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

[parsifal]

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.

So, why would the US on the west coast react differently to that on the east coast. On the east coast the convoys were more vital, because they were carrying oil from the carribbeam (and other strategic materials) vital to the whole war effert, but the slaughter was about two to three times as large as that which might occur in the Pacific/Indian Ocean.

Also, US Shipping in the entire theatre was a significant proportion of the whole theatres Merchant fleet. i dont know the numbers, but it has to be at least 40% in 1941-42.

Lets assume that your strategy involves US controlled shipping only, and that only emergency convoys are authorised to PH, and nowhere else. lets say that that begins in January, and does not finish until about August. These are very rough figures, and Im only suggesting them to point out the flaws in your suggestion, and why it would lead to catastrophe in the theatre.

There is likely, to be disruption of the local economies on the western seaboard. Rail could undertake to compensate to a degree, but re-routing cargoes from and to the Ports, over to railheads is going to cause a lot of local disruption. I dont know how much, but a lot. In England, the british found it necessary to maintain their coastal convoys, even through the height of the BOB, because a cessation of these convoys would have hurt the british economy very badly. And this was in England, where railways are everywhere!!!!


But the disruption in the US, whilst bad, is not fatal. I agree with that. Based on the reports for the british, you are probably looking at an economic ruin for the Northwest (including the Canadian west caost i would think, as well as Alaska), and say about a 5-10% reduction in manpower and production outputs for the whole country

In the pacific, because the shipping lanes are not working, or working to emergency standards only, the operations of the US fleet will need to be curtailed severely, and operate from the west coast only. This is well beyond the reach of the Japanese fleet. But it means now that the conquest of SE Asia occurs in record time, no later than the end of february, as the collapse is rapid, and catastrophic. Military convoys to Australia and India are attacked by air, surface and submarine, and massacred. All of the economies of Australia and New Zealand are completely wrecked, as the wool and wheat crops are left on the docks to rot. there is no supply of military material. Faced with such a catastrophe, with the Pacific bases like Fiji and Noumea gone, because the US has undertaken such a catastrophic retreat from the theatre, and apparently abandoned by England as well, the two dominions have no choice but to sue for peace with the enemy, If they dont they face the very real prospect of invasion (see below as to where the men and shipping for such an invasion will come from).

In the Indian ocean, the blockade becomes more or less complete, and India is reduced to to a starving hotbed of discontent. If you dont believe me, have you ever wondered why Chandra Bose was used by the japanese. In 1943 the worst famine in history to date took place in Bengal, with millions dying. Partly there was a breakdown in the rail net, as too much rail capacity was used up on military purposes. There were riots and mutinies everywhere, and large numbers of troops had to be diverted from the front, just to maintain control. It was a major factor in why so little activity occurred in 1943 on the Burma front. Eventually order was restored, by restoring the food supply chain (with wheat from Australia), but in this case, the food shortage is for the entire country, and for a much longer period. moreover because no foodstuffs have gotten out of Australia (and America is too far away, and no exports are getting out anyway) the revolt is nationwide, and uncontrollable. India is lost to a nationwide mutiny, a revolt, and the promise by the japanese to provide rice and wheat, from the now surrendering Australians (which they probably dont honour).

In China, the collapse occurs somewhat earlier, because the allies have had to suspend shipments of supplies there before they even start properly. For similar reasons, the Nationalist are forced to either retreat to the outer provinces (and reduced to insignificance), or surrender outright. The communists I believe would continue to fight, because they alone have learnt to fight as a guerilla force. However, the Japanese, by achieving victory, have been able to release something like up to 50 divisions, able now to face the american counteroffensive, but before that, to bully the dominions and the Indians into surrender.

