities to blunt or push back any Japanese advances in the central Pacific.



"Offensive capabilities" in Samoa or New Hebrides is the last thing the Navy is thinking about in the winter of 1941

*Quoted - Dwight Eisenhower*


> In Dec 1941 there was no assurance that the Japanese would not launch a major amphibious assault on Hawaii or possibly even on the mainland, the *Navy felt that the carriers should be reserveved for reconnaissance and defence*. The garrison in Hawaii was so weak that there was general agreement between the War Navy departments that *Hawaiian air ground forces should be re-inforced as rapidly as possible and that should take priority over other efforts in the Pacific*.



This is how the situation was when the US had *all* their carriers intact and only a couple of escort vessels damaged at Pearl. In 1941 the USN has about 100 fairly modern destroyers, {+ about 70 older ones decomissioned in reserve that could be used after some overhaul.} If the USN had lost another 25+ destroyers some cruisers at Pearl in addition to the ones lost in the Far East, they will have almost a third of the in-service destroyers out of action. 



renrich said:


> That scenario would have probably lengthened the war by a year or more.



Now if the US UK were facing an Axis U-boat blitz against shipping, destruction of the tank farm, sub base repair facilities on Oahu, loss of carriers escort DD's at Pearl + some commando "spoiler" attacks against the US mainland, the US counter attack against Japan would probably be set back by far more than a year.


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## syscom3 (Feb 25, 2008)

> What do you mean irregardless of subs? Will they just keep sending tankers unprotected until some get through? The US does not have enough escorts to bring tankers and support the carriers in 1942. If you mean that they send the Navy to escort oil tankers that would preclude action in the South Pacific



The USN had enough destroyers on hand to escort the tankers necessary to restock the oil tanks at Pearl. There is simply not enough Japanese subs to blockade the ports, patrol the coasts and patrol the high seas. Would the US have the ability to fight offensively for the first few months? No. But inevitably, and sooner than you would suppose, the US would have the oil available to go on the attack deep into the SW Pacific. Remember..... no battleships means a far lower oil reserve requirement.



> Originally Posted by syscom3
> 6) The Japanese had to secure the Philipines, Malaya (and Burma),the NEI and Eastern Indian ocean prior to any offensive action into the SW Pacific.
> What possible connection is there between the IJA campaign in Burma and the IJN fleet activities in the South Pacific?



The Japanese had to defend its flanks because of the war in China and the potential British strengths in India and the Indian Ocean. Are you foregtting about the IJN rmapage through the Indian Ocean in March 1942?



> Originally Posted by syscom3
> 7) The USN was fully capable of reinforcing Samoa, Fiji and the New Hebrides with enough ground and air units to make a Japanese invasion very costly.
> Actually no, they were not capable at all.



The IJN failed in two of its three invasions on defended beaches. And the only success was at Wake, which was taken on the 2nd attempt due to a depleted USMC force on the island. There is nothing in the historical record to suggest the IJN had the doctrine and equipment to succed at other locations that were sufficently defended. All it took was a dug in force of US troops prepared for the battle and the Japanese were "goners"



> You are basing what they "could have done" on 20/20 hindsight on the exact capabilities of the Japanese. At the time there was no way of knowing what the Japanese would do, so caution defense of the USA proper was the #1 concern, not operations in some far-away Pacific location.



The US was already building up islands in the Pacific prior to the outbreak of hostilities. Samoa and Fiji already had serviceable airfields. Canton, Palmyra, Johnston and several others were already on the list.



> Originally Posted by syscom3
> 8 ) The fact B17's were present meant the IJN had to move very cautiously outside of their protected area's of the Marshalls and Gilberts.
> Without US carriers to provide any fighter escort the Japanese won't be that concerned about B-17s



The Japanese were quite concerned about the B17's as they were so damn hard to bring down. As patrol bombers, they were invaluable.



> Originally Posted by syscom3
> 9) Even if the three carriers at pearl were caught and knocked out of action, the other three carriers would provide plenty of offensive capabilities to blunt or push back any Japanese advances in the central Pacific.
> "Offensive capabilities" in Samoa or New Hebrides is the last thing the Navy is thinking about in the winter of 1941.



The historical record indicates otherwise. The US in 1941 was already planning the buildup of the islands along the sea lanes to Australia. And if the fleet was tethered to Pearl due to the fuel situation, they still could patrol a few thousand miles out and keep the sea lanes open. No Coral Sea battle, but no inaction either.



> In Dec 1941 there was no assurance that the Japanese would not launch a major amphibious assault on Hawaii or possibly even on the mainland, the Navy felt that the carriers should be reserveved for reconnaissance and defence. The garrison in Hawaii was so weak that there was general agreement between the War Navy departments that Hawaiian air ground forces should be re-inforced as rapidly as possible and that should take priority over other efforts in the Pacific.
> This is how the situation was when the US had all their carriers intact and only a couple of escort vessels damaged at Pearl. In 1941 the USN has about 100 fairly modern destroyers, {+ about 70 older ones decomissioned in reserve that could be used after some overhaul.} If the USN had lost another 25+ destroyers some cruisers at Pearl in addition to the ones lost in the Far East, they will have almost a third of the in-service destroyers out of action.



The Japanese could only do so much damage to Pearl. They were limited to three attack strikes of which they had to knock out the capital ships, the airfields and the port facilities. Only so much can be done. None of the destroyers would have been sunk, unless the battleships or airfields or port facilities are hit.



> Originally Posted by renrich View Post
> That scenario would have probably lengthened the war by a year or more.
> Now if the US UK were facing an Axis U-boat blitz against shipping, destruction of the tank farm, sub base repair facilities on Oahu, loss of carriers escort DD's at Pearl + some commando "spoiler" attacks against the US mainland, the US counter attack against Japan would probably be set back by far more than a year.



The war in the Pacific would have unfolded exactly as it did. As mentioned before, the USN was going to outnumber the Japanese in mid 1943 (with better aircraft and weapons too). Just look at the facts. beginning in fall of 1943, a fleet class carrier was going to enter operations every single month! The battles in the SW Pacific in the Solomons might not have occured. But the big fleet clashes would occur in the Gilberts and Marshalls and the Japanese would lose it right then and there.

And then again, the IJN had the ability to damage pearl, but never had the capacity to destroy it. All damage there was repairable and temporary.


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## Freebird (Feb 28, 2008)

syscom3 said:


> *The USN had enough destroyers on hand* to escort the tankers necessary to restock the oil tanks at Pearl. Would the US have the ability to fight offensively for the first few months? No. But inevitably, and sooner than you would suppose, the US would have the oil *available to go on the attack deep into the SW Pacific.*



The US would not be able to go on major offensive operations in the first half of 1942.

The US had 94 "modern" DD's completed from 1935 {Farraguts} up to and including 21 "Greaves" class in 1941, of which 2 dozen or so are still training working up. Of the older "Flush deck" or "4 stacker" DD's built before 1920, 11 have been modified as ASW escorts, 37 that have been or are undergoing upgrade to Minesweeper/Minelayer, Seaplane Tender or Fast Transport. 14 of the "4-stackers" are in the Far East fleet, and of the other 50 odd "4 stackers", the US Navy does not feel confident to use them for ASW/Fleet operations, as they would just be floating targets. In fact, even while the U-boats were sinking ships right off the US East coast, these DD's were left in port.



From Wikipedia said:


> Despite the urgent need for action, little was done to try to combat the U-boats. *The USN was desperately short of specialised anti-submarine vessels.* The shortages arose partly because the massive new naval construction programme had prioritised other types, and partly because the destroyers that were available remained inactive in port, even while freighters and tankers were being sunk in coastal waters. By Jan 1941 *there were 13 destroyers idle in New York Harbour,* yet still none were employed to deal with the immediate threat, and over the following nights more ships were sunk.



Second Happy Time - Wikipedia, the free encyclopedia

So if the Japanese sink or damage 25+ DD's at Pearl, for ASW capable DD's this leaves only about 5 dozen in the Atlantic/Gulf Coasts, and only a dozen or so in the Pacific.



Syscom3 said:


> *The historical record indicates otherwise*. The US in 1941 was already planning the buildup of the islands along the sea lanes to Australia. Samoa and Fiji already had serviceable airfields. Canton, Palmyra, Johnston and several others were already on the list. And if the fleet was tethered to Pearl due to the fuel situation,* they still could patrol a few thousand miles out and keep the sea lanes open.*





syscom3 said:


> Even if the three carriers at pearl were caught and knocked out of action, the other three carriers would provide plenty of offensive capabilities to blunt or *push back any Japanese advances in the central Pacific*.



*I would think that Eisenhower's own words are a pretty good indication of the "Historical record"* The key word you used was "planning". The US did plan and in fact did buildup to some extent in the nearby islands. The Japanese attack throws all of these plans out the window, as there are barely enough escorts to bring troops hardware to Hawaii, Bermuda, Trinidad, Iceland, and the small islands near to Hawaii. The Navy had no escorts abvailable to patrol "thousands of miles out' or to "push the Japanese back" in the Central Pacific. *They have the capability to do less than half of what you have planned.*


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## syscom3 (Feb 28, 2008)

freebird said:


> *I would think that Eisenhower's own words are a pretty good indication of the "Historical record"* The key word you used was "planning". The US did plan and in fact did buildup to some extent in the nearby islands. The Japanese attack throws all of these plans out the window, as there are barely enough escorts to bring troops hardware to Hawaii, Bermuda, Trinidad, Iceland, and the small islands near to Hawaii. The Navy had no escorts abvailable to patrol "thousands of miles out' or to "push the Japanese back" in the Central Pacific. *They have the capability to do less than half of what you have planned.*



Ike knows his army stuff in the Atlantic, but not the details on the Pacific.

You are forgetting some imprtant facts. Hawaii is not that far from the US. Theres plenty of tnakers to bring the oil to Hawaii, and theres anough escorts around to make sure they get there.

The IJN does not have enough subs to cover the ports and sea lanes in the Pacific.

The IJN doesnt have the resources to exploit anything east of the Gilberts.

You dont need a large force to defend the small islands south of Hawaii. A few battalions is often more than enough. And as history proved, the IJN was inept in invading defended beaches. 

There already were B17's available in Hawaii and the west coast to patrol the sealanes and make life difficult for any submarines.


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## Freebird (Feb 29, 2008)

syscom3 said:


> There is simply not enough Japanese subs to blockade the ports, patrol the coasts and patrol the high seas.



The Japanese subs do not need to "blockade" or patrol the open ocean, they would lurk around the US ports and sink targets of oppertunity, just as the German U-boats did. {and very effectivly too}

In effect it produces a "counter blockade" which ties up the US escorts, as the USN cannot know exactly where the subs will strike, so they would have to try to escort all major warships, to prevent loss.

I think you are counting on too much ASW capability from the US Navy in 1942, which they simply did not have.


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## Freebird (May 19, 2008)

syscom3 said:


> Ike knows his army stuff in the Atlantic, but not the details on the Pacific.



???? Ike was posted in the Philippines for several years before Pearl, he had a detailed knowlege of the military political situation in the Pacific. He was one of the most qualified people to analyze both the Allied Axis military capabilities in the Pacific theater and to recommend US strategies from the fall of 1941, which is why Marshall asked him to do exactly that.



syscom3 said:


> You are forgetting some imprtant facts. Hawaii is not that far from the US. Theres plenty of tnakers to bring the oil to Hawaii, and theres anough escorts around to make sure they get there.



True, but by using the limited number of escorts to accompany re-supply ships to Hawaii they won't be able to be used to escort warships in the SW Pacific, or to escort supplies to Fiji, NZ and Australia



syscom3 said:


> The IJN does not have enough subs to cover the ports and sea lanes in the Pacific.



They wouldn't need to patrol sea lanes, just having a couple of the 63 IJN subs lurking within 20 - 50 miles of each major Allied port in the Pacific would be enough. 



syscom3 said:


> The IJN doesnt have the resources to exploit anything east of the Gilberts.



Depends what you mean by "exploit". The Japanese troops were the most capable of operating with minimal supplies, so even landing a company or two, + a few floatplanes patrol aircraft would give the US problems.



syscom3 said:


> You dont need a large force to defend the small islands south of Hawaii. A few battalions is often more than enough. And as history proved, the IJN was inept in invading defended beaches.



This is exactly my point! The US only had about a division available in the fall of 1941 {excluding troops already deployed} so posting "a few battalions" to defend these islands reduces the # of troops available and ADDS to the strain on cargo ships as these troops will need regular sustenance + supplies to build defences, structures, airfields etc. 



syscom3 said:


> There already were B17's available in Hawaii and the west coast to patrol the sealanes and make life difficult for any submarines.



The Air Force would not allow their aircraft to be used for naval patrol, just as Bomber Command didn't want it's newer bombers used by Costal Command in 1941, they were given hand-me-down Battles, Hampdens, Ansons etc.

Even if some of the B-17's were used, they did not have the trained crews, radar, or night equipment that was needed to be effective. Remember that the US aircraft were not used and did not play a role on the East Coast in early 1942, even as the U-boats were ravaging Allied shipping


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## parsifal (May 20, 2008)

Have only just discovereed this thread. Am at work at the moment, taking a short break. i can see that the capabilities and limitations of the IJN submarine force are not clearly understood. Some simple statistics to start with. Are people aware that the the IJN submarines managed to sink nearly 1.2 million tons of shipping, most of it in the first 14 months of the war, with never more than 10 submarines (and mostly far less than that), allocated to corsair operations. japanese subs were magnificiently offensive vessels, but with insufficient care taken on defensive measures. japanese submarine men never fully appreciated the effectiveness of allied ASW. Magic Intercepts for Subs was not possible until the Subs started to make supply runs in 1943, because the Navy was forced to use the Army's well understood "water transport" codes. 

However, it is a complete furphy to suggest that the pacific was a safer haven for Allied MS, on the basis of its geography. The sheer vastness of the pacific, coupled with the extreme long range of the IJN Subs, coupled with the extrme short range, and short supply of USN escorts, coupled with the reactionary attitudes of persons like Adm king, who alsmost lost the war because of his refusal to adopt convoying tactics, all point to the fact that had the japanese IHQ adopted a more modern approach to the use of their submarines (something repeatedly recommended by the japanese submarine commanders before and at the beginning of the war), there would have been a much increased loss of tonnage for the US

I have a new book at home jointly written by a Japanese and an American, hot off the presses, that I am avidly reading at the moment. Will make some further comments later when i go home

Regards

Michael


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## Freebird (May 20, 2008)

parsifal said:


> Have only just discovereed this thread. Am at work at the moment, taking a short break. i can see that the capabilities and limitations of the IJN submarine force are not clearly understood. Some simple statistics to start with. Are people aware that the the IJN submarines managed to sink nearly 1.2 million tons of shipping, most of it in the first 14 months of the war, with never more than 10 submarines (and mostly far less than that), allocated to corsair operations.
> 
> However, it is a complete furphy to suggest that the pacific was a safer haven for Allied MS, on the basis of its geography. Had the japanese IHQ adopted a more modern approach to the use of their submarines (something repeatedly recommended by the japanese submarine commanders before and at the beginning of the war), there would have been a much increased loss of tonnage for the US
> 
> Michael



What I was looking at is this. The German U-boats started out with only FIVE subs for drumbeat, and only arrived on station at the end of January. Still the top 80% of boats sunk an average of about 40,000 tons each on their first patrol. If the Germans Japanese had planned together, they should be able to deploy 125 subs on the US east coast, gulf of Mexico, Pacific Indian Oceans {that is 60 Japanese subs, 65 U-boats} all ready to strike at Allied shipping starting the day after Pearl. Is there any reason why the top 80% of subs {100 subs} couldn't sink an average of 40,000 tons on the first patrol? That would be 4 million tons in the first month.


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## Glider (May 20, 2008)

One reason behind the success of Drumbeat was that the attack was a suprisem there was some evidence but not much and no preventative action was taken. A build up of this nature would I am sure have been spotted and action taken.
Don't get me wrong, it would have been a major blow for the Axis forces if only because the defence would have been undertaken by inexperienced forces. I just don't think that it would have been of the order you are implying.


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## Freebird (May 20, 2008)

It would involve the Japanese being realistic enough to know that submarines were far more effective against merchants than warships, judging by the performance of the German U-boats. The U-boats had a difficult time penatrating an ASW screen, wheras unescorted merchants were easy pickings. The Japanese should also not only concentrate on the US fleet, but have a couple of boats at all of the major Commonwealth ports on the Indian Ocean 



freebird said:


> Of the 63 Japanese Ocean-going subs they could send out,
> 3 subs to each of the following:
> 
> San Diego
> ...



Most of the ports were poorly protected, so even if there was advance knowlege little could be done. And unlike the US, the UK cannot "lock down" the shipping in port, because the lifeline through the Indian Ocean to Egypt India must be kept flowing


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## starling (May 20, 2008)

i am no expert but the jerry and japs could and should have blown the panama canal to bitts,and not just the lock gates,everything to do with it.the allies may have been in a rather precarious position then.also,if stalingrad was captured,jerry would be in complete control of south russia,just look at a map.yours,starling.


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## parsifal (May 20, 2008)

Hi freebird

Your scenario is entirely plausible, however, it is what might be referred to as a "dream run" for the submarine men. If such co-rdination had been attempted, there would have been almost certainly a large amount of planing needed, and if that was needed, a much greater risk of the allies finding out about it. Consider this, until April '42 the IJN JN 25 naval codes were secure, and the IJN submarine codes even moreso, however magic intercepts were routinely being read by the US. In the ETO, the Kriegsmarines enigma codes were finally broken in June 1941. If the co-rdination you are talking about had been attempted, it is almost certain that the alies would have found out about it.

