Lack Of Japanese Anti-Submarine Tactics

[YM]

Everyone states that the US's use of unrestricted submarine warfare played a crucial war in fatally weakening Japan's ability to conduct the war, primarily by cutting of oil shipments from the Dutch East Indies as well as the transport of other crucial raw materials to the Japanese Home Islands. I have seen may authors claim that the Japanese never developed effective counter-measures such as the Allies used in the Atlantic against the German U-boats. They didn't even organize a convoy system. One argument said the Japanese Navy was never interested in the problem because it had an offensive doctrine and guarding merchant ships didn't fit in with this (actually the professional officers of the British Royal Navy also didn't like escorting convoys, but the RN did get around to providing the convoys with protection anyway).

My question is if the Japanese leadership saw the country was being strangled by the American submarine offensive, why didn't they crack the heads of the Navy and the merchant marines to do something about it? I am quite puzzled by this.
Does anyone know the answer to this?

[LWD]

By the time it was obvious a significant amount of the IJN's vessels had already been attrited. Furthermore carrier raids were also causing significant damage. They did build some small ASW vessels and convoy but there was a distinct lack of material. WWI had been an eye opener for the British the Japanese really hadn't had to deal with a serious submarine offenisve until 43 or so.

[steverodgers801]

The Japanese leadership were the ones who didn't understand ASW warfare until it was too late. A major problem was ASW was not glamorous so what good commanders were available didn't want the job.

[Rob Stuart]

H.P. Willmott observes that part of Japan's shipping capacity problem was the lack of central control. The army, the navy and the civilian government each controlled a portion of the shipping bottoms and used its ships exclusively for its own purposes. He says that there were cases where empty ships passed each other going in opposite directions - for example, empty army ships returning from the southern resource area after delivering reinforcements or supplies and empty civilian ships heading to the resource area to collect raw material. In contrast, all UK-controlled shipping was centrally managed so as to minimize such wastes of capacity.

[Maxschnauzer]

By the time it was obvious a significant amount of the IJN's vessels had already been attrited. Furthermore carrier raids were also causing significant damage. They did build some small ASW vessels and convoy but there was a distinct lack of material. WWI had been an eye opener for the British the Japanese really hadn't had to deal with a serious submarine offenisve until 43 or so.

This quick look at Japanese ASW weapons capability bears that out. The IJN was apparently playing catch-up until 1943 before they could deploy more effective weapons.http://www.navweaps.com/Weapons/WAMJAP_ASW.htm

This low priority can be seen in the performance of the USA submarines vs. the Japanese ASW efforts. Japanese surface ships sank 17 USA submarines, aircraft sank eight and one was shared. In addition, one British submarine was sunk by aircraft and one by surface ships. By contrast, Allied Submarines sank 1,152 Japanese merchant ships of 4,861,317 gross tons, with the USA submarines accounting for about 98% of the totals. An equally impressive number of Japanese warships were sunk by submarines, with the giant aircraft carrier Shinano being the largest.

The question remains why were they derelict in this area. I think steverodgers801 may be onto something in that ASW was not a high priority for warriors striving to follow the bushido code and all that. But it's hard to understand why they didn't connect the dots that the successful tactics that their German ally had with U-boats prior to the Enigma compromise could be used against them by the Allies if they didn't develop effective countermeasures ASAP.
There may have also been an air of complacency grounded in the attitude that after Pearl Harbor a naval victory was inevitable so why worry about the little stuff but concentrate on battleships and carriers to hurry up and get the job done.

[LWD]

The Russo-Japanese experiance loomed very large in IJN circles. Thus the "Decisive Battle" doctrine. They should have looked at the North's use of the "Annaconda" strategy during the ACW. However Japanese planning frequently failed to take into account reactions or even doctrine of their opponents. See for instance:
http://www.navweaps.com/index_tech/tech-067.htm
and
http://www.navweaps.com/index_tech/tech-064.htm

[glenn239]

Japanese strategy was to win a short war. Investing too heavily in ASW was aiming for a long war - the type of war Japan had no hope of winning. The OP indicates that lack of ASW 'fatally weakened' Japan's ability to fight. That may be true, but the larger narrative was that American industrial resources made it impossible for Japan to win a long war, ASW or no.

[LWD]

Good point, I'm not sure they looked at it that way but in hindsight quite correct.

[OpanaPointer]

Good point, I'm not sure they looked at it that way but in hindsight quite correct.

Zimm's book breaks down the issue into several scenarios from short war to long war. The long war scenario was unwinnable for Japan, so they ignored it. Their war plans were built around the US doing what Japan wanted them to do.

