SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
Like convoy escorts with better ASW capabilities.
Yamato logic for single-engined, single seat fighter
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Admiral Beez
Major
I don't expect those would be IJAAF priorities, or even within their lane. That's IJN territory. To be honest, I can't think of any major IJAAF projects that came to fruition. Of course the Nakajima Ki-84 is an improvement over their Ki-43, but where is Japan's home grown and earlier alternative to the Nakajima Kikka?
Thumpalumpacus
Colonel
The IJN was pretty happy to step out into supporting IJA operations in the Solomons and to a smaller extent into New Guinea in the first half of the war. I think the IJAAF was worried about increasing operational tempos in China and SEA and didn't have the resources to support the island-chain defenses their strategy called for.
Not so much about lanes but about who has more airplanes and aviators, and where are they needed, and where is deployment feasible?
The IJA requisitioned and even built a small fleet for its own use, including plans for escort carriers. Actual escorts though, they left to the IJN.
The IJN had 63 submarines on 7 Dec 1941, around 12 of them operated off the US West Coast in Dec 1941 sinking IIRC 3 merchant ships and damaging 2.Built a bunch of convoy escorts?
Figured out that a bunch of subs that could attack Allied supply ships or raw material transport may have been a good idea?
Heck, build more tankers to get the captured oil back to Japan.
And I have not even crossed over going from navy and ship building to aircraft engine building and petrochemical engineering
There is a bunch of things we can go back and figure out where the resources could have been better spent.
Another interesting fact is that 1938-40 Japan tested high underwaterspeed sub, Submarine No. 71, its max. underwater speed was 21.25 knots. Those tests helped the development of the high underwater speed I-201 class, only 8 completed before the end of the War and Ha-201 class, only 10 completed. None of those 18 made operational patrols.
The RN has had high underwater speed (14 knots) hunter-killer subs already during the WWI, the R-Class, but they were ahead of their time and were difficult to control at high underwater speeds and were poor boats on surface . So they were scrapped after the WWI. R4 survived into the 1930s as a high-speed ASW target.
Ps. I remembered wrongly, in fact 8 I-201 class subs were laid down but only 3 completed and so only 13 high underwaterspeed boats were completed but none of those made operational patrols.
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The Japanese actually increased their tanker capacity in 1942, and not just through the capture of Allied tonnage. But their shipbuilding industry was never going to succeed it delivering enough tonnage when the major part of their oil imports in the run up to WW2 was being carried to Japan on US owned vessels. Even less so after the Allies started targeting tankers specifically from late 1943.
As for getting the oil back to Japan, your statement misses two important points that meant a large part didn't need to go back to Japan.
1. Japanese tankers were able to haul oil from the DEI oilfields and refineries direct to the major fleet bases at Truk & Rabaul until late 1943 / early 1944.
2. In Jan 1944 the IJN moved a significant proportion of its fleet down to the Singapore area to be near its oil supplies. (That move caused a panic amongst the Allies who worried about a repeat of Operation C and saw major movements of ships and aircraft to the theatre and around Australia). It was from bases in the DEI that large elements of the IJN fleet sailed ahead of the Battle of Philippine Sea in June 1944 and Leyte Gulf in Oct. They also moved a substantial part of their pilot training down to the DEI to be near the fuel supplies.
Both these things helped reduce the demand for tanker tonnage.
Shortround6
Lieutenant General
We may have gotten a little off track?
I am not sure if this means that the Japanese Army tries to to make the 2000hp engine and the super fuel while the Navy continues with Yamatos or if the Japanese nation
shifts its priority emphasis from large Battleships to air power and also shifts from a Navy First to an Army First military doctrine.
Can the Japanese do both or is it one or the over as far finances/industrial capacity goes?
Japanese Army and Navy couldn't even agree on ammunition for machineguns. Navy giving up their new battleships for future Army fighters/bombers was not a likely outcome.
Trying to build super fighters in 1941-42 is going to take a lot work regardless of which service does it or even if they share. The US only got 2000hp fighters into front line squadrons service in more than a couple of squadrons in the spring/summer of 1943 so we are talking about the the Japanese beating the US by around 11/2 to 2 years. British got the Typhoon in service in 1942 but that was pretty much a major crap fest for most of 1942.