What is far more plausible as a "what if", is if the two axis powers did not co-ordinate their efforts until after PH. This would have required a greater level of co-rdination, and some forceful convincing by the KM submariners, to try and get the intransigent Japanese IGHQ to fully adopt tonnage warfare as the principal means of employment for the IJN subs. IF the IJN subs had been employed in this way, the estimated losses for the USN in the Pacific is in the order of 3.6 million tons. In 1943 it still would be substantial (as evidenced by the IJNs operations in the Indian Ocean), because the convoys in the wide spaces of the Pacific (and Indian oceans) would have required a truly massive ASW effort by the US to protect. It would in my opinion, have extended the war by at least two years, and almost certainly have led to substantial postponements in the Manhatton project. There is no telling the damage this slight alteration in the use of axis resources may have had if adopted. However, I cannot say with certainty that it would have led to the demise of the allied cause, just put a huge dent in it


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## syscom3 (May 21, 2008)

I dont believe the IJN subs sank that amount of merchant tonnage. Provide a source please.

The IJN command staff had a bad habit of micro managing their subs, and commanding them through excessive radio chatter. The USN knew about the whereabouts of many of the subs and rerouted conveys to avoid them. And even managed to intercept them on occasion and sink them.

In the post war weeks of the war, the US had sufficient assetts on the west coast to minimize the sub threat. The Japanese were always short on subs, had a huge ocean to patrol, and after loosing a couple of them, their whole plan would collapse like a deck of cards.


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## parsifal (May 21, 2008)

syscom3 said:


> _*I dont believe the IJN subs sank that amount of merchant tonnage. Provide a source please.[/*I]
> Best source that i have are:
> The Japanese Submarine Force And WWII, Carl Boyd Akihiko Yoshida, Bluejacket Books, 1995, 2002
> Japanese Warships Of WWII , AJ Watts ian Allan, 1966, 1967
> ...


_

There is an excellent source for the wartime called DANFS (Dictionary Of American Naval Fighting Ships), which you can use to verify your claims if you like_


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## syscom3 (May 21, 2008)

From the combined fleet website:

"Bagnasco credits the Japanese submarine fleet with sinking 184 merchant ships of 907,000 GRT."

"Compared to German submarines, Japan's huge boats were relatively easy to sight visually and with radar, slow to dive, hard to maneuver underwater, easy to track on sonar, and easy to hit. Japanese hulls were also not as strong as those of German boats, and therefore could not dive as deeply nor survive such rough treatment."

AS I suspected ..... the IJN subs would be hard pressed to maintain a high tempo of operations. Just by losing several subs either by being sunk or damaged, their hypothetical campaign would fall apart.


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## parsifal (May 21, 2008)

Your source does not include ships damaged, and not returned to service, and ships damaged and subsequently captured

Like all aspects of the Japanese war machine, any losses are basically irreplaceable, however, how does the loss of a few submarines casue the whole capaign to fall apart? This didnt happen historically, where the "tempo" of Japanese submarine operations was higher than that being envisaged in this hypothetical. There does not appear to be any logic to the argument you are posing

I dont think the Freebird scenario is practical, let me make that clear, but the arguments you are mounting against it arent logical, or based on any sort of proper analysis. If you can explain or clarify your position, that would help your position enormously


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## syscom3 (May 21, 2008)

The IJN had so few subs available, that just by losing a couple here and there, the area's of coverage for each remaining boat would get larger and larger.

There are too many ports to cover (continously) with an ever present simple ASW that would have drastically educed the effectivelness of the subs. Maintain operations for a few weeks, yes. Maintain ops after a month, nope.


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## parsifal (May 21, 2008)

But that is exactly what they did do. with just 4 boats in the Indian ocean, and six boats operating in the antishipping role in the southern oceans, the Japanese were able to sink something like 200000 tons of shipping over a sustained period lasting more than six months. The other boats of the fleet were operating in the fleet support role, so there were no reserves to speak of

The numbers of ports actually works against the ASW forces far more than the Subs. moreover the Loss rates occurring in 1942 were being more tha n matched by new construction in 1942 and the early part of 1943.
You are not supporting your argument with factual data, at least to any great extent. What are you relying on as a source to make your position?


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## Freebird (May 22, 2008)

syscom3 said:


> I dont believe the IJN subs sank that amount of merchant tonnage. Provide a source please.
> 
> The IJN command staff had a bad habit of micro managing their subs, and commanding them through excessive radio chatter. *The USN knew about the whereabouts of many of the subs and rerouted conveys to avoid them.* And even managed to intercept them on occasion and sink them.
> 
> *In the post war weeks of the war, the US had sufficient assetts on the west coast to minimize the sub threat*. The Japanese were always short on subs, had a huge ocean to patrol, and after loosing a couple of them, their whole plan would collapse like a deck of cards.



The scenario I am postulating is this. Yamamoto and others realize that even "total success" at Pearl is only a temporary fix, the will have to come up with something better if they want to avoid having the huge US industrial capacity bury them after 2 -3 years {which is exactly what happened} If they look carefully at the results achieved by the U-boats in early WWII + WWI, this offers the best possibilty to neutralize the huge Allied advantage. 

The Japanese strategy therefore, is to work in concert with the Germans {insofar as they are both attacking shipping and straining limited ASW reaources}. *The convoys were not "re-routed" because there were no escorted US convoys at all for basically the first 4 - 5 months*, after this they concentrated on the Eastcoast where "drumbeat" was wreaking havoc, so the limited ASW resources were sent there. 

*What are these "sufficient assets?* The US will have about 5 dozen modern DD's total for all oceans, and did not yet have any ASW corvettes or Frigates. The older "flush decks" were next to useless because they lacked sonar, ASW and trained crews. During the spring of '42, while the U-boats were ravaging shipping off the US east coast, there were over a dozen of these older DD's in the eastcoast ports, they were not sent out as the US Navy felt they were useless against subs, and would only be "floating targets" Also remember that of these 5 dozen or so modern DD's, most would be needed to escort warships leaving very few for shipping escort or ASW


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## Hunter368 (May 22, 2008)

Freebird,

For my opinion I think the Germans and Japanese could of really laid a hurting on USA shipping, for a limited time.

Damn Germany did by herself as it was, hurt US shipping badly for a limited time.

Combined I think both could of laid a more severe beating on USA shipping and for a longer time frame also. But in the end USA still would of beaten them, just taken longer.


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## parsifal (May 22, 2008)

freebird said:


> *What are these "sufficient assets?*_ The US will have about 5 dozen modern DD's total for all oceans, and did not yet have any ASW corvettes or Frigates. The older "flush decks" were next to useless because they lacked sonar, ASW and trained crews. During the spring of '42, while the U-boats were ravaging shipping off the US east coast, there were over a dozen of these older DD's in the eastcoast ports, they were not sent out as the US Navy felt they were useless against subs, and would only be "floating targets" Also remember that of these 5 dozen or so modern DD's, most would be needed to escort warships leaving very few for shipping escort or ASW_



Hi freebird.

There is a really excellent site that you can deduce the available US ASW resources. In the Pacific they were pitifully weak. On the west coast there were a few old style destroyers, needed mostly to train new crews for the newly arriving warships of the fleet, and too short ranged to be of any real help in the sort of long distance escorting that would be needed in the Pacific. There were also a few CG cutters and the like, only really adequate (barely) for local harbour defence.

Anyway, this site might be of interest to you

World War II Armed Forces - Orders of Battle


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## Freebird (May 22, 2008)

syscom3 said:


> "Compared to German submarines, *Japan's huge boats were relatively easy to sight visually and with radar, slow to dive, hard to maneuver underwater, easy to track on sonar, and easy to hit.* Japanese hulls were also not as strong as those of German boats, and therefore could not dive as deeply nor survive such rough treatment."
> .





parsifal said:


> Hi freebird.
> 
> There is a really excellent site that you can deduce the *available US ASW resources. In the Pacific they were pitifully weak.* On the west coast there were a few old style destroyers, needed mostly to train new crews for the newly arriving warships of the fleet, and too short ranged to be of any real help in the sort of long distance escorting that would be needed in the Pacific. There were also a few CG cutters and the like, only really adequate (barely) for local harbour defence.



That's what I deduced as well. Japan's subs would indeed be more vulnerable to detection, but during the first year or so there are so few Allied ASW assets in the Pacific it won't make any difference


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## Hunter368 (May 22, 2008)

parsifal said:


> Hi freebird.
> 
> There is a really excellent site that you can deduce the available US ASW resources. In the Pacific they were pitifully weak. On the west coast there were a few old style destroyers, needed mostly to train new crews for the newly arriving warships of the fleet, and too short ranged to be of any real help in the sort of long distance escorting that would be needed in the Pacific. There were also a few CG cutters and the like, only really adequate (barely) for local harbour defence.
> 
> ...



Well known fact indeed.


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## syscom3 (May 22, 2008)

I show 80 DD hulls assigned to the Pacific Fleet. And thats exclusive of the 20 or so that was in the PI and assigned to the Asiatic Fleet.

The coastal area's of the west coast could be patroled to a certein degree using aircraft, smaller armed escorts and whatever DD's could be spared.

Would the allies take some hits from the IJN subs? Yes. Would it be as crippling as what the KM was doing in the Atlantic? NO! Could the IJN sustain operations? NO!

The fact remains that the IJN had far to many ports and shipping lanes to cover with far to few subs to do it. 

And the allies could have used their own subs to counter the IJN subs. Even though our torpedo's didnt work, the IJN didnt know it either.


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## Hunter368 (May 22, 2008)

syscom3 said:


> The coastal area's of the west coast could be patroled to a certein degree using aircraft, smaller armed escorts and whatever DD's could be spared.
> 
> 
> 
> ...


*



USA subs would not of been a huge counter to enemy subs IMO. Not like a visible large DD force always with convoys or near ports.

Click to expand...

*
See above


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## Freebird (May 22, 2008)

syscom3 said:


> I show 80 DD hulls assigned to the Pacific Fleet. And thats exclusive of the 20 or so that was in the PI and assigned to the Asiatic Fleet.



Syscom most of those DD's are the older "four-stackers" and are not equipped for anti-sub escort or ASW.



freebird said:


> The US would not be able to go on major offensive operations in the first half of 1942.
> 
> The US had 94 "modern" DD's completed from 1935 {Farraguts} up to and including 21 "Greaves" class in 1941, of which 2 dozen or so are still training working up. Of the older "Flush deck" or "4 stacker" DD's built before 1920, 11 have been modified as ASW escorts, 37 that have been or are undergoing upgrade to Minesweeper/Minelayer, Seaplane Tender or Fast Transport. 14 of the "4-stackers" are in the Far East fleet, and of the other 50 odd "4 stackers", the US Navy does not feel confident to use them for ASW/Fleet operations, as they would just be floating targets. In fact, even while the U-boats were sinking ships right off the US East coast, these DD's were left in port.



Most of the 94 modern DD's + the 11 "flush decks" modified for ASW would be really of much use, not the older DD's nor the Transports/Seaplane tenders/minesweepers. I posted this scenario *IF* the Japanese had knocked out the US carriers at Pearl, and launched the "third wave" that took out the fuel tanks, the sub base destroyed or damaged the 29 DD's sitting at Pearl. After taking into account 20 - 25 newly launched still working up, + the losses at Pearl you are only left with 60 -70 "modern" destroyers.

* If the older "four-stackers" had been any use why do you think they were left in port during "Drumbeat"? 

Can you tell me why the ASW actions in the Pacific would be any more effective than in the Atlantic?*




Wikipedia said:


> A significant failure in US pre-war planning was lack of any ships suitable for convoy escort work.
> Despite the urgent need for action, little was done to try to combat the U-boats. The USN was desperately short of specialised anti-submarine vessels. The shortages arose, partly because the massive new naval construction programme had prioritised other types and partly because the destroyers that were available remained inactive in port, even while freighters and tankers were being sunk in coastal waters. At least 25 Atlantic Convoy Escort Command Destroyers had been recalled to the US east coast at the time of the first attacks. At this time there were 13 destroyers idle in New York Harbor, yet still none were employed to deal with the immediate threat, and over the following nights ''U-123'' was presented with a succession of easy targets, most of them burning navigation lamps. At times, U-123 was operating in shallow coastal waters that barely allowed it to conceal itself, let alone evade a depth charge attack.



Despite the massive loss of shipping the US Navy was not able to sink *ANY* U-boats until April, when it sunk 1, and it sunk 1 more in May. So for the first 6 months of the war they sunk only 2 U-boats.

In fact I would think that the ASW efforts in the Pacific would be *much less* effective, as most of the DD's equipped for escort/ASW had been transferred to the Atlantic fleet pre-war.


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## Hunter368 (May 22, 2008)

Agreed


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## syscom3 (May 22, 2008)

The I-73 was sunk off of Midway on Jan 27 1942, because of intell reports tracking her across the Pacific.

Thats because the IJN were quite chatty. And there is nothing to indicate they would have remained quieter in this scenario. End result is the allies would have a good idea where the subs are and can take actions as appropriate.

And so what if the DD's that were the four stacks with minimal anti-sub gear? The IJN subs didnt know that and would have to deal with them as if they had the gear.


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## Hunter368 (May 22, 2008)

syscom3 said:


> The I-73 was sunk off of Midway on Jan 27 1942, because of intell reports tracking her across the Pacific.
> 
> Thats because the IJN were quite chatty. And there is nothing to indicate they would have remained quieter in this scenario. End result is the allies would have a good idea where the subs are and can take actions as appropriate.
> 
> ...



See above


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## parsifal (May 23, 2008)

syscom3 said:


> *I show 80 DD hulls assigned to the Pacific Fleet. And thats exclusive of the 20 or so that was in the PI and assigned to the Asiatic Fleet.*
> 
> I think your numbers are about right, however very few of these DDs could be spared for Covoy Escort, because they were needed for fleet support work. Surprisingly, perhaps, fleet DDs are not ideal ASW weapons, particularly in the USN where the emphasis was on fleet support over ASW work. To be effective at ASW, you really need dedicated assets, with the training, experience, teamwork and equipment to do the job. The USN fleet DDs whilst a general ASW capability at the beginning of the war had none of these requisite capabilities. This meant that they were not that good at sinking or even suppressing enemy subs. This was proven on both the east and the west coasts. It was only later, as British developed tactics, systems and training began to be adopted that the US ASW capability began to improve
> 
> ...



I can only reppeat my earlier point, you need to back up your position with some reasonable facts, rather than thump the table like this


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## Hunter368 (May 23, 2008)

Interesting stuff, parsifal.


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## syscom3 (May 23, 2008)

The IJN actually had some subs operating off of the west coast in the weeks after Pearl Harbor and their results weren't exactly impressive. Why would that change in your scenario?

As for the DD's, if fleet operations needed to be curtailed for a while so the DD's could concentrate on ASW activities, then so be it. The allied fleet doctrine was not chiseled in stone, and it proved to be quite flexible.

In ASW work, heres the definition of success:
1) Sink the sub outright. Or:
2) Damage the sub so it has to return to port. Or:
3) Disrupt its attack and keep it under water untill the convoy or ship has passed by.
Any type of escort or airplane can perform #2 and #3. As long as the sub doesnt shoot a torpedo at its target, then mission is accomplished. Now think about that when it came to the poorer maneuverability and weaker hulls. The probability of damaging the sub is a lot higher than that of the german subs.

As for the 4 stack DD's not having ASW gear ..... it wouldnt take too long for them to be retrofitted for depth charge racks and some type of sonar. Would that happen overnight? No. Would it be accomplished within a month? Yes. In the meantime, all the four stackers would need to do is to make their presence known and the IJN subs would have to take evasive action.

The IJN was never known for its logistics and fleet train capabilities. Damaged subs needed to go to Japan for most repairs. And because of the vast distances in the Pacific, that means transit times lasting weeks. And those are weeks in which it isnt participating in patrols.

Same with the subs you have patroling off of the Panama Canal and west coast of the US. Look at your transit times between Kwajelein and those locations. it will take them weeks to get on station, and return back. 

And finally I have to repeat ...... the IJN didnt have a lot of boats, and the loss of a only few of them would disrupt your plans.


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## parsifal (May 23, 2008)

syscom3 said:


> ][*I]The IJN actually had some subs operating off of the west coast in the weeks after Pearl Harbor and their results weren't exactly impressive. Why would that change in your scenario?[/I*]
> There were actually 10 Boats, per my previous post, but their primary mission was to attack military targets, with only a secondary priority being given to the merchant shipping. The result was that only 8 steamers steamers totalling 64670 tons (my previous post was in error, as i forgot to add a couple of I-boats to the tally) had been sunk by the end of January.
> By contrast, the three groups operating in the far east (groups "Ko", "Otsu" "Hei") with a total of 25 Boats had sunk more than 250000 tons in the same period. In this latter case, the I-Boats in the far east were temporarily given the opportunity to trat MS targets the same priority as naval targets. They were not forced to conserve torpedoes, by ignoring civil targets, in the vain hope that "better" military targets might present themselves at a later date.
> 
> ...



You need to reveal your sources to more convincingly support your arguments. Your table thumping lecturing technique is only decreasing your credibility i would suggest


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## Hunter368 (May 23, 2008)

Good information Parifal. Nicely said and done. Very good information and facts.


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## syscom3 (May 23, 2008)

Parifal, and your sources?

You seem to be making the fatal assumption that the IJN will emulate KM tactics and shipbuilding techniques, using widely optimistic assumptions for the IJN to conduct intense operations several thousand miles from their bases.

And then you widely discount allied countermeasures and make the assumption that the allies will behave exactly as you want them too.


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## parsifal (May 23, 2008)

Ive already given you the two sources that I am mostly relying on, plus some idea of my hands on experience.

For the record, I have also already said that I did not think Freebirds hypothetical was all that practical, however, putting that practicality issue aside, I looked at plausible outcomes simply if the japanese swung over to a mercantile strategy, with some help from the KM. . There are no wildly optimistic assumptions, they are merely extrapolations of existing tonnage rates per boat, if the IJN sub fleet had been fully committed to a mercantile strategy. "Wildly optimistic" would be an appropriate label if i was to attempt to argue that the IJN subs could achieve the same tonnage rates as the Germans. I have not attempted to argue any increased production for the IJN, nor have i tried to argue any special invulnerability. its all there, for anyone who cares to look objectively. For the record also, I have also said that I did not think this alternative strategy would be ultimately successful. My objectives are very limited...what would be the effect of a IJN mercantile strategy in 1942-3.