In addition to this middle eastern supplies of oil are now under severe threat, and in effect no longer available. The southern Lend lease route to Russia is blocked, oil exports to england blocked, and the middle eastern campaign under severe threat, because all foodstuffs, many of its troops pulled out (australians, new zealanders, and Indians at least), so now your withdrawal is affecting the european theatre as well

One other thing, because of the early fall of the far east, the japanese have managed to capture perhaps another 250000 tons of shipping from the far eastern ports. They do not lose the 800000 that they did in 1942, because American subs have been pushed outside the range of the major Japanese shipping arteries (they are forced to operate from the west coast, which limits them to the outer limits of the the empire...Kwaj, Eniwetok etc). With the extra shipping, Japan is able to import raw material to Japan at an elevated rate, and output of material for war is thereby increased. By how much I am not sure, but given there was roughly a 30% decrease in military output because of shortages, it could anything up to that figure (ie 30%)

I wont say that the events I have portrayed will happen exactly as I suggest, but i do know that the allied defences were interlocking, and interdependant. Removing one part like that has massive flow on effects in other areas. I have outlined just one possible scenario. One thing i can assure you of, a pull out like what you have suggested would have catastrophic effects on the outcome and conduct of the war, far moreso than if the convoys soldiered on, and kept up the fight against the japanese, regardless of losses.

Nimitz had a sign above his desk. I dont remember the exact wording but it said something like "BEFORE YOU ASK OR SUGGEST ANYTHING, DO WE HAVE THE SHIPPING?" You might do well to consider the implications of that message as well.

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.

See my quotes above. I think the war could end long before August '45, but not the way you would predict

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

 

[Freebird]

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?"

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.

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.

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.

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.

 

[Wildcat]

.
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

 

[parsifal]

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

In order for the blockade scenario to work , the japanese must sustain their efforts relentlessly. This is why Sys was trying to say they (the Japanese) would abandon the policy after only a few losses. I dont agree with that summation, but neither is a blockade of just a few weeks going to achieve anything either. in the case of the Pacific, it is the interdiction of traffic, not so much the tonnages that do the damage. So, if the targets disappear, because they dare not risk the Japanese subs waiting for them, then the Japanese have won anyway. If the MS comes out unprotected, or inadequateky protected (as it must, in the beginning), then the Japanese sink a significant proportion of them, and the outcome is the same as the "no comee outee" strategy. If the the US attempts a major effort too early, to somehow break the Japanese hold over the Allies, the US will probably suffer a major defeat, and still be in deep do dos. But the key to all this, is for the Japanese to maintain th blockade (which only requires to be partially successful in order to work)..

One other thing, Japanese submarines were designed for Pacific operations. Many i-Boats were equipped with their own seaplanes, and they were backed up by a maritime SAR force which by March was being re-equipped with Search aircraft capable of long range patrols of over 24 hours duration, and ranges approaching 2000 miles (each way). The subs were exceptionally lonranged, and exceptionally fast (in a surfaced condition). Provided they adopted some of the practices of the KM, they could rapidly deploy to areas where major convoys were located, and then deal with them, or, if too heavily defended, spot for the surface fleet, which could descend on the convoy and dispatch it with a carrier strike

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.


The Japanese only needed to maintain a force of six boats in the Indian Ocean, in order to cause majopr disruption to the India bound convoys, in 1943. If the germans had been willing to offer help in this theatre in 1942 (perhaps by sending the LR Italian cruiser subs there, to work out of Singapore), the demise of the Allies in that theatre could have been hastened.

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

 

[Soren]

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.

 

[Freebird]

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.

 

[Wildcat]

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.

 

[Freebird]

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

 

[Wildcat]

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.

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.

 

[Freebird]

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}

 

[Freebird]

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.

 

[pbfoot]

food for thoughtsounds pretty good

 

[parsifal]

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

 

[syscom3]

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.

 

[HealzDevo]

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...

 

[parsifal]

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

 

[syscom3]

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.

 

[Freebird]

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.

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.

 

[HealzDevo]

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...

 

[Danielmellbin]

Just to answer the original question: no!