Upper Limits of Imperial Japanese Aerospace Technology

[JoblinTheGoblin]

This thread primarily concerns the maximum theoretical or hypothetical potential of Japanese engine development, and of Japanese superprops and jet/rocket-powered aircraft (mainly fighter or reconnaissance aircraft), inclusive of a date range beginning from the Mukden Incident of 1931 and continuing through to the Japanese Surrender in 1945. However, discussion of missile technology, slower roles such as those of long-range heavy bombers or even cargo planes, rotorcraft technology, and to a lesser extent, metallurgy, radar, radio, and other technologies that are in some non-negligible way related to aviation.

While I expect discussion on possibilities in real history (or "our timeline", OTL) to be both more reliable and more fruitful (the theoretical limits), I will suggest multiple, rather fanciful scenarios for the purpose of exploring the hypothetical limits of Japanese technology. Though they are rather implausible, if not impossible, let's say that some alien space bat (an ASB, the 'demon' in this case, so to speak) is involved behind each:

1. Greater collaboration between scientists and the military. I've heard from other sources on the internet that, supposedly, the Japanese military generally lacked as much interest in scientists, or science for that matter, as those of other powers, and, apparently, were as traditional as a modern military of the time could be.
2. Ease of tensions / cooperation and collaboration between the IJN and IJA, but with a focus on the Southern Strategy*, for resources. The ASB might have his work cut out for him here.
3. Alternate allies and enemies, preferably allies with useful resources such as high-octane fuel and high quality metals. Take your pick of allies and enemies. The alternate geopolitical situation need not result in war, but tensions should be high enough to necessitate improvements in the military. This is important to mention as it has claimed in the past that wartime pressures had, to some degree, negative impacts on research and development of new technologies in Japan.
4. Access granted by the ASB to the process and technology for the production of high-octane fuel. I will go no further than this for the most part.
5. Any combination of the above.

Now, the aforementioned scenarios will likely require significant alterations to work at all, possibly to the extent that Japan would rendered almost unrecognisable. Still, I hope that these scenarios manage to serve as starting points for discussion, even if such discussion may lead to their removal from consideration.

In truth, this thread is about coming up with hypothetical props, jets, and perhaps, rockets and missiles, for wartime Imperial Japan, as well as potential improvements, or variants, for existing designs.

 

[cherry blossom]

The easiest trick for an alien space bat would be to point out that there was a lot of oil under Manchuria. If that was discovered in about 1933, the larger oil industry might well be able to produce good high octane aviation fuel. Of course, the other consequence might be no Pacific War. Thus we might be discussing Japanese aviation over 1941-5 with the same enthusiasm as we discuss Swedish aviation.

We don't actually need a very skilled alien space bat. In the 1930's oil was expected to be found where there had been shallow seas. However, from the 30's T.S. Lee believed that oil might be found where there had been long lived lakes as under Manchuria and eventually persuaded China to look in the 1950's. T.S. Lee was ethnically Mongolian but felt that he was Chinese. If he had been a Mongolian nationalist, he might have been interested in five nations living in harmony and then he only needed to persuade the IJA.

Added as edit: Probably easier to find as Li Siguang Li Siguang - Wikipedia and possibly best as J.S. Lee although https://www.jstor.org/stable/214371 gave me T.S. Lee.

 

[Shinpachi]

IJN was providing a speedometer of max limit 800kt (about 1,480km)/hour for the J7W1 as the jet-engined version was to come up sooner or later as the J7W2.

 

[JoblinTheGoblin]

The easiest trick for an alien space bat would be to point out that there was a lot of oil under Manchuria. If that was discovered in about 1933, the larger oil industry might well be able to produce good high octane aviation fuel. Of course, the other consequence might be no Pacific War. Thus we might be discussing Japanese aviation over 1941-5 with the same enthusiasm as we discuss Swedish aviation.

I was thinking of more radical options, and had forgotten about this particular trope.

