Japanese capital ship construction

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When combat is joined the Americans lose far more then the Japanese due to quality of pilot difference's.

There were four carrier battles in 1942, in all four of them the Japanese lost more planes and air crews than the Americans.
 
..............I read that Yamamoto's faction wanted to delay the war until the Japanese economy had grown significantly larger.
The problem is that the window before the two ocean navy is ready is very small and after that you are looking at 20+ ? (if ever) years till the Japanese economy will have grown significantly to be a able to challenge the USA.

Will the china situation allow you to sit out that long as well as it will only be worse if Europe/USSR has sorted out its own current problems?
 
The problem is that the window before the two ocean navy is ready is very small and after that you are looking at 20+ ? (if ever) years till the Japanese economy will have grown significantly to be a able to challenge the USA.

Will the china situation allow you to sit out that long as well as it will only be worse if Europe/USSR has sorted out its own current problems?

I agree with that too. Events beyond Japan's control had made it 1941 or never.
 
Something i have found recently while reading about this subject (japanese shipyards, shipbuilding etc.) from japanese wikipedia.

It appears that at least as far as Yokosuka is concerned, the schematic at the beginning of this topic is not accurate. Shinano was built in an entirely new dry dock built specifically for it (#2 in the scheme, but it was actually Yokosuka dock no. 6), not in the same one as Shokaku. Instead of Unryu in the #2 , it should be Shinano starting from May 1940. So it looks like all that was built in that drydock was Shinano.

This leaves the question of what was built after Zuikaku. The shipyard itself has been very busy with conversions (Zuiho, Shoho, Ryuho), and also built Noshiro. So either Noshiro was built in one of the smaller docks and the one where Shokaku was built was busy with conversion work until Unryu was laid down in August 1942, or the same but Noshiro was built in the same dock before Unryu (the dates of launching and laying down respectively for the CL and CV are very close).

Also while very useful, the details of slipway lengths for the major japanese shipyards from Miketr's post earlier is probably more indicative of the "class" of slipway, rather than the actual length.

Here's a japanese wiki article on Yokosuka naval yard, history of each dock and especially details about sizes:
https://translate.google.co.uk/tran...%E6%BF%83_%28%E7%A9%BA%E6%AF%8D%29&edit-text=

Unfortunately, i have not been able to find similar details about the other major shipyards at Kure, Mistubishi-Nagasaki and Kawasaki, though you can use the japanese wiki link at the bottom for some articles on the other shipyards. Though certainly such info must be available in Japan, so if anyone from our japanese members can help on that subject, it would be very welcomed!
 
As for Shinano, again from japanese wiki, it appears there were a variety of reasons for it to be converted to CV after Midway (apare from the pressing need for CVs of course), one of them being the fact that Kashino (that carried the 46cm guns to the shipyards) was sunk, other was the problem of the thick armoured plating, in light of the new priorities it would of course have been a major diversion of resources, and finally the nine required 46cm guns were not ready either (according to navweps five were finished or building when production was presumably stopped in 1942) and the same question of priority and resources applies to them too.

Another factor is the fact that the construction lagged after the war preparations were implemented in late 1941, so the orginial schedule to launch in October 1943 could likely not have been met even if they would continue to continue building it as a BB after Midway. I know i had my " brilliant" idea about finishing it as a BB-CV with six 46cm guns (five were built or building in 1942, but there were also two test guns available), but of course almost the same issues apply about armour even if they cut as many corners as possible, so launching is unlikely to happen before the first part of 1944, but at least there would still be a chance for it to be ready for Leyte (if not, at least Yamato would not be alone for Ten-Go, or even better for us buffs, it somehow still gets torpedoed in late 1944 but survives as it would completed, as they perhaps would not be able to repair it at that point -like Junyo- it might be used as a floating battery and gets captured), and the drydock would be then free for whatever they would build by then, probably small convoy escorts or subs of various types, suicide craft etc.

It's difficult to make out the translation in detail, but if i'm understanding it correctly it appears the article says that right after Midway there was an initial plan to rapidly prepare the hull for launching as soon as possible without regard to the project, just to get it out of the way, this being tenatively planned for October 1942. Scrapping was expected to last two years. This to me, seem the best option under the circumstances, get the hull out of the way asap, get another Unryu in there in late 1942 which will be finished in autumn 1944, and in parallel scrap the No.110 hull and use the steel for other more pressing priorities.

Anyway, here is the article:
https://translate.google.co.uk/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=https%3A%2F%2Fja.wikipedia.org%2Fwiki%2F%25E4%25BF%25A1%25E6%25BF%2583_%2528%25E7%25A9%25BA%25E6%25AF%258D%2529&edit-text=

There's a lot of interesting stuff on japanese wikipedia, found some about the shadow carriers as well (Taigei, Tsurugisaki, Takasaki), if i have time i'll adress that in the respective topics.
 