Army was fighting a large war in China since July 7th 1937. While the Army was designing/getting new planes they were also trying to build new tanks, new artillery and new small arms, while keeping up with losses and expanding the army in general. Navy was playing a very secondary role (very few losses).
The Chinese had crap for an air force in the 1930s. Handfuls of purchased aircraft (dozens not hundreds) mostly ill trained pilots and a few mercenaries. Japans Army did not need super fighters to fight China. They didn't need super fighters (2000hp) to fight the Dutch or France or the British colonies in any plans of 1936-39 leading to a war in 1941. Maybe they should have planned for really good fighters (1200-1500hp) in 1941-42? Going for 2000hp is just a bridge too far.
I am not sure if this means that the Japanese Army tries to to make the 2000hp engine and the super fuel while the Navy continues with Yamatos or if the Japanese nation
shifts its priority emphasis from large Battleships to air power and also shifts from a Navy First to an Army First military doctrine.
Can the Japanese do both or is it one or the over as far finances/industrial capacity goes?
Japanese Army and Navy couldn't even agree on ammunition for machineguns. Navy giving up their new battleships for future Army fighters/bombers was not a likely outcome.
Trying to build super fighters in 1941-42 is going to take a lot work regardless of which service does it or even if they share. The US only got 2000hp fighters into front line squadrons service in more than a couple of squadrons in the spring/summer of 1943 so we are talking about the the Japanese beating the US by around 11/2 to 2 years. British got the Typhoon in service in 1942 but that was pretty much a major crap fest for most of 1942.
Army was fighting a large war in China since July 7th 1937. While the Army was designing/getting new planes they were also trying to build new tanks, new artillery and new small arms, while keeping up with losses and expanding the army in general. Navy was playing a very secondary role (very few losses).
The Chinese had crap for an air force in the 1930s. Handfuls of purchased aircraft (dozens not hundreds) mostly ill trained pilots and a few mercenaries. Japans Army did not need super fighters to fight China. They didn't need super fighters (2000hp) to fight the Dutch or France or the British colonies in any plans of 1936-39 leading to a war in 1941. Maybe they should have planned for really good fighters (1200-1500hp) in 1941-42? Going for 2000hp is just a bridge too far.
ThomasP
Chief Master Sergeant
Just some thoughts:
Unfortunately, foresight is one of the requirements for many of the what-ifs.
In all seriousness, they would probably have been better off using the resources tied up in the Yamato and Musashi to expand their carrier force and escorts, along with expanding their naval pilot program. The only chance they really had to win the war in the Pacific was to hit the US hard enough in the first stage(s) of the war that the US would decide not to pursue the war (for whatever reason) or at least not for some time, thereby allowing the Japanese to consolidate their gains in the CBI and PTO. How much difference would an extra fleet carrier or three have made at Coral Sea or Midway, particularly if you remove the bad luck factor?
Having said the above, the UK could easily(?) have had a 2000 BHP engine in service in 1940-41 if they had thought they needed one, simply by pursuing development based on the 'R' engine of 1932 - if they had started early enough. Japan had the engineers, so if the IJA/IJN had realized in 1935 that a 2000 BHP engine was going to be necessary in 1941 they could probably(?) have managed it. Maybe they would have to have based the engine on another nation's engine, or maybe not. But as is questioned above, would they have had to sacrifice something else of significance, and if so, what?
In order to have thought they would need a 2000 BHP fighter/interceptor within 5-6 years, what would they have needed to envision? Would they to have realized the potential of the US/UK long range heavy bomber forces? Could they have expanded their fighter and strike forces enough to make a war of attrition across the island campaign untenable in the eyes of the US?
Unfortunately, foresight is one of the requirements for many of the what-ifs.
In all seriousness, they would probably have been better off using the resources tied up in the Yamato and Musashi to expand their carrier force and escorts, along with expanding their naval pilot program. The only chance they really had to win the war in the Pacific was to hit the US hard enough in the first stage(s) of the war that the US would decide not to pursue the war (for whatever reason) or at least not for some time, thereby allowing the Japanese to consolidate their gains in the CBI and PTO. How much difference would an extra fleet carrier or three have made at Coral Sea or Midway, particularly if you remove the bad luck factor?
