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

[Freebird]

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.

 

[Freebird]

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.

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

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.

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.

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.

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

 

[parsifal]

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

 

[Freebird]

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.

 

[Glider]

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.

 

[Freebird]

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

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)

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

 

[starling]

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.

 

[parsifal]

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

 

[syscom3]

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.

 

[parsifal]

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

From these sources it is possible to deduce a pretty clear picture of Allied Merchant shipping losses due to submarine action, including nearly 250000 tons laid up in ports due to damage, and subsequently captured by the advancing Japanese. The list also includes ships damaged and not returned to service, which accounts for just under 100000 tons

This is the list

I-1 Class; 9 ships; 46833 t
I-153 Class; 20 ships; 79348 t
I-121 Class; 5 ships; 20009 t
I-64 Class; 15 ships, 66081 t
I-168 Class; 3 ships, 43723 t
I-6 Class; 2 ships; 11321 t
R0 33 Class; 3 ships; 43723 t
I-7; 7 Ships; 41902 (top scorer)
I-174 Class; 10 Ships; 31046 t
I-16 Class; 21 Ships; 107809 t
I-9 Class; 22 Ships; 119854 t
I-15 Class; 73 Ships; 464342 t
Ro-100 Class; 9 ships; 48764 t
I-176 Class; 3 ships; 11552 t
R0-35 Class; 1 ship; 12000 t
I-12 Class; 1 ship; 7176 t
TOTAL: 1124794 tons
Note that there is approximately 150000 further tons in dispute, as it is unclear as to the source of the losses. i have not included these in the above lists

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.

If they did, they werent using it to any appreciable degree (or alternatively it was not hurting them much) in the critical year of 1942. Japanese sub losses were quite tolerable throughout 1942. In 1943 they began to rise, and in 1944, after the the IJN was forced to try and use its subs enmasse as emergency supply vehicles, did the losses become catastrophic. The listed loss dates simply dont add up or support what you are saying. If you need confirmation, I can supply the loss dates of every commissioned IJN sub. You will be surprised I think

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.

Thats a matter for the debate. Can you provide the figures that you have on the numbers and type, so that I can compare with my own sources. type(s) of escorts are important to determine the ranges and equipment, or whether they were still part of the reserve fleet.

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

 

[syscom3]

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.

 

[parsifal]

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

 

[syscom3]

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.

 

[parsifal]

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?

 

[Freebird]

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

 

[Hunter368]

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.

 

[parsifal]

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

 

[Freebird]

"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."
.

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

 

[Hunter368]

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

Well known fact indeed.

 

[syscom3]

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.