However, from the 30's T.S. Lee believed that oil might be found where there had been long lived lakes as under Manchuria and eventually persuaded China to look in the 1950's. T.S. Lee was ethnically Mongolian but felt that he was Chinese. If he had been a Mongolian nationalist, he might have been interested in five nations living in harmony and then he only needed to persuade the IJA.

Added as edit: Probably easier to find as Li Siguang Li Siguang - Wikipedia and possibly best as J.S. Lee although https://www.jstor.org/stable/214371 gave me T.S. Lee.

At the very least, I now have confirmation of the existence of such an individual, however important that actually is.

IJN was providing a speedometer of max limit 800kt (about 1,480km)/hour for the J7W1 as the jet-engined version was to come up sooner or later as the J7W2.

Really? I've never seen this piece of information anywhere else, at least on the Anglophone internet. At the end of the day, though, it's simply a speedometer limit, and one that would exceed the level flight speed any aircraft of the time, never mind Japanese aircraft. Doesn't really give any indication of any practical, real-world capabilities. I might have to clarify on what I mean by speed, it's primarily level-flight speed, less so climb rate or diving speed.

 

[mack8]

This is a huge subject, there are so many permutations and possibilities even without the need for ASB. One can have a look at the OTL 1945 fighter brutes, and jet and rocket powered aircraft, the japanese had in prototype form or being designed. Ki-87 and A7M3 anyone? Or Ki-83, Ki-94, N1K5-J, J6K Jinpu etc. etc. Imagine these bad boys being in service say 1944 or even earlier. Presumably, this scenario still implies a war?

But indeed, the manchurian oil is vital to this scenario, the next question being, could the japanese make 100 octane fuel from said oil?
Then they need good materials for turbos and 2 stage superchargers, can they source that from somewhere?

If they have the two above, then next is a bit more foresight in fighter design/specs. In the west already the first retractable gear fighters flew in 1935, and Japan DID too in 1936, but in their quest for maneuverbility they rejected that and went for the Ki-27 instead. In this period there were also avoidable delays due to vaccilation, fighter competitions etc. Again the IJNAF was a bit more foresighted, they adopted the A5M/Ka-14 as soon as they saw it's performance. The IJAAF could have done the same, adopt the Nakajima PE (basically the Ki-27 prototype) as soon as they saw what's capable of. They could have saved at least a year, which is eons in WW2 fighter development.

Next, could they bring forward the prototypes Ki-43, 44, 45 etc even a few months if they save development time/competition time (by dopting the PE straight away)?

Suppose they fly the Ki-43 a few months early, and if the IJAAF is not so obsessed with turning performance, and a keener eye on adopting the latest developments, you can imagine a shorter wing (as used in the -II model), 3 blade-prop, running on 100 octane Ki-43 already in production and SERVICE in 1940. Preferably ejector exhausts too, afterall the Bf-109E, Spitfire etc. already have them. And if they get the Ho-103 heavy MG ready a bit earlier, imagine if most IJAAF fighter sentais fly these super Ki-43s in 1941, instead of the poor Ki-27. The allied air units were hard pressed in OTL as it was 1941-42, in this scenario they will probably brushed aside summarily.

Same applies to the Ki-44 and Ki-45, a few sentais could already be flying them in 1941.

Applying the same quite small changes to the A6M, namely 100 octane fuel, jet exhausts, shorter wing, 100 rpg for the wing guns, and you have an even more deadly carrier fighter. Maybe with the increase in power from 100 octane fuel they could add a modicum of fuel tank and pilot protection too (even the OTL Ki-43 had rubber coated fuel tanks).

This is just scratching the surface as to what was possible even in 1941.

 

[Jeffrey Ethell Collection]

Before you get too far into describing and analysing the various aerospace projects the IJAAF & IJNAF were working on late war you have to understand the mindset of the Koku Hombu, who would issue specifications for new aircraft types for manufacturers to design and build prototypes for evaluation.

What I would say, and some of you can shoot me down in flames if you like, is there was no real demand by the Koku Hombu to the aeronautical designers of the various manufacturers for very many aerospace projects apart from the aforementioned Kyushu J7W2 Shinden, the jet powered version of the J7W1.