[steverodgers801]

Its the same mentality that caused Japanese subs to ignore allied shipping. Coordination was not a strong point of the Japanese military, individual performance including planes and ships was more important then group success.

[OpanaPointer]

Another reason they didn't do well with ASW is that they were reluctant to build dedicated escorts. The reason, if you can all it that, was that they would win a short war, so escorts weren't going to be needed.

[ChristopherPerrien]

H.P. Willmott observes that part of Japan's shipping capacity problem was the lack of central control. The army, the navy and the civilian government each controlled a portion of the shipping bottoms and used its ships exclusively for its own purposes. He says that there were cases where empty ships passed each other going in opposite directions - for example, empty army ships returning from the southern resource area after delivering reinforcements or supplies and empty civilian ships heading to the resource area to collect raw material. .

Taking this football a little further, also explains the lack of a developed ASW doctrine and the woeful, almost non-existent building of dedicated ASW ship's, like DE's and ASW sloops and cutters.

The IJN didn't want to do ASW because they didn't need it with the freighters they used and their destroyers protecting their larger ships by default. And they hated escorting Army and civilian shipping. IJN destroyers were meant for surface combat and any heavy investment for ASW or ASW for other branches was considered a waste and a loss of face. They thought they could get by with airplane patrols , and their limited number of ASW, "coast defense" boats. Using [urlhttp://en.wikipedia.org/wiki/Category:Escort_ship_classes[/url] I count about 169 ASW/coast defense warships for WWII.

The army considered their shipping needs to be of such short range, China-PI mainly, that they were not going to own/operate integral ASW assets. Also the IJA had its own inertia against doing much in the ASW area because that was viewed as encroaching on an IJN area (water/sea-combat :roll: ) which was viewed by the IJA as a loss of face in itself.

The civilian Japanese Merchant Marine was basically left out in the cold because of such stupid thinking; As neither the IJN or IJA, felt any sense of responsibility for providing ASW to civilian ships. And there were so few ASW IJN/IJA assets anyway that the JMM were rarely escorted and half-heartedly when it was done. Prayer was the best, and often only, ASW protection the JMM had.

With such 3 headed thinking and the main possible provider of ASW (the IJN) not needing ASW except for their own ships, and seeing ASW as a loss of face compared to "ship to ship battle ", it should be no wonder that little thought was given to ASW doctrine by the Japanese , and even less action toward building dedicated ASW assets.

One last thing and I don't know how to say. But basic Japanese military thinking in WWII was opposed to ASW as most of basic ASW doctrine demands waiting on an enemy sub to attack before being able to "react", the Japanese simply could not envisage conceding initiative to the enemy like that. Even when they attempted to set up "ambushes" , they made the first moves, Midway/Leyte Gulf. The extremely tedious aspects of searching and waiting for an enemy which are so common to ASW were simply somewhat counter to Japanese thinking at the time.

I found this little gem while looking for ASW escorts, It is a Naval Institute Press pub, by a Capt. Atsushi Oi, an IJN staff officer,Grand Escort Command HQ http://dreadnoughtproject.org/friends/d ... %20asw.pdf

[LWD]

The US didn't start the war with a lot of DE's and such either yet caught up pretty quickly. How much of it was poor planning and how much was due to limited resources?

[OpanaPointer]

The US didn't start the war with a lot of DE's and such either yet caught up pretty quickly. How much of it was poor planning and how much was due to limited resources?

The US was in the grip of the Great Depression, like the rest of the world, and defense spending was a low-priority.

[LWD]

I understand that but the US was able to produce significant numbers of DE's by the second quarter of 43. Of course it was jump starated to some extent by British orders but looking at the warships production table in:
http://www.combinedfleet.com/economic.htm
for 42 and DDs it was 86:10 in favor of the US, for 43 it was 128:12 for DDs and the US produced another 298 "escorts" in that period. In total the Japanese produced only a few (18? type A kaibokan?) escorts. But especially after Midway their resources were going to carrier production. The US had the resources to produce the above escorts as well as carriers. My impression is the Japanese resorces were pretty well committed and any devoted to escorts would have to come from those already committed. The fact that they haulted work on the Shiano during this period is also significant in this regards I beleive. They weren't just short of materials, but workers, and perhpas facilities.

From:
http://en.wikipedia.org/wiki/Destroyer_escort
Japan produced 18 Type A kaibōkan and 37 Type B kaibōkan both significantly smaller than US DEs.