1930's Japanese Navy - What would you have done differently?

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Garyt

Senior Airman
354
25
Jan 2, 2014
And this should be without the advantages of hindsight, but perhaps with the knowledge of some of the more enlightened leadership. As an example, Yammamoto was a supporter of air power and would probably like to have seen more emphasis placed on carriers than battleships.
 
Some of the changes would need to have the cultural changes happen before implementation. Eg. the emphasis on the trained manpower their well being - those don't grow on trees, so you better design the aircraft with a degree of protection. Rotate the crews.
Whatever ship enemy uses, it is a target for one's submarines. Forget the 'decisive battle' - so the Yamatos don't get build, but the aircraft carriers instead. As an island nation, remember how much the German subs troubled the UK in the Great war, and act accordingly. Compare the capabilities of own AAA outfit vs. the capabiliies of own dive bombers, the result will be that something better than 25mm is needed, and in increased numbers. Radar is a mandatory item.
It is, of course, questionable whether Japan possessed necessary resources to implement the changes - increased number of carriers also means greater number of A/C and trained crews, a possible introduction of escort carriers and other anti-sub hardware is another new drain to the resources. Some savings can be achieved via non-building the Yamatos, though.
A more capable IJN also needs more fuel, that is a major road block.
 
Funny, Tomo, I was going to post my answers but felt it was kind of silly to answer my own question :D

But what you posted was very very similar to what I was going to post.

design the aircraft with a degree of protection.

I'd do the same thing, but with just one issue. I thought Japanese were having problems building larger horsepower engines, so if you don't increase the horsepower and up armor the Zero for instance, do you merely have a Japanese version of something that performs like the heavier version of the Buffalo?

So the Yamatos don't get build, but the aircraft carriers instead.

I think I read somewhere when comparing costs, you could build 2+ Shokaku's for a Yamato.

As an island nation, remember how much the German subs troubled the UK in the Great war, and act accordingly.

Considering Japan's ability in designing torpedoes, perhaps they should have an ASW homing torpedo like the US Fido earlier. And some more advance depth charge type throwers would have been helpful, like the Hedgehog. And a convoysystem should have been used from day 1 of the war.

compare the capabilities of own AAA outfit vs. the capabiliies of own dive bombers, the result will be that something better than 25mm is needed, and in increased numbers.

Here is where I think we have too much foresight. According to post war reports the Japanese still felt at the end of the war that their 25mm was a capable AA weapon. And I wonder how much has to do with the weapon itself - fire control may have been part of the issue, as well as the fact that Japanese AA would get lesser results as US aircraft was more durable than Japanese aircraft. And with the 25mm, it had a good muzzle velocity and cyclical rate of fire. Maybe a hopper type loading system the the 40mm Bofors could work, or even making them belt fed. But the mounts on the 25mm seemed to be a big problem, too slow to traverse and too much vibration on the triple mounts. How much of this is 20/20 hindsight I don't know.

But the 5"/50 used by destroyers was horrible for AA, and you would think that would be easy to figure out. Too slow traverse/elevation, lack of maximum elevation, very difficult to load at high angles of elevation. The fact that these were competent anti-surface weapons but struggled as AA would have been rather obvious I would think. THe problems again though seem to be as much of a mount issue as a gun issue, so fix the mounts if possible or go with the 3.9"/60 gun.

A more capable IJN also needs more fuel, that is a major road block.

Don't know exactly what to do there, but better ASW would surely help. And I have read it was as much of insufficient refining operations as it was raw crude itself, so a little more spent on infrastructure for refineries may have helped.
 
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Considering Japan's ability in designing torpedoes, perhaps they should have an ASW homing torpedo like the US Fido earlier. And some more advance depth charge type throwers would have been helpful, like the Hedgehog. And a convoysystem should have been used from day 1 of the war.

For the Japanese Fido to work, much more is needed than a workable 'dumb' torpedo - namely the electronics that works for the task. The eagerness to have the 'Fido-like' torp was another thing - sub hunting was not something IJN was eager to do until too late.

Here is where I think we have too much foresight. According to post war reports the Japanese still felt at the end of the war that their 25mm was a capable AA weapon. And I wonder how much has to do with the weapon itself - fire control may have been part of the issue, as well as the fact that Japanese AA would get lesser results as US aircraft was more durable than Japanese aircraft. And with the 25mm, it had a good muzzle velocity and cyclical rate of fire. Maybe a hopper type loading system the the 40mm Bofors could work, or even making them belt fed. But the mounts on the 25mm seemed to be a big problem, too slow to traverse and too much vibration on the triple mounts. How much of this is 20/20 hindsight I don't know.

