Alternate warships of nations

[CV12Hornet]

For the Brits, by the time word reaches them about these conversions they're already locked into the four Illustrious-class, and don't have the immediate resources to lay down a fifth. This isn't a shipyard problem, per se - the Brits have at least two and probably more building slips to spare. The industrial resources just aren't there. An entirely new design is out of the question on time grounds.

I agree that either a third Implacable is added in the 1939 or 1940 estimates, or else a crash program of a couple of Ark Royal repeats is authorized. As far as shipyards, the slips at Newcastle-Upon-Tyne, Birkenhead, and Barrow-In-Furness are all freeing up as KGV and Illustrious-class launch in the first half of 1939.

 

[Athelstane]

For the Brits, by the time word reaches them about these conversions they're already locked into the four Illustrious-class, and don't have the immediate resources to lay down a fifth. This isn't a shipyard problem, per se - the Brits have at least two and probably more building slips to spare. The industrial resources just aren't there. An entirely new design is out of the question on time grounds.

I agree that either a third Implacable is added in the 1939 or 1940 estimates, or else a crash program of a couple of Ark Royal repeats is authorized. As far as shipyards, the slips at Newcastle-Upon-Tyne, Birkenhead, and Barrow-In-Furness are all freeing up as KGV and Illustrious-class launch in the first half of 1939.

Exactly my thought. But I was unclear on yard availability, so that is helpful.

If Chamberlain wants to go on the cheap, then maybe some squadrons of Hurricanes get sent to Malaya, though it would probably have to happen before the Fall of France -- though it is also possible that after Barbarossa and the Japanese move into southern Indochina, Churchill is more willing to reinforce Malaya with fighters, since the IJN is about to have fleet carriers coming out its ears. An interesting dynamic would be how the Australians and Kiwis would react, and if they would bring pressure to bear on Whitehall. It is hard to say, since the value of carriers still was not adequately appreciated in 1938.

The Brits will be concerned at this accession to Japanese naval air power. The U.S. Navy will likely be just shy of foaming at the mouth. If they don't learn about it in time for passage of the Naval Expansion Act/Second Vinson of 1938, I think we see an emergency supplemental for a fourth Yorktown passed by the summer of 1939. Since Indiana was building in one of the big NN slips, she might get Essex's, and Essex would get CV10's, and so on. I am wondering how hard the IJN would be trying to keep the conversions a secret.

 

[Athelstane]

It would have to be much earlier than the Two Ocean Navy Act.

If the Japanese are commencing the conversions in 1938, and the U.S. gets wind of it, then the 1938 Vinson Act (passed in May) is much closer to the mark. Adding another Yorktown when they're already putting Hornet into the pipeline makes perfect sense. Essex design work wasn't far advanced enough yet, and they're in a hurry by this point (which is why Hornet got ordered in the first place).

That would probably make it available by end of spring 1942, when it would be a godsend to Nimitz. Of course, it's likely to have a lot of the same teething issues as Hornet did, but hey, you take what you can get.

I do not know if the IJNAS flight schools or the Japanese aviation industry could supply the 400 additional fliers or 200 aircraft?

Normally I would (of course) agree, Mac. But if the IJN is putting this in train by 1938, I think it is reasonable to think that they have the time to adjust their training programs to produce the pilots in time. That is...a good four years or so to work with. Especially if they want to raid the light carriers for the best pilots.

Aircraft production is an interesting question, however. Hmmmm....

• The Japanese produced about 500 A6M Zeros by the end of 1941, and I have my doubts they can increase that by much without cutting into other aircraft production. It is enough to fill out 8 fleet carrier fighter complements if you prioritize those squadrons over absolutely everything else.
• The Japanese produced 661 B5N Kates by late 1941. Again, probably enough with top priority -- they only need 40-50 or so to do two more carrier complements.
• The D3A1's might be a push. They only started production at the end of 1939, and not much above 300 had been produced by end of summer 1941. While it might be possible to get enough set aside for two new carriers, I am less sure there will be enough stick time for training by the war begins. Otherwise, they make do with D1A's, oor raid the light carrier squadrons, or just short themselves in the interim, unless they are willing to seriously rework military aircraft production priorities.

Obviously the pilots need stick time in these new aircraft, and that's why this gets tricky. Simply having an airplane rolling out the factory door is not enough. The pilots need time learning these new machines. So you have to factor that into the schedules.

I think it's at the margins of doability, with the lead time we are talking about, but this reinforces my suspicion that the two new carriers don't go to Pearl Harbor, but get sent south instead, where the risk is lower. They would probably do some training with the Kido Butai carrier divisions in mid-late 1941, though.

