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

[Cryhavoc101]

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...

Yes (I didn't check the spell checker) and corrected - thanks

It could be a case of IJN embarrassment and IJA shock at the loss of men and equipment in such a way that could get them working together

Its a big ask I know but if the Army held it over the Navy I am sure that they would take steps to limit future embarrassment before their real enemy (The IJA that is)

 

[JudgeKing]

Yet would the infant Kriegsmarine be willing to hand over such useful vessels?

Germany was building six U-boats for the ROCN in OTL until WW2 broke out in Europe.

 

[Kantai Kessen]

Yes (I didn't check the spell checker) and corrected - thanks

It could be a case of IJN embarrassment and IJA shock at the loss of men and equipment in such a way that could get them working together

Its a big ask I know but if the Army held it over the Navy I am sure that they would take steps to limit future embarrassment before their real enemy (The IJA that is)

Why does this prospect of cooperation make me strangely happy?

I can also see major repercussions in other areas if this happens, such as in Guadalcanal and the Solomons.

 

[Kantai Kessen]

Germany was building six U-boats for the ROCN in OTL until WW2 broke out in Europe.

Huh, really? Could you show me your sources because I have never heard of that, and am genuinely curious?

 

[Cryhavoc101]

Germany was building six U-boats for the ROCN in OTL until WW2 broke out in Europe.

And the boats do not have to come from Germany!

 

[Cryhavoc101]

Why does this prospect of cooperation make me strangely happy?

I can also see major repercussions in other areas if this happens, such as in Guadalcanal and the Solomons.

We all like to see people get along

I can see the early USN Sub ops being even worse and suffering heavier losses in the period Dec 41- 43

Of course this is likely to drive greater change - faster in the USN Submarine Arm than OTL in order to win the tonnage war

 

[El Pip]

Huh, really? Could you show me your sources because I have never heard of that, and am genuinely curious?

Wikipedia claims it was a pair of Type IIB U-boats. Ordered in late 1937 but the Japanese objected, there appears to have been some sort of argument about them (they took a very long time to build, but were standard boats, so I guess they were 'on stop' for a long period). In any event the Germans took-over the order and commissioned them into the Kreigsmarine in 1940 as training boats.

 

[marathag]

The seaplane carriers could be useful in ASW, but I think that needs more investigation

Small flying off platforms used by autogyros, as well. IJA had been interested in them since 1939, the Kayaba Ka-1 or the Kokusai Ki-76, inspired by the German Fieseler Storch liaison aircraft.
Both were later fitted with small depth charges during the war

 

[YYJ]

Regarding this, here is some more info I found:

2nd Special Squadron (Japanese Navy) - Wikipedia

en.wikipedia.org

The IJN was capable of good ASW if they put their minds to it, it seems.

This seems like a workable POD, in World War 1 with the both the opportunity and the time for the IJN to adjust doctrine and equipment. Have the 2nd Special Squadron have a much rougher go of it in the Mediterranean. As it was they had one destroyer torpedoed. Have the flagship Izumo torpedoed with heavy loss of life.

Or have Japan send a token force of troops to the Mediterranean in 1917 and have that troop ship torpedoed. Make one of the dead a VIP, like a senior general, or a member of the Imperial family. Make it an event that lodges in institutional memory. Have a promising admiral's career very publicly destroyed by the shame of letting the sub get through. Have the Army stuck on "Remember the <something> Maru" and constantly badgering the IJN for better ASW protection for its troop ships.

Or give the Germans a fleet of U-Boats at Tsingtao at the start of World War One and let them play havoc with the Japanese ocean lines of communication.

In response to these challenges, if the navy is stubbornly dedicated to Decisive Battle doctrine at the expense of ASW, have a higher power create a separate branch dedicated to ASW, something like the Coast Guard or the Voskva PVO. Equip them with the old destroyers that outlive their usefulness as fleet destroyers, like England did with their World War One destroyers in the battle of the Atlantic, and with smaller slower sub-chasers that do not require full sized shipyard slips to build. Let Japan de-rate the older destroyers if they need to dodge treaty limits. Make this new service a career path for ambitious young officers who see their paths of advancement blocked by the existing power structure in the IJN. A smaller pond where one can achieve glory.

 

[Sapa Inka Wiraqucha]

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.

tl;dr -- the fish is rotten from the head down, but the Army is worse than the Navy​

Begging your pardon, but the Army was even worse at allocating funds than the Navy. If anything, they were even more resistant to change and innovation than the Navy, since the Navy officers at least visited foreign schools and went sightseeing in foreign lands during their educational period, giving them at least some view on what the world looked like and what it could do. The Army had none of that.
Sure, the Army produced great generals like Yamashita, Okamura and Hata, but their education was still limited.