I am simply looking at what happened historically, in the Atlantic, and then extrapolating that if a similar situation was to arise in the Pacific. In the Atlantic, the US countermeasures failed miserably, faced with a far greater threat from the Germans. In the pacific, there are no special circumstances to sugeest that they would operate any differently. In fact there are some issues (like the presence of the powerful japanese surface fleet) that would suggest a far worse allied effort. i would suggest that it is yourself who is making wildly optimistic projections about what might have happened in this scenario, giving the USN capabilities it just did not possess, assuming decisions, like convoy, that are most unlikely to happen, assuming reactions from the japanese that are not borne out historically etc etc


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## Hunter368 (May 23, 2008)

Agreed


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## Freebird (May 23, 2008)

parsifal said:


> Hi freebird
> 
> Your scenario is entirely plausible, however, it is what might be referred to as a "dream run" for the submarine men. If such co-rdination had been attempted, there would have been almost certainly a large amount of planing needed, and if that was needed, a much greater risk of the allies finding out about it. Consider this, until April '42 the IJN JN 25 naval codes were secure, and the IJN submarine codes even moreso, however magic intercepts were routinely being read by the US. In the ETO, the Kriegsmarines enigma codes were finally broken in June 1941. If the co-rdination you are talking about had been attempted, it is almost certain that the alies would have found out about it.
> 
> What is far more plausible as a "what if", is if the two axis powers did not co-ordinate their efforts until after PH. This would have required a greater level of co-rdination, and some forceful convincing by the KM submariners, to try and get the intransigent Japanese IGHQ to fully adopt tonnage warfare as the principal means of employment for the IJN subs. IF the IJN subs had been employed in this way, the estimated losses for the USN in the Pacific is in the order of 3.6 million tons. In 1943 it still would be substantial (as evidenced by the IJNs operations in the Indian Ocean), because the convoys in the wide spaces of the Pacific (and Indian oceans) would have required a truly massive ASW effort by the US to protect. It would in my opinion, have extended the war by at least two years, and almost certainly have led to substantial postponements in the Manhatton project. There is no telling the damage this slight alteration in the use of axis resources may have had if adopted. However, I cannot say with certainty that it would have led to the demise of the allied cause, just put a huge dent in it





parsifal said:


> Ive already given you the two sources that I am mostly relying on, plus some idea of my hands on experience.
> *
> For the record, I have also already said that I did not think Freebirds hypothetical was all that practical*, however, putting that practicality issue aside, I looked at plausible outcomes simply if the japanese swung over to a mercantile strategy, with some help from the KM. . There are no wildly optimistic assumptions, they are merely extrapolations of existing tonnage rates per boat, if the IJN sub fleet had been fully committed to a mercantile strategy. "Wildly optimistic" would be an appropriate label if i was to attempt to argue that the IJN subs could achieve the same tonnage rates as the Germans.
> 
> I am simply looking at what happened historically, in the Atlantic, and then extrapolating that if a similar situation was to arise in the Pacific. In the Atlantic, the US countermeasures failed miserably, faced with a far greater threat from the Germans. In the pacific, there are no special circumstances to sugeest that they would operate any differently. In fact there are some issues (like the presence of the powerful japanese surface fleet) that would suggest a far worse allied effort.



Parsifal what parts of the scenario are "not practical"? 

I agree with you that the idea of total joint planning would not work, it would be more along the lines of "separate but parrallel. Germany had been asking the Japanese in 1939 +1940 to joinin the war, but this got a cool reception. Things changed in 1941 with the allied steel oil embargo on Japan.

Now look at it from the viewpoint of the Japanese. The smartest planners in Japan figure out that attacking merchant shipping is the best way to cripple the US war effort. It would be a huge advantage for Japan if the U-boats are attacking US shipping on the US east coast at the same time. However Japan can not plan on Hitler doing anything so stupid as to declare war on the USA. {remember the Axis pact requires German assistance only if Japan is attacked, if the Japanese start hostilities then there is no obligation} I would put forward that it was possible to have 2 separate simultaneous wars - UK USSR vs Germany Italy, while the USA fights only Japan. {perhaps withonly some lend-lease}

Now, Japan approaches Germany with a proposition: Japan will enter the war against USA UK, {which Germany wants} if Germany will also declare on the USA. {Japan was reckless IMO for not asking this, risking having the US concentrate everything on Japan}. Germany would know that Japan was planning to attack the Allies, and roughly when. {They would not know the exact date or about Pearl} The U-boat fleet would thus have a couple of vital months to prepare for drumbeat, and to have U-boats milch cows off the east coast as the time came {perhaps based in Martinique} This way there is not a 5 week delay between "Pearl" and the start of "Drumbeat". There is the possibility that some information may leak out, but it will likely be discarded as disinformation. *Remember that the US War Dept. had advance warnings of an impending Japanese attack, yet it was little help if any. The US also has advance warning from the British about the onset of "Drumbeat" yet this did not seem to be of any help.*

Japan can also take the time to prepare for war by having a couple of boats on station in all of the important Pacific Indian Ocean ports. *The difference between stating the sub offensive right away in Allied harbours compared to several months later is huge.* Parsifal have you been to any of the Pacific/Indian ports? I have sailed into Brisbane, Sydney, Melbourne, Hobart, Auckland, Suva, Tonga, Honolulu, and have seen the ports of Portland, San Diego, San Fransico, LA have lots of time spent sailing the Puget sound {Seattle/Tacoma} around Vancouver. It would not be too difficult for a Japanese sub to sneak into one of these ports, which had minimal if any protection {most all ASW had been pulled to the east coast} On the early morning of Pearl the Japanese subs surface in the harbour and start to pick off ships at anchor.
*
Also I would be interested in your estimation of the possible tonnage per boat probable for the first 2 months of the war*. I believe that of the first 5 Drumbeat boats that arrived in mid-January, 80% of the boats sunk an average of 40,000 tons each. {20% were ineffective} This is what was achieved with the USA having 5 weeks to prepare. If they only had a few days preparation it could be more than that. Are you supposing that the Japanese subs could be 1/2 or 2/3 as effective as Germanys? If Germany Japan can deploy 125 subs against Allied ports the Allies could easily lose 2 or 3 million tons a month for the first few months. And we have only been considering the US response to the Japanese sub offensive, what defences would be available in Mombasa, Zanzibar, Durban, Mogadishu, Karachi, Aden, Abadan, Bombay, Calcutta, Madras, Bangalore etc etc? With the British ASW defences already stretched to breaking, I doubt much help if any could be sent. Most of the convoys in this period only went as far as Capetown, if even that far. When it comes right down to it, every Allied hull sunk is another nail in the war effort, regardless of which ocean it is lost in


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## syscom3 (May 23, 2008)

Freebird, good suggestion for the subs to sneak into the harbor and commence firing in the late morning of Dec 7th.

And I would even credit the IJN (had they done that) to sink a lot of boats. But then, after firing their torpedo's, its time to sail back to Kwajelein for a reload, and the USN would have a month of respite.

But then, theres always the reaction the USN would have after a few weeks, and the west coast would continually get more secure as aircraft and DD's are brought into play.

If there is one thing thats different between the Pacific and Atlantic, is the shear vastness of the ocean, and the Japanese achilles heel of no air recon to find the ships. 

Unlike the Atlantic, the Pacific had the vastness for indivdual ships to "dissapear" from the subs. And there is a fundemental difference between the ETO and PTO ..... England needed vast numbers of ships to support its industrial and population base. The US, at a minimum, only needed enough ships to keep Hawaii supplied, and that wasnt a lot of tonnage needed.

So the only way this scenario could unfold on the US west coast is:

1) A surprise sub attack in the harbors, inflicting lots of damage.
2) A drop in tempo of sub activities in the days following as the subs need to reload their torpedo's.
3) A change in the Pacific fleets activities as more emphasis in ASW activities.
4) The IJN subs reappearing off the west coast after 4 weeks, but a greatly increased ASW effort from air and sea assetts.
5) Increasing ineffectiveness on the part of the subs due to sub sinkings, sub damage and countermeasures.


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## fly boy (May 23, 2008)

freebird said:


> If the Axis had made joint plans for an attack on the USA Allies, involving submarines, commandos and covert operations to begin at the same time as the Pearl Harbour attack, could it have succeeded?
> 
> *1.) The U-boat war*
> 
> ...



they might have they might have...


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## parsifal (May 24, 2008)

Hi Freebird



freebird said:


> _*Parsifal what parts of the scenario are "not practical"?
> 
> I agree with you that the idea of total joint planning would not work, it would be more along the lines of "separate but parrallel. Germany had been asking the Japanese in 1939 +1940 to joinin the war, but this got a cool reception. Things changed in 1941 with the allied steel oil embargo on Japan.*_
> The impractical bits is the level of co-ordination needed, plus the starting assumption. The japanese knew about tonnage warfare, but chose not to adopt it. The submarine Admirals in the IJN were constantly recommending that this strategy be adopted, but were consistently ignored or overruled.Its not that IGHQ was immune to the suggestion, its just that they, like the US were totally wedded to the concept of the strategic battle, into which mercantile warfare, the Jeune Ecole concept of naval warfare played no part. The primary job of the submarines was to attrition the US Battlefleet as it advanced across the Pacific to enage the IJN battlefleet. The I-Boats were designed for this specific and specialized purpose, and would have been very good at it IMO. They were extremely long endurance, with high surfaced speeds that would enable them to attack, move to the next position ahead of the advancing US forces, scout with their own onboard aircraft etc etc. of course things didnt work out that way. The Carrier TFs were just too agile for the Japanese to emploiy mobile tactics, so they were reduced to putting up static patrol lines (like everybody else) and hope for the occasional ambush. They had some spectacular successes with that, but nothing like what they had hoped for. And all the while, whilst employed on these fruitless patrol and picket lines, the allied mercahnt men glided lithely by.
> ...



Hope this is of some help


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## Freebird (May 24, 2008)

Parsifal what evidence do you have of boom defences at the time of Pearl? I don't think any of the ports had this {other than Pearl + Manila} as they were not at war in the Pacifc, but perhaps put in place some months later.

I know for a fact that Vancouver did not, as the outer harbour is several miles wide at the entrance. Obviously Moreton bay {Brisbane] would be too big too. How wide is the entrance to Pr. Philip at Melbourne? Puget Sound san Fransico bay are also too big for a boom. Now the inner harbours the Navy docks would probably be protected that way, but the freighters anchored out in the approaches most certainly would not. 

From what I have read {and seen personally} things at the other Pacific/Indian ports {Suva, Mombasa, Zanzibar, Noumea, Tonga} are more lax, often times the rules procedures are ignored. {just as the Italian booms at Taranto were not in place}


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## parsifal (May 24, 2008)

Incomplete i am afraid. At a gues i would say Singapore, Bombay, Surabaya and probably Calcutta. Likley also Hong Kong.

As far as Australia is concerned, I know that Sydney did, and have to disagree with you by saying also that Melbourne did as well. the Port of Brisbane is a river, at the headwaters of Moreton Bay, a very shallow body of water that any Sub would have to traverse in a surfaced condition for more than 100 miles. The boom defences in Sydney were not completely fullproof however, as the Midget sub attack in May shows, 

I still stick to th e theory that attacks into harbours by full sized subs is not practical. Putting aside the harbour defences issue for a moment, which i admit i cant answer completely, IMO subs entering the harbours would not be able to dive, and would be very easy targets in most cases. For the japanese, operating as corsairs, in my opinion, in the open reaches of the ocea, is a far more prudent option


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## syscom3 (May 24, 2008)

If the IJN began a systematic slaughter of shipping off the west coast, then no doubt, the ships crews would decide not to sail and remain in port "untill something was done".

Losses go down but the war effort is impacted to some degree.

In the long run, anything that happens to be delayed in 1942 becomes irrelevant, after 1943.

The war ends exactly as scheduled on Aug 15th 1945.


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## parsifal (May 24, 2008)

syscom3 said:


> *If the IJN began a systematic slaughter of shipping off the west coast, then no doubt, the ships crews would decide not to sail and remain in port "untill something was done".
> 
> Losses go down but the war effort is impacted to some degree*.
> 
> ...




Keeping the shipping lanes open was esstial to the overall allied effort. Shutting down the US MS effort in the pacific Theatre and Indian ocean would have had catastrophic effects on the war


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## Freebird (May 25, 2008)

syscom3 said:


> Freebird, good suggestion for the subs to sneak into the harbor and commence firing in the late morning of Dec 7th..



Thanks. By the way Syscom, I agree with you that there are alot of things that could go wrong, it's a good thing for us that The German Japanese high command tended to ignore good military advice. This scenario represents a "worst case scenario" for the Allies, the type of calculation that should be made - "what is the most damage the enemy can inflict?"



syscom3 said:


> And I would even credit the IJN (had they done that) to sink a lot of boats. But then, after firing their torpedo's, its time to sail back to Kwajelein for a reload, and the USN would have a month of respite


 The Japanese subs carry 12 - 20 torpedoes and have a high endurance, so by the time they need to return to re-arm they should have sunk 6 - 10 merchants or more, a huge amount of tonnage to lose.
The Japanese also had quite a few "sub tenders", so only a badly damaged boat would need to return to japan. 



syscom3 said:


> But then, theres always the reaction the USN would have after a few weeks, and the west coast would continually get more secure as aircraft and DD's are brought into play..



With a more concentrated effort on the east coast, I have a feeling {as parsifal mentioned} that the US Navy will send whatever limited ASW it has to the east and "shut down" Pacific shipping, with the consequences he mentioned. 



syscom3 said:


> Unlike the Atlantic, the Pacific had the vastness for indivdual ships to "dissapear" from the subs. And there is a fundemental difference between the ETO and PTO ..... England needed vast numbers of ships to support its industrial and population base. The US, at a minimum, only needed enough ships to keep Hawaii supplied, and that wasnt a lot of tonnage needed.



The US indeed could concentrate its shipping on Hawaii the near islands, which would impact the Pacific theatre. By far the most vulnerable would be the UK's war effort in N. Africa its defence of the CBI theatre, they cannot stop the shipping pipline without dire consequences.




parsifal said:


> As far as Australia is concerned, I know that Sydney did, and have to disagree with you by saying also that Melbourne did as well. the Port of Brisbane is a river, at the headwaters of Moreton Bay, a very shallow body of water that any Sub would have to traverse in a surfaced condition for more than 100 miles. The boom defences in Sydney were not completely fullproof however, as the Midget sub attack in May shows,
> 
> I still stick to th e theory that attacks into harbours by full sized subs is not practical. Putting aside the harbour defences issue for a moment, which i admit i cant answer completely, IMO subs entering the harbours would not be able to dive, and would be very easy targets in most cases. For the japanese, operating as corsairs, in my opinion, in the open reaches of the ocean, is a far more prudent option



Parsifal, I can agree with you about halfway. In Australia which probably had the most protected ports, the Axis subs could lurk outside the ports and on the coastal shipping routes, which probably had enough traffic to be effective. I don't see this being practical in the open areas of the Pacific ocean. after the first month of sinking some ships in the SE Pacific {Tonga, Fiji, N. Caledonia, Tahiti etc, the shipping traffic would probably dry up, the Japanese boats would probably be re-deployed. The US Canadian Pacific ports are not only mostly unprotected {and impossible to boom}, but provide ideal hunting hiding ground for subs. The large, deep bays in Juan de Fuca {Vancouver}, Puget sound {Seattle Tacoma}, San Fransisco have dozens of small, deep, uninhabited inlets that would allow the subs to hide in, surfacing at night to hunt targets of oppertunity, or ships entering/leaving the harbour. 

As the west coast ports begin to curtail sailings a losses mount alarmingly, the japanese could send more boats to East Africa/Indian ocean to help strangle the Commonwealth war effort.


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## Wildcat (May 25, 2008)

parsifal said:


> .
> As far as Australia is concerned, I know that Sydney did, and have to disagree with you by saying also that Melbourne did as well. the Port of Brisbane is a river, at the headwaters of Moreton Bay, a very shallow body of water that any Sub would have to traverse in a surfaced condition for more than 100 miles. The boom defences in Sydney were not completely fullproof however, as the Midget sub attack in May shows,



Out of interest, here is some info on the coastal defences of Moreton Bay/Brisbane River area in WWII.
RAN Station 4 Indicator Loop and Harbour Defence Asdic Station, Bribie Island, QLD
British Mine Layer, HMS Atreus, mines Moreton Bay ("Job Fifty-one")
Cowan Battery, at Cowan Cowan, Moreton Island
Seaward defences for Moreton Bay
Fort Bribie, Bribie Island, QLD
RAN Station 6, Fairmile Advanced Operating Base, Bribie Island, Queensland


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## parsifal (May 25, 2008)

freebird said:


> *Parsifal, I can agree with you about halfway. In Australia which probably had the most protected ports, the Axis subs could lurk outside the ports and on the coastal shipping routes, which probably had enough traffic to be effective. I don't see this being practical in the open areas of the Pacific ocean. after the first month of sinking some ships in the SE Pacific {Tonga, Fiji, N. Caledonia, Tahiti etc, the shipping traffic would probably dry up, the Japanese boats would probably be re-deployed. The US Canadian Pacific ports are not only mostly unprotected {and impossible to boom}, but provide ideal hunting hiding ground for subs. The large, deep bays in Juan de Fuca {Vancouver}, Puget sound {Seattle Tacoma}, San Fransisco have dozens of small, deep, uninhabited inlets that would allow the subs to hide in, surfacing at night to hunt targets of oppertunity, or ships entering/leaving the harbour. *
> 
> 
> I dont have much knowlewdge about the US west coast ports, but as Wildcat points out in his post, there is quite a bit of evidence to suggest that the ports in Australia were given some level of protection. I dont think Australia was alone in providing port defences. The commonwealth had been at war for three years, we had suffered the effcts of raiders, and had been fretting about Japan since the war in Europe boke out. Ine the acase of singapore, the port was protected by the big guns, as well as proper passive defences. There were also extensive minefieldws around the port. Singas was the main fleet base in the far east, along with Trincomallee and to a lesser extent Colombo. I am about 90% sure as well that Surabaya, the main RNN base was also protected. Protecting you harbours is a fundamental first step in wartime, and the main reason that enemy forces dont try these Guere De Course activities directly into the harbours of an opponent. For an idea of what usually happens in these circumstances, look at what happened at Dieppe.....a massacre basically
> ...