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The Japanese aviation programs had several major problems. Almost all of their aircraft were designed with inadequate crew protection meaning if you lose the plane you lose the crew, and the lack of armor and self sealing tanks in general meant if they got hit it was a bad thing. US planes were more rugged overall and had better crew protection. Range and maneuverability were optimized at the expense of survivability. Raw materials such as aluminum and high quality steels for engines were always in short supply. As the war went on aviation fuel declined in quality and quantity, so the ability to train pilots with adequate flight time was problematic (the Germans had this problem as well). lastly, experienced pilots were not rotated back to become instructors, so valuable experience was lost.

The ability of Japan to produce adequate numbers of competitive aircraft as the war went on was problematic at best. Their ability to expand their training program to produce more pilots (and aircrew) got worse as the need became greater between lack of fuel to fly training missions and quality instructors. Like much of the rest of their war plan they did not consider expanding the training pipeline to refill combat losses, let alone expand their air forces. Likewise there was little thinking about improving the aircraft they started the war with on the scale that was required.
 
The Japanese aviation programs had several major problems. Almost all of their aircraft were designed with inadequate crew protection meaning if you lose the plane you lose the crew, and the lack of armor and self sealing tanks in general meant if they got hit it was a bad thing. US planes were more rugged overall and had better crew protection. Range and maneuverability were optimized at the expense of survivability. Raw materials such as aluminum and high quality steels for engines were always in short supply. As the war went on aviation fuel declined in quality and quantity, so the ability to train pilots with adequate flight time was problematic (the Germans had this problem as well). lastly, experienced pilots were not rotated back to become instructors, so valuable experience was lost.

The ability of Japan to produce adequate numbers of competitive aircraft as the war went on was problematic at best. Their ability to expand their training program to produce more pilots (and aircrew) got worse as the need became greater between lack of fuel to fly training missions and quality instructors. Like much of the rest of their war plan they did not consider expanding the training pipeline to refill combat losses, let alone expand their air forces. Likewise there was little thinking about improving the aircraft they started the war with on the scale that was required.

agreement... the Japanese Naval Aviation pilot training could barely replace operational losses (which were frightfully high in the 1930s and 1940s, for everyone, including the Americans) and light combat losses based on what they suffered in China. They were indeed a Samurai Sword... which are known to be extremely brittle.

American flak was murderous, more so when the proximity fuse shows up, and American fighters were just good enough even before the development of the Thach Wave and learning to fly in pairs to inflict serious losses every time they fought the Japanese carrier arm.

Toss in the general flimsy construction of Japanese Naval combat aircraft (which is tied to inadequate powerplants which is tied to less than efficient manufacturing techniques, tools and shortages of skilled labor) and the carrier arm is not going to improve much no matter how many carriers it has. Now more surface ships would be helpful, especially escorts, if the Japanese actually focus on ASW, but not sufficiently helpful to delay the result of the war significantly.
 
Since this is diverting to aircraft, i will just point that is better to first read about the pre-war maru programs including vast increases in aircraft units and aircraft production itself, trying to keep pace with the american shipbuilding and aircraft production program. That even that was not enough (and that is in hindsight only) it's another matter, it's about attrition and being increasingly outnumbered, but the continuous expansion was always there. I have made the case previously about the scale of IJN and IJA aircraft numbers and aircraft building which were far SUPERIOR to US figures up to 1940. All that cost huge amounts of money, which was a very finite sum. This is not to say they have not done mistakes and could not have done things better, but the point is, they were expanding as much as they could under the circumstances. There a lot of stereotyping around (like they didn't "bother" to increase aircraft production and pilot training and other such statements) which imo is simply not true and intentionally or not, highly misleading.

As for the armour and self sealing tanks part, you must of course be aware that just before entering WW2 the americans had many aircraft without any of those features, the F4F-3 and early SBD had no such features afaik, and i suspect the TBD was the same, also same with early P-40 models etc. The situation changed rapidly of course once the war started. As known the japanese didn't wanted to sacrifice range for protection for their existing early war aircraft, though they changed their mind pretty quickly and almost all new wartime models had such features (though there were still some exceptions i think, possibly B6N and D4Y early models f.e.). While such an approach might somewhat be understandable as far as single engined aircraft are concerned (because their performance is easily degradable by relatively small weight increases, if one puts self sealing tanks on a Zero it's combat radius will be reduced significantly under 500nm, plus reduced speed and maneuverability), it was indeed a clear mistake not to adopt self sealing tanks for larger, multi-engine aircraft from the beggining though (G4M, H6K late models, G3M late models etc.).

Finally as to carriers, i beg to differ on what is said above, the carrier was THE strategic weapon in the Pacific war, and for the japanese the more they have in the crucial 1942-1943 period the better for them, because they could keep the front away from their shipping lines as much as possible, IF things go according to plan (which they didn't in OTL, but that is another matter). So having couple more carriers in 1942 would potentially have a much more noticeable strategic impact (if those two extra carriers translate for instance in not losing Guadalcanal and not getting sucked in the dreadful attrition war in the Solomons from autumn 1942 to early 1944) than building more ASW craft, though of course, that will be very helpful too, especially in concert. As to aircraft for those carriers, again the point has been made that they had comparatively plentiful of aircraft and pilots for them IF they avoid the Solomons attritional spiral. Likley 1944 is still almost as bad as OTL, but that is another subject.
 