The quirk with 25mm was that it was ill able to hit a dive bomber before it was way down in the dive - the 40mm have had significantly higher effective ceiling. And an ingenious ammo loading system, if I may add.

But the 5"/50 used by destroyers was horrible for AA, and you would think that would be easy to figure out. Too slow traverse/elevation, lack of maximum elevation, very difficult to load at high angles of elevation. The fact that these were competent anti-surface weapons but struggled as AA would have been rather obvious I would think. THe problems again though seem to be as much of a mount issue as a gun issue, so fix the mounts if possible or go with the 3.9"/60 gun.

The IJN was expecting from their destroyers to fight much more the surface targets/threats, rather than enemy A/C? They were not alone in this, of course.
 
For the Japanese Fido to work, much more is needed than a workable 'dumb' torpedo - namely the electronics that works for the task. The eagerness to have the 'Fido-like' torp was another thing - sub hunting was not something IJN was eager to do until too late.

That's what I am talking about really, the eagerness. You would think an island nation that saw another island nation get hammered by sub warfare in WW1 would realize that threat to their own nation - and make significant efforts to shore up their ASW defenses. As they seemed to appreciate torpedoes more than any other nation you would think it would be right up their alley, IF they had the motivation.

The IJN was expecting from their destroyers to fight much more the surface targets/threats, rather than enemy A/C? They were not alone in this, of course.

That is indeed true, and maybe even partially right, as much surface warfare was at the destroyer/light cruiser level. But still, to have a competent surface to surface weapon like the 5"/50 and to not make it a true dual purpose weapon is just gross negligence IMO. How hard would it have been to correct some of the short comings? Allow it to elevate to 75 degrees, not 55 as I think was the case in most destroyer mounts, and to not have a faster traverse/elevation speed? The Japanese had some in the Navy with good foresight as to the increasing value and lethality of aircraft. You would think they would have realized the enemy would also have a capability to sink ships by air.

As to the aircraft though, I'd at least add self sealing fuel tanks to the zero, and shorten it's phenomenal range. Great range is nice, but IMO the self fueling fuel tanks and a range more equivalent to US fighters would work fine.
 
Problem with Zero's tanks was that they were located in wings, and that means they were 'shallow'. Any worthwhile protection will eat up much of the volume, like it was the case for the P-39 (down from 200 in un-protected tanks to 120 gals in protected ones) or even for the P-38 (from 400 down to 300). Fuselage tanks tended to be a more 'cubic', so even once the protection was added, the decrease in capacity was maybe 10-25% at worse - like it was case for F4F (really small decrease) and P-40 (un-protected capacity was 180 gals, down to ~140 with full protection; tanks were partially in the wings).
 
Gotcha. Just as a real rough guess, what percentage of fuel do you think a true self sealing fuel tank would be lost in a Zero? Or even a Val or Kate?

I forgot to add this earlier as well, the lack of a power rammer made the 5"/50 difficult to load when the guns were trained over 45 degrees or so.

If you really think about it, the Japanese aircraft and anti aircraft put them at a huge disadvantage in the attrition you would see in Air to Ship and Ship to Air combat, exacerbating their low production of trained pilots.

Their 5" weapons were very poor AA, their capital ship mounted dual purpose weapons were better but still compared poorly to the US dual purpose weapon. The 25mm was inferior to the 40mm, And I think the Oerlikon 20mm was a fair amount better than the Japanese 25mm.

Add this to the fact that Japanese craft were lightly armored or unarmored and did not have self fueling fuel tanks.

Compound all of this later in the war with radar assisted fire and VT fuses, and there was not real comparison to the losses that would be expected by an aerial assault of enemy vessels.
 
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The fuel capacity was about 150 us gals in the Zero (depending on the version?), radius (ie. go out vs. enemy, engage in combat, return home) is listed at 467 nautical miles (here) when carrying a drop tank. Cut the internal fuel by 1/3rd due to switch to a proper s-s tank and it is only 100 gals available of internal fuel - should make maybe 300 nmi, or almost 350 statute miles?
 
Just thought I'd add if you look at early carrier airforce vs. task force combat you will see what I find interesting results.

I'm referencing Coral Sea, Midway, Santa Cruz, the carrier engagements prior to the Guadacanal campaign which severely reduced the training level of Japanese pilots.

In these battles, even with the Zero vs Wildcat advantage in air to air combat, the Japanese suffered more severe aerial losses.

I think this would be largely a result of more effective US AA, and more fragile Japanese planes. And by "more fragile I do not mean the airframes, but things like armor and self fueling fuel tanks.
 
