10 moments that changed the course of the war at sea

[neil hilton]

Thats what I read too.
It was the Automedon documents that revealed this weakness to the Japanese so they could attack through the back door. They also revealed that the RN fleet that was supposed to be stationed at Singapore was no longer there. From which the IJN brass determined they could attack Malaya without too much trouble while at the same time their mobile fleet could be attacking PH in force.
The main problem to Japanese plans for an opening offensive was the dispersing of their fleet in order to tackle Singapore and PH simultaneously. So it could be said the Automedon documents solved their plans problems and gave the Japanese the green light for war.

[jrsteven00]

Thanks for commenting on the list.
I still need to do much more research to pin down an accurate list--and define my search criteria better.

Right now - however - my target is those small, unknown (or inexplicable) moments or decisions that had out-sized or unforeseeable impact on the war.

Big battles or campaigns like Midway and Leyte Gulf don't work so well because they are 1) Well known , 2) Sprawling, and 3) Tough to add insight to.
I'm much more interested in the micro breakthroughs and decisions that led to those battles (like the impact of the Doolittle Raid, cracking the Purple code on the Battle of Midway, or launching the dive-bombers at max range).

I do have one follow-up question, however.
I've read in several sources that U.S. submarines in the Pacific Theater strangled the Japanese war-fighting ability by sinking hundreds of merchant ships. But to achieve these results, the U.S. fleet had to replace cautious sub captains with more daring, younger, captains. This change-over even occurs in Herman Wouk's WW2 book, War and Remembrance. (Wouk served on destroyer/minesweepers during the war).

That nugget led to my point, #7, listed below:
7-Replacing cautious U.S. submarine commanders with aggressive officers (Increased destruction of Japanese merchant shipping) - 1942-45

Can anyone direct me to a good book, thread, or source to help confirm or elaborate this point?
I wonder if there's a business school case study written about it - as it's a classic case of changing management to achieve better results.
I'd appreciate it.
Thanks,
Jason Stevenson

[lwd]

For the war in the Pacific the Doolittle raid may be one of the more important perhaps even for the entire war.

[RF]

Indeed, I did mention this in a post earlier in this thread which apparently wasn't picked up.

[RF]

Another aspect not picked up so far - rather surprising for this website - is that the loss of the Bismarck resulted in the end of KM warships operating in the Atlantic on Hitler's orders.

[neil hilton]

The main outcome of the Doolittle raid was to prod the Japanese into attempting to extend their defensive perimeter further eastward. Thus they went for Midway, which allowed the Americans to set an ambush because they had broken the purple code. So it could be said it was the breaking of the code that was the more important thing not the Doolittle raid. Because they had broken the codes the USN could have set up an ambush no matter what direction the Japanese had gone in, even if the Doolittle raid had not occured.
Having said that, the USN only actually knew the Japanese where heading for Midway because of the 'lack of fresh water on AF' radio deception trick. I would say that was the more important factor in the turning of the war in the Pacific.

As for the war in the Atlantic. I would say the most important incident was the capture of U110s four rota enigma machine and code books intact by HMS Bulldog on 9th May 1941, it was only 3 months of setting I believe but it gave the boffins at Bletchley Park something to work on. The German surface fleet was never really big enough to form a consistent to the shipping lanes to Britain. In reality the u-boats didn't at the beginning of the war, Donitz asked for 300 uboats, by the time he got them it was too late. But it was a close run thing for a while.
Another point regarding this was that Donitz never fully realised that the enigma had been broken, even though the uboats weren't sinking as much as expected, if he had he could have easily changed them and turned the tables again. That is a very interesting point. I believe he thought the reasons for the down turn in uboat results was the work of spies not codebreaking.

[Byron Angel]

Thanks for commenting on the list.
I still need to do much more research to pin down an accurate list--and define my search criteria better.

Right now - however - my target is those small, unknown (or inexplicable) moments or decisions that had out-sized or unforeseeable impact on the war.

Big battles or campaigns like Midway and Leyte Gulf don't work so well because they are 1) Well known , 2) Sprawling, and 3) Tough to add insight to.
I'm much more interested in the micro breakthroughs and decisions that led to those battles (like the impact of the Doolittle Raid, cracking the Purple code on the Battle of Midway, or launching the dive-bombers at max range).

I do have one follow-up question, however.
I've read in several sources that U.S. submarines in the Pacific Theater strangled the Japanese war-fighting ability by sinking hundreds of merchant ships. But to achieve these results, the U.S. fleet had to replace cautious sub captains with more daring, younger, captains. This change-over even occurs in Herman Wouk's WW2 book, War and Remembrance. (Wouk served on destroyer/minesweepers during the war).

That nugget led to my point, #7, listed below:
7-Replacing cautious U.S. submarine commanders with aggressive officers (Increased destruction of Japanese merchant shipping) - 1942-45

Can anyone direct me to a good book, thread, or source to help confirm or elaborate this point?
I wonder if there's a business school case study written about it - as it's a classic case of changing management to achieve better results.
I'd appreciate it.
Thanks,
Jason Stevenson

..... I highly recommend SILENT VICTORY by Clair Blair. Although published back in 1974 (since reprinted several times), it remains one of the best histories of US WW2 submarine operations in the Pacific theater IMHO.


Byron

[lwd]

The main outcome of the Doolittle raid was to prod the Japanese into attempting to extend their defensive perimeter further eastward. Thus they went for Midway, which allowed the Americans to set an ambush because they had broken the purple code. So it could be said it was the breaking of the code that was the more important thing not the Doolittle raid. Because they had broken the codes the USN could have set up an ambush no matter what direction the Japanese had gone in, even if the Doolittle raid had not occured.

While the code breaking arguably had a greater impact it was hardly a "moment" it was an extended effort that gradually netted more and better information. Furthermore the impact of the extension of the defensive perimeter was greater than just the battle of Midway. The Japanese were already stressed logistically. Pushing the perimiter out further not only stressed this system even further it weakended them all along the perimeter.

Having said that, the USN only actually knew the Japanese where heading for Midway because of the 'lack of fresh water on AF' radio deception trick. I would say that was the more important factor in the turning of the war in the Pacific.

Even without Midway or at least without the carrier battle there the turning point was coming soon. If the US hadn't known ahead of time about Midway there's still a very good chance that the Japanese would have failed to take the island and even if they had it would have become the proverbial "albatross around there necks".

shipping lanes to Britain. In reality the u-boats didn't at the beginning of the war, Donitz asked for 300 uboats, by the time he got them it was too late. But it was a close run thing for a while.
Another point regarding this was that Donitz never fully realised that the enigma had been broken, even though the uboats weren't sinking as much as expected, if he had he could have easily changed them and turned the tables again. That is a very interesting point. I believe he thought the reasons for the down turn in uboat results was the work of spies not codebreaking.

I've seen it suggested that Huff Duff played a bigger part in the defeat of the U-boats than Enigma.

[RF]

Enigma didn't just defeat the U-boats. Huff Duff certainly was significant in itself, the reading of enigma codes gave opportunity for the destroyers with Huff Duff to be better deployed and thus make better use of it.

[lwd]

Enigma didn't just defeat the U-boats. ...

Indeed it's biggest contributions are arguably elsewhere. At sea it may have effected things in the Med more than the Atlantic as it allowed the targeting of supply vessels and to some extent undermined German Italian cooperation. But like codebreaking this wasn't an effect due to a particular "moment" it was a process that took place over most of the war.