The only way for the allies to avoid all of this is for the US to grit its teeth, and fight it out, regardless of losses. If they did that, therer losses would be substantial, but at the end of it, the alliance needed to defeat the Axis is still intact, and the road to victory assured. Any other "shortcut" adopted by the allies (and the US in particular) would only lead to defeat in my opinion


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## Soren (May 25, 2008)

Good debate Freebird Parsifal.

Personally I believe it possible for the KM IJN to achieve Freebirds scenario, but it wouldn't be a walk in the park. 

The most important thing for the Axis would be to cause the most US casualties in their first strike, taking out the Carrier fleet. If that was achieved the IJN would make sure that the German Japanese subs would have turkey shoot, not having to worry about anti sub a/c. Any B-24 or Catalina trying to enter the airspace would be intercepted sht down by Zeros. From that point on it would be extremely hard for the Allies to regain control of the Pacific.

But again the above relies upon the Axis achieving a very successful surprsie strike and atleast severely crippling the Carrier fleet.


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## Freebird (May 26, 2008)

Wildcat said:


> Out of interest, here is some info on the coastal defences of Moreton Bay/Brisbane River area in WWII.



Thanks very much, Wildcat. I see that most of the defences were constructed in mid 1942, much the same as in Vancouver, where gun batteries were built about the same time.

Wildcat do you know if there were any ASW squadrons in the Brisbane area in Dec '41 - Mar '42?

Parsifal I think that probably only Sydney, Melbourne, and the major Royal Navy bases {Singapore, Ceylon}
had halfway decent properly manned defences, the others were still in peacetime mode {more on that later} In the case of Singapore, the subs do not need to penetrate the naval base, as the subs can wait in the straights to attack ships before they get to the Island.


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## Wildcat (May 26, 2008)

freebird said:


> Wildcat do you know if there were any ASW squadrons in the Brisbane area in Dec '41 - Mar '42?



No. 23 squadron (Hudson and Wirraway), which was based at Archerfield (Brisbane) was engaged in seaward patrols in this time period. In the Dec '41- Jan '42 timeframe, the unit's Hudson's were up daily carrying out these patrols. In late Jan, the Hudsons were posted out to help form 32 sqn at Port Moresby, therefore it was left up to the squadron's Wirraways to carry on with the seaward patrols. Interestingly on the 24th of March '42, a Wirraway dropped two bombs on a submarine roughly 50 miles off the coast of Brisbane, a brown substance came to the surface however what effect the bombs had on the sub was unknown.


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## Freebird (May 27, 2008)

Wildcat said:


> No. 23 squadron (Hudson and Wirraway), which was based at Archerfield (Brisbane) was engaged in seaward patrols in this time period. In the Dec '41- Jan '42 timeframe, the unit's Hudson's were up daily carrying out these patrols. In late Jan, the Hudsons were posted out to help form 32 sqn at Port Moresby, therefore it was left up to the squadron's Wirraways to carry on with the seaward patrols. Interestingly on the 24th of March '42, a Wirraway dropped two bombs on a submarine roughly 50 miles off the coast of Brisbane, a brown substance came to the surface however what effect the bombs had on the sub was unknown.



Interesting. In Vancouver we had Ansons at the training base at Jericho, and Hampdens were used for training at Patricia Bay on Vancouver island. However I think that none of them had airborne search radar at this time, and I suspect that the Hudsons probably did not either. 

Wildcat I believe that the cargo freighters anchor in Moreton bay, near Manly, if I remember correctly? {I was there in 1988 so it's been some time}
Then when a space opens up the tugs would help the ship up the river to dock unload is this correct?

If the situation is similar to Vancouver, where we had only 3 or 4 cargo berths in the inner harbour Fraser river, so there would usually be 5 - 10 ships anchored in the large outer bay, waiting to be either loded or unloaded


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## Wildcat (May 29, 2008)

freebird said:


> Interesting. In Vancouver we had Ansons at the training base at Jericho, and Hampdens were used for training at Patricia Bay on Vancouver island. However I think that none of them had airborne search radar at this time, and I suspect that the Hudsons probably did not either.


Yeah, I doubt our Hudsons had ASV at this time aswell. Infact I don't think they were ever installed in our Hudson force at all - though I could be wrong.




freebird said:


> Wildcat I believe that the cargo freighters anchor in Moreton bay, near Manly, if I remember correctly? {I was there in 1988 so it's been some time}
> Then when a space opens up the tugs would help the ship up the river to dock unload is this correct?
> 
> If the situation is similar to Vancouver, where we had only 3 or 4 cargo berths in the inner harbour Fraser river, so there would usually be 5 - 10 ships anchored in the large outer bay, waiting to be either loded or unloaded



I'm not sure how it all works on the Brisbane river, sorry mate. Emac might know the particulars.


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## Freebird (May 29, 2008)

Wildcat said:


> I'm not sure how it all works on the Brisbane river, sorry mate. Emac might know the particulars.



Oops I should have checked the state flag first!   

Where were the shipping terminals in S. Australia in WWII? Are they in Encounter bay/Lake Alexandria? Or right in Adelaide proper? 

Is the bay there protected enough to have docks on the coast, or are they inland? {Up the river}


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## Freebird (Jul 22, 2008)

Parsifal I will re-post your reply on this thread as it mainly deals with the submarine question...

*Quote=Parsifal*

I have never said that small scale raids against the US are not impossible, or that compared to history a greater effort could not have been mounted. however, what I think is a mistake is the diversion of such a large amount of high quality assets off on what I consider to be minor operations. The primary function of the U-Boats has to be the sinking of ships, and any deviation away from that objective by ANY U-Boats, is a defeat for the Axis, and a victory for the allies. In fact the way to assist by Special Operations is to seek ways to to enhance that capability. Sinking a few ships by submarine, and then knocking out a refinery, or an oil well, is not working to the same purpose. if you have a few less ships, then a knocked out refinery is not going to increase allied probls. What needs to be done is to sink ships by submarine, and to sink ships (or its equivalent) using other means to augment the process. 

The prime target to achieve this would be to look for some way to render the panama canal inoperative, even if temporarily. if it gets knocked out, or made unusable, the pressure on US shipping becomes immense. Moreeover, even a small delay of say two months might be enough to tip the whole balance of power in the pacific, its that serious.

Now, Panama was one of the most heavily guarded targets prewar from landward attack. It was protected by more than a full brigade of troops pre-war, and this was rapidly increased soon after hostilities broke out. So, IMO a landward attack is not a great idea.

However, the US has two achilles heels pre-war, and continuing for many months into the war. Its ASW capability is abysmal. Less well known is its hopeless minesweeping capability. My idea would be to exploit those two weaknesses to the maximum. 

The ASW weakness would require many more U-Boats to be sent to the western hemisphere immediately upon hostilities breaking out. This would require a re-deployment of the 62 boats in the med, and the 15 boats from the arctic for as rapid as possible re-deployment to the US and carribean. I would also push forward as many of the boats currently under training, about 90 to the US as soon as possible, even if those boats are not fully trained, or trained to quite the samer high standards as are usually demanded in the Km. 


The result of all this expediancy is that instead of having just 6-10 boats with which to undertake Drumbeat, the germans have 60-100. Sure, some of them arent fully trained but they are carrying mines rather than torpedoes, or spares and fuel for the front line subs. The aim here is to produce a submarine equivalent of a "thousand bomber raid", to create an event of such shock value, that it is likley to affect allied nerves and planning, and thereby give germany and Japan vital breathing space.

To assist in this effort, I would augment the minelaying effort by prepareing as many fast blockade runners as I could with as many mines as they could covertly carry. In late 1941, I believe there were as many as 30 German controlled blockade runners still at sea. If all of them were carrying 100 to 150 mines, and were ordered to move to various locations in the carribean, particularly off shore of Panama Canal, and rather than just blindly rush and declare war straight after PH, but rather wait a few days or a week whilst the blockade runners were put into position, then lay the mines just before the DOW, using the newer versions of mag mines, which the US could not sweep, my opinion is that utter chaos would reign in the US and carribean for many months.

Historically, the Germans only laid about 300 mines off the US coast. those few were quite devastating sinking, IIRC about 10 ships. Now, what I am talking about is a sudden minelaying effort, aimed at sowing something like 5-8000 mines, and backed up by a sub force of 50-100 U-Boats, properly supplied. 

The result IMO would have been utter chaos for the US, and its allies. it is not beyond the realms of possibility to suppose the loss of 2-3000000 tons of shipping in a month. Morever, the mining of the approaches to the Canal, would have been the equivalent to the loss of a further 2000000 tons, at least.

The losses of this magnitude would not have won the war , in itself, and would not have been sustainable, but it would have had major impacts on US thinking. The possibilities, IMO might have included

1) A major reduction of Shipping for the pacific, significantly delaying the counteroffensive in the pacific.
2) Suspension or delay in the blue water navy currently under construction in favour of increase MS and small ship production.
3) A cut or abandonment of the more agressive parts of US aircraft production, such as the heavy bomber program, to free up more resources for MS and escort production.
4) Diversion of more DDs and carriers to Europe from the Pacific.
5) Reduction or abandonment of the Arctic Convoys to Russia. 
6) Diversion of more RN assets to assist the USN in its coastal convoy battles. Woulds almost certainly have resulted in the loss of malta

These name just a few of the advantages that might become possible. They dont win the war, but they lead to some mighty big changes to the way the allies prioritise the war, and may possibly lead to a negotiated peace, rather than unconditional surrender.


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## pbfoot (Jul 22, 2008)

food for thoughtsounds pretty good


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## parsifal (Jul 22, 2008)

Thanks Freebird

In the pacific, the Japs had only 10 boats off the US west coast, and these had only a secondary mission of anti-shipping. They consequently only sank about 60000 tons in that first month.

However, they also had, I think, 15 boats stationed around Hawaii, with an exclusive anti fleet mission. These boats were prohibited to from making any attacks against shipping targets. they were saving their torps for the departure of the Pacific Battlefleet, which never came.

One wonders what would have happened if all 25 boats off the US west coast had been given anti-shipping as their primary mission. In the NEI this did happen, with over 40 Allied Merchantmen lost or damaged (and then captured, as a result. From memory (and I may stand corrected on this), I believe that losses in that first 60 days in the NEI region ran to over 500000 tons. That was achived with three flotillas totalling 24 Boats IIRC.

It would not be unreasonable to suppose that US losses would have been similar, if the I-Boats had been properly tasked in the first place....

Add that 1000000 tons from the pacifc, with the 2-300000 guesstimated losses from an enhanced german raid, and you have got a whole lot of trouble for the Allies


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## syscom3 (Jul 22, 2008)

> 1) A major reduction of Shipping for the pacific, significantly delaying the counteroffensive in the pacific.



Yes, quite possible.



> 2) Suspension or delay in the blue water navy currently under construction in favour of increase MS and small ship production.



Not a chance. The fleet already was well along in its construction phase. And that included the production oh hundreds of DD's and DE's. Perhaps the first change in priorities would be to minimize amphib ship building capacity in favor of others.



> 3) A cut or abandonment of the more agressive parts of US aircraft production, such as the heavy bomber program, to free up more resources for MS and escort production.



Not a chance. Airplanes are the best ASW assetts the allies had. Especially the four engined types. And theyre built of aluminum, not steel.




> 4) Diversion of more DDs and carriers to Europe from the Pacific.



No. The carriers would remain in the Pacific, although they would be tethered to stay close to Hawaii.




> 5) Reduction or abandonment of the Arctic Convoys to Russia.



Yes.




> 6) Diversion of more RN assets to assist the USN in its coastal convoy battles. Woulds almost certainly have resulted in the loss of malta



Yes.


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## HealzDevo (Jul 23, 2008)

I think though, that a combined German/Japanese offensive could have made things very hot for the US. Think about the fact that a lot of the US was considered relatively free from submarines. It would have a big impact at least on public morale in the US at the least having larger numbers of ships sunk virtually on their doorstep. Remember the last time there was a major engagement with a foreign enemy close to the US homeland would have been the War Of Independence against the British...


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## parsifal (Jul 23, 2008)

Syscoms reply suggest that nothing really needs to be done if the Axis upped the tonnage war for a short period. That somehow catastrophic losses on US shipping was somehow not that important. Therefore, no change would be required in US war plans. To say the very least, its a strange reaction to what many considered the number one threat to allied survival. Sys seems to think that somehow by ignoring the problem, it will simply go away, and that the frontline operations so very favoured by the Americans can proceed as if nothing had happened.

My reaction as the imaginary el supremo of the axis forces, would be to deliver more of the same to the Americans, until they were forced to either sit up and take notice, and pour more resources into the "small end of town", ie the asw and tonnage war. And these resources have to come from somewhere.....

So my reaction to the US el supremos (ie Admiral/general sys) is to deliver another month or two of catastrophic losses. so in February/March 1942, American losses aagain touch somewhere in the vicinity of 4 million tons, with a further 2 million tons being needed over the historical model, due to the effects of the mining effort in Panama. For the period December 1941 through to the end of March 1942, they have lost the equivalent of about 11 million tons of shipping, including the 2 million tons denied as a result of the panama mining operation (at a guess) and can no longer even support the domestic ecopnomy, let alone consider ANY force projection overseas. The carriers, and the fleet at pearl, can no longer be supported and must redeploy back to the west coast, where the domestic shortages of oil mean that they can no longer even train. The vast quantities of aircraft that historically should be running out of the factories are faltering, because there are serious shortages of oil, and other strategic materials. Workforce morale is faltering, because certain foodstuffs and other commodities are in acute short supply. Many factories lie idle as a result of the catastrophic losses to the American Merchant fleet.

Of course, this could be avoided, but the US command has to react to the "operation enhanced drumbeat" in a radical and complete way. And that means quite massive, if temporary changes in the US production regimes, and operational priorities. I would like to now what that might be


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## syscom3 (Jul 23, 2008)

The change in the production priorities of the shipyards can not be done over night. If the hull is mostly completed on the slip, then it would have been completed, simply because demolishing it would take more time than it was worth. And dont think that the boilers and machinery can simply be removed from the capital ships and reused in smaller ships. Theres issues of size, weight, performance, etc.

I say there would be little if any change in the output of the warships in the yards simply because there was nothing to be done in the short term, and the warships had to be built.

And I also take issue with the supposition that the KM and IJN could maintain tempo's like this scenario on an open ended basis. It couldnt be done and eventually the effectiveness drops off as subs are lost or damaged and allied countermeasures are put into place.

And it is extremely unlikely that the US would just abandon Hawaii. The USN could always get enough tankers to Pearl to keep its carriers operating in a low tempo pace of operations. In fact, the carriers would probably be used first in escorting convoys from the mainland to the islands. And once the IJN "smelled" warships .... then any number of their subs would be pulled from commerce raiding to warship hunting with the resultant drop in potential attacks on merchant men.


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## Freebird (Jul 23, 2008)

syscom3 said:


> The change in the production priorities of the shipyards can not be done over night. If the hull is mostly completed on the slip, then it would have been completed, simply because demolishing it would take more time than it was worth. And dont think that the boilers and machinery can simply be removed from the capital ships and reused in smaller ships. Theres issues of size, weight, performance, etc.
> 
> I say there would be little if any change in the output of the warships in the yards simply because there was nothing to be done in the short term, and the warships had to be built.
> 
> And I also take issue with the supposition that the KM and IJN could maintain tempo's like this scenario on an open ended basis. It couldnt be done and eventually the effectiveness drops off as subs are lost or damaged and allied countermeasures are put into place.



The question is how much Allied shipping will be lost in the first 6 - 12 months of the conflict, before these measures take effect. For the first 6 months there is very little that can be done, as you point out it takes time to change shipyard output. I would think that the Axis production of subs could keep up with those lost to damage, as the ability of the US to sink them using ASW is almost nil during the first 6 months.



syscom3 said:


> *Andd it is extremely unlikely that the US would just abandon Hawaii.* The USN could always get enough tankers to Pearl to keep its carriers operating in a low tempo pace of operations. In fact, the carriers would probably be used first in escorting convoys from the mainland to the islands. And once the IJN "smelled" warships .... then any number of their subs would be pulled from commerce raiding to warship hunting with the resultant drop in potential attacks on merchant men.



Agreed, the US would concentrate on getting the convoys to Hawaii. I don't think that the Japanese subs would be pulled away, as they are far too slow to catch a carrier, and would not likely be sitting in front of Pearl Harbour at the exact time that the convoy arrives. Assuming that some competent minds are planning the offensive, they realize what the KM learned, that against a well protected convoy with well trained ASW assets, the subs are usually unable to attack, and often damaged/sunk. The German switch to attacking unprotected targets in more distant oceans produced better results.

The main effect IMO would be a huge reduction in the available effort that the US could mount in SE Asia/Australian theaters, as they put the most effort into Hawaii. Another option for the US is "lockdown" where they would just keep the shipping in port until there is available escort. The US could afford to do this - Britain can't!

The effect on the USA pales in comparison to the effect on the British Empire, as the huge losses in shipping force the UK to cancel Artic convoys, pull shipping ASW assets into the North Atlantic to keep enough cargo flowing to the UK. 

The effect on the Indian Ocean lanes would be total disaster, resulting in the loss of Egypt, Palestine, Persia and probably India Sudan as well.

The loss of all Russian convoys, an opening up of the Caucasus from the south, along with the elimination of the need to send 250,000 troops to Tunisia in the fall of 1942 could easily allow the Axis to prevail in defeating the USSR.


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## HealzDevo (Jul 27, 2008)

Still depending on when the decision was made, they could get rid of the Bismarck and make maybe three to four German submarines out of the resources for that. Similarly Yamato on the Japanese side could have been made into more submarines. Also get rid of the Graf Zeppelin and there is a lot more submarines. Quite simply then the matter remains to go after them. Preferably in 1941 to have them ready at the time of Pearl Harbour to create nuisances of themselves as soon as War breaks out. Remember the story of Happy Days for the U-Boats. Well they could have been achieved much better by sinking Cargo boats much closer to the US. With maybe one of the Island Chains having been seized as a naval base...


