Japanese logistics, purchase programs and war booty, reality and alternatives 1936-44

[Shortround6]

They would have needed to remove some main armament turrets, or something like that, on many ships in order to make room for more AA and radars

This is very true and it is true for most (all?) destroyers before the late 1930s.
Some of the Japanese DDs from WW I and the early 20s had a pair of 6.5mm machine guns, replaced by a pair of 7.7mm guns. Even swapping for or adding a twin 13.2mm Hotchkiss mount is starting to push things

What is a little weird is that the Japanese had 100-200 British pdr Pom-Pom guns in the 1920s. They were not happy with them and they tended to get replaced by the 25mm Hotchkiss.
The British put time/effort into the WW I 2pdr to get the guns/ammo used in WW II so it is hard to say.

Most (all?) Navies biased their destroyers to torpedo and surface action in the 1920s/30s.
British and Americans had large numbers of WW I destroyers they could down grade to escorts (not enough but a lot more than anybody else had).

But Japan had considerations that other countries (except for England) did not have. Their trade routes were much longer than WW I destroyers could really deal with.
The planned attack on the DEI really shows the problem, It is over 1300 miles from the North of Borneo to just north of Taiwan, let alone getting to Japan.
Much of the raw materials that Japan wanted to seize were hundreds of miles further than their 'normal' trade routes.

Several things happened the first year of the Pacific war to help lull the Japanese into a false sense of security. The British had withdrawn their subs from Singapore. Holland had been over run and the DEI was trying to hang on pretty much by it self. Parts/supplies for the Dutch subs in the DEI were not as plentiful as they might have been. The rapid collapse of the Philippines took out the US Navy sub base, moving operations to either Australia or Pearl Harbor. The US torpedoes sucked so the US subs were not very effective (and for a few other reasons) so the expected losses due to subs in 1942 were within the expected losses the Japanese high command had anticipated. Perhaps they goofed here, They could absorb losses during a short war. But the losses are cumulative and they could not replace the early losses and as the war went on and the loss of transport only got steadily worse. even 20-30% fewer losses in 1942 might have been worthwhile.
On the flip side, while the US was not inflicted a lot of losses on Japanese merchant ships, the Japanese were not sinking very many US subs. The US sub commanders, unlike some of the admirals had a good idea where the problems were were even if they didn't know how to fix them. The US was not getting the results they wanted but they were not loosing very subs either. The US could afford to wait to see if things changed (fix the torpedoes). Had the Japanese been sinking more subs and the US subs been getting even few kills perhaps the US might have changed/modified their strategy?
But escorting merchant ships was not in the mindset of the Japanese navy. In fact even later in the war one account claims that many of the escort commanders had graduated from the merchant fleet academy and not from actual naval academy. Granted many British and US officers were reserve officers and while there were class distinctions it may not have been as bad as in Japan? There were no AS training schools.

The Japanese didn't really need more Emily's.
What they needed were planes closer to the Catalina or perhaps a twin closer to the Martin Mariner.
Something they could built two of instead of one Emily.

 

[tomo pauk]

The Japanese didn't really need more Emily's.
What they needed were planes closer to the Catalina or perhaps a twin closer to the Martin Mariner.
Something they could built two of instead of one Emily.

Good point about the Japanese making the Catalina equivalent.
Emily was a great design, but it was one of the biggest and most expensive flying boats made, with 1800+ HP engines and heavy & big airframe that will be using fuel like there is no tomorrow.
Catalina used the engines that were perhaps 3rd tier US engines (meaning there was a lot of them), of the modest power, and just two of these - all the factors contributing to the quick ramp-up of the production, and that production was of the American type
Making the Japanese Catalinas around the Sakae or Zuisei would've perhaps meant 5 of these vs. two of Emilys? But even the 2:1 ratio equals to another ~170 flying boats, that will go a long way to plug the gaps in the aerial coverage.

The same math can be applied to the H6M Mavis, that was made in 216 copies.

Here is the Japanese 'baby Catalina', the Aichi H9A.

 

[Zmauky]

Well, I would say, even though I'm nowhere near an expert, that the problem is twofold.

The first is the military mindset, and the second is the possibility to design (copy/license) something and then produce it.

Technologically, Japan was certainly not behind in the 1930s and 1940s. Well Japan had cavity magnetron radar technology before the UK (and they offered it to the Germans who were not interested), Long Lance and keel breaking torpedo (Indianapolis), multiple types of jet engines, rockets, radar....but no the ability to produce them in quantities for total war.
Especially not sophisticated electronic equipment.