Moreover, the Army had a system whereby the junior officers would take it upon themselves to be the enforcers of religious zeal and chest-thumping patriotism, and would denounce and assassinate both civilians and superiors they felt were not being patriotic enough. When things weren't going their way, for example a superior doesn't want to invade X country right fucking now, different junior officer factions decided to force their superiors to do something by... expediting the process.
Look up Manchurian Incident. Once these incidents happened, the Army was forced to follow them in because not doing so would be seen as unpatriotic and defeatist, which would lead to... trouble. Thus, the higher officers were forced to go along with it, and generally tried to keep out of their way as much as possible.

This would lead to situations where junior officers would rise, find themselves in the position of their once-superiors, and decide to do something bloody stupid to show off their patriotism, like invade friendly nations' colonies! I'm not kidding. Look up Rikichi Ando: he's the guy who started the Pacific War by invading French Indochina while the Japanese government was negotiating with them for military access. This provoked the American oil embargo! This, uncharacteristically, led to Ando being forced into retirement.

Generals, especially generals who had been around a long time and had accumulated a well-known political career as Army moderates, lived in mortal fear of these guys, because they recognized that a.) they would get Japan in shit it couldn't get out of, b.) they wouldn't hesitate to kill superiors, and c.) they wouldn't hesitate to kill members of enemy factions.

Note, by the way, that while the Navy was noticeably less prone to this kind of behavior, it still engaged in assassinations to the max.

Look up: League of Blood incident, May 15 incident, invasion of Manchuria, invasion of Indochina, February 26 incident, March incident, Imperial Colors incident, November incident.

There may be more I've missed.​

 

[steamboy]

One big issue was how the IJN viewed the use of their subs. As CalBear said the IJN wasn't just wedded to the idea of the Decisive battle but built an altar and then rivited itself to it. And subs were part of this. They, like destroyers were expected to attrite the USN as it came over to help relieve the Phillipines and IJN captains were trained to almost exclusively go for warships. And if given the option between going for a warship or transports, if you said 'transports?' you'd probably be denied the chance of command, because you HAD to go for Warships. And this had been drummed into them since the 20's. So basically you'd have to completely change the way the IJN works, and how it views subs.

Oh and ween them off the idea that convoy's are defensive and thus below any REAL officer's duty and notice because its dishonourable to do such defensive acts and insulting to the Yamato spirit.

And as Sapa Inka Wiraqucha also pointed out the army was basically insane and the navy honestly wasn't much better. Higher ranking officers brawled with one another over points of doctrine or what they felt was right or points of honor, and Yamamoto had pissed off so many in the Army that there was a very good reason that he spent his time aboard a battleship as often as possible. Because there was less chance of some crazed junior army officer trying to assassinate him.

Imperial japan was a crazy military that happened to also have a country attached.

 

[CalBear]

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?

Major issue with this sort of strategy is that, well, the technology didn't exist. What you are describing is similar to late Cold War NATO doctrine, specifically the use of SURTASS trawlers with attendant ASW air assets. That requires not just excellent passive sonar (which was simply hydrophones in the 1930s-40s) with the ability to detect contacts one or two hundred kilometers away (hydrophone might get five miles in excellent conditions) and a method to process millions of data point so that patch of krill 20 miles west can be sifted out from the submarine cruising along five miles behind it

Another method is to create Hunter-Killer groups centered on a escort carrier (a real one, not the IJA version that was meant to handle one or two liason aircraft or autogyros) with three or four escort ships (what the RN called corvettes and the USN called destroyer escorts). These, however require air superiority, actually close to air supremacy given that if they run into even a well armed patrol bomber there is a very real chance that the CVE will become a statistic and are only effective while hunting along a convoy route (which actually makes them a negative asset if used as a forward screen since the presence of the HK Group means that there is a significant enemy formation nearby.

Not sure what putting a couple more underarmed BB would accomplish since they will count against WNT/LNT gross tonnage limits. You can butterfly away the Treaties, but all that really accomplishes is bankrupting the Japanese Empire. The whole reason the WNT and the successor LNT came about was the horrifying reality in both Tokyo and London that the United States had all the money it needed to sink their fleets by piling up bags of quarters on them until they capsized (or, put another way, the U.S. had six South Dakota (1920) class battleships AND six Lexington class battlecruisers under construction AT THE SAME TIME while both the Japanese and British were trying to assemble the funding for a building program to construct four BB and four BC each over the space of 5-7 years). The U.S. Congress was also seriously considering authorizing some variant of the "Maximum Battleship" i.e. Tillmans if necessary as a follow up. You will sometimes see comments regarding the "danger of an arms race" for the reason the WNT happened. There was not going to be an arms race. The U.S. had already won it, and had terrifying amounts of funding available to simply bury any other player, the WNT was an spending moderator. The Japanese couldn't have completed their 8/8 programs in 15 years, especially after the 1923 Tokyo Earthquake, and the British would have literally been trying to outspend the bankers loaning them the money to spend. The irony, of course, is that the only ships that actually were of serious utility by the time of WW II were the battlecruiser conversions that resulted from the implementation of the WNT.

