IJN subs: bad luck or bad doctrine

[Eugen Pinak]

There were no regular Allied convoys going to either of those places.

That is quite a claim given the campaign on Guadalcanal involved upwards of 60,000 men lasting 7 months.

You can try to find those convoys here: https://en.wikipedia.org/wiki/List_of_A ... ic_Convoys

BTW, there were regular convoys to Port Moresby in 1942, though no exact dates of their existence are given.

Because I can count, you know. Very lousy blockade of those two points by one subdiv each requires 8 subdivs (1 on position, 1 going to position, 1 returning from patrol and 1 resting and repairing). IJN submarine force in 1942 had c.14-16 subdivs - and that's including old boats.

Please tell me where I mentioned the word 'blockade', let alone implied it, in any of my posts.

So you simply have no idea, that Japanese submarines actually operated off both Port Moresby and Guadalcanal? Otherwise I fail to see, what's all this "concerted effort" of yours is all about.

[Akira Takizawa]

I read somewhere that they were, more or less, obliged to "miltary" tasks by their code of honour or https://en.wikipedia.org/wiki/Bushido .
Attacking possibly unarmed merchant ships wasn`t in accordance with that.

No, it is a myth in the West. Shojiro Iura, who was a stuff of IJN submarine department wrote as follows in his book.

"I was delighted to hear that the commerce raiding by submarine would commence. Submarines could devote their own task of attacking merchant, free from the subordination to warship fleet. I imagined submariners who would jump for joy to know it."

Taki

[Andy H]

Bad doctrine formulated on pre-existing ideas of what there role would be and how they'd operate, prior to WW2.

Pre-war submarine doctrine was roughly similar for all major navies, excluding German.

Hi EP

Yes it was but the Japanese failed to change it in line with events and were always playing catch, and with the addition to the other aspects you've raised, lead to there woeful performance.

Regards

Andy H

[Eugen Pinak]

Bad doctrine formulated on pre-existing ideas of what there role would be and how they'd operate, prior to WW2.

Pre-war submarine doctrine was roughly similar for all major navies, excluding German.

Hi EP

Yes it was but the Japanese failed to change it in line with events and were always playing catch,...

Can you elaborate this? Because I fail to see, how IJN submarine service can change its doctrine "in line with events"?

[Andy H]

Bad doctrine formulated on pre-existing ideas of what there role would be and how they'd operate, prior to WW2.

Pre-war submarine doctrine was roughly similar for all major navies, excluding German.

Hi EP

Yes it was but the Japanese failed to change it in line with events and were always playing catch,...

Can you elaborate this? Because I fail to see, how IJN submarine service can change its doctrine "in line with events"?

Hi EP

The IJN Sub force went to war with a set doctrine to how the were going to fight/contribute to the naval victory, yet that doctrine was found wanting very early on. With such failings being self-evident, rather than doing something about it, they effectively did nothing and its more astonishing given the close ties with the KM U-Boat arm. That they didn't apply the lessons the Germans learnt by formulating a new doctrine that could contribute in a more meaningful manner.

Regards

Andy H

[Eugen Pinak]

The IJN Sub force went to war with a set doctrine to how the were going to fight/contribute to the naval victory, yet that doctrine was found wanting very early on. With such failings being self-evident, rather than doing something about it, they effectively did nothing and its more astonishing given the close ties with the KM U-Boat arm. That they didn't apply the lessons the Germans learnt by formulating a new doctrine that could contribute in a more meaningful manner.

Alas, like with Kingfish's "could have made a difference", all I can hear from you is nice phrases about "doing something" and "meaningful manner" But "something" is not an answer, you know.
Yes, IJN submarines did tried different tactics and techniques - included those learned from the Germans. But copying from looses doesn't help you to become a victor. They've invented some new tricks of their own - and, IIRC, in 1942-45 achieved more successes against Allied big warships, than Germans. But what new doctrine can they formulate??? To abandon fleet work and hunt merchant shipping, while US landing forces moving to invade Japan? Well, German submarines tried that doctrine - and ended with defeat, despite having way better position to hunt merchant shipping.

[Catnip]

I just happened to be reading United States Strategic Bombing Survey, Pacific: Interrogations of Japanese Officials, OPNAV-P-03-100 and came across the interrogation of Vice Admiral Shigeyosh Miwa, CinC Sixth Fleet (submarines). So to sum up my perspective on poor Japanese submarine performance during WWII:

1. At beginning of war relatively few submarines: 64 hulls with 45 operational.

2. Combat losses and inability to replace them. (See: USS England.) 40 submarines had been lost in the first six months of 1944, for example.

3. Strategic operations frustrated at Midway and Solomons by efforts of US code breakers. (USS England)

4. Army insistence submarines be used as supply transports during Solomon Island and Alaska campaigns. These were lengthy campaigns, afterward submarines needed significant maintenance and repair.

5. Later in war attrition and operational losses exemplified by fact only four of about 16 submarines were able to respond to the Sho alert for battle of Leyte Gulf.