Let's add to that the duplication of development programs (army - navy). So there is a shortage of production capacity.
And if the kinsei Zero (yes - should have had it instead of the sakae at least with A6M3 model) was so overpowered that it wiped out all the American planes over Midway in round two within year or less with 5 or 15 to one they wouldn't have stood a chance.

And military philosophy ... since it's a lazy Sunday morning, I won't look for a source but ...

Someone wrote nicely that Japan waged war on the principle of the 18th century. That is, two warring armies met, clashed, the better/stronger/smarter/better equipped was won. After the battle, the winner and loser sat down at the table, agreed on a peace/truce and moved on. They missed the lessons of World War I (they didn't really have a Western Front) and Japan didn't realize that wars had changed and become total. They went to war like let's give a strong slap to the opponent and then agree on what we will keep.

And that's why the army (and especially the pilots) was still based on samurai. So the emphasis in the planes themselves (and tactics) was placed on individual superiority (maneuvering abilities and pilot training ).
I (can) understand the kamikaze tactic, the hard military logic of numbers speaks in its favor, besides, if my burned cities are behind me, then there is also the motivation of all those pilots.
Pointless banzai charges and seppuku suicides for emperor and pride - not really.
And the cynical component that the kamikazes had is also missing - we can say that a couple of thousand planes are for the sunk 30 or so ships not in favor calculation, but that's not the whole story. The USN was pretty shaken up after Okinawa.

And there is a general strategic mistake - I would say (again) Yamamoto. The Navy planned 'one' decisive battle in its waters (along with the fleet AND AVIATION), and they carried out the PH. And if we can say - then the battleship was the king and the basis of the fleet ... but Pearl was attacked from the air and not bombarded by the guns of the fleet. And yes - they were sure that aviation would sink the battleships (Taranto).

So even the best equipment and training cannot correct strategic mistakes and arrogance. Like when, when planning the attack on Midway, they brought back two "sunken" carriers because who would care about junior officers playing the enemy.

Although I find the intellectual experience (and there is a lot to learn and broaden one's perspective) in such discussions - I'm afraid that not even a 'super maxi' Zero would fix the situation in which Japan was found itself.

And now I have to stop, so not to become a thread killer .

 

[tomo pauk]

So even the best equipment and training cannot correct strategic mistakes and arrogance. Like when, when planning the attack on Midway, they brought back two "sunken" carriers because who would care about junior officers playing the enemy.

One wonders how much of a change of a mindset is required for the roles to be reversed - have the top brass 'play' the enemy side (USA, mostly) in the war games, and junior officers 'play' the Japanese forces.

 

[Zmauky]

Big stick and juicy carrot. .

Not the first and last time that self-confidence and/or ignorance results in disaster.
For example, land a helicopter landing party at an airport and don't think that the opponent has rocket launchers nearby (and that they won't run away in fear).
Or plan a fleet attack from three (4?) directions and when you (accidentally) manage to reach the strategic objective (transport ships full of un-landed troops) retreat due to possible losses. True there are more than a few naval battles where the Japanese Navy could (should) have had a little more banzai mentality.
The Japanese army did have its enlightenment in Khalkhin Gol, the navy remembered Tsushima.

Unfortunately, Japanese politics is not my strong point, but maybe some incentive for the seppuku of selected individuals from the divine Emperor?

 

[GrauGeist]

The Japanese did have an amphibious type similar to the PBY, but never took advantage of it. It was the Aichi H9A, used mostly.for training.

Another asset Japan had, but did not use to it's full extent, was their submarine force. Their tactics and doctrine were nowhere near as aggressive as the USN and Kreigsmarine, even though their subs were comparable.

 

[EwenS]

Well, I would say, even though I'm nowhere near an expert, that the problem is twofold.

The first is the military mindset, and the second is the possibility to design (copy/license) something and then produce it.

Technologically, Japan was certainly not behind in the 1930s and 1940s. Well Japan had cavity magnetron radar technology before the UK (and they offered it to the Germans who were not interested), Long Lance and keel breaking torpedo (Indianapolis), multiple types of jet engines, rockets, radar....but no the ability to produce them in quantities for total war.
Especially not sophisticated electronic equipment.

