More effective Japanese ASW in ww2

[Monk78]

Very. Also, in 1942 & 1943 single & twin engined bombers became very effective in sinking Japanese cargo ships. John Ellis in 'Brute Force' has the annual ships lost by Japan sorted by method. Mines, submarines, aircraft. The results for 1942-1943 are surprising. Even in 1944 aircraft were still accounting for 20% of total losses. Losses to mines surged back up in 1945 when access to the home islands became practical.

Were Japanese mines more advanced than that of Allies ?

 

[CV12Hornet]

Were Japanese mines more advanced than that of Allies ?

No. The Japanese invested little into mines in the interwar period, as such "defensive" weapons were not considered of much value to the very offensively-minded IJN.

 

[phx1138]

No. The Japanese invested little into mines in the interwar period, as such "defensive" weapons were not considered of much value to the very offensively-minded IJN.

They didn't do sweeping well, either. USN subs could have given them nightmares, had Nimitz (AIUI) not been hostile to mining.

 

[Alanith]

No. The Japanese invested little into mines in the interwar period, as such "defensive" weapons were not considered of much value to the very offensively-minded IJN.

You’d have thought they’d have been seen as an excellent way to whittle down the USN a little bit more prior to the decisive battle.

 

[phx1138]

You’d have thought they’d have been seen as an excellent way to whittle down the USN a little bit more prior to the decisive battle.

You can't lay them in open ocean, where the "decisive battle" is going to be fought.

Edit:
Nor in the path of the approaching Americans, where attrition would be a good thing. That's what subs were (supposed to be) for.

 

[Monk78]

Did the Japanese have any rocket mines or the ones that shot a torpedo like CAPTOR?

 

[McPherson]

From straits of Tsushima to La perouse straits can the Japanese navy adopt a more effective ASW strategy in ww2 to counter USN subs In home waters
Also can they place more and better minefields in those straits ?

No. The answer is not obvious, but let me develop the thesis.

I think you'd have to get the IJN to realize that a great decisive battle is going to perhaps need time to arrange, and that during that time, the Empire's sealanes will need protecting.

The IJN knew this from their WWI experience in the Mediterranean Sea. Until that incompetent, Yamamoto, skewed their naval war-planning, the scheme was to force early decisive battle early on the basis of the "Through Ticket to Manila" and when that was changed on them during the Hoover administration with "phased advance", the new planning was attrite and decrease. In neither plan did the IGHQ naval section for any reason believe that Japan could build or operate ASW forces as well as a battle fleet. The money, industrial base and technical manpower was not there. It was battle fleet and short war or nothing. They gambled on the battle fleet and lost.

I thought about getting rid of Kantai Kessen, but the more I thought about it, any Japanese war based on attrition against the US wouldn't make it out of the planning stages.

See previous comments.

There were some officers who served as observers in the RN during the First World War who took notice of the effects of the submarine against the UK's merchant shipping. They did compile reports, but were not listened to much, and even later on when concerns were raised, for a variety of reasons, they were dismissed or little action taken.

See previous comments. They were listened and the reports noted, but the IJNGS had to choose between the two options. They could not have both.

See my post here for further information, notably of interwar thinking and even exercises in this regard. The issue was a known one and something could have been done, but you need a way to get it more widespread acceptance, and for that you need to get past the "Black Shoes" and the Carrier lobby. Not an easy call.

Cannot afford it. Split the resources and the Americans will CRUSH Combined Fleet even at the reduced 1930's USN condition and then kill the merchant marine.

Best Options/PODs I Can Think Of:

- Germany gives China early U-Boat models in the 30s, which temporarily cause havoc in Japanese Sea Lanes, thus forcing Japan to adapt the way it thinks.

What U-boats?

- Have Germany deploy U-Boats to Asia before the beginning of WW1. Said U-Boats cause havoc of Entente operations in the Sea of Japan/South China Sea.

They tried.

- Have the army gain even more political influence in Japan at the expense of the navy. Army dictates that the main role of the Navy is to transport and supply the army instead of seeking the decisive battle.

They did.

- As mentioned above by another poster, naval officers from Japan did observe and research British saw warfare. Making their role more prominent in post ww1 naval development is possible.

As I noted, the staff hashed these two options out and came to the only Japanese solution possible.

- Have the Washington Naval Treaty further limit battleship, cruiser, and carrier production for all nations including Japan, influencing Japan to build more destroyers in otl, putting it in a better position to protect it's sea lanes.

Oh that will work. Now the USN is building submarines like crazy.

Slightly off topic but remember Japan has limited resources. Being better at asw most likely means a weaker carrier fleet and less battleships, thus limiting Japan's offensive abilities in WW2.

How many aircraft carriers did USN subs kill?

How effective is mining in Japanese straits both for USN and IJN

Depends. USN mining and port mouse-holing early war was "mixed". Japanese mining efforts resulted immediately in HELL'S BELLS and intensive USN bathythermographic and underwater geographic mapping. The concept of "lanes" and current riding was developed late war.

From The Japanese Navy in World War II, Naval Institute Press. According to Atsushi Oi, who was involved in the IJN's attempts to set up escort forces and then develop a convoy strategy, there were plans to create a cordon because of the impact convoy would have on shipping circulation.