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## Danielmellbin (Jul 29, 2008)

Just to answer the original question: no!


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## Freebird (Jul 29, 2008)

Danielmellbin said:


> Just to answer the original question: no!


*
OK Daniel, perhaps you can explain how the Allies can wage war against Japan Germany with shipping losses 2, 3 or 4 times as severe as happened? *

With a complete lack of ASW escorts the shipping losses will continue to mount, until the offensive effort grinds to a halt. 

And don't think that "They can just build more ships" - they can't. Allied shipbuilding capacity is about 1.2 million tons/month MAXIMUM, even with a severe shortage they were not able to push this higher. With the German U-boat effort at less than 50%, and the Japanese at perhaps 25%, the U-subs were able to sink 600,000 - 650,000 in several months, the best month was over 800,000 tons BY SUBS ALONE. Add to this sinkings by Axis aircraft, mines, accident, weather etc. Now consider if both Germany and Japan devoted 100% resources to sink Allies shipping right from 1941 then they could EASILY account for 1.5 - 2.5 million tons PER MONTH! The shipping "import crisis" will begin not in mid 1943, but will be in the spring of 1942.


*THE ALLIES CANNOT FIGHT THE WAR WITHOUT SHIPPING*!!!


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## Danielmellbin (Jul 29, 2008)

freebird said:


> *
> OK Daniel, perhaps you can explain how the Allies can wage war against Japan Germany with shipping losses 2, 3 or 4 times as severe as happened? *
> 
> With a complete lack of ASW escorts the shipping losses will continue to mount, until the offensive effort grinds to a halt.
> ...



Taking into consideration the lack of depth in the German and Japanese war economy, oil&rubber supply and their other military goals it is impossible that they could have substained their other war efforts had such a shipbuilding programme been made. Moreover the brittish transportfleet alone was at 18 million tons at the start of the war - and capable of producing 1 million more every year (all this is excluding the US which had an even larger stock capacity - Wages of Destruction, p.398 )). Even if a sinking ratio of 600.000 tons a month was reached by the Germans (Doenitz original goal) it would be some time before britains merchant tonnage would reach critical level. And if the Germans had completely gone for broke and reserved all the precious resources to reach the 600 or so U-Boats it would take (at a total minimum cost of 1 billion reichsmarks just for construction) - Britain and the US would have engaged even more fervently in countermeasures - causing further attrition and cost. The Japanese U-boat arm was even more at odds. Thier boats where not of the same quality as the Kriegsmarine and their naval codes where broken long before the enigma was cracked. At any rate the U-Boats became obsolete as a weapon for the axis during 1943. Only a premature development of the type XXI could have given Germany a renewed if somewhat small offensive naval capability. All in all I find it impossible to see how the Axis could have strangeled the allies through naval attrition. Productioncapacity and the economic and technological facts simply make it nonrealistic IMO.


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## parsifal (Jul 29, 2008)

hi daniel

What is being proposed here is not an increased output of u-boats/I-boats, rather a re-ordering of priorities, and a change in operational status. For the germans, there were massive diversions of U-Boats to the Med and the Arctic. If these boats had been diverted to the Atlantic, as donitz had wanted, ther would have been a significant increase in tonnage losses, for no additional economic cost to Germany.

In the case of the Japanese, the change would have reequired some change in strategic thinking, that is admittedly difficult to justify. However, there were constant recommendations from the Japanese submarine commaqnders to switch to a mercantile warfare strategy, similar to the german employment. These wre consistently overruled by the Japanese High command, so the resistance to the change in strategy was coming from the top, and not the operational commanders.

If you add the additional 65 I-Boats, and the additional 80 U-Boats to the battle in 1942, the equation starts to look quite different.

To maintain the british economy at subsistence level, the british calculated that they needed a minimum of 7 million tons of shipping. however, the british also had other worldwide committments, to her overseas empire , the neutrals and the dominions. For Australia alone, the committment of shipping was about 2 million tons. Without this committment of shipping, the economic benefits of Australia, who provided the lions share of wheat to feed india, and wool for various military purposes, would have been lost, and Australia would have faced economic ruin within a year. there were similar committments allover the world that had to be met or the grand allianc being forged by the british at the time would have surely failed, as well as very real economic ruin for many members of the United Nations.

I have a book "British shipping in WWII" SG Sturmey Athlone Press 1962. In this book, it discusses this issue in a fair amount of detail. To maintain Britains worldwide committments, Sturmey estimetes a minimum need of not less than 15 million tons. Thats exclusive of any military needs. So when you talk about 18 million tons, and suggest that this represented a comfortable margin for losses, i have to strongly disagree. Allied shipping in 1942 was in very short supply, and every loss was being keenly felt. The needs of operation Torch, for example, caused a reduction in strategic oil reserves in England, such that these reserves were down to about 3 months supply by the beginning of 1943. So the margin for losses was very tight indeed. any significant increase in losses over historical levels was going to have a drastic effect on operations everywhere. The loss of an additional 1 million tons, for example, would have precluded any landings into North Africa, and would have also severely affected the buildup for Alamein 9which demanded the diversion of some 800 merchantmen totalling well in excess of 3.2 million tons of shipping).

It is also important to keep in perspective the actual production of shipping in this period. In 1942, the year we are looking at, the US produced 5.5 million tons, the british 1.3 million, and "others" 0.7 million tons, for a total of 7.5 million tons. The Americans controlled a further 12 million tons of shipping at the beginning of the war, but this was pretty stretched as well, due to the losses that had been sustained by the british in the period 1939-42. in short there was very little fat left on the bone when the US entered the war.

From december 1941 through to June 1942, 4.7 million tons. I have estimated, that with U-Boats diverted from the tactical theatres, and the IJN committed to the tonnage battle, these losses would have been basically tripled, to approximately 11 million tons. At 11-12 million tons, there would have been a nett deficit, compared to history of at least 7 million tons. This is not enough to knock out the allies, but it is enough to bring a complete halt to all offensive operations for at least a year, and would severely test the political resolve of the grand alliance. just as an example, the ability to import grain to India would have been severely strained. there were sever riots in Bengal in 1943 for this very reason (which explains why the Japanese chose to invade in 1944) with even less food availble, it is quite possible that india would have descended into chaos. 


It is not possible to win the war by the u-Boats alon, however, the British could only defeat the Axis by the formation and maintenence of a worldwide grand alliance. The security of this grand alliance could be threatened by shipping losses, in the manner I have described. In addition, the loss of even quite small amount of merchant tonnages, brings offensive capability for the allies to a complete stop, probably for at least a year (but depending on the scale of losses). In that period, the Japanese and the germans gain vital breathing time....time to bring Russia to her knees, time to isolate and force the surrender of Australia, time to fortify the Japanese outer perimeter, , time to build the Atlantic wall, time to introduce jet technologies.

You are right to assert that the Allies commanded a massive economic advantage over the Axis. however , where they were not at an advantage, was in the area of manpower. if the offensives of 1942 had not progressed, and the Axis had gained some time with which to prepre more thoroughly, the manpower losses for the allies would have inevitable increased. This may well have been sufficient to force th allies to the negotiating table, which in the latter half of the war was the objective the axis needed to aim for.


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## Freebird (Jul 30, 2008)

Danielmellbin said:


> Taking into consideration the lack of depth in the German and Japanese war economy, oil&rubber supply and their other military goals it is impossible that they could have substained their other war efforts had such a shipbuilding programme been made. Moreover the brittish transportfleet alone was at 18 million tons at the start of the war - and capable of producing 1 million more every year (all this is excluding the US which had an even larger stock capacity - Wages of Destruction, p.398 )).



No, actually the British/Allied stock was about double the US stock in 1941.

Both the US UK were desperatly short of shipping from 1941 -1944

Thanks to Al Schlageter for the U-boat data

http://www.ww2aircraft.net/forum/ww2-general/question-you-u-boat-experts-10338.html#post290913



AL Schlageter said:


> Got this off some BB somewhere, sometime.
> 
> British merchant ship construction capacity from 1939-1941 did not exceed 1.2 million GRT per year.
> US merchant ship construction in 1939 was 0.242 million GRT.
> ...







Danielmellbin said:


> Even if a sinking ratio of 600.000 tons a month was reached by the Germans (Doenitz original goal) it would be some time before britains merchant tonnage would reach critical level.



A few months actually.

The British shipping fleet had kept ahead of sinkings up to 1941, mainly because they had absorbed the Dutch Norweigan fleets into the war effort.

Of the 20.5 million British controlled tons in the fall of '41, about 15.5 were "dry". {excludes oil tankers} Of this 15.5 mill/tons about 10% is unavailable at any one time due to repairs, breakdowns, war damage, in drydock etc.

Of the approx 14 million tons, the breakdown is in the map below.

Note that this is *total tonnage*, so the estimated 5.5 million tons on the "round the horn" route to Egypt India take an average 4.5 months round trip, giving a total of about 1.2 million tons/month of supplies delivered to the armies in Egypt, Africa, Palestine, CBI etc. Cargo taken on the return trips included Iron, Coal, Rubber and other supplies from India, Africa etc.

Remember that if an immediate Axis sub offensive results in convoys instituted in the Indian Ocean Pacific as well, convoys reduce shipping efficiancy by 10 -20% {due to delays in assembling convoys, routing conflicts port facilities overloaded - as all ships arrive together}

Also by beginning offensives in all Oceans right away it will overload an already inadequate escort capability of the Allies.

If the Allies respond to huge shipping losses by closing ports where no escort is available this also reduces capacity.

Another point is that we are using the total building capacity in our calculations, yet only considering U-boat sinkings. There were also significant losses due aircraft, mines, weather, accident etc.

It is not unreasonable in our hypothetical scenario to expect a loss in capacity due to all causes of 10 - 12 million tons after 4 months, of which at least 8 million would be British. This further breaks down to 2 million tons of tankers, and 6 million of dry cargo capacity.

*Taking a look at the map below, where would you subtract this 6 million tons?*
{Remember that about 2.5 million tons in the Australian/Pacific fleets is Aus/NZ owned shipping, which could not be comendeered}

The only real option is to eliminate most or all the Africa-Indian Ocean route, which would cause the total abandonment of the war effort in Africa/CBI



P.S. Parsifal, I used the best available data to estimate the capacity of the shipping routes, do you have any corrections/additions to my map?


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## parsifal (Jul 30, 2008)

Hi freebird

I looked at your map. To be honest, i am not sure about its correctness

I have attached a map of my own, taken from a book "Undersea Warfare" Richard Humble New English Library, 1981

The thickness of the lines indicates the comparative weight of traffic. This type of graphic display would require the area of each "shipping lane" to be calculated, in order to determine the amount of shipping tonnage allocated to that route, but it gives some idea of the world wide committments of the allied controlled MS fleets


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## Freebird (Jul 31, 2008)

parsifal said:


> *The Americans controlled a further 12 million tons of shipping at the beginning of the war*, but this was pretty stretched as well, due to the losses that had been sustained by the british in the period 1939-42. in short there was very little fat left on the bone when the US entered the war.



Where did you get 12 million tons? I had read closer to 9?


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## parsifal (Aug 1, 2008)

I was relying on the figures given in Janes for 1939. I dont know what US losses were for the period 1939-41, but I expect them to be not too high


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## Danielmellbin (Aug 2, 2008)

parsifal said:


> hi daniel
> 
> What is being proposed here is not an increased output of u-boats/I-boats, rather a re-ordering of priorities, and a change in operational status. For the germans, there were massive diversions of U-Boats to the Med and the Arctic. If these boats had been diverted to the Atlantic, as donitz had wanted, ther would have been a significant increase in tonnage losses, for no additional economic cost to Germany.
> 
> ...



The rate of attrition in the east was causing the Germans much more attrition than that which was or could have been inflicted on the western allies. Although a favorite subject for armchair generals the Germans could simply never have won the war in the east. Their manpower reserves where already fully commited in Barbarossa.

Since the point isn't an increase in u-boat production but an improved usage of those already available then I don't see any chance of the theoretical numbers flying around becoming reality. Mainly for two reasons

1. They assume that the allies do not react. Further sinkings would have increased/improved convoy defenses, research priority, production capacity etc...
2. They assume that the U-boats could have sunk the needed tonnage by early 43 at the latest. Production capacity and technology make it impossible for any ammount of U/I-Boats to make any difference beyond that time.

What could have been achieved by using the odd 80 extra u-boats and a better doctrine for the Japanese would certainly have caused the allies considerable hurt and delays. But not have altered the course of the war.


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## parsifal (Aug 2, 2008)

Danielmellbin said:


> The rate of attrition in the east was causing the Germans much more attrition than that which was or could have been inflicted on the western allies. Although a favorite subject for armchair generals the Germans could simply never have won the war in the east. Their manpower reserves where already fully commited in Barbarossa.
> 
> Since the point isn't an increase in u-boat production but an improved usage of those already available then I don't see any chance of the theoretical numbers flying around becoming reality. Mainly for two reasons
> 
> ...



Eastern Front is problematical, and i am the first to admit that with the forces available, the historical campaign undertaken by the Germans was at the top end of the effectiveness scale, rather than the bottom. Still the supply of Lend Lease to Russia would almost certainly have been curtailed, the Luftwaffe would have been somewhat stronger, and ther would have been at least some additional manpower diverted to the east. Conversely, the amount of manpower for the Soviets would have decreased quite dramatically, since the large numbers of men released from agricultural production as a result of the huge quantieis of grain shipped to Russia under Lend Lease, would no longer be available. 

Perhaps a minor point, but food fopr thought, the Stalingrad airlift might have been successful, with the air transport that was diverted to Tunisia diverted to Russia. in addition, the Germans would have been able to occupy North Africa, and press on to the Middle east, thereby threatening Russia from the South. In this circumstance, Turkey is almost certaihnly going to cave in and join the Axis, or at least allow rights of passage. If that happened, all of a sudden, the security of the eastern Front becomes problematic

Your assessment is looking at the problem from the point of view of production only, or rather, direct losses in production. But the shipping losses being touted here would, in my opinion have other spin off effects, such as the famine and revolt in India, the economic ruin of key allies, and the sapping of manpower resources. What is at threat most of all is the security of the alliance needed to defeat Germany. Germany was not defeated by any single nation, it was a worldwide coalition, with even the marginal South American states playing their part. Without secure shipping routes all of this is under severe threat.

You mentioned that a "quid pro quo" would be likely if the tonnage losses shot up. I tend to agree with that, but ther are members of this forum that seem to think that a re-ordering of priorities in the face of such a catastrophe is not required 

In the case of the british, it would be difficult to see them increasing merchant tonnage production, because of the very poor state of her shipyards. She may have increased escort production, but only to a marginal degree. The most likley reaction from the british would be to withdraw some, or all, of her fleets from places like the med, the Arctic, perhaps even the far east. All quite possible, but none without serious consequnences

In the case of the US, capacity to increase tonnages certainly exists, but only at the expense of delaying other programs. The most obvious would be the large capital ship program underway, or a curtailment of the APB programs, possibly vehicle production, or AFV production. None of these changes could be undertaken without very dire consequences to other elements of the allied war effort. Not minor delays, major ones

Plus ther is the issue that the US simply lacked the skills in 1942 to undertake a convoy war properly.

I have not said that the U-Boat war would win the war, but I have postulated that it would achieve significant delays, which you have not challenged. I have also indicated that the achilles heel for the allies was manpower, and that the U-Boats, by achieving a delay in the Allied counteroffensive may well then suffer huge increases in Manpower losses, that they could not sustain. This may well have led to a retreat from the "unconditional surrender" position that had been adopted in the Atlantic Charter. In other words, survival of the Axis regimes


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## Freebird (Aug 5, 2008)

About the map, I am fairly ceartain that it is approximately accurate, as I used the map you posted, as well as other shipping info to make it. The monthly total for UK "dry" imports is ~ 2.4 - 2.5 million tons, as the minimum requirement was about 26 million tons at the 1941 ration levels. 50% of imports came from North America, the rest from S. America Africa. The monthly total "dry" exports to Mid East/Indian Ocean is about 1.2 million tons monthly. {5.5 million tons x 4.5 month average round trip}



parsifal said:


> I was relying on the figures given in Janes for 1939. I dont know what US losses were for the period 1939-41, but I expect them to be not too high



Did you get that from the web? Is there a link?

I think that total might be including the Army Navy supply ships tankers, not available for general cargo.

The US flagged Merchant Marine of 1,000 tons or more is about 8.25 million tons. There is ~ 7.2 million tons in Dec 1940, + 800,000 tons built in 1941 + 500,000 tons of interned Axis shipping seized after Dec 7/41. In 1941 they probably lost ~ 250,000 tons to retirement, accidents, sinkings, and transferred to UK. 

{Check table 1 in "American Shipping Situation"}

The American Shipping Situation 

Now as to Daniel's your points about the ultimate effect on the war, perhaps we can go into that a bit later, after we can estimate the net shipping effect. His question about the possible Allied responce is a good one, some interesting ideas.

To start with let's look at the scenario, if we assume that:

1.) The Japanese give general information to the Nazi's about their intent to go to war. The Nazi's have about 3 - 4 months notice, but do not know exact plan or date. The Germans agree to support Japan in war against USA.

2.) The Submarine Admirals manage to convince Tokyo Berlin that subs are the best way to win the war, both sides make sub warfare a priority.

3.) The Japanese agree to interdict cargo going to the Soviet Far East, this may result in increased tensions on the Manchurian border.

4.) Germany prepares some logistical options for subs in the Caribbean, possibly involving supplies from Vichy/Mexican ports

5.) Japan launches the attack as originally planned in the first week of November, and sinks the 3 US Pacific carriers.

6.) The Axis prepare some "spoiler" commando attacks in the Western Hemisphere, to increase US uncertainty, and to distract Government public attention from the main threat - the sub offensive. 