Having said the above, the UK could easily(?) have had a 2000 BHP engine in service in 1940-41 if they had thought they needed one, simply by pursuing development based on the 'R' engine of 1932 - if they had started early enough. Japan had the engineers, so if the IJA/IJN had realized in 1935 that a 2000 BHP engine was going to be necessary in 1941 they could probably(?) have managed it. Maybe they would have to have based the engine on another nation's engine, or maybe not. But as is questioned above, would they have had to sacrifice something else of significance, and if so, what?
In order to have thought they would need a 2000 BHP fighter/interceptor within 5-6 years, what would they have needed to envision? Would they to have realized the potential of the US/UK long range heavy bomber forces? Could they have expanded their fighter and strike forces enough to make a war of attrition across the island campaign untenable in the eyes of the US?
Shortround6
Lieutenant General
Thank you gentlemen.
My suggestion for the subs was based on hindsight and is part of knowing that the Japanese 12 (?) subs off the west coast did so little. Imagine a dozen German type IXs operating off the West coast for several weeks in Dec 1941? Supplies/reinforcements to Pearl Harbor and further east would have been at a near standstill, coastal trade on west coast would also have been much reduced. Major shifts of escort ships (and ASW aircraft) from the Atlantic to the Pacific would have been taking place for several month in early 1942.
The US did shift a lot of forces as it was, but if the Japanese had sunk 12-15 ships and damaged another 4-6 in 2-3 weeks? And if the Japanese had sent 6-8 boats back in Feb-March or April of 1942? Japanese subs didn't do a whole lot (much of anything?)for stopping supplies/reinforcements reach Pearl Harbor in 1942 or 1943 either. Or for things reaching Australia. I know that was not the Japanese role for subs but that is doctrine/training and not the boats themselves (although they were less than ideal for commerce raiding).
Anticipating the needed oil transport needs of 1942 and later in 1936-38 would have been hard. Idea was that the Japanese navy would push back the enemy leaving the transports unmolested. We know that didn't happen from 1943 on but who knew in pre-war years. If somebody is looking for an easy answer to what to do instead of the Yamato class then more tankers is an easy answer.
Japanese had 21-22 years to study submarine warfare of WW I and over two years to study the Battle of the Atlantic. Yes they had ordered some escorts but in sort of prototype quantities (plans could sit on the self until needed?). One or more were overly complicated. Japanese DDs and escorts were woefully short of sensors and even numbers of depth charges. for an Island nation that relied on imports of many things this was a major failing. Japanese escort commanders were considered 2nd rate. Not by their enemies here (although that too) but escort duty was sometimes seen as a demotion or dead end command. Some commanders had not gone to the Naval Academy but to the merchant marine academy. If there was a caste system in the RN against the "wavy navy" one can only imagine the regard that regular Japanese naval officers held the escort commanders in.
Japanese training in ASW was also rather sketchy regardless of which schools they went to.
As mentioned in a different thread the Japanese overclaimed sub kills at around a 9-10 ratio which also hindered even basic improvements to ASW capabilities. Not helped by most Japanese small ships being overweight/top heavy to being with. Just trying to put on an extra 12-18 depth charges seems to have a problem.
There were a number of other paths that the Japanese navy could have taken if one assumes that the Yamato was not a good idea. We can also look at the US battleships. What did many of the US battleships after North Carolina class accomplish aside from shore bombardment? Hindsight is a wonderful thing
My suggestions were what could the Japanese navy have planned differently in 1936-39 rather than going the Yamato route. My list was not large and there were many other possibilities. We are also using hindsight
My suggestion for the subs was based on hindsight and is part of knowing that the Japanese 12 (?) subs off the west coast did so little. Imagine a dozen German type IXs operating off the West coast for several weeks in Dec 1941? Supplies/reinforcements to Pearl Harbor and further east would have been at a near standstill, coastal trade on west coast would also have been much reduced. Major shifts of escort ships (and ASW aircraft) from the Atlantic to the Pacific would have been taking place for several month in early 1942.