 

[marathag]

Note, by the way, that while the Navy was noticeably less prone to this kind of behavior, it still engaged in assassinations to the max

But the had the bloody minded goal of one thing, taking over China.
Everything else was means to reach that end.

No Oil from US sanctions?
The Army plan was to go south and take the DEI oil. to protect those routes, invade Philippines.
Problem solved, Conquest of China continues.
Navy had the grand scheme to do the whole Co-prosperty Sphere, and sail all the way over to Hawaii for that and attempt to sink the US Fleet.
Army was not big on that.

 

[Jellico]

The Army ran their own navy because they didn't trust the Navy to do the job. Start with a bad sinking by the Russians or Germans and go from there?

Can you have large flying boat based ASW? Japan has them, unlike escorts, if nothing else they can play a suppression role.

 

[CV12Hornet]

The Army ran their own navy because they didn't trust the Navy to do the job. Start with a bad sinking by the Russians or Germans and go from there?

Can you have large flying boat based ASW? Japan has them, unlike escorts, if nothing else they can play a suppression role.

Not enough of them. The Japanese, even counting prewar production, had less than 400 large flying boats through the entire war. The Germans built almost as many large flying boats as the Japanese did, to say nothing of the RAF's 700+ Sunderlands. Further, both the Brits and Germans supplemented their flying boats by large numbers of conventional land-based patrol bombers. That's not going to happen for the Japanese.

Doctrine doesn't help either, as the large flying boats were to be used as reconnaissance platforms and the occasional bombing mission.

 

[CalBear]

Regarding this, here is some more info I found:

2nd Special Squadron (Japanese Navy) - Wikipedia

en.wikipedia.org

The IJN was capable of good ASW if they put their minds to it, it seems.

Actually closer to saying that after IJN and RN squadrons had wiped out German raiders the Japanese sent three obsolete cruisers and a significant fraction of their destroyer complement to the Med. the result was one heavily damaged IJN destroyer resulting in the death of 2/3 of the ship's company, rescue of roughly a brigade of troops from a previously sunk British transport and zero submarines sunk. Overall, a nice piece of seamanship and excellent force projection in support of an ally, but of limited effectiveness.

 

[CalBear]

The Army ran their own navy because they didn't trust the Navy to do the job. Start with a bad sinking by the Russians or Germans and go from there?

Can you have large flying boat based ASW? Japan has them, unlike escorts, if nothing else they can play a suppression role.

Interesting idea. The H8K was one of the, if not the, best flying boat of the war (there are fans of the Short Sutherland and the of course the PBY was of great utility, but the Emily was IMO not only the top dog, but arguably the best aircraft the Japanese Empire ever produced). Problem is that the H8K was very resource intensive to produce.

 

[Draconis]

Interesting idea. The H8K was one of the, if not the, best flying boat of the war (there are fans of the Short Sutherland and the of course the PBY was of great utility, but the Emily was IMO not only the top dog, but arguably the best aircraft the Japanese Empire ever produced). Problem is that the H8K was very resource intensive to produce.

Did the Japanese have an effective surface search radar to fit in the Emilys? The USN subs would have been submerged during the daytime anyway. Without a good way to detect surfaced subs at night I don't see how much of a difference having more Emilys would make.

 

[Jellico]

Did the Japanese have an effective surface search radar to fit in the Emilys? The USN subs would have been submerged during the daytime anyway. Without a good way to detect surfaced subs at night I don't see how much of a difference having more Emilys would make.

You have to get on station first. If nothing else you are forcing the US subs to travel under water in the day time.

But as noted, numbers (and engines) are the problem.

 

[CalBear]

Did the Japanese have an effective surface search radar to fit in the Emilys? The USN subs would have been submerged during the daytime anyway. Without a good way to detect surfaced subs at night I don't see how much of a difference having more Emilys would make.

No. IJN radar tech was at least a generation behind any of the other major players. The U.S. ASB, to use just one example, which was deployed in early 1942, was superior to anything the IJA/IJN deployed during the entire war, it was small and light enough to be deployed on carrier capable aircraft, while even late into the war the Japanese sets were so heavy and bulky that they were largely limited to Heavy bombers and didn't make their first appearance until mid 1944.