The US, Britain & Germany all had magnetic pistols for their torpedoes on the outbreak of war, so that hardly puts Japan ahead technologically. All experienced difficulties with them in practice. But having a magnetic exploder did not prevent them being triggered bycontact with the ships side.

The I58 fired a spread of 6 torpedoes at the Indianapolis set to a depth of 4m (13ft) per her CO during the USN enquiry into the loss of the ship. Five of these had magnetic exploders fitted. But given the running depth v the draught of the ship, the magnetic exploder clearly played no part. Whitley gives her mean draft as 21ft and she was probably a bit deeper in the water than that in 1945. 2 or 3 hits were obtained.

The 24" Long Lance fitted to IJN surface ships, not submarines, was a nasty shock for the Allies. This weapon was part of Japan's plan to degrade the power of the US fleet as it crossed the Pacific before engaging in the "Decisive Battle". But in 1942 they proved unreliable as the crews were found to be adjusting the sensitivity of the exploders thus making them too sensitive and liable to premature detonation.

Incidentally the RN developed a 24.5in torpedo designed around 1923 for the Nelson class battleships (its only use). Range was 15,000 / 20,000 yards at 35 / 30 knots with a 743lb warhead powered by oxygen enriched air. Long Lance developed in 1933, was 21,900 / 35,000 / 43,700 yards at 48-50 / 40-42 / 36-38 knots with a 1,080lb warhead powered by a kerosene-oxygen wet heater.

As for "sophisticated electronic equipment" or the lack of it, that does not do the Japanese justice. It is true that they failed to exploit radar and in particular to develop the command and control facilities to direct aircraft using it. On the other hand they did succeed in understanding virtually all the Allied shipborne radars thus allowing them to plan their attacks to exploit weaknesses. That proved particularly effective with the kamikaze attacks off Okinawa.

 

[Shortround6]

Japanese subs were a weird bunch. They had capabilities that the Germans and US did not have. They also had liabilities that the the Germans and US did not have.
Many/most of the Japanese subs were long ranged and had high surface speeds.
This also meant they were large which made them better visual targets, better radar targets and better sonar targets.
They also did not turn well, at least compared to many other subs so making sharp turns wasn't quite as good at dodging a depth charge attack.
The large subs also took longer to dive, which gave aircraft more time to get into bomb range.
They also were not (usually) designed for deep diving. They could not use the 3rd dimension very well.

This trade off between size and different capabilities were well known to both the British and the Germans. The US didn't have a much choice as those two as their main opponent required long range (size) to get into Japanese waters. But the Japanese ASW capabilities sucked which means that the US lost comparatively few boats.
The British lost 75 boats during WW II. The British also had the 2nd highest kill to loss ratio after the US subs.

Japanese subs were large and very, very expensive. A small Japanese sub was the size and power of a German MK IX.

 

[GrauGeist]

The three classes of USN subs used during the war, were a little over 310 feet long or roughly 50 feet shorter than the USN's Gleaves and Fletcher class destroyers.

 

[GrauGeist]

By the way, here's the wiki page that has info (and pics) for Aichi's H9A.

Aichi H9A - Wikipedia

en.m.wikipedia.org

This could have had potential to be Japan's PBY equivalent.

The H6K was a great aircraft (as was the H8K), but the H9A would have been more practical and required less strategic materials for production.

 

[EwenS]

Another dedicated ASW aircraft, but one that came along too late to influence anything.

Kyushu Q1W - Wikipedia

en.m.wikipedia.org

The B5N Kate and B6N Jill were also used in the ASW role late in the war, gaining ASV radar to help theceearch process.

 

[Shortround6]

The Aichi H9A was pretty but it was too small. It was slightly larger than a Grumman Mallard.
While the Japanese needed a lot of AS planes it needed them in 1943 (or 1942 for experience). The 1944 is too late.
They needed planes with two 1100-1300hp engines, not 700hp engines. And not 1500-1800hp engines out of their first line aircraft.

 

[GrauGeist]

Ok, let's keep in mind that we're going over what Japan could have done to improve their position at the onset of the Pacific War.

Their recon abilities had sufficient coverage in short and long range aircraft, but no intermediate recon utility aircraft like the PBY.

This is where a type like the H9A could have been built on.

Yes, was a bit smaller (but not by much) than the PBY, however, it was amphibious and held potential to fill that gap.
As an advanced trainer, it didn't need more powerful engines or nessecary electronics, so of course it's historical performance isn't all that impressive.