The US did shift a lot of forces as it was, but if the Japanese had sunk 12-15 ships and damaged another 4-6 in 2-3 weeks? And if the Japanese had sent 6-8 boats back in Feb-March or April of 1942? Japanese subs didn't do a whole lot (much of anything?)for stopping supplies/reinforcements reach Pearl Harbor in 1942 or 1943 either. Or for things reaching Australia. I know that was not the Japanese role for subs but that is doctrine/training and not the boats themselves (although they were less than ideal for commerce raiding).
Anticipating the needed oil transport needs of 1942 and later in 1936-38 would have been hard. Idea was that the Japanese navy would push back the enemy leaving the transports unmolested. We know that didn't happen from 1943 on but who knew in pre-war years. If somebody is looking for an easy answer to what to do instead of the Yamato class then more tankers is an easy answer.
Japanese had 21-22 years to study submarine warfare of WW I and over two years to study the Battle of the Atlantic. Yes they had ordered some escorts but in sort of prototype quantities (plans could sit on the self until needed?). One or more were overly complicated. Japanese DDs and escorts were woefully short of sensors and even numbers of depth charges. for an Island nation that relied on imports of many things this was a major failing. Japanese escort commanders were considered 2nd rate. Not by their enemies here (although that too) but escort duty was sometimes seen as a demotion or dead end command. Some commanders had not gone to the Naval Academy but to the merchant marine academy. If there was a caste system in the RN against the "wavy navy" one can only imagine the regard that regular Japanese naval officers held the escort commanders in.
Japanese training in ASW was also rather sketchy regardless of which schools they went to.
As mentioned in a different thread the Japanese overclaimed sub kills at around a 9-10 ratio which also hindered even basic improvements to ASW capabilities. Not helped by most Japanese small ships being overweight/top heavy to being with. Just trying to put on an extra 12-18 depth charges seems to have a problem.
There were a number of other paths that the Japanese navy could have taken if one assumes that the Yamato was not a good idea. We can also look at the US battleships. What did many of the US battleships after North Carolina class accomplish aside from shore bombardment? Hindsight is a wonderful thing
Shortround6
Lieutenant General
Agree with most of this except
Having said the above, the UK could easily(?) have had a 2000 BHP engine in service in 1940-41 if they had thought they needed one, simply by pursuing development based on the 'R' engine of 1932 - if they had started early enough.
It took until 1946 (?) to get 2000hp out of a single stage Griffon. They got just over 1700hp out of the Griffon in 1942 using 12lbs of boost.
Do not underestimate the advantages that racing fuel can give an engine. Or what you can get out of engine for about 1 hour before it breaks.
Racing Napier Lions were good for 875-900hp without superchargers and 1350hp with a supercharger as an example.
Racing fuel (often methanol based) allows you to burn more BTUs of fuel for the same amount of air. Racing fuel will take more heat out of the air from the supercharger than gasoline will (much more heat) because of a higher heat absorption due to vaporization and the fact that is more fuel being evaporated. And racing fuel often has a lower flame temperature. This sort of a trade off. You are burning more BTUs of fuel but the peak temperature of the flames is lower. Heat load on the engine is??? any unburned fuel going out the exhaust carries more heat that the same amount of unburned gasoline. Pure methanol would allow a higher compression than just about anything short of 100/130 fuel. Some of the blends used are certainly questionable
Of course having a reliable 1600hp engine in mass production in the winter 1940/41 would have been a major advantage.
Kasei might be an option for a heavier fighter until the Homare arrives? Granted it's diameter equalled the R-2800 while generating hundreds of hp less, but might still be better than being stuck with the Sakae as the mainstay fighter engine for most of the war?
Weren't practically all(?) Japanese aero engines air cooled radials? The one liquid cooled engine that saw service in some volume was a license produced DB 601.
Not saying the Japanese would have been incapable of figuring out liquid cooled engines, but it would have taken time. And starting out with a very complex H-24 design sounds like a recipe for failure.