Question: suppose that the Allies lose ~ 2.5 - 3 million tons in the first month, and ~ 2 million tons in month 2. *How long do you suppose it would take for the Allies to make plans for some drastic measures to reduce sinkings? *I would think that after 6 - 8 weeks, after the first month's losses are recorded and tabulated there would be some emergency sessions to work on the problem. I would assume that they would need at least 1 month of data, and it takes a couple more weeks for overdue ships to be declared lost, for losses to be added up etc.


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## parsifal (Aug 5, 2008)

Hi freebird

No, it is not an electronic link, but i have scanned the british and US pages of Janes that refer to the shipping under their direct control

However, even this does not reveal the full extent of shipping availability. Because of the neutrality Act, the British would detain any ship thought trading or aiding the enemy (best example I can think of is the detaining of the two Spica Class TBs transferred from Italy to Sweden by the RN in 1940). This meant that virtually the entire worldwide neutral shipping fleet was available in an emergency. This included fleets great and small (eg the Argentinian fleet of some 334000 tons, plus the Norwegian fleet of some 4.5 million tons). Typically, the british are credited with being able to control up to 27 million tons at the beginning of the war.

However wartime losses had made significant inroads up until the end of 1941. The British lost nearly 5 million tons in 1940, and about 4.5 million (from memory) in 1941. They also lost about 800000 tons in 1939. The french fleet was never enlisted until after 1942, and norway, denmark, and the netherlands lost or had seized about 1.5 million tons after they were invaded.

I dont know how much American shipping was lost prior to her entry, but her replacement of losses was virtaully zero. Nearly all production up to 1941 was being sent to Britain. American merchantmen were not permitted to enter the war zone after 1939, until the Lend lease Act (up to that time it wa strictly "Cash Carry")


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## Freebird (Aug 6, 2008)

Hmm interesting, the only difference seems to be that Janes includes ALL ships including river lake traffic, and presumably ferrys too, as they would be registered Merchan Marine as well.

I also looked up the Merchant Marine site, it confirms that there were only 492 ships of ~4 million tons in the overseas trade. {including Panama, US bases territories}



usmm.org said:


> American Flag Ships 1939
> American Flag ships in foreign trade or trade with U.S. possessions and territories [including Alaska and Hawaii] as of April 1939.
> 
> There are 492 ships on this official U.S. government list prepared by the U.S. Maritime Commission. If a ship is not on this list, but was an ocean-going ship, it was probably engaged only in coastwise voyages, for example, New York to New Orleans, or Seattle to Los Angeles.



American Flag ships in foreign trade or trade with U.S. possessions as of April 1939

So it seems, if you subtract all of the ferrys river/lake ships of < 1,000 tons, the usable starting total in 1941 is between 8 million - 9 million.


But setting aside the exact tonnage, the key question seems to be how long the Allies will allow their shipping losses in "freefall", before they do something. A huge stumbling block will be Admiral King, he might delay needed measures by a couple of months or more. As Syscom mentioned earlier, the US can stop all unescorted ships, and concentrate the limited escorts on heavily protected convoys to Hawaii, Panama, South America.

For the British it would probably be strong convoys in a box between the UK, Halifax, Freetown Aruba. Possibly also from Calcutta-Singapore-Australia Sydney - Port Moresby to keep the supply lines open. Otherwise there will not be enough additional escorts for at least 8 - 10 months, so it is hard to see how they could keep the ships sailing to the Indian Ocean via the Cape. By having a "lock-down" of unescorted ships it will only precipitate the collapse of the desert army in Egypt. 

I suspect that the Allies would go into "shipping crisis" mode after losing between 5 - 8 million tons. What is your thought?


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## parsifal (Aug 6, 2008)

The allies were in "shipping crisis" with the historical losses. if you double that, they are beyond that point....

The unkown so to speak is what can they do. Kings attitude to ASW was basically if he didnt think about shipping losses they would somehow just go away. The Americans were so wewdded to the Mananian idea of the "decisve battle", that it was very difficult for them to re-adjust to the "small war" ideas that were needed to fight the Battle of the subs (cant call it Battle Of the Atlantic anymore). you saw Sys's reaction to my suggestion that capital ship copnstruction might need to be curtailed for a while to make room for merchantmen, and small ships. "Not a chance!!!!" was the reply, as I recall, rings like a quotation from Admiral Kings Diary. Admiral King in the historical campaign let things slide until about March 1942, by which time US losses were running above the 2 million tons mark. I think the US reaction and eventual wake up to the fact that they could lose the war if they didnt do something was more linked to the tonnage losses rather than the date, so if our scenario sinks 3-4 million tons in the first month, the US is going to start to react more or less straight away

But its one thing to relaize that a big problem exists, and another to make effective countermeasures work. historically it was August before there was any effect from US countermeasures instituted in March, and in this hypothetical, the problem facing the Americans is much worse, with 80 boats attacking them in the Atlantic 9instead of an average of about 20), and say 30-40 Japanese Boats on the pacific Front. In every sense of the word, the US would be fighting a two front war for which it was neither doctrinally or materially equipped to deal with.

My opinion is that massive withdrawals would be required, from the pacific and the med. the US would need to allow the british to assisst them, and probably place a british admiral with ASW experience to run the show for them. AThe destroyers pulled back from the med, along with nearly all of the USN DDs, would need to be retr4ained and formed into escort groups, very quickly, to minimize losses, A Huge chunk from Bomber command would need to be re-assigned to a much enlarged Coastal Command, which would incorporate virtually all of the USAAAF assets (which at that time were being used to train the rapidly expanding Army and Navy air services. These would need to be re-trained, and equipped for a primarily ASW role, which has the unfortunate effect of delaying the big expansion, but cant be helped given the seriousness of the emergency.

With measures like these, the U-Boats could still be defeated by the middle of 1943. But a massive delay of perhaps a year has occurred in that time, with indeterminate consequences


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## Freebird (Aug 6, 2008)

parsifal said:


> The allies were in "shipping crisis" with the historical losses. if you double that, they are beyond that point....



True enough, in fact the UK was in severe "crisis" the day after Pearl Harbor, before "Drumbeat" sank a single ship. There was an extreme shortage of capacity to the Middle East CBI, it was always a question of which theatre would get supplied and which would go without. Part of the problem with the Desert Army in the first half of 1942 was that CBI Australian fronts soaked up most of the avilable new units.

But historically the crisis did not come to a head until the spring of 1943 with the "British Import Crisis". The Allies lost about 8.2 million tons in 1942, {6 by U-boat} of which about 5.5 million was British. The Commonwealth built 1.8 million tons, the US built 5.2 million tons in 1942. So although the Allies lost a total of 1.2 million tons, the British lost far more than the US. 

The "Import Crisis" was resolved by transferring Indian Ocean ships to the Atlantic, and with US shipping switched to UK delivery, with the effect of:

1.) Certain US operations in the Pacific were reduced or delayed
2.) The 1943 Burma offensive was weakened and ultimately failed
3.) Millions died in the 1943 Bengal famine



parsifal said:


> The unkown so to speak is what can they do. Kings attitude to ASW was basically if he didnt think about shipping losses they would somehow just go away. The Americans were so wedded to the Mananian idea of the "decisve battle", that it was very difficult for them to re-adjust to the "small war" ideas that were needed to fight the Battle of the subs (cant call it Battle Of the Atlantic anymore). you saw Sys's reaction to my suggestion that capital ship copnstruction might need to be curtailed for a while to make room for merchantmen, and small ships. "Not a chance!!!!" was the reply, as I recall, rings like a quotation from Admiral Kings Diary.



Indeed, and we should be careful to judge the response on what was "reasonable" within a historical sense, with the information that they had at the time. I would consider that our Axis "sub strategy" to be "reasonable" as Hitler was basically on board with the U-boat offensive idea, and it is not unreasonable that the Japanese sub proponants could convince Yamamoto that shipping was the most vulnerable part of the Allied war effort.

However, as you point out there is virtually no chance that the US would abandon the BB program to build shipping. I think Syscom's point was that since the BB's were mostly already 60 - 90% built, it would not make much sense to cancel them. {At 75 - 80% built, the BB could be moved out to free drydock space, while the final superstructure guns were finished in berth}
Also I don't think that the construction of shipping could be increased by much, for besides the Iowa class BB's, there was very little that was not vital. DD's, DE's CV's CL's were all badly needed for operations convoy escort. The CA program had many of it's hulls converted to CVL's also badly needed. I don't think that slowing aircraft production to increase shipbuilding could have much effect for 8 - 12 months


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## Freebird (Aug 6, 2008)

parsifal said:


> Admiral King in the historical campaign let things slide until about March 1942, by which time US losses were running above the 2 million tons mark. I think the US reaction and eventual wake up to the fact that they could lose the war if they didnt do something was more linked to the tonnage losses rather than the date, so if our scenario sinks 3-4 million tons in the first month, the US is going to start to react more or less straight away



This is the primary reason why I would be in favor of commando "spoiler" attacks, to divert attention away from the shipping crisis. Another effect of the increased tension in the Caribbean/Latin America is that the USN would be under more pressure to build up forces bases in the theater {On bases leased from the UK at Jamaica, Trinidad, Barbados, Bermuda etc}. By forcing the USN to use DD's shipping to supply these bases, they increase the burden.

I would think that in 4 - 6 weeks the "crisis" mode would be realized in Whitehall, as the UK "shipping bureau" kept track of all ships, and Gen. Brooke Adm. Pound were already both very aware of the problem. 

In the US it was a different story. The lack of a "shipping bureau" meant that it was often weeks or months before they became aware of losses, and the general inexperience and inertia of the top level USN meant that it might well take many months for any concrete action.

I also think we should consider the UK response seperately from the US



parsifal said:


> But its one thing to relaize that a big problem exists, and another to make effective countermeasures work. historically it was August before there was any effect from US countermeasures instituted in March, and in this hypothetical, the problem facing the Americans is much worse, with 80 boats attacking them in the Atlantic 9instead of an average of about 20), and say 30-40 Japanese Boats on the pacific Front. In every sense of the word, the US would be fighting a two front war for which it was neither doctrinally or materially equipped to deal with.



Very true.



parsifal said:


> My opinion is that massive withdrawals would be required, from the Pacific and the Med. the US would need to allow the British to assist them, and probably place a british admiral with ASW experience to run the show for them.



I can't see how the {anti-UK} King would ever agree to put a British Admiral in charge. Even if he were forced to do so, he would be so uncooperative as to make the effort useless. 

I don't think that they can abandon the Med without jepordising the whole war. If the supply to Egypt, India Malaysia is cut off, this would result in a retreat to Sudan/South Africa and Australia. This could allow an Axis victory.

With all supplies to Russia cut off {Arctic, Pacific Indian Oceans}, a possible re-deployment of several armies to Russia, Axis attack on Russia via the Caucasus, and without the huge diversion of troops to Africa in the fall of '42, there would be no Russian victory at Stalingrad, Germany may well have conquered the USSR in 1943.

The Allies have to figure a way to keep the African CBI fronts viable 



parsifal said:


> The destroyers pulled back from the med, along with nearly all of the USN DDs, would need to be retrained and formed into escort groups, very quickly, to minimize losses, A Huge chunk from Bomber command would need to be re-assigned to a much enlarged Coastal Command, which would incorporate virtually all of the USAAAF assets (which at that time were being used to train the rapidly expanding Army and Navy air services. These would need to be re-trained, and equipped for a primarily ASW role, which has the unfortunate effect of delaying the big expansion, but cant be helped given the seriousness of the emergency.



I would agree with most of this.



parsifal said:


> With measures like these, the U-Boats could still be defeated by the middle of 1943. But a massive delay of perhaps a year has occurred in that time, with indeterminate consequences



More like 2 - 3+ years. The problem is that the U-boats were never "defeated", but by the end of 1942 the average monthly construction exceeded the monthly sinkings. By this time {as mentioned in previous post} the net Allied aggregate loss was only 1.2 million tons, while there was a dramatic increase in the need for shipping. {with more US participation + longer supply lines} 

If by the end of 1942 the Allies have lost an estimated 10 - 12+ million tons vs. 1.2, it may take a further 12 - 20 months to rebuild AFTER monthly building exceeds sinkings. At that point it would take many further months to replenish the depleated critical supplies at the many overseas bases, before further operations could be planned.


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## syscom3 (Aug 6, 2008)

> you saw Sys's reaction to my suggestion that capital ship copnstruction might need to be curtailed for a while to make room for merchantmen, and small ships. "Not a chance!!!!"



Its the truth. The shipyards with the hulls of the capital ships already substantially completed could not over night just stop production and rebuild them as destroyers. They would have finished them, launched them then begin building the escorts.

Same with the slips with carriers being built.

Building warships is a tad more complicated than making trucks or aircraft.



> 1.) Certain US operations in the Pacific were reduced or delayed.



True. I would suspect that the Japanese would eventually come to capture Papua NG, but not much more. By summer of 1942, their logistics were in tatters from their rapid gains, and needed a breather to recover. But its irrelevant because in the summer of 1943, the US had the resources to begin a systematic offensive through the Central Pacific.



> 2.) The 1943 Burma offensive was weakened and ultimately failed



It didnt matter what happened in the CBI.


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## Freebird (Aug 6, 2008)

syscom3 said:


> Its the truth. The shipyards with the hulls of the capital ships already substantially completed could not over night just stop production and rebuild them as destroyers. They would have finished them, launched them then begin building the escorts.
> 
> Same with the slips with carriers being built.
> 
> Building warships is a tad more complicated than making trucks or aircraft.



Yes and this does make the most sense. Even if it was needed to abandon BB's under construction, the USN would never do it. At that point in the war, they didn't know that BB's would not be needed to play a great role in the Pacific, they wanted to re-build the BB's after Pearl.



syscom3 said:


> True. I would suspect that the Japanese would eventually come to capture Papua NG, but not much more. By summer of 1942, their logistics were in tatters from their rapid gains, and needed a breather to recover. But its irrelevant because in the summer of 1943, the US had the resources to begin a systematic offensive through the Central Pacific.



Had the resources IN THE USA, very true, but how to ship it overseas?

In 1943 the US shipyards got up to speed, producing 13 million tons. However if the total shipping loss by the end of 1942 was 10 million tons, not 1.2 - it would take 75% of the entire 1943 production just to make up losses. Would Roosevelt be willing to allow the UK to be starved into surrendering before launching a Pacific offensive? I think not. Also if the attack on Panama succceeds, what % of the shipyards are in the Pacific?



syscom3 said:


> It didnt matter what happened in the CBI.



In the historical model it did not because the Commonwealth maintained enough supplies to hold the Japanese at the Indian border. However if the Japanese are able to conquer India as well it provides enormous problems for your re-conquest of the Pacific.

The key point is that by cutting off supplies to Russia and breaking UK control of the Indian Ocean Middle East, Germany has a good chance of eliminateing serious Soviet opposition by mid 1943.

Would the USA support 1943 operations against Japan while the European theatre collapses? I think not. Roosevelt, Stimson Marshall were all agreed on "Germany First", and in the event of a 1942 collapse of the USSR were in favor of a "suicide" attack into France to try to shift Nazi forces away from the Soviet front.


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## pbfoot (Aug 6, 2008)

A point that might be overlooked was that up until 41 very few U boats had been sunk bt ASW aircraft I believe the number was 2 , but with a radar that was able to work at longer ranges the numbers began to increase rapidly , I believ the Happy Times were well over by late 41 with advent of a serious search radar that had range at lower altitudes


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## Freebird (Aug 7, 2008)

pbfoot said:


> A point that might be overlooked was that up until 41 very few U boats had been sunk bt ASW aircraft I believe the number was 2 , but with a radar that was able to work at longer ranges the numbers began to increase rapidly , I believ the Happy Times were well over by late 41 with advent of a serious search radar that had range at lower altitudes



I believe it was actually in mid 1942 that the technology began to turn the tide. 

In any event, it was only *experienced, well-equipped* ASW units that had any real effect.

During the crisis off the US seaboard, they were only able to sink the first U-boat in April, and during the first 6 months of the war there were only 3 or 4 sunk in US Atlantic waters. It was not ASW that limited the German offensive, it was a lack of U-boats to sink the dozens of available targets.


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## parsifal (Aug 7, 2008)

pbfoot said:


> A point that might be overlooked was that up until 41 very few U boats had been sunk bt ASW aircraft I believe the number was 2 , but with a radar that was able to work at longer ranges the numbers began to increase rapidly , I believ the Happy Times were well over by late 41 with advent of a serious search radar that had range at lower altitudes



aircrafts principal role in ASw is not so much to sink boats. They are there for two main reasons. Firstly to suppress the sub 9ie keep it submerged, therby robbing the boat of its mobility), and secondly to give advance warning to the convoy of the position of the raider. This can allow the deployment of a hunter killer group to hunt down and destroy the contact, and more importantly allow the re-routing of the convoy.

To undertake this mission you need a lot of aircraft, with a long range. The only force fitting that profile in 1942 was Bomber Command


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## parsifal (Aug 7, 2008)

freebird said:


> I believe it was actually in mid 1942 that the technology began to turn the tide.
> 
> In any event, it was only *experienced, well-equipped* ASW units that had any real effect.
> 
> During the crisis off the US seaboard, they were only able to sink the first U-boat in April, and during the first 6 months of the war there were only 3 or 4 sunk in US Atlantic waters. It was not ASW that limited the German offensive, it was a lack of U-boats to sink the dozens of available targets.



Not true. Experienced air units were needed to sink the boats, but as I pointed out to PB this was not the key function of air assets, it was to force the boat to submerge, become a static unit as a result, and provide adbvance warning and spotting services to the offensive hunter groups and the convoys alike.

Sinkings increased in the latter half of 1942, principally at the hands of the ASV night capable units of coastal command. U-Boats typically would surface at night to recharge their batteries, in the3 belief that they could not be spotted by the air patrols (particualrly in the bay Of biscay). With ASV the allies became adept at stalking the surfaced boat and then illuminating the taerget with either starshell or Leigh Lights, for the final run in. A lot of boats were lost until the introduction of the METOX Radar detection system 

The first use of ASV Radar was in 1940, but the combination of leigh Light and ASV radar was not undertaken until the latter half of 1942. Wing Commander Humphry de Verde Leigh (later OBE DFC AFC) developed the Leigh light, effectively a powerful flood light steered by the ASV radar. This allowed ASV radar equipped aircraft to search for U-boats at night. The U-boat was initially tracked by the radar with the light following the radar track but switched off. Once the returns were lost, the light would be switched on and the U-boat would be bathed in light and very vulnerable, the first successful attack was on U502 on 5th July 1942. The sudden light was often the first indication that the U-boat had been found and the Leigh light was initially very successful, particularly in the Bay of Biscay.