I found some of this info in Admiral Richard Bates' The Battle for Leyte Gulf, Strategical and Tactical Analysis, Volume II

I believe somebody also mentioned a good book on the subject which I think I've read but can't remember now.

[Takao]

It's not that Japanese submarine doctrine of going after warships was wrong...it's that Japanese submarine search doctrine was at fault, possibly with less than adequate sonar/hydrophones. For instance, the Japanese placed some 25 U-Boats around Pearl Harbor. Yet despite the many US warships running to & fro, the Japanese subs sighted few targets and attacked even less. Then, despite redeploying 9 U-Boats to the busy shipping lanes off the US West Coast, they sighted few merchants and sank less. Japanese submarines stayed submerged during daylight hours and only surfaced at night to recharge batteries and patrol. Hence, their search area was quite limited. The aircraft carrying submarines could an did extend their search range with aircraft, but this was also limited to night operations.

Further hindering Japanese lack of success was that they had no equal to ULTRA/MAGIC, which was able to place US submarines in the path of potential warship targets or merchant convoys.

We should also not forget that the Japanese never had a numerous submarine force. At the start of the war, there were only 63 operational submarines(48 I-Boats & 15 of the smaller RO type). The Japanese found it hard to increase the size of the submarine fleet as losses often outpaced construction. From the early period of the war, the Japanese added 20 submarines, but lost 21.

Compounding their problem of numbers was not just the dimension of the Pacific War(from the Indian Ocean to the shores of the US West Coast), but also the many unforeseen tasks(hauling mini-subs, transporting supplies, kaiten attack, etc) that IJNHQ required the submarines to perform. These further diluted the number of submarines that were able to focus on the main task as at hand.

[Kingfish]

You can try to find those convoys here: https://en.wikipedia.org/wiki/List_of_A ... ic_Convoys

Just so I am clear, that list is what you would consider a "regular convoy"?
Havana to Key West? Aruba to Curacao? Dakar to Freetown? How about Bristol Channel to France (lasted one sailing).

Really?

[Takao]

IIRC, convoys to Guadalcanal were numbered, not initialed, so they won't be on the wiki list. But, if you read through the various warship deck logs on Fold3, you will find plenty of references to convoys going to Guadalcanal.

[Andy H]

The IJN Sub force went to war with a set doctrine to how the were going to fight/contribute to the naval victory, yet that doctrine was found wanting very early on. With such failings being self-evident, rather than doing something about it, they effectively did nothing and its more astonishing given the close ties with the KM U-Boat arm. That they didn't apply the lessons the Germans learnt by formulating a new doctrine that could contribute in a more meaningful manner.

Alas, like with Kingfish's "could have made a difference", all I can hear from you is nice phrases about "doing something" and "meaningful manner" But "something" is not an answer, you know.
Yes, IJN submarines did tried different tactics and techniques - included those learned from the Germans. But copying from looses doesn't help you to become a victor. They've invented some new tricks of their own - and, IIRC, in 1942-45 achieved more successes against Allied big warships, than Germans. But what new doctrine can they formulate??? To abandon fleet work and hunt merchant shipping, while US landing forces moving to invade Japan? Well, German submarines tried that doctrine - and ended with defeat, despite having way better position to hunt merchant shipping.

Hi PE

You've just highlighted the issue in that the Japanese sank more 'big warships' than the Germans (42-45). The IJN Subs were wedded to the big fleet actions, either recce or support of and found little profit/honour going after merchant ships. Both Kingfish and Takao have mentioned the other aspects that made the IJN subs returns so poor.

From the book I mentioned earlier:-
The formidable undersea arm of the IJN operated aimlessly and without a coherent strategy in the opening months of 1942. Inflexible pre-war battle objectives usually held sway, or any new ones were often ill-conceived......In the battles of the Coral Sea and Midway the submarine force again failed to measure up to prewar expectations, but the Navy high command continued to hold that submarines should be chiefly used to assist in the decisive battle of capital ships (which they were totally unsuited for)….The highly dispersed operations characterized much of Japanese strategic and operational activity during the war. The occasional entreaty advocating concentration against enemy sea LoC and extended US supply lines, particularly to the South Pacific and Australia, was always played down and usually rejected.

Regards

Andy H

[Takao]

You've just highlighted the issue in that the Japanese sank more 'big warships' than the Germans (42-45). The IJN Subs were wedded to the big fleet actions, either recce or support of and found little profit/honour going after merchant ships. Both Kingfish and Takao have mentioned the other aspects that made the IJN subs returns so poor.

The "honor" aspect is a Western myth. Pre-War Japanese naval strategists had realized that the US was a self-sufficient nation and that commerce warfare would neither defeat the US, nor hamper it's ability to prosecute A war with Japan. Also, they realized that the US could rapidly replace their merchant vessels, while replacing warships would require some time. Hence, they focused on warships as targets. While a respectable strategy, it does not take into account on how a commerce war might slow the US march across the Pacific. But, again, the Japanese were banking on a short war, not one of attrition.