That being said, as we've seen it's perfectly possible to produce very well performing fighters also with radials, so I think for Japan it would have made sense to continue focusing on them.
ThomasP
Chief Master Sergeant
By 1938 the Japanese had a fair amount of experience with liquid-cooled engines, starting with the Mitsubishi Hi Shiki (licensed Hispano-Suiza V8Fb) after WWI, to the Hiro Type 14 (licensed? Napier Lion W12), to the Hiro Type 90 (licensed Lorraine W12E) and Type 91 (licensed Lorraine W12F) of the late-1920s to the mid-1930s, to the Mitsubishi Type 93 (licensed Hispano-Suiza V12 series) from early- to the late-1930s, to the Kawasaki Ha-9/Type98 (licensed BMW VI+ V12 series) from the early-1930s thru WWII (not sure when they stopped production).
The detail modified versions of the BMW came in 1st in production numbers at about 2000 total. I think the Hispano-Suiza V8 series came in 2nd at about 1300 total. Admittedly, not anywhere as much liquid-cooled experience as the UK, France, or Germany, but not far behind the US in 1938.
Plus, to reiterate, we have to assume that the What-If scenario allows enough time to develop the engine or it is automatically not possible.
In this case, if the Japanese had the foresight to realize tha a ~2000 BHP engine would be necessary by 1941, when would they have to start? My estimate is no later than 1935. What exact form the engine would take is open to question of course.
As Shortround 6 pointed out up-thread, in order to get 2000 BHP engine out of a 36.7L V12 engine the size of the Griffon you needed at least 100/130 grade fuel. In theory the 43L X24 Vulture was good for 1800 BHP with 100/130 grade, so give it an extra 400 rpm via the Sabre design and what would you get? I see no real reason the Japanese could not do as well - if they put the resources into it.
Historically, during WWII the Japanese aircraft company Yokosuka worked on the YE2 47.6L W18 (2500 BHP on test runs in 1944) and the YE3 62.4L X24 (2500 BHP on test runs in 1943) but they went by the wayside due to the needed personnel and man-hours going to other areas. I do not know what grade of fuel these engines were tested on, but I would assume it was no more than 91 grade. Design work on both of these engines began in 1940.
In effect, the designers at Yokosuka went for greater displacement in order to get the higher power with lower grade fuels.
Incidentally, the frontal cross-section of the YE2 W12 was about 11 ft2 while that of the YE3 X24 was less at about 9 ft2. For comparison, the cross-section of the P&W R-2800 is about 15 ft2.
The detail modified versions of the BMW came in 1st in production numbers at about 2000 total. I think the Hispano-Suiza V8 series came in 2nd at about 1300 total. Admittedly, not anywhere as much liquid-cooled experience as the UK, France, or Germany, but not far behind the US in 1938.
Plus, to reiterate, we have to assume that the What-If scenario allows enough time to develop the engine or it is automatically not possible.
In this case, if the Japanese had the foresight to realize tha a ~2000 BHP engine would be necessary by 1941, when would they have to start? My estimate is no later than 1935. What exact form the engine would take is open to question of course.
As Shortround 6 pointed out up-thread, in order to get 2000 BHP engine out of a 36.7L V12 engine the size of the Griffon you needed at least 100/130 grade fuel. In theory the 43L X24 Vulture was good for 1800 BHP with 100/130 grade, so give it an extra 400 rpm via the Sabre design and what would you get? I see no real reason the Japanese could not do as well - if they put the resources into it.
Historically, during WWII the Japanese aircraft company Yokosuka worked on the YE2 47.6L W18 (2500 BHP on test runs in 1944) and the YE3 62.4L X24 (2500 BHP on test runs in 1943) but they went by the wayside due to the needed personnel and man-hours going to other areas. I do not know what grade of fuel these engines were tested on, but I would assume it was no more than 91 grade. Design work on both of these engines began in 1940.
In effect, the designers at Yokosuka went for greater displacement in order to get the higher power with lower grade fuels.
Incidentally, the frontal cross-section of the YE2 W12 was about 11 ft2 while that of the YE3 X24 was less at about 9 ft2. For comparison, the cross-section of the P&W R-2800 is about 15 ft2.
