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

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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.

See above
 
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.


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?




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.
 
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.
 

See above
 

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
 
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.
 

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
 
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.
 
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
 


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
 
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.
 

they might have they might have...
 
Hi Freebird


Hope this is of some help
 
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}
 
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
 
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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