There was no question that the best way to prevent the mounting shipping losses was to adopt a convoy system in full measure. As we have seen, however, in the fall of 1943 the cry was still loud for a faster circulation of shipping. On the other hand, there was no hope of an early remedy for the extreme shortage of escort vessels. The GEHQ, caught in this dilemma, hit upon the idea that faster shipping circulation would not necessarily be unfeasible if the best use of geographic advantage could be made. The idea occurred first to Admiral Oikawa. He himself penciled the plan, the heart of which was as follows:​

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1) The sea area linking the East China Sea, the Taiwan Strait, and the South China Sea was to be made safe from submarine intrusion, so that within this sea area merchant ships would be able to sail independently, without forming a convoy, and thus secure the highest possible efficiency of shipping circulation. For this purpose, the island chain comprising the Ryukyus, Taiwan, the Philippines, and Borneo was to be connected with mine barriers. As for places where minelaying was not feasible, land-based radars and sonars as well as patrol planes and patrol vessels would guard the sea gaps.​

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2) The sea belt along the Nampo Shoto (including the Bonin and Volcano islands) and the Mariana Islands was to be guarded by radar stations that would be installed on these islands, as well as by patrol planes and ships, so that enemy submarines would find it difficult to invade the sea belt. Convoys would sail within the belt.​

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3) The sea lanes along the southern coast of Honshu (between Yokohama and Kobe) and along the eastern coast (between Yokohama and the ports of Hokkaido) would be guarded with shore-based radars, patrol planes, and patrol ships, so that ships would be free to sail safe from the submarine menace. In those days the Sea of Japan and the Yellow Sea were not infested with submarines.​

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The idea was very enthusiastically received in government circles, although the Naval General Staff gave half-hearted support. The people of the Naval General Staff first insisted that all mines then on hand had to be reserved against the probable emergency of Russian entry into the war. Though this obstacle was at last surmounted, and though the government consented to appropriate necessary materials (especially steel) for the production of a sufficient number of mines, only four minelayers were made available. The minelaying took so much time that only the East China Sea and the Taiwan Strait had been partly mined before the air supremacy over the projected sea area had been wrested from Japan’s hand. As for shore-based radars, the blueprint was completed in no time, but only one or two stations were actually installed before Okinawa was taken.​

The concept was "bastion defense". The correct counter would be lanes, current riding, Hell's Bells and the "snort" boat. The snort boat never happened because the war was too short for it to be retro-fitted.

Interesting thanks I thought the waters there were just too deep for effective mine warfare? But probably mines had evolved a lot more since the days of World War I

Most of USN submarine combat occurred, either on the surface or in submerged conditions in waters of 200 meters depth or less.

Can, yes. Will? No. Not without a major shift in training, doctrine, & officer education, which essentially makes it not IJN any more.

See previous comments.

IJN took the doctrine of attack more seriously, AFAICT, than any other navy. (Even RCN resisted landing torpedo tubes, fearing it would keep DDs from being available for escorting the battle line.)

The IJNGS was also completely incompetent.

IJN A/S training was laughably bad, & officers assigned to A/S were (near) the bottom of the barrel. (It's not clear to me if submarine officers were actually considered lesser status.)

Agreed. Submariners? Does Takeo "Braindead" Takagi jar the memory?

IJN officers were dismally unqualified in their understanding of the importance of logistics.

Operation MO, was as bad as Operation MI in the sloppy staffwork. The SNLF and IJA troops scheduled for the Port Moresby Shark Feeding Frenzy were headed into an Australian buzz saw onto beaches that the IJN had not properly hydrographed or reconned. The only question was would the defenders run out of bullets and shells before the Japanese ran out of bodies. Supply seems to have been a MacArthur / Blamey bolo, too.

As you can see, fixing these things is an enormous task. I'm not at all sure when you'd have to begin, or how you'd achieve it. Not having IJN fall in love with Mahan would be a start--but that raises the question why they did (along with so many other navies) in the first place, & how you fix that. IMO, you need to start sometime after the First Sino-Japanese War, & no later than the end of the Russo-Japanese War. Much after that, the trouble is so baked in, you're hooped, IMO; indeed, if you don't get at it in (before!) the RJW, it may already be too late.

The problem was not too much Mahan, but not enough. Pre-war LRMP interlocking commerce defense from the air would have been an OBVIOUS Mahan observation from Alfred Thayer... But all offense and short war meant RIKKO and no CORLEONE to the IJNAS.

Oikawa's idea of using extensive mine barriers might have worked, if Japan had actually executed it. Clearly, the lack of understanding by senior officers played a role. (Only 4 MLs? ) Whether it would have proven too porous to prevent USN subs from getting through anyhow is another matter.

No, it would not. So the IJN gets 16 submarines instead of the historical 8. What is the IJN going to do, when not if, Uncle builds 600 snorting Tenches?

 

[The Tai-Pan]

It is not a matter of tech, it is a matter of mindset. The Japanese Navy was steeped in the pursuit of Mahanian glory in massive fleet conflicts. ASW isn't part of that so they had little patience for it, and it only got the lowest priority and least ambitious officers.

 

[McPherson]

Yes, but... The assessment of US capabilities was very different in that era. Plus US submarine doctrine had two parts: 1. Large fleet submarines would scout ahead of the Battle Line and make opportunity attacks on capitol ships. @. Smaller coastal submarines would provide point defense of naval bases, like Cavity on Luzon, or Oahu. A Guerre de Course against enemy cargo ships was discussed by US naval officers, but the book doctrine and training was for the two items above.

The Japanese navy, it is claimed, brought unrestricted air and submarine warfare on themselves via Pearl Harbor. As we know now, PLAN ORANGE from 1935 onward had unrestricted air and submarine warfare embedded. City killing and merchant ship massacres, were not what was "meant" by unrestricted warfare, but that is how it turned out. How the weapon system actually works dictates how it will be used.