In an organic chemistry exam, university students are sometimes asked for an explanation of this fact (it's fairly trivial).
I've always been impressed with the skill and ingenuity of the Japanese aircraft designers of the era and I believe they would have come up with something somwhat different than expected. Since the Yamato design was driven by the size of the gun, I'm going to start there. Annnnd, yes facts be damned. In my proposal, the Japanese would design this around the novel, at the time, idea of the rotary cannon. I propose a three or six barrel cannon firing through the the hub of the engine in centerline with a large weapons magazine behind the engine and before the cockpit. They might also be inspired by the turbo-supercharging system from the P-47 and adopt a similar approach. This would result in a larger body profile like the J2M but possibly more elongated. Anyway, that's my proposal.
In my proposal, the Japanese would design this around the novel, at the time, idea of the rotary cannon. I propose a three or six barrel cannon firing through the the hub of the engine in centerline with a large weapons magazine behind the engine and before the cockpit. They might also be inspired by the turbo-supercharging system from the P-47 and adopt a similar approach. This would result in a larger body profile like the J2M but possibly more elongated. Anyway, that's my proposal.Shortround6
Lieutenant General
Sounds really good unless you have a hangfire which can make things real interesting and probably ruin your whole day
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
So, don't use beehive shells?
How often do rotary barrel guns actually jam? Its my understanding that they are pretty resistant in that regard.Sounds really good unless you have a hangfire which can make things real interesting and probably ruin your whole day
ThomasP
Chief Master Sergeant
The modern type Gatlings have mechanical extraction mechanisms for taking a dud round out of the chamber while the rest of the barrels are loading and firing, that is they do not rely on gas operated blow-back or recoil operated removal of a dud round or fired cartridge case.
View: https://www.youtube.com/watch?v=6mIig1fC2TU
As long as the motor/feed mechanism has power (usually either electric or electro-hydraulic) the gun can be run without firing a round while the cartridges are still loaded and extracted. It is possible for a jam to occur (usually it requires something to break) but is much less likely than any(?) other feed system in use on automatic weapons.
View: https://www.youtube.com/watch?v=6mIig1fC2TU
As long as the motor/feed mechanism has power (usually either electric or electro-hydraulic) the gun can be run without firing a round while the cartridges are still loaded and extracted. It is possible for a jam to occur (usually it requires something to break) but is much less likely than any(?) other feed system in use on automatic weapons.
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Shortround6
Lieutenant General
what I am referring to is if the cartridge doesn't go off exactly when the primer is hit (or electrical impulse hits primer).
On most of the modern all the barrels are exposed. If the cartridge goes off partway to the next station (before the extractor moves it very far? the shell exits the gun a little off center and there is little harm done. But if you are depending on all the shells to go through a tube only a few mm bigger than shells and and you get even a 1 in 10,000 chance slight delay where does the shell go?
This is one reason why the Germans stopped trying to put big 30mm cannon in synchronized positions Like wing roots of FW 190s. The shells exit from the barrel varied to much from when the firing pin or electrical impulse hit the primer. This was worse with the bigger cartridge cases and unless you were trying to synchronize to a propeller with fixed gun or using a rotating gun in a tube it is not a problem. Cartridge goes off a small fraction of second late in the fixed barrel gun, the gun still cycles a fires again. Most shooters may not even notice.
On most of the modern all the barrels are exposed. If the cartridge goes off partway to the next station (before the extractor moves it very far? the shell exits the gun a little off center and there is little harm done. But if you are depending on all the shells to go through a tube only a few mm bigger than shells and and you get even a 1 in 10,000 chance slight delay where does the shell go?
This is one reason why the Germans stopped trying to put big 30mm cannon in synchronized positions Like wing roots of FW 190s. The shells exit from the barrel varied to much from when the firing pin or electrical impulse hit the primer. This was worse with the bigger cartridge cases and unless you were trying to synchronize to a propeller with fixed gun or using a rotating gun in a tube it is not a problem. Cartridge goes off a small fraction of second late in the fixed barrel gun, the gun still cycles a fires again. Most shooters may not even notice.
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