It is possible that pilot quality could suffer for the light carrier squadrons, unless the IJN can somehow really do some major flexing in war economy planning early enough.

 

[Athelstane]

P.S.

I do not know if the IJNAS flight schools or the Japanese aviation industry could supply the 400 additional fliers or 200 aircraft?

@Kantai Kessen has not told us complement size, but I am guessing that it's going to be more like 75 planes/pilots per deck than 100.

 

[eltf177]

I do not know if the IJNAS flight schools or the Japanese aviation industry could supply the 400 additional fliers or 200 aircraft?

One thing the IJN absolutely must do is lower their standards. So few men were accepted into the schools and many flunked out for trivial reasons. Admittely the pilots won't be quite the elite they were IRL but there will be more of them. And going up against the USN and RN they're going to need every pilot and aircrew member they can get.

I agree more aircraft are possible but they're going to have to displace something else like "Nell" or "Betty" bombers. And that's going to have a ripple effect...

 

[McPherson]

P.S.



@Kantai Kessen has not told us complement size, but I am guessing that it's going to be more like 75 planes/pilots per deck than 100.

One needs spare pilots and planes. There is a 10% loss of plane and pilot per quarter factor built into "peacetime" operations.

 

[Athelstane]

One needs spare pilots and planes. There is a 10% loss of plane and pilot per quarter factor built into "peacetime" operations.

Sure. I was acually factoring that in. But I just want to be clear on what would actually be on board, operationally, at any given time.

 

[Athelstane]

One thing the IJN absolutely must do is lower their standards. So few men were accepted into the schools and many flunked out for trivial reasons. Admittely the pilots won't be quite the elite they were IRL but there will be more of them. And going up against the USN and RN they're going to need every pilot and aircrew member they can get.

It's a good point.

I suppose my first thought is: In a world where the IJN's brown shoes have the moxie to get two battleships converted to flattops in 1938, they should be able to flex enough to force all the other necessary adjustments, too -- some way, some how.

 

[Count of Crisco]

I wonder if the conversion of the Nagato's to carriers would delay the Yamato's entry into service to any serious degree.

 

[Kantai Kessen]

P.S.



@Kantai Kessen has not told us complement size, but I am guessing that it's going to be more like 75 planes/pilots per deck than 100.

In the post I said 57 aircraft per ship. With the peacetime losses taken into account that means about 63 planes assigned per ship.

 

[Kantai Kessen]

Normally I would (of course) agree, Mac. But if the IJN is putting this in train by 1938, I think it is reasonable to think that they have the time to adjust their training programs to produce the pilots in time. That is...a good four years or so to work with. Especially if they want to raid the light carriers for the best pilots.

Aircraft production is an interesting question, however. Hmmmm....

• The Japanese produced about 500 A6M Zeros by the end of 1941, and I have my doubts they can increase that by much without cutting into other aircraft production. It is enough to fill out 8 fleet carrier fighter complements if you prioritize those squadrons over absolutely everything else.
• The Japanese produced 661 B5N Kates by late 1941. Again, probably enough with top priority -- they only need 40-50 or so to do two more carrier complements.
• The D3A1's might be a push. They only started production at the end of 1939, and not much above 300 had been produced by end of summer 1941. While it might be possible to get enough set aside for two new carriers, I am less sure there will be enough stick time for training by the war begins. Otherwise, they make do with D1A's, oor raid the light carrier squadrons, or just short themselves in the interim, unless they are willing to seriously rework military aircraft production priorities.

Obviously the pilots need stick time in these new aircraft, and that's why this gets tricky. Simply having an airplane rolling out the factory door is not enough. The pilots need time learning these new machines. So you have to factor that into the schedules.

I think it's at the margins of doability, with the lead time we are talking about, but this reinforces my suspicion that the two new carriers don't go to Pearl Harbor, but get sent south instead, where the risk is lower. They would probably do some training with the Kido Butai carrier divisions in mid-late 1941, though.

It is possible that pilot quality could suffer for the light carrier squadrons, unless the IJN can somehow really do some major flexing in war economy planning early enough.

Here is what the Japanese would need just to equip the carriers, not taking peacetime losses into account:

• Akagi: 21 F, 18 DB, 27 TB
• Kaga: 21 F, 27 DB, 27 TB
• Soryu: 21 F, 18 DB, 18 TB
• Hiryu: 21 F, 18 DB, 18 TB
• Shokaku: 18 F, 27 DB, 27 TB
• Zuikaku: 18 F, 27 DB, 27 TB
• Hiyo: 21 F, 18 DB, 18 TB
• