AHC/WI: Better IJN anti-submarine warfare in WW2

Your challenge, should you choose to accept it, is to get the IJN's anti-submarine doctrine, ships, planes and other equipment into fighting shape for the Pacific War by December 1, 1941. You may use any POD after 1900; you must stay within historical resources used on the IJN. However, not building new battleships is NOT allowed, given the IJN's mindset at the time.

Having achieved this, how do you see the Pacific War changing?

EDIT: the POD used to be limited to 1930, but I decided to change that for extra fun.
 
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marathag

Banned
PoD: a vast Purge, with the IJN clique losing their heads in 1936.
So you now have the IJAN, Imperial Japanese Army Navy.

The Army is much more concerned about transport across the water, than the Chimera of 'Decisive Battle' where the USA begs for peace afterwards.
They pay more attention to details.like freighters, and how to protect them.
 
PoD: a vast Purge, with the IJN clique losing their heads in 1936.
So you now have the IJAN, Imperial Japanese Army Navy.

The Army is much more concerned about transport across the water, than the Chimera of 'Decisive Battle' where the USA begs for peace afterwards.
They pay more attention to details.like freighters, and how to protect them.
C'mon, that ain't very realistic. It also risks tying down the fleet in operations off China.
 
C'mon, that ain't very realistic. It also risks tying down the fleet in operations off China.
There really isn't a realistic way for this to happen is the problem. The cult of Kantai Kessen disdained ASW work in anything other than a fleet context, both because it was considered "beneath" officers all gunning for torpedo or gunnery commands and because the war was expected to be short and as such there was little point protecting trade.

Further, Japan simply doesn't have the resources to both provide for the Kantai Kessen fleet and provide an ASW convoy force. Japan's naval industry was running full-tilt or close to it the entire time.
 

CalBear

Moderator
Donor
Monthly Donor
C'mon, that ain't very realistic. It also risks tying down the fleet in operations off China.
Of course it isn't realistic.

It is, however, the only real chance of getting the sort of massive change in focus required.

The Japanese didn't have the funding to create both a potent offensive naval force AND a strong ASW presence. Simply not enough money for building hulls. The change in strategic thought also requires a wholesale removal of every Eta Jima graduating class since 1900. The Japanese Navy was entirely wed to a single strategic vision, namely the Decisive Battle. Anything that did not advance that vision was going to be regulated to the sidelines with low funding and the poorest quality officers. The Japanese also, thanks to Decisive Battle and the WNT/LNT compelled to emphasize offensive potential for nearly every platform. Destroyers carried remarkable torpedo armament, including a full set of reloads since their mission was to pare down the enemy surface fleet as it progress to the chosen sight of the Decisive Battle (not carved in stone but expected to be near Formosa, where the enemy could be entirely surrounded by Japanese land based air and where IJN vessels would be able to engage while in full supply; yes it was breathtakingly foolish). Same went for all other major classes. Japanese ships were also designed to be be far more potent than their American or British counterparts since the Japanese had to expect to be outnumbered based on 5:5:3 (this was one of the driving factors behind the Yamato class, three Yamato were judged to be capable of engaging five 35,000 ton 16" gunned battleships with success and only acceptable damage).

This strategic vision extended to training of officers. Officers were expected to be extremely, even foolishly, aggressive and those chosen for higher command were always of this mold. Even those seen by the West post-war as the best strategists were almost unbelievably aggressive (with Yamamoto being the 1st among Equals in this regard). ASW is many things, recklessly aggressive is not amongst those things.

All combined this created a Navy that was in no way suited for ASW, be it in equipment, technology, strategic vision, or leadership.

Only way to serious change that is a fresh sheet of paper. Of course that Navy would also have gotten rolled by the Allies in 18 months, so the changes wouldn't really have mattered.
 

marathag

Banned
Only way to serious change that is a fresh sheet of paper. Of course that Navy would also have gotten rolled by the Allies in 18 months, so the changes wouldn't really have mattered
With my IJAN, there wouldn't be the vast strike across to Pearl Harbor, wouldn't have the gear or attitude for that.
But they could still take the Phillipines and DEI, and play defense while victory in China was always just one more campaign season away.
With US following the Prewar planning, it will be more than 18 months before the IJAN and USN can even come to blows in any large combat, as I still see the lesser shadow of the IJAN still beating the tar out of the local ABDA in 1942
 

CalBear

Moderator
Donor
Monthly Donor
With my IJAN, there wouldn't be the vast strike across to Pearl Harbor, wouldn't have the gear or attitude for that.
But they could still take the Phillipines and DEI, and play defense while victory in China was always just one more campaign season away.
With US following the Prewar planning, it will be more than 18 months before the IJAN and USN can even come to blows in any large combat, as I still see the lesser shadow of the IJAN still beating the tar out of the local ABDA in 1942
Of course Rainbow was based on the IJN fleet as it was. Change that side of the equation and there may be changes on the other. The key, of course, is if the Philippines are seen a defensible with the alteration of forces.
 

marathag

Banned
Of course Rainbow was based on the IJN fleet as it was. Change that side of the equation and there may be changes on the other. The key, of course, is if the Philippines are seen a defensible with the alteration of forces.
That's why I picked 1936, most all that the Navy really needs has been built, and can focus more on escorts and ASW.
RIP Yamato, you never made it past the hull.
So there is not a huge difference in what is afloat in 1941, other than the USN figuring out that the 'enlarged 16" Nagano class' were being broken up.
And seems to be chatter on more seaplane carriers like Mizuho and Nisshin being constructed, along with other non restricted tonnage.

The big change was Japan agreeing to the terms of the WNT, rather than leaving at the end of 1936 and being a signatoryof the 2ndLT, agreeing to 5:5:3 and 14" guns, blaiming the Previous Government that had been swayed by the now removed Naval Faction for the previous bellicose statements over naval matters.
 

Grey Wolf

Donor
You could introduce it into the annual exercises with more force. I'd need to read up on it all again, to explain how. But if it became an element of them
 
Of course it isn't realistic.

It is, however, the only real chance of getting the sort of massive change in focus required.

The Japanese didn't have the funding to create both a potent offensive naval force AND a strong ASW presence. Simply not enough money for building hulls. The change in strategic thought also requires a wholesale removal of every Eta Jima graduating class since 1900. The Japanese Navy was entirely wed to a single strategic vision, namely the Decisive Battle. Anything that did not advance that vision was going to be regulated to the sidelines with low funding and the poorest quality officers. The Japanese also, thanks to Decisive Battle and the WNT/LNT compelled to emphasize offensive potential for nearly every platform. Destroyers carried remarkable torpedo armament, including a full set of reloads since their mission was to pare down the enemy surface fleet as it progress to the chosen sight of the Decisive Battle (not carved in stone but expected to be near Formosa, where the enemy could be entirely surrounded by Japanese land based air and where IJN vessels would be able to engage while in full supply; yes it was breathtakingly foolish). Same went for all other major classes. Japanese ships were also designed to be be far more potent than their American or British counterparts since the Japanese had to expect to be outnumbered based on 5:5:3 (this was one of the driving factors behind the Yamato class, three Yamato were judged to be capable of engaging five 35,000 ton 16" gunned battleships with success and only acceptable damage).

This strategic vision extended to training of officers. Officers were expected to be extremely, even foolishly, aggressive and those chosen for higher command were always of this mold. Even those seen by the West post-war as the best strategists were almost unbelievably aggressive (with Yamamoto being the 1st among Equals in this regard). ASW is many things, recklessly aggressive is not amongst those things.

All combined this created a Navy that was in no way suited for ASW, be it in equipment, technology, strategic vision, or leadership.

Only way to serious change that is a fresh sheet of paper. Of course that Navy would also have gotten rolled by the Allies in 18 months, so the changes wouldn't really have mattered.
What about treating ASW as an aggressive act in the Kantai Kessen mindset? Destroyers searching for and destroying enemy submarines to destroy their scouting lines in advance of the Decisive Battle, and removing the threat to the capital ships - just like would be done against the enemy screen.

Though then there is the question of designing and building ships for that, since pure Fubuki-style DDs won't work.

At the same time, could you pull the middle turrets from the Fusos and Ises and build two BBs with grandma's dentals? I also know that the turrets used during the rebuilds of Nagato and Mutsu were those originally intended for the Tosa-class battleships. Could they be used?
 
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That's why I picked 1936, most all that the Navy really needs has been built, and can focus more on escorts and ASW.
RIP Yamato, you never made it past the hull.
So there is not a huge difference in what is afloat in 1941, other than the USN figuring out that the 'enlarged 16" Nagano class' were being broken up.
And seems to be chatter on more seaplane carriers like Mizuho and Nisshin being constructed, along with other non restricted tonnage.

The big change was Japan agreeing to the terms of the WNT, rather than leaving at the end of 1936 and being a signatoryof the 2ndLT, agreeing to 5:5:3 and 14" guns, blaiming the Previous Government that had been swayed by the now removed Naval Faction for the previous bellicose statements over naval matters.
If resources are saved by not building the Yamato-class, could the IJN refit the old light cruisers to act along the lines of Isuzu, i.e. a dedicated AA/ASW cruiser? I'd also like the Hiyo-class to be improved and toughened up if possible.

The seaplane carriers could be useful in ASW, but I think that needs more investigation.
 
Your challenge, should you choose to accept it, is to get the IJN's anti-submarine doctrine, ships, planes and other equipment into fighting shape for the Pacific War by December 1, 1941. You may use any POD, but it cannot be before the London Naval Treaty of 1930; you must stay within historical resources used on the IJN. However, not building new battleships is NOT allowed, given the IJN's mindset at the time.

Having achieved this, how do you see the Pacific War changing?
Have the Chinese operate a small number of submarines in the late 30s that despite their small number inflict something of a 'drumbeat' like attack on Japanese freighters supplying Japanese forces in China that shocks the Japanese beyond the actual real impact of the losses.

This creates a cliché clique within the IJN or possibly as crazy as it might sound the IJA (they did operate their own Aircraft carrier), forming a small but fiercely determined group of ASW orientated officers from which a far better than OTL ASW doctrine and force can grow.
 
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Further to the above - the Germans did a lot of training of Chinese forces in the 30s.

Have them also provide a handful of coastal U-boats and officers to train them.
 

Driftless

Donor
At that late date(mid '30's), with no war experience to shift thought patterns, what would be the driver to make such a significant change in doctrine, training, and budget? IF such a shift in focus were to occur, it would need to be earlier, perhaps mid WW1 with several Japanese "star" officers as observers with the British fleet, seeing the threat of the U-boat. Even then, given the economic/strategic situation of the Japanese Navy as noted above, I think it would be a hard sell.
 
At that late date(mid '30's), with no war experience to shift thought patterns, what would be the driver to make such a significant change in doctrine, training, and budget? IF such a shift in focus were to occur, it would need to be earlier, perhaps mid WW1 with several Japanese "star" officers as observers with the British fleet, seeing the threat of the U-boat. Even then, given the economic/strategic situation of the Japanese Navy as noted above, I think it would be a hard sell.
The IJN and RN were best buddies pre-WW1. I can definitely see that happening; after all, they did deploy a DD flotilla in the Med. Perhaps they could be sent to the Isles during the 1917 crisis?
 
Have the Chinese operate a small number of submarines in the late 30s that despite their small number inflict something of a 'drumbeat' like attack on Japanese freighters supplying Japanese forces in China that shocks the Japanese beyond the actual real impact of the losses.

This creates a cliché within the IJN or possibly as crazy as it might sound the IJA (they did operate their own Aircraft carrier), forming a small but fiercely determined group of ASW orientated officers from which a far better than OTL ASW doctrine and force can grow.
Don't you mean 'clique' rather than 'cliché' (sorry for nitpicking, but 'cliché' doesn't work).

I can actually see that happening and shocking the Japanese a lot, especially since the Chinese are to them an 'inferior race', on the naval front specifically as well as generally, (memories of the Yalu River still around) and them gaining such successes would be especially infuriating. Also, could they consider it 'honourable' within the bushido code (which was widespread in the IJN at the time, though by no means dominant), to protect helpless merchant vessels from predatory, cowardly submarines?

In that case, it might actually be the IJA pushing for ASW. But they are mortal enemies with the IJN and only imperial intervention could get them to agree...
 
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