Certainly Mitsubishi had the rocket powered J8M Shusui the licence-built copy of the Messerschmitt Me 163 Komet. Could this design have been the basis of a rocket powered spacship? I don't know that there was any real impetus for such a redevelopment of that design for space. You would no longer need those huge bat like wings of the Shusui/Komet so the basic design was not even suitable for space travel.

Some aircraft designs may have operated successfully in low earth orbit with a major redesign/re-engineering but why not just design a new purpose built space plane type from scratch?

I think the Germans were way ahead with the Saenger or Sänger, a German concept design for a two-stage-to-orbit spaceplane. Very advanced, and it needed to be. Were the Japanese aerospace designers even operating in the same space as the Seanger designers? I doubt it.

Many science fiction authors and film script writers have the Germans way ahead in the space race, as seen in the movie Sky Captain and the World of Tomorrow, often shortened to Sky Captain, a 2004 science fiction action-adventure film on this very topic.

I'm interested in this topic so please, if you know of other Japanese aerospace projects, I would love to read about them here.

SAENGER Orbital Rocket Ship

Moky for JEC

 

[cherry blossom]

Coming back to this after a long pause, I note that the raider Komet German auxiliary cruiser Komet - Wikipedia left Germany on 3rd July 1940 and entered the Pacific in September. Extended operations in the Pacific required resupply either by the USSR or Japan and presumably there had been some German - Japanese discussions before Komet sailed. Germany was also negotiating with Japan towards the Tripartite Pact Tripartite Pact - Wikipedia. Thus Germany wanted things from Japan, including perhaps rubber shipped from Indochina or Thailand and then sent via the Trans Siberian Railway, and doesn't seem to have given much in return. A more aggressive Japanese approach to the negotiations would demand that Germany load details of any technology that Japan suspected that Germany possessed onto Komet or Germany could forget about cooperation. The difficult question is what might have been loaded onto Komet and would it have helped Japan.

One obvious possibility is a prototype of the Fw 190, which might have suggested the close cowling of radial engines seen on the Ki-100 and D4Y3 from late 1940 rather than from 1943. Another possibility might be details of the tooling required to make fuel injectors (the BMW 801 would have supplied new ideas to compare with the DB 601 that Japan had already purchased).

More low hanging fruit would be the DB 601E, which were probably just becoming reliable (The Secret Horsepower Race has "The DB 601 E would be going into low-level series production from May 1939 onwards, ..." on page 103 but this may describe plans as of April 1939).

One or more of the Fw 187 A-0 aircraft could have been sent without worrying the Luftwaffe and perhaps the IJN might have fitted it with two DB 601E engines to compare it with the Nakajima J1N, which first flew in May 1941.

Can we imagine details of Seetakt, Freya and Würzburg A [7.0] The Battle Of The Beams arriving in Japan in September 1940?

Jet aircraft were not really ready to impress as the He 280 was only tested as a glider from September 1940. However, some details of this and the earlier He 178 and their engines could have been sent.

Similarly, work had started on the Fritz-X and Hs 293 but they were far from ready for service.

 

[EwenS]

Settingt the little political problem of Komet sailing nearly two months before the signing of the Tripartite Pact aside, just how much material could the Komet have carried?

She was the smallest of the German raiders - 3,287grt. These ships when converted lost much of their hold space to increased bunkers for oil fuel, store rooms, magazines, space for 2x Arado 196, 30 mines and a small craft to lay them, and crew accommodation (for 279 men, several times that of a normal merchantman) etc.

Politically AIUI, the Germans seem to have been keener on the Pact than the Japanese.