Metox was the German answer to the Leigh light rendering it completely ineffective. The Metox sets received the transmitted pulses from the ASV and rendered them as audible beeps. It enjoyed the usual advantage of radar detectors over radar in that the signal is direct and only had to travel one way whereas the radar has to detect the very weak reflection from the submarine.[3]. Most radars increase the number of pulses and decrease the width of the pulses when switched to a shorter range, the shorter pulse widths allow the radar to look at closer objects. The Metox exploited the fact that once the radar operator changed the range indication from 36 miles to 9 miles (15 km), the pulse repetition frequency of the radar's transmitter doubled. Radar cannot detect any reflections returned earlier than half a pulse width so when the U-boat was closer than 9 miles the operator would change to the shorter scale. If the Metox set started beeping at twice the rate, the U-boat knew that they had been detected. By the time the aircraft approached the U-boat's position enough to energise the Leigh light, the U-boat was well under the water. As a bonus, the Metox set would also provide warning in excess of visual range in daylight.

Metox was eventually countered by a version of the 10 centimetre H2S which Metox couldn't detect and once again the Leigh light forced U-boat crews to refuse to run surfaced at night. Even during the day, the U-boats were easy prey as the new radar was easily able detect the U-boat's periscope.


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## parsifal (Aug 7, 2008)

_Yes and this does make the most sense. Even if it was needed to abandon BB's under construction, the USN would never do it. At that point in the war, they didn't know that BB's would not be needed to play a great role in the Pacific, they wanted to re-build the BB's after Pearl_.

Not referring to the BBs, or more specifically the nearly completed BBs. There were large number sof DDs, CAs, CLs, and all manner of other ships not suited to ASW work, along with huge numbers of other ships that were years away from completion. Given the clear and immediate danger of this sub campaign on steroids, all of this effort flies in the face of the immediate needs of the country, namely small cheap ASW escorts, made ready for service within 5-6 months of laying down, and vast ly increased access for the Merchant tonnages to the vastly more efficient navy yards which at that time were almost exclusively reserved for Blue water naval construction 

_Had the resources IN THE USA, very true, but how to ship it overseas?_


Err, not completely. The US was still a nett importer of raw materials, from various parts of the world. Without access to foreign markets and resources, the US economy, just like every other world economy suffers in terms of efficiency. The US was admittedly luckier than most, but by no means immune, or even substantially imune from the effects of a blockade. 

In the historical model it did not because the Commonwealth maintained enough supplies to hold the Japanese at the Indian border. However if the Japanese are able to conquer India as well it provides enormous problems for your re-conquest of the Pacific.

This also applies to China, which almost certainly would succumb unless supported by the US. US does not have the manpower to take on the japanese army head to head. the result is a bloodbath in the pacific. 

_The key point is that by cutting off supplies to Russia and breaking UK control of the Indian Ocean Middle East, Germany has a good chance of eliminateing serious Soviet opposition by mid 1943.

Would the USA support 1943 operations against Japan while the European theatre collapses? I think not. Roosevelt, Stimson Marshall were all agreed on "Germany First", and in the event of a 1942 collapse of the USSR were in favor of a "suicide" attack into France to try to shift Nazi forces away from the Soviet front._

In other words, a comprehensive collapse of the grand alliance. The means to victory would dissolve if the U-Boats are not restrained from any runaway success[/QUOTE]


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## Freebird (Aug 14, 2008)

parsifal said:


> Not true. Experienced air units were needed to sink the boats, but as I pointed out to PB this was not the key function of air assets, it was to force the boat to submerge, become a static unit as a result, and provide adbvance warning and spotting services to the offensive hunter groups and the convoys alike.



Sorry, I was not very clear, I was meaning experienced ASW *naval* units, as training practice were needed in ASW group operations, where a skilled flotilla leader could keep a sub "pinned" on sonar while directing the others into position to depth charge. The U-boats had also become skilled in changing direction evading DC attacks, when the hunter lost sonar contact as it moved in to DC range. 



parsifal said:


> *Freebird* - Yes and this does make the most sense. Even if it was needed to abandon BB's under construction, the USN would never do it. At that point in the war, they didn't know that BB's would not be needed to play a great role in the Pacific, they wanted to re-build the BB's after Pearl.
> 
> Not referring to the BBs, or more specifically the nearly completed BBs. There were large number sof DDs, CAs, CLs, and all manner of other ships not suited to ASW work, along with huge numbers of other ships that were years away from completion. Given the clear and immediate danger of this sub campaign on steroids, all of this effort flies in the face of the immediate needs of the country, namely small cheap ASW escorts, made ready for service within 5-6 months of laying down, and vastly increased access for the Merchant tonnages to the vastly more efficient navy yards which at that time were almost exclusively reserved for Blue water naval construction



Mainly I agree with you, however there is virtually zero chance that Admiral King will agree to this in the first 5 or 6 months. About the best I could see is in mid 1942, after the US loses 4 or 5 million tons a *partial *re-order. Probably King would insist on completing the Iowa's, convert all building DD's to ASW, complete the CA's CL's with less than a year left, convert many newer CA hulls to CVL's, and scrap all cruisers with more than 18 - 24 months to completion.

As a practical matter, by the time the USN realizes the true scale of the problem, convinces the leadership of the drastic measures needed, tool up build the ASW DE's corvettes, any relief would only come at the end of 1942.



parsifal said:


> Had the resources IN THE USA, very true, but how to ship it overseas?
> 
> Err, not completely. The US was still a net importer of raw materials, from various parts of the world. Without access to foreign markets and resources, the US economy, just like every other world economy suffers in terms of efficiency. The US was admittedly luckier than most, but by no means immune, or even substantially imune from the effects of a blockade.



I was mainly referring to *military* resources, but as regards to food, oil mineral resources, the USA has the option, in exteme circumstances, of halting ALL shipping, and the mainland will not starve, freeze, or be in danger of invasion. The British have no choice but to keep the ships moving, or face collapse of the Empire.



parsifal said:


> The key point is that by cutting off supplies to Russia and breaking UK control of the Indian Ocean Middle East, Germany has a good chance of eliminateing serious Soviet opposition by mid 1943.
> 
> In other words, a comprehensive collapse of the grand alliance. The means to victory would dissolve if the U-Boats are not restrained from any runaway success



There is a good chance of that happening. It's hard to predict the effect on the USSR, however it is clear that continued Allied support of the Indian Ocean theatre becomes extremely difficult, if not impossible.


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## syscom3 (Aug 15, 2008)

Parsifal, I'm still waiting for you to explain why the allies would continually take huge losses without changing their tactics.

Its like your planning on the allies to basically do nothing different for months on end.


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## parsifal (Aug 15, 2008)

syscom3 said:


> Parsifal, I'm still waiting for you to explain why the allies would continually take huge losses without changing their tactics.
> 
> Its like your planning on the allies to basically do nothing different for months on end.



The huge losses would continue because in the face of a massively reorganised and enhanced assault directed on the Allied merchant fleet, your preferred response was to do nothing. The US was able to nearly lose the war when being assaulted by an average of something like 20 Boats per month attacking them, how much more shipping would be lost if the defences are spread so much thinner (over two oceans instead of just one) and with an average of someting like 70 Boats dedicated to attacking them in any given month (being about 40 German Boats and 30 Japanese). With thinner US defences, and more subs, it is inevitablel that the shipping loss rates will go up, and the sub loss rates will go down. 

It was not me that proposed to do nothing in response to this threat. I postulated that against such a clear danger the allies would be more or less forced to make big changes to their deployments (for the RN in particular, but also in the use and deployment of the USN DD force). Your response to this hypothetical was that basically nothing needed to be done, in particular you totally rejected the need to halt dockyard efforts to get a blue water navy completed, in favour of getting increased MS tonnage out, and of course to increase the output of small ASW escorts out as well. This was precisely what the Brits were forced to adopt in 1940 with her capital/large warship production more or less curtailed until 1942.... In the USNs case this proved unneccesary with the historical looses, but with the enhanced U-Boat campaign being toutedor postulated here, even the US would need to bow to such pressure and temporarily curtail her Blue water strategy. You rejected that, which means that the US merchant fleet continues to be decimated, and the Allies ultimately, and quickly lose th war. 

You misunderstood me. I was very much advocating a change in tactics, production, and deployment of allied resources. I took your respones to be that no change would be needed,that the problem was minimal, and it would tend to dissipate itself with time.....like it was a minor problem not needing a grat deal of attention. This i consider to be a war losing strategy......moreover, a change in tactics for the Us also requires a change in the expenditure of industrial power... they need to invest in an ASW fleet, and replace increased MS losses NOW if they are to ensure the survival of the alliance.....


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## pbfoot (Aug 15, 2008)

parsifal said:


> aircrafts principal role in ASw is not so much to sink boats. They are there for two main reasons. Firstly to suppress the sub 9ie keep it submerged, therby robbing the boat of its mobility), and secondly to give advance warning to the convoy of the position of the raider.


 54% of the U Boats that were submerged and robbed of their mobility permantly were sunk by ASW aircraft from Jan 42 til May 43


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## Freebird (Aug 15, 2008)

pbfoot said:


> 54% of the U Boats that were submerged and robbed of their mobility permantly were sunk by ASW aircraft from Jan 42 til May 43



*That's an 18 month period Pb - How many U-boats were sunk off the US east coast in the first 4 months after Pearl?* - *ZERO*

U-85: sunk 14 April by destroyer USS Roper off Cape Hatteras, first sinking in US waters 
U-352: sunk 9 May by cutter USCGC Icarus off Cape Hatteras 

*In the first 6 months after Pearl Harbor, despite heavy shipping losses only TWO U- boats were sunk off the US East coast!*

Two more U-boats lost in June in US waters.

U-157: sunk 13 June by cutter USCGC Thetis off Havana, Cuba 
U-158: sunk 30 June by Mariner aircraft (USN VP-74) west of the Bermudas 

The bulk of the U-boats you quote in you "54%" were sunk from the end of 1942 - May 1943. 

The Axis have a "free shot" against the Allies in the Western Atlantic for the first 6 months after "Pearl", as the US have very minimal ASW available, and Admiral King resists attempts to counter U-boat attacks.



syscom3 said:


> Parsifal, I'm still waiting for you to explain why the allies would continually take huge losses without changing their tactics.
> 
> Its like your planning on the allies to basically do nothing different for months on end.



Syscom, there will be an Allied reaction, but because of the stubborness of King the US unpreparedness, it will be several m onths befor anything can be done that will have a real effect. Besides a few U-boats sunk off the US fron April - June, the US response came after 4 - 7 months, Costal blackouts in April, convoys in May, and a total "Lock down" keeping all ships in port, in July after losses had piled up.

The responce to a much more severe attack would be quicker by a month or so, but the damage would already be done. It was also very helpful to the Axis that Admiral King had taken over command from Adm. Stark

The US is a completely different system than the British, as the lack of a central shipping board means that nobody has an accurate grasp of where the ships are and how many are lost. Ships were also free to sail where or when they wanted, unlike the British that forced all Atlantic shipping into convoys. The WWII US command lacked the "Chiefs of Staff" meetings that the British had, and also Admiral King's command did not keep track of merchant losses in a timely fashion. I don't think the US will be capable of any counter strategy for 3-4 months.



Wikipedia said:


> In the United States there was still no concerted response to the attacks. Overall responsibility rested with Admiral King, but King was preoccupied with the Japanese onslaught in the Pacific. Admiral Andrews' North Atlantic Coastal Frontier was expanded to take in South Carolina and renamed the Eastern Sea Frontier, but most of the ships and aircraft needed remained under the command of Admiral Royal E. Ingersoll, Commander-in-Chief, Atlantic Fleet, who was often at sea and unavailable to make decisions. Rodger Wynn's detailed weekly U-boat situation reports from the Submarine Tracking Room in London were available but ignored. Offers of civilian ships and aircraft to act as the Navy's "eyes" were repeatedly turned down, only to be accepted later when the situation was clearly critical and the Admiral's claims to the contrary had become discredited


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## Freebird (Aug 15, 2008)

parsifal said:


> The huge losses would continue because in the face of a massively reorganised and enhanced assault directed on the Allied merchant fleet, your preferred response was to do nothing.
> 
> It was not me that proposed to do nothing in response to this threat. I postulated that against such a clear danger the allies would be more or less forced to make big changes to their deployments (for the RN in particular, but also in the use and deployment of the USN DD force). Your response to this hypothetical was that basically nothing needed to be done, in particular you totally rejected the need to halt dockyard efforts to get a blue water navy completed, in favour of getting increased MS tonnage out, and of course to increase the output of small ASW escorts out as well. You rejected that, which means that the US merchant fleet continues to be decimated, and the Allies ultimately, and quickly lose th war.
> 
> You misunderstood me. I was very much advocating a change in tactics, production, and deployment of allied resources. I took your respones to be that no change would be needed,that the problem was minimal, and it would tend to dissipate itself with time.....like it was a minor problem not needing a grat deal of attention. This i consider to be a war losing strategy......moreover, a change in tactics for the Us also requires a change in the expenditure of industrial power... they need to invest in an ASW fleet, and replace increased MS losses NOW if they are to ensure the survival of the alliance.....



Parsifal, I'm not sure if that was Syscom's position or if that was his interpretation of the USN mentality. 

In the hypothetical scenario we are anticipating what the most likely Allied responce would be, not what WE might do. 

Your ideas generally make sense, but would not be adopted by the USN for a half year or more, at which time the damage has been done. 

Also why do calculate only 40 U-boats? From Uboat.net the U-boat total seems to be about 220 at the end of 1941, if they can keep 120- 130 or so on patrol at any one time, they should be able to have 80 - 90 per month to attack shipping off the US East coast, Gulf of Mexico  Caribbean. I had annticipated that the advance warning of the japanese attack allowed the Germans to arrange to send some U-boat supply ships in the Caribbean.


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## pbfoot (Aug 15, 2008)

If the U boats could sink 2 a day for every day of the war they might have a chance but the Liberty ships alone were coming down the slip a that rate . The fact remains ASW aircraft were not just there to keep the subs submerged they sank the bulk of the U boats post 41 . Yes the US was slow off the draw for U boat warfare but certainly light years faster in their aquiring the tactics needed then Coastal Command


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## parsifal (Aug 16, 2008)

Hi freebird



freebird said:


> Parsifal, I'm not sure if that was Syscom's position or if that was his interpretation of the USN mentality.
> 
> In the hypothetical scenario we are anticipating what the most likely Allied responce would be, not what WE might do.
> 
> ...



Acknowledge that we need to look at the most likley outcome of the allies. Whilst i view the US capability in ASW at the beginning of the war to be backward, I do not consider the US leadership to be incompetetent. if faced with massive losses, they would have reacted much more quickly than they did historically. Thgis would have to be the "quid pro quo" that I spoke about eleswhere. Historically the US showed itself to be extremely adaptable, from the very start. As an example, up to pearl Harbour, the USN war stratgies were based around the battleship. There were of course advocates of carrier based strategies, but these were in the minority, and their views did not represent the policy position of the USN at the wars start. Within a month the USN had adapted its Mahanian strategies from being centred around Battleships, to being centred around carriers. When they saw just how effective carriers were, they never went back to the battleship strategy 

In just the same way, if faced by a massive underwater threat, I see no reason why the US would not have adapted its strategic position to meet this alternative very quickly. Granted that it would take longer than no time to achieve certain things, specifically, the training and tactical doctrine, the equipment, and the experience, which would have taken 6 to 9 months to start to acquire, however, there are some things that they could have done more or less straight away. The most obvious is the adoption of a proper convoy system, the next is the redeployment of the fleet destroyers (although not an ideal ASW weapon, they could act as an extemporised escort, with additional DC racks and sonar, in stead of enhanced AA and Radar being the main improvements of the first months of the war. The USN could also do what the British had to do, things like quickly convert trawlers and other coastal craft to provide inadequate, but at least some form of escort. Away from the sea, they could have adopted much greater austerity measures in the civilian community, and directed the resources coming off the lines ...meaning aircraft....to ASW rather than the sharper end of the forces). 

There is every possibility that the axis would sink a lot f ships, but IMO the USN could do enough from day 1 of the battle to survive. But it certainly is not a minor threat, and certainly requires more than a "business as usual approach" in order to win that battle. What i am not sure of is what the longer term effects of such a change in strategic priorities might bring. It would have delayed the offensives against the axis, but would the axis have taken advantge of that I dont know

The reason I only give the 40 additional boats to the germans is because of the limited endurance of te U-Boats. At the beginning of the war, the KM had something like 50 boats available, of which 40 or so were suited to Atlantic operations. This number remained more or less the same (with new Boats only just keeping up with losses) for about a year. Whilst the operational rate increased dramatically after the fall of france, the average daily availability in that first year of the war was about 12 Boats, as I recall. The reason for this is that whilst the endurance of a U-Boat was in the order of only 15 days, or so, as compared to those of the I-Boats, which could be as hig as 60 days in a pinch. granted, by 1942, the germans were stretching the endurance limits of their boats by the adoption of expedients that allowed them to stay at sea for about 25-30 days.... however the refit times on return to port for all Boats 9of any nationality) remained the same. It generally took about a month to turn a boat around after a patrol and ready it for sea again, to say nothing for getting the crew ready again. So this means that for any given 90 day period, the IJN Boats could spend up to 60 days at sea (Patrol-Refit), whilst the german boats would only be able to spend 30 days (Patrol-Refit-Patrol). Therfore, the German availbility out of a total force of 80 boats in 1942 is going to be about 50%, particulalry since some of those 80 are still in training.....