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This thread is something the wiking might post, but instead of about Germany it's about the Japanese capital ship building, to be more precise the organization of it or more accurately the lack of organization. In particular the panic that gripped the Japanese command after Midway which meant a fair bit of ordering, canceling and halting ships already in production not to mention that there were a fair bit of bottlenecks on the slipways with ships taking up a lot slipways for much longer then they should have.


Overall there doesn't seem to be to much problems with resources such as steel, or engines for capital ships, in the last two years Japan built and finished at least nine capital ships with several more building at the time of surrender. So to me it seems more like a problem with slipway space instead of resources.


This is not about not building the Yamato-class and instead building carriers for the resources, that's a non-starter to me, you have to move back into the Russo-Japanese war at least to find a PoD to change that or an act of god (i.e. The Emperor intervenes, which isn't happening).
So in essence Japan had six slipways that had the capacity to build capital ships, with one additional enlarged mid-war.


In Yokosuka you had the Naval Ship Yard, with slipway #1 and slipway #2 enlarged in early -43.
Kure Naval Ship yard had the #1 and #2 large enough.
Nagasaki had the Mitsubishi #1 and #2 slipways.
And at Kobe Kawasaki had slipway #1.


I'm attaching a very helpful picture someone with a fair bit of knowledge of this compiled.
View attachment 240228


To me there seems to be four large roadblocks that if removed or changed would help immensely.


Roadblock no.1 is the Shinano at Yokusuka slipway #1, it spent four years and four months on the slipway, not to mention that materials for two Unryū-classcarriers (#5002 and #5005) were used to finish the Shinano as a pretty crappy carrier. The Yamato spent two years and nine months on the slipway and Musashi two years and one month. So launching and finishing the Shinano as a battleship would free the slipway at around July/August -42 for new construction. An Unryū-class carrier could then be laid down and launched a bit over a year later. So for the time, materials and slipway space to build the Shinano as a crappy carrier you'd instead get a powerful battleship and a decent carrier, seems like a bargain to me.


Roadblock no.2 is hull #111 at the Kure slipway #1, the fourth unnamed and unfinished Yamato-class battleship. Either never lay down it, or finish the hull, laid down in November -40 means it would, using the same timetable as the Musashi, could be launched in January or February -43. This would delay the Katsuragi by two or three months, more or less unacceptable as that would mean December -44 or January -45 before it's commissioned. So the best idea is to not lay down hull #111. A Taihō-class could be laid down instead in November -40 and launched, even following the very slow timetable of the Taihō, early -42 which then frees up the slipway for another Unryū-class carrier that can be launched a year later and finished summer -44.


Roadblock #3 and #4 is the Jun'yō and Hiyō at Mitsubishi #2 and Kawasaki #1 respectively. These begun as ocean liners and was converted into what best could be described as mediocre carriers, they were slow, vulnerable even by Japanese standards and with small air complements, better to not convert them and build two repeat Shokaku-class or two Taihō-class instead. The Jun'yō was begun converting in March -39 a repeat Shokaku would have launched in September -40 if laid down instead. Followed by a Taihō launched then in early -42.


If instead of the Hiyō the repeat Shokaku would launch in May -41 which could also be followed by another Taihō.


So to summarize by not building #111 and convert the Jun'yō and Hiyō it would give the Japanese the following:
Shokaku-class #3 built at Nagasaki Mitsubishi slipway #3, launched September -40, commissioned December -41/January -42.
Shokaku-class #4 built at Kobe Kawasaki slipway #1, launched in May -41 and commissioned September/October -42.
Taihō-class #1 built at Nagasaki Mitsubishi slipway #3, launched March/April/May -42, comissioned winter -43/-44.
Taihō-class #2 built Kure Naval Ship Yard slipway #1, launched January/February -42, commissioned summer -43.
Taihō-class #3 built at Kobe Kawasaki slipway #1, launched summer -42, commissioned winter -43/-44.


This leaves slipway capacity during the second half of 1942 for three Unryū-class carriers following a disaster at Midway. If the Shinano is finished as a battleship it adds a 4th Unryū-class carrier all that would be commissioned during 1944. Together with the other three Unryū-class carriers built on the other three slipways not meddled with above this gives a large number of fleet-carriers both during -43 as well as in -44.


Now linking to Jon Parshall's Combined Fleet homepage and the industrial disparity between Japan and USA is not really productive to this, USA will outproduce Japan.


The question is, what happens if Japan even after losing four carries to two during Coral Sea and Midway still has carrier superiority during the second half of 1942 with four Shokaku-class carriers with an additional three Taihō-class carriers during 1943.
Does Guadalcanal still happens and if it does what happens when Japan has carrier superiority?
Will Japan make a second attempt at Port Moresby as was planned?
What happens if the US navy still looses the Wasp and Hornet?

View attachment 240228

The US accelerates its submarine program and a lot more SubPAC aces show up. No tankers means more useless hulks to pick off in 44 and 45.

And Cartwheel still happens; so nothing changes there since it was land-based air that made that happen.
 
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