[brcorts]

There are many great thoughts posted here, that it really got me thinking on the topic. As far as replacement of U.S. submarine skippers goes, I know of one book in particular that does discuss this policy. "Submarine!" , written by Edward L. Beach. The author is best known as the skipper of U.S.S. Triton that circumnavigated the world submerged, and as having written "Run Silent, Run Deep", that was made into a movie. While that last was a work of complete fiction, "Submarine!" was one of his first books and details his wartime experiences aboard U.S.S. Trigger, U.S.S. Tirante, and U.S.S. Piper. It also discusses issues of U.S. submarine strategy and doctrine as applied during the war. It also includes several referneces to other well known U.S. subs and their deeds as described to him by people that were present. It is an older book, written in the early 1950's when such things were still of great interest, and events were still fresh in the minds of so many. You should be able to find what you are looking for in there. The book is long out of print, but copies can still be found on Amazon.
Choosing the policy of submarine skipper replacement may prove to be difficult for you though. The policy was never an official one to the best of my knowledge and each submarine and commanding officer was evaluated primarily ontheir merits. Many skippers were replaced due to a lack of aggressiveness but I am not so sure that it had as much to do with age as it did temperment. If you would like to include an event from U.S. submarine history I would suggest the sighting of the Japanese fleet on its way to the Mariannas. I am unable to recall which particular submarine initially sighted the IJN task force but because of a contact report sent by that particular boat, COMSUBPAC ordered the repositioning of its forces along the IJN's route. This lead to the sinking of 2 IJN carriers by U.S. submarine. Shokaku was sunk by U.S.S. Cavalla, and Taiho by U.S.S. Albacore. Both IJN carriers were 1st line ships and thier loss set up the Mariannas Turkey Shoot. The Japanese found themselves not only out Admiraled, but they were also outnumbered as a result of the sinkings. Japanese Naval Aviation was eliminated as a viable threat to the USN after this engagement. While the Japanese retained carriers they did not have the planes or aircrews to put aboard them after that battle. This all stemmed from a contact report by a submarine that was not in position to attack themselves, but acted as the eyes of the USN, and helped set up a major vistory that sealed the fate of the IJN.

[neil hilton]

The actual codebreaking effort both in the Atlantic and the Pacific were long term endeavors but the use of those little golden nuggets of info produced many 'moments that changed the course of the war at sea'

As lwd said the codebreaking and the Doolittle raid resulted in the weakening the whole Japanese defensive perimeter in the Pacific. This in turn made it easier for the Americans to send their invasion fleets west and gradually take all those Japanese held islands. This raises another decision point in the history of the war. Why didn't the Japanese Army, which had millions of troops in China not redeploy some to hold those Pacific islands? I know the IJN and the IJA saw each other as competitors for glory and such but not helping in such a case seems suicidally stupid.

[Bgile]

Why didn't the Japanese Army, which had millions of troops in China not redeploy some to hold those Pacific islands? I know the IJN and the IJA saw each other as competitors for glory and such but not helping in such a case seems suicidally stupid.

Because they didn't have the necessary shipping. Their shipping was taking terrible losses as it was. Look how difficult it was to reinforce Guadalcanal. The more islands they tried to defend, the more of them the US would have bypassed, and attrited their shipping even more than historically, which was decisive in any case.

[lwd]

The troops in China were rather tied down fighting the Chinese. They did redeploy some and lost an amazing number of troops at sea. There was a thread (actually a several threads) on this over on the ijn board. Here's a recent on about a maru sunk with 2,000 troops and 500 horses aboard:
http://www.j-aircraft.org/smf/index.php?topic=9551.0
Here's another on the 2nd tank division: http://www.j-aircraft.org/smf/index.php?topic=9185.15
One on the 12 the division: http://www.j-aircraft.org/smf/index.php?topic=9002.0
There were some summary threads but they may not be available anymore.
The Japanese were also having a hard time supplying the forces they had on the various Pacific Islands. Moving more out there would have meant increased logistics problems, probably more cargo ships sunk, and likely more bypassed troops.

[RF]

The troops in China were rather tied down fighting the Chinese.

And the Americans, operating air forces in China itself plus ground forces operating via the Burma Road. As the war went on the American effort in China became increasingly important, not least because the air bases there provided the launch pad for the bombing of Japan itself, an often overlooked side show that did substantially hasten Japan's defeat.