Better history of Komet' s trip here

Battleship Bismarck, Tirpitz, Scharnhorst, Gneisenau, Admiral Hipper, Blucher, Blücher, Bluecher, Prinz Eugen, Deutschland, Lützow, Lutzow, Luetzow, Admiral Scheer, Admiral Graf Spee, Hilfskreuzer, Graf Zeppelin, Bismark, Tripitz, Classic Warships, W

Website about the battleships Bismarck & Tirpitz. Stories, photographs, technical details, drawings, models, discussion forum, Hilfskreuzer and much more.

www.bismarck-class.dk

 

[JoblinTheGoblin]

The primary focus of this thread is on indigenous developments in Japanese aviation, less so imports, unless the Japanese can do anything innovative, with the actual hardware, besides ramming them into ships and B-29s, or strapping the odd bit of equipment here and there.

I mean, the Italians did develop a home-made experimental jet fighter, even if its performance was unimpressive. The Japanese did have an interest in ramjet technology early on, but nothing substantial emerged from it.

 

[GrauGeist]

There was the Nakajima Kikka and the Nakajima KI-201, the latter being under development by war's end.

 

[JoblinTheGoblin]

German-inspired designs. The former was a good prototype for 1942, the latter was never completed and was, at a glance, a slower Me-262 with slightly inferior armament.

 

[ThomasP]

Japanese scientists and engineers were quite good, more or less as good as the US and Europeans. But, during the period of the 1930s through WWII Japan was tied up in the war in China and then WWII, their focus was of necessity on the development and production of equipment needed for the respective theaters. They did not have the industrial resources needed to develop every promising new idea they came up with.

 

[cherry blossom]

There have been academic studies trying to address how good Japanese engineers were such as "The origins of Japanese technological modernization" by Tom Nicholas, Explorations in Economic History 48 (2011) 272–291.

This has "In 1885 patents per capita in Japan was just 0.6% of the level in the United States whereas by 1940 it was 44%." and notes "Analysis of historical patent citations shows that Japanese domestic inventions patented in the United States were equally as technologically significant as inventions patented by British and German inventors in that country."

 

[ThomasP]

Hey cherry blossom,

Thanks for the reference to the book "The origins of Japanese technological modernization". That is one I will have to read.

 

[Shortround6]

Just looked up the population of Japan and the US in 1940
Japan...............73 million
US...................132 million.

even if we claim the average education was the same the Japanese just don't have as many people either thinking things up or being able to to put ideas on paper (draftsmen turning other peoples ideas into blue prints) just to due to the population difference.

Now factor in education, industrial base and so on and things get a lot harder.

Now factor in that most advanced technology is increasingly complicated and you need a lot of little advances to get the "big idea/concept" to actually work.

 

[Shinpachi]

Traditionally, Japanese people were familiar with wood working.
I still feel that metal work is bothersome to create something if it is not my job.
My father took decades to decide purchasing a lathe for his hobby.

 

[Shinpachi]

I repaired this plastic air pump with glue several times when the folding stand destroyed the receivers easily.
Idea of making the receivers of metal existed in my brains from the beginning but it had taken 10 years before I gave up the glue repair.

Other choices I thought were -
1. It is quick to buy new one but it's costly as this one still can be used after repair.
2. If I was a designer of this pump, I would suggest making it of aluminum alloy, not plastic, and be rejected because of higher costs.

This is a Japanese mindset of a former engineer.

 

[JoblinTheGoblin]

Japanese scientists and engineers were quite good, more or less as good as the US and Europeans. But, during the period of the 1930s through WWII Japan was tied up in the war in China and then WWII, their focus was of necessity on the development and production of equipment needed for the respective theaters. They did not have the industrial resources needed to develop every promising new idea they came up with.

I have made this post under the assumption that your post is a response to both my preceding post and my dismissal of C cherry blossom 's idea for Japan to, essentially, rely on German technology. This is not a thread on German aerospace technology.

My thread involves discussion of scenarios where these scientists and engineers would have at least some of the resources, in some non-negligible capacity, required in the development of such "promising new ideas". There have been similar discussions to mine on other forums and websites, but they generally revolve around Germany, the United States, the Soviet Union, and to a slightly lesser extent, Great Britain.

 

[ThomasP]

My post is in response to the original post.

 

[JoblinTheGoblin]

Well, even so, my second point still stands.