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## parsifal (Aug 16, 2008)

The best source on U-Boat losses that i could find whilst aay from my library resources (I am away for the weekend) was U-Boat net

_U-boat losses by cause
In the following table I attempt to list all U-boat losses by type of loss. There are some duplications in the listing (i.e. boats being paid off and then either scuttled or surrendered) but this as accurate as I can make it right now. This is based on the very latest research and will probably not match older sources.

Ships 264 Includes a few losses to merchant ships 
Aircraft 250 Includes all ship-based aircraft 
Aircraft Ships * 37 
Missing 52 See U-boats missing in Action 
Air raids on ports 43 Check out this page. 
Mines 35 
Captured 3 U-110, U-505 and U-570 

Scuttled 242 Read about Operation Regenbogen 
Surrendered 155 Most scuttled in Operation Deadlight 
Paid Off 37 Usually battered or "tired" boats 
Accidents 25 Losses to accidents or "friendly fire" 
Other (+) 7 

Total 1154 (1149 individual boats) 

* This does not indicate aircraft carriers, all those victories are in the "Aircraft" category. This means co-operation between aircraft (most often land-based) and escort vessels.

+ These include the 4 boats taken over by Japan in the Far East at the time of the German surrender (U-181, U-195, U-219 and U-862). This figure also includes the 2 boats U-573 and U-760 interned during the war in Spain. Finally it includes the only boat that was lost to land-based artillery, U-78 sunk by Soviet guns.

What about the missing boats?
The boats listed as missing were lost to aircraft, ships, mines and accidents. Hopefully further research will lessen this number (it has actually increased in the last years as many former claims were judged to be against something else than U-boats).

Created: 25 April, 1999. There is some slight chance that this data is not 100% accurate but it should be as accurate as possible using the best data I have right now. I will continue to work on this database and possibly edit this page somewhat._


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## parsifal (Aug 16, 2008)

US Production of merchant shipping amounted to 5.5 million tons in 1942, as i recall


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## syscom3 (Aug 16, 2008)

The most probable course of events would be the following:

In the Atlantic:
1) The KM would run amok and inflict punishing losses on the allies for a month or so.
2) The losses would diminish quickly simply because of the "facts on the ground". Untill the ships could sail under escort, they wouldn't be sailing at all.
3) The first allied counter measures would be for the AAF to provide daytime patrol and escorts. This would blunt (but not eliminate) the daytime threat from the U-Boats.
4) Within 2 months, the existing escorts of the USN would all be equipped with adequate (meaning minimally acceptable) ASW gear, which further would reduce losses. 

My point - The allies always showed the capacity to quickly change strategy and tactics. Don't assume that just because they were going to get their ass's kicked for a month or two, that they would continue to bend over for the KM.

In the Pacific:
1) The reality of the logistics of supporting the forces holding onto the pacific islands along the US-Aussie lines of communication is far simpler than that of supporting forces in the ETO. The forces on the islands were essentially light infantry battalions (or brigades) which didn't have the logisitics burdens as a full up regular infantry division. It wouldnt be that difficult for the navy to get a cargo ship to these atolls once a month to resupply them.

2) The IJN sub force never had the competency as the KM and as events proved and were more easily blunted. They were far fewer in numbers, had a far more difficult logistics issue of support, and were tracked with a good degree of accuracy through ULTRA.

As for ship building:
No doubt that escorts vessels would get higher priority, but it wouldn't be at the expense of the carrier or light cruiser programs. They were well along in construction, and it would take too much time and effort to stop them and convert over to building DD's and DE's. Instead, more materials would be made available to complete (faster) the DD's already under construction. As for the smaller ships .... the existing shipyards that were inland, would build them first, before building the amphib vessels.


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## parsifal (Aug 16, 2008)

I see that the response is basically "more of the same", namely, that a u-boat campaign four times the size and capability over the historical was "no big deal" and "nothing to worry about"!!!!!!!!!!

There are holes in the response allover the place, but to name just few....

The costs to maintain a single division in the pacific, was, on average, about *nine* times that for the cost of maintaining a division in europe. the costs of even a modest holding operation in the pacific are enormous. historically the campaign at guadacanal pushed the abilities of the Allied Merchant ,Marines to the breaking point. There were virtually no reserves for the allies without jeopodising or risking the integrity of the alliance itself, so unless ther is a wholesale withdrawal from somewhere, in 1942, then something or all of the allied stucture is going to break. By opting to maintain the offensive in the central and southern pacific (the least important of all the theatres of operation then being faced by the allies), then something really important is going to break, like China, Russia, britain or India.

Witholding the ships (presumably from the main trade routes) from sailing is just not an option, or at least it is an option that leads straight to the bottom for the allies. There are less than 3 months reserves of oil in britain for a start. The world economy, on which all the hopes of the allies rest, is anchored completely on the continued movement of shipping. You just cannot say "oh we will stop the movement of shipping, that will solve the problem" That would lead to the rapid political, social and economic collapse of nearly all the western world, including that of the US. Continued mercantile trade was essential. not just desirable....if it had ben possible to do that, the British would have closed down all but the atlantic run years before that...

I agree that if re-equipping and retraining the USN Destroyer force for ASW work had been a priority, it would have helped. Learning how to use it and work as effective teams is another matter. if you lack quality, you have to try, as best you can, to compensate for that lack of ability by pouring in the numbers. And the only place you can do that is by stripping out your pacific fleet of nearly every ASW platform that it possesses. That means no carrier operations, no distant force projection, and a big respite for the japanese. 


I do agree basically with your points 3 and 4, they point to the road to winning. however, i cannot help but detect that you see achieving this outcome as a relatively easy and quick capability to achieve. If so, you could not be more mistaken. it would take a huge investment of manpower, resources and technique learning for the US to achieve this, not a couple of weeks or months. 

I agree also that the strong points of the allies was their adaptability, but this should not be measured in defeating a U-Boat offensive of this kind in a matter of weeks or months, rather at least a year in my opinion. In that time the allies have to continue to tough it out, divert resources to shipbuilding, and pull back from areas where they dont need to be. 


The flaw in this hypothetical is its assumption that the Germans and the japanese would recognize tonnage losses as a war winning strategy. I am the first to concede tht, and have repeatedly criticised it as unrealistic to expect (particularly the Japanese). however, on the assumption that they could somehow be brought around to see this as a possible strategy, I see it as a huge threat to allied survival, and one that needs more than just a passing drawing of breath . It would have needed a diversion of a massive effort (which could only be provided by the US) 

Your assumption about the IJN subs are just not correct. When dedicated to tonnage attacks, they achieved sink rates comparable to the U-Boats (on a per sortie basis) and in 1942 were not significantly more vulnerable than u-boats. they took greater losses later, because they continued to be used to attack heavily defended targets, whilst the Ultra advantage you talk about really only affected I-Boats being used on supply runs. I-Boats being used to atack shipping actully suffered very low attrition ratessimply not that vulnerable whilst so engaged. Japanese I-boats did have some technological weaknesses (as well a some rathe sloppy evasive techniques), but these were not a significant factor until the allies learnt how to find and attack them, and possessed the sufficient numbers of escorts in order to prosecute such attacks effectively 9generally a ratio of about 6:1 escort to U-Boat was needed. 

By continuing with the carrier and Light cruiser programs (and those later BBs as well), you are diverting the limited manpower at the US disposal away from manning of the vital defences. I think everyone here is in basic agreement, that time is of the essence if the US is to save itself and that of its allies. Every trained man has to go into the small ships, and every inch of dockyard capacity has to be diverted into the "small end of town" if the allies are going to emerge with th least amount of damage. 

Fighting a two front war for the USN was its worst nightmare, and something it never really was forced to do.


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## Freebird (Aug 16, 2008)

parsifal said:


> Acknowledge that we need to look at the most likley outcome of the Allies. Whilst i view the US capability in ASW at the beginning of the war to be backward, I do not consider the US leadership to be incompetetent.



"Incompetent" is a little strong, but "weak" would be more accurate.

Considering King's handling of the submarine threat, and Stimson's Marshall's adamant insisting on a landing in France in 1942, {Sledgehammer Imperator}, there was not anyone in the top echelon with a good understanding of modern war or a solid plan to fight the war.



parsifal said:


> if faced with massive losses, they would have reacted much more quickly than they did historically. Thgis would have to be the "quid pro quo" that I spoke about eleswhere. Historically the US showed itself to be extremely adaptable, from the very start. As an example, up to pearl Harbour, the USN war stratgies were based around the battleship.



The leadership of the USN was concerned with "warships", it was not overly worried about cargo ships, that is the difference



parsifal said:


> In just the same way, if faced by a massive underwater threat, I see no reason why the US would not have adapted its strategic position to meet this alternative very quickly. Granted that it would take longer than no time to achieve certain things, specifically, the training and tactical doctrine, the equipment, and the experience, which would have taken 6 to 9 months to start to acquire.



Mainly correct, the real question is how much damage can the Axis do in the first 6 months before some kind of equilibrium is reached



parsifal said:


> however, there are some things that they could have done more or less straight away. The most obvious is the adoption of a proper convoy system, the next is the redeployment of the fleet destroyers, quickly convert trawlers and other coastal craft to provide inadequate, but at least some form of escort.



Again you are considering "could have", not what would have been most likely, or even at all probable given the USN leadership at the time. The idea of convoys, coastal blackouts, using auxilliary ASW ships patrol aircraft was suggested to the USN and Admiral King in the first few months *several times* while losses were becoming serious, *and was absolutely rejected every time!* These measures were finally grudgingly adopted after 6 - 7 months. A much heavier loss might force the US to do this perhaps 2 months earlier, but not before about 3 - 4 months had gone by, at the earliest.



parsifal said:


> There is every possibility that the axis would sink a lot of ships, but IMO the USN could do enough from day 1 of the battle to survive. But it certainly is not a minor threat, and certainly requires more than a "business as usual approach" in order to win that battle.



Business as usual is exactly what the USN will do in the first few months. And yes, *the USN will survive*, operations will just be set back a few months. The real damage will be to the British Merchant Marine, which cannot keep up with sinkings, and cannot stop sailings without isolating many overseas troops.



parsifal said:


> The reason I only give the 40 additional boats to the germans is because of the limited endurance of te U-Boats. At the beginning of the war, the KM had something like 50 boats available, of which 40 or so were suited to Atlantic operations.



*The Germans had 244 U-boats in Dec 1941* according to Uboat.net.

The Germans comissioned 312 U-boats from 1935 - 1941, of which 68 were sunk in that period. Germany is producing 20 new U-boats/month at this time

So at the end of 1941 Germany had 203 U-boats {Type VII/IX} plus a further 41 coastal boats {type II} If only 50% of these are available for patrol in any given month, that gives 122 U-boats.....

uboat.net - The U-boat War 1939-1945

U-boat production:
1935 (14)
1936 (21)
1937 (1)
1938 (9)
1939 (18)
1940 (50)
1941 (199)
1942 (237)
1943 (284)
1944 (229)
1945 (91)


Total: 1153





parsifal said:


> This number remained more or less the same (with new Boats only just keeping up with losses) for about a year. Whilst the operational rate increased dramatically after the fall of france, the average daily availability in that first year of the war was about 12 Boats, as I recall.



They had 45 boats when war broke out, most of which were only coastal boats. 



parsifal said:


> Therfore, the German availbility out of a total force of in 1942 is going to be about 50%



Out of 244 boats this would be 122....

Seems a reasonable estimate, however for a planned "special occasion" {ie massive U-boat attack after "Pearl"} they could probably have 65% - 70% ready to go, then drop down to ~ 50% in following months. Another thing to consider is that with a few months advance warning, not only could Doenitz have all of his U-boats in position outside the ports on "Pearl + 1", but could have some neutral freighters in position in French or Spanish ports in the Caribbean West Africa, to re-supply the U-boats *without having to sail back to Germany*. Since there would be very few U-boats damaged by the weak patrol ASW in the first few months, the U-boats should mainly need just food, fuel more torps, not major repairs.


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## Freebird (Aug 16, 2008)

syscom3 said:


> The most probable course of events would be the following:
> 
> In the Atlantic:
> 1) The KM would run amok and inflict punishing losses on the allies for a *month or so.*



The British should have the faster response, as the British Shipping board keeps track of all ships, the Chiefs of Staff are already focused on the problem and will not delay in action. 

I would think that it would take about 4 weeks of data on ships sunk, and the British Admiralty CoS would take action within 1 - 2 weeks. Then allow for 2 more weeks for actions to be carried out, as it takes time for orders to get to ships already at sea, for aircraft escorts to be transferred etc. So the total should be 6 - 8 weeks for the British.

I would allow ~ 1 extra month for sunk ships to be tallied and Adm King informed. {no central clearing house for shipping - must wait for scattered reports from all ports of overdue ships}

Then I would allow ~ 1 more month as King vetoes corrective measures until the crisis becomes unavoidable. 

So about 3.5 - 4 months for the US to recognise the problem, decide on action, and relay instructions to all units. On the + side the US is less vulnerable than the British, huge losses can be rebuilt with production, and there is no looming "calamity" for the US, unlike the British.




syscom3 said:


> 2) The losses would diminish quickly simply because of the "facts on the ground". Untill the ships could sail under escort, they wouldn't be sailing at all.



Agreed, this would be the short term solution. After about 4 months the US would probably resort to only sailing heavily escorted convoys to vital outposts, Iceland, Bermuda, Hawaii, Australia, Palmyra Johnson etc.

However productivity would suffer without rubber, bauxite, tin, chromium, manganese etc. that come from South America Africa.

Also the buildup in the ETO counter-attacks in the Pacific would be delayed



syscom3 said:


> 3) The first allied counter measures would be for the AAF to provide daytime patrol and escorts. This would blunt (but not eliminate) the daytime threat from the U-Boats.



Agreed, after about 4 months I could see this to help. Again, part of the delay would be resistance from the Air Force to switching bombers to ASW patrol. {same problem from Bomber Command!}



syscom3 said:


> 4) Within 2 months, the existing escorts of the USN would all be equipped with adequate (meaning minimally acceptable) ASW gear, which further would reduce losses.



I think your estimate is a few months too optimistic. There are already about 20 older DD's in the shipyards awaiting conversion to ASW, but there is a delay getting space ASW equipment in the first few months.



syscom3 said:


> My point - The allies always showed the capacity to quickly change strategy and tactics. Don't assume that just because they were going to get their ass's kicked for a month or two, that they would continue to bend over for the KM.



Yes, again I largely agree with you, the KM IJN need to do the maximum damage in the first 4 - 6 months, before targets become more difficult to sink



syscom3 said:


> In the Pacific:
> 1) The reality of the logistics of supporting the forces holding onto the pacific islands along the US-Aussie lines of communication is far simpler than that of supporting forces in the ETO. The forces on the islands were essentially light infantry battalions (or brigades) which didn't have the logisitics burdens as a full up regular infantry division. It wouldnt be that difficult for the navy to get a cargo ship to these atolls once a month to resupply them.



I think you are correct, the paranoia at the time means that re-inforcing the Pacific bases is top priority to meet an {expected} Japanese attack.

The downside is that the support sent to Australia SE Asia would suffer.



syscom3 said:


> 2) The IJN sub force never had the competency as the KM and as events proved and were more easily blunted. They were far fewer in numbers, had a far more difficult logistics issue of support, and were tracked with a good degree of accuracy through ULTRA.



ULTRA? Do you mean Magic? Actually I don't see the IJN using more than about 25% of its boats in US waters, as a bunch of sinkings in the first few months will hamper US shipping by delays, convoys, caution. The main damage the IJN would cause is in SE Asia Indian Ocean, where the British have very little ASW to spare from the Atlantic, and where they cannot suspend shipping except under extreme circumstances.



syscom3 said:


> As for ship building:
> No doubt that escorts vessels would get higher priority, but it wouldn't be at the expense of the carrier or light cruiser programs. They were well along in construction, and it would take too much time and effort to stop them and convert over to building DD's and DE's. Instead, more materials would be made available to complete (faster) the DD's already under construction. As for the smaller ships .... the existing shipyards that were inland, would build them first, before building the amphib vessels.



Yes that makes sense, in any event there is no way that King would cancel most BB's CA's Cv's anyways


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## Freebird (Aug 29, 2008)

Quoted...



Nikademus said:


> -Freebird,
> 
> As promised, I looked up the information from Blair's "Hitler's Uboat War" regarding the Uboat component thrown into the mix along with a Russian setback. At the beginning of 1942, the Atlantic portion of the Uboat force stood at 64 boats. (19 x Type IX's, 44 x Type VII's and the U-A) 22% of this force (14 boats), were not combat ready. Of the 50 remaining boats, U-A was undergoing a conversion into a U-Tanker, 1 x Type IX and 4 x Type VII's were homebound or in Germany being overhauled, repaired or being retired. Four more Type VII's were in France undergoing repairs while Artic transfer was in Germany for overhaul before joining the Atlantic group.
> 
> ...


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## parsifal (Sep 3, 2008)

Been away for nearly three weeks guys, but Im back now. Intersting discussions by all. I should re-start the discussion by saying that there is no "right" answer to this sort of discussion. its a question of deducing likley outcomes, and likley reactions.

With regard to the very detailed and excellent accounting of the U-Boat fleet, by nikademus, I would make only one comment really. Type VIIs were used in the Gul of mexico, from a very early start in the campaign. by accepting quite appalling living arrangements, and providing additioanl fuel tanks (later), they were able to achieve patrol times of about 9 days in the gulf with their Type VIIs.

The range and endurance of the Type VII was extended progressively as the war progressed, At the beginning of the war, its range was typically quoted as about 5000 miles, and about 20 days. As the battle of the Atlantic moved further out into the Atlantic, the germans found it necessary to adopt various measures, some relating to operational usage, some to technological changes to the design (mostly adding more fuel tanks to the design no easy excercise in a CG senitive piece of equipment like a submarine. By the time of the attacks on the US weat Coast and the gulf were implemented, many Type VIIs were achiving Patrol times of close to 35-40 days, and an effective operation radius of 6-8000 nm. But unlike the assertions by soren in that other thread, ther was not much room left to se these subs as transports if they were used to the limits of their endurance.


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