From the book I mentioned earlier:-
The formidable undersea arm of the IJN operated aimlessly and without a coherent strategy in the opening months of 1942. Inflexible pre-war battle objectives usually held sway, or any new ones were often ill-conceived......In the battles of the Coral Sea and Midway the submarine force again failed to measure up to prewar expectations, but the Navy high command continued to hold that submarines should be chiefly used to assist in the decisive battle of capital ships (which they were totally unsuited for)….The highly dispersed operations characterized much of Japanese strategic and operational activity during the war. The occasional entreaty advocating concentration against enemy sea LoC and extended US supply lines, particularly to the South Pacific and Australia, was always played down and usually rejected.

Regards

Andy H

If you look deeply at the matter, the IJN submarine force was not so formidable - it was composed of a mixed bag of long-range & short range subs, as well as a mix of old & new submarines, besides it being a mix of submarines suited for a variety of purposes, but unable to focus on one task.

While their early war strategy was not "aimless", it was some what incoherent, with submarines being sent out for reconnaissance, mining, midget submarine, and attack sorties. However, this can be said also of Kido Butai, as the Japanese tried to find a suitable mission for it after Pearl Harbor.

While the submarines were to have a place in the Decisive Naval Battle, unlike the battleships, the submarines were not held in reserve. Instead, they were sent on various sorties all over the Pacific. At Coral Sea, the submarines did not figure much in the battle, because they were otherwise occupied elsewhere. A few were belatedly sent after the American carriers, but they never found them.

At Midway, the more modern aircraft carrying submarines were sent north to the Aleutians, instead of scouting for th he American carriers. While the older submarines were sent to Midway to form the ticket lines. True to form, the older submarines arrived late & missed the US carriers.

Striking merchant shipping was always advocated, however there were always to few submarines to go around for the tasks at hand. As such, even the more important ones could not be concentrated on. Further, given the IJN submarines' lack of locating targets, had they been concentrated on SLOCs, they probably would not have been successful.

[Eugen Pinak]

I believe somebody also mentioned a good book on the subject which I think I've read but can't remember now.

"The Japanese Submarine Force and World War II" [Carl Boyd, Akihiko Yoshida]

You can try to find those convoys here: https://en.wikipedia.org/wiki/List_of_A ... ic_Convoys

Just so I am clear, that list is what you would consider a "regular convoy"?

What - no more wise advises to IJN submariners?

IIRC, convoys to Guadalcanal were numbered, not initialed, so they won't be on the wiki list. But, if you read through the various warship deck logs on Fold3, you will find plenty of references to convoys going to Guadalcanal.

The question is not in the designation. The question is - those convoys were not regular convoys, that moved from A to B and back to A on regular intervals, so IJN submarines could at least predict their arrival. They were irregular convoys, sent to Guadalcanal wherever possible. So either IJN submarines can provide 24/7 blockade, or their interdiction efforts will be based on luck (unless they have Magic/Ultra, of course).

The IJN Subs were wedded to the big fleet actions, either recce or support of and found little profit/honour going after merchant ships.

Yes-yes.
When IJN sends 21 submarines to Midway and Aleutians in 1942 - that's bad. When USN sends 25 submarines to Midway and Aleutians in 1942 - that's very good.
When IJN sends c.16 submarines to Marianas in 1944 - that's bad. When USN sends c.28 submarines to Marianas in 1944 - that's very good.


And as Takao already correctly mentioned - "honor" aspect is a Western myth. IJN submariner did worked against merchant shipping. But they had neither resources, nor targets, justifying abandonment of fleet support operations.

From the book I mentioned earlier:-
The formidable undersea arm of the IJN operated aimlessly and without a coherent strategy in the opening months of 1942. Inflexible pre-war battle objectives usually held sway, or any new ones were often ill-conceived......In the battles of the Coral Sea and Midway the submarine force again failed to measure up to prewar expectations, but the Navy high command continued to hold that submarines should be chiefly used to assist in the decisive battle of capital ships (which they were totally unsuited for)….The highly dispersed operations characterized much of Japanese strategic and operational activity during the war. The occasional entreaty advocating concentration against enemy sea LoC and extended US supply lines, particularly to the South Pacific and Australia, was always played down and usually rejected.

If you replace "IJN" for "USN" and vice-versa, you'll get the description of USN submarine operations in the same period
As for the "concentration" - it's easier to say, than to do. I've posted my calculations above.

[Takao]

As for books I would also reccommend:
Submarines of the Imperial Japanese Navy by Norman Polmar & coauthor whose name I forget

I-Boat Captain by Zenji Orita

Sunk by Hashimoto


Kaigun: Strategy, Tactics, and Technology in the Imperial Japanese Navy by Evans & Peattie.
(While this subject is not the focus of the book, it is discussed quite thoroughly)

[Kingfish]

What - no more wise advises to IJN submariners?

Yes, I would advise them to ignore the routes into and out of Ironbottom sound and instead concentrate their boats in the straits of Florida, where the "regular convoys" are.