The emphasis on maneuverability, that favors a lighter aircraft, might be a result of somewhat 'romantic' look at the air combat. Namely, two aircraft are pitted one against another, no pilot is allowed to disengage (=run away) even if it can (despite the capability of the A/C). Realities of air combat were that enemy bombers need, if not outright must be downed. That requires having a strong armament, LMGs will struggle against the bombers. Also, fighters are of no use if they can't catch enemy bomber. The bomber will fight back with it's own guns - a fighter need to carry a degree of protection. When we add together those 3 requirements (need for heavy armament, protection, speed), a fighter that has all of that will not be a light one. Here is a road bump, even when the Japanese were aware of air warfare lessons from Spanish civil war, and their experiences in the war in China, that they don't have an engine powerful enough to provide for those requirements.
 
that they don't have an engine powerful enough to provide for those requirements.

Any idea why that was? Technological issues? I've wondered that myself and never really have found an answer. Lack of motivation for building such engine perhaps?

That requires having a strong armament, LMGs will struggle against the bombers. Also, fighters are of no use if they can't catch enemy bomber. The bomber will fight back with it's own guns - a fighter need to carry a degree of protection.

Looks like the Zero has 2 of these requirements down. We must remember the Zero was an early war plane that had to fight on through the war with little significant improvements.

The 2x 20mm + 2 x7.7 LMG are actually a pretty heavy armament for early war. Equivalent to maybe 6-7 x .50 cals if you believe the 3:1 ratio of 50's to make one 20mm. The Ammo supply was a bit low for certain, though this was at least increased from 60 to 100 per gun pretty early on. And for it's time, it was indeed a fast plane. Biggest issue is lack of self sealing tanks or armor, and this indeed was it's achilles heel. And I think it was more of an issue against bombers than fighters - you can out maneuver an opponents fighter or be tough to get a good lock on. But against a bomber you are facing and aircraft who cannot train as much firepower on you as you can on it generally, but you will usually be subject to such lighter firepower even when you have out-maneuvered the bomber. Here armor (I would think most importantly in this situation the windscreen and fuel tanks) makes a marked difference.

I'd be curious as to the amount of Zeroes shot down by strike aircraft vs the amount of US fighters shot down by strike craft in the early war. Don't count any vs. 4 engined bombers, as the Papanese did not have anything like a B-17 early on.
 
And this should be without the advantages of hindsight, but perhaps with the knowledge of some of the more enlightened leadership. As an example, Yammamoto was a supporter of air power and would probably like to have seen more emphasis placed on carriers than battleships.

Leaving aside the best option for Japan -- which was to shoot all the right-wing loonies who were killing people who didn't want to go to war with just about anybody -- the IJN needed to improve its aviation training regimen and remember that the job of navies isn't to fight the other guy's battle line: it's to guarantee one's control of the sea. That may involve shooting up battleships, but it also involves not letting the other guy sink your merchant ships with near-impunity. The IJN was so bad at that, the Japanese Army started building escort vessels!
 
This is a bit out of the hands of the Navy, but seeing if you could get some better technology sharing with your axis ally. Like pperhaps better torpedoes for Germany, earlier and better radar for Japan.

Seems like the Allies were far better at technology sharing than the Axis, even early war when communication was easier. At least the US and GB did this very well.

For that matter, the US and GB seemed to share technology better than the Japanese Army and Navy did with each other!
 
Any idea why that was? Technological issues? I've wondered that myself and never really have found an answer. Lack of motivation for building such engine perhaps?

There was only one big powerful engine around, a 1500 HP Kasei when Japan was moving from from A5M and Ki-27 to the A6M and Ki-43, and that engine was to be used on the land based IJN bombers at 1st. The fighters got to be designed around the ~1000 HP engines then available, and IMo Japanese designers have done a very good job.

Looks like the Zero has 2 of these requirements down. We must remember the Zero was an early war plane that had to fight on through the war with little significant improvements.

The IJN dropped the ball because of a too late installation of the Kinsei in the Zero, only two prototypes were built of the A6M8. They also have had the option to install the Ha-103 engine, as used on the Ki-44.

The 2x 20mm + 2 x7.7 LMG are actually a pretty heavy armament for early war. Equivalent to maybe 6-7 x .50 cals if you believe the 3:1 ratio of 50's to make one 20mm.

Problem was that Ki-43 (IJA, but still) never received cannons, apart from too late prototypes. Another problem was that availability of the Zero was pretty low against what the West was capable to throw in the fray. Another thing is that USN rated the Hispano, a most powerful 20 mm cannon, as equal to 3 HMGs, while the early drum fed Type 99 was of far lower MV (525 m/s vs. 880 for the Hisso II) and somewhat lower RoF than Hispano. Things got better when the 99-2 was introduced, with better MV and ammo supply, but also a lower RoF - now 480-490 rpm vs. Hispano II at 600.
It's maybe 2:1, ratio of the IJA cannon vs. .50 BMG 'kill capacity'? The Japanese batteries were of far lower weight than USA ones, of course.

The Ammo supply was a bit low for certain, though this was at least increased from 60 to 100 per gun pretty early on. And for it's time, it was indeed a fast plane. Biggest issue is lack of self sealing tanks or armor, and this indeed was it's achilles heel. And I think it was more of an issue against bombers than fighters - you can out maneuver an opponents fighter or be tough to get a good lock on. But against a bomber you are facing and aircraft who cannot train as much firepower on you as you can on it generally, but you will usually be subject to such lighter firepower even when you have out-maneuvered the bomber. Here armor (I would think most importantly in this situation the windscreen and fuel tanks) makes a marked difference.

Against the F4F, F2A and Hurricane, it was as fast or faster, 330 mph, later maybe 350 mph. Less so against P-40, P-39, let alone P-38 or contemporary European stuff (Spitfire, Bf-109, Fw-190) it was slower. Soviets were a bit faster, too, especially the MiG 1/3.
The lack of protection was a major shortcoming of the Japanese fighters for a good part of the war. Especially if we take as a truth that 3/4s of the fighter planes were shot down before the victim knew it is in someone's crosshairs.
 
Any idea why that was? Technological issues? I've wondered that myself and never really have found an answer. Lack of motivation for building such engine perhaps?

They had more powerful engines, they were just much larger and heavier. Navies refusal to allow the use of the Mitsubishi Kinsei engine is a bit harder to understand.

The Kasei was about 400lbs heavier and 8in bigger in diameter.
 
Things got better when the 99-2 was introduced, with better MV and ammo supply, but also a lower RoF - now 480-490 rpm vs. Hispano II at 600.
It's maybe 2:1, ratio of the IJA cannon vs. .50 BMG 'kill capacity'? The Japanese batteries were of far lower weight than USA ones, of course.

Strictly on power, not muzzle velocity and range, I'd give even the 99-1 a 2.5:1 vs a .50 Caliber. And a 7.7mm should probably be 1/3 of a .50
overall, probably equal to the 6 x.50 arrangement on many US fighters, other than the H)-1 was not the most accurate at range.
 
BTW - Heavy Cruisers. Torpedoes or no Torpedoes? There was not going to be that huge decisive battle the Japanese had so geared up for, at least not in the way they thought it would unfold. So Torpedoes or no? I'd have to say no, other than perhaps if they really scaled back on battleships giving the heavy cruisers something for opponent's battleships to worry about is not a bad idea.

Another question too - There were 4 old battleships that did not see a ton of action, the Fuso/Yamashiro and Ise/Hyuga. I'm not sure what would be gained from scrapping them, but would that be worth it? I guess what I am asking is what could be done with the raw materials gained from scrapping these vessels?

Heck, even if you get 10 or so Destroyer Escorts for the cost of scrapping one it may not be that bad of an idea. The manpower and support costs at least would be saved.

If this is done and the Yamato's not built, you have the 4 Kongo's and the 2 Nagato's only as far as Japan's battle fleet is concerned.
 
Re. torpedoes on the cruisers - Japan has a shortage of destroyers vs. the USN, so leaving capable torps around could present an asset.

In case the Yamatos are cancelled, scraping the old battlewagons will put the IJN in a big disadvantage. We might want to bulk up the AAA suite, among other modifications, so those can act as bodyguard ships for 25-knot aircraft carriers? Not all of the Japanese carriers were 30+ knot machines.

Strictly on power, not muzzle velocity and range, I'd give even the 99-1 a 2.5:1 vs a .50 Caliber. And a 7.7mm should probably be 1/3 of a .50
overall, probably equal to the 6 x.50 arrangement on many US fighters, other than the H)-1 was not the most accurate at range.

The USN 'equation' put the Hispano's worth at 3 BMGs since the Hispano was firing not just a heavy shell, but it was fired at great MV and decent RoF. Those 3 things greatly increase the hit probability, and that also means greater kill probability.
The 99-1 was firing a shell of about equal weight as Hispano, so it might got the same marks just based on that. It would score significantly lower than the Hispano II, though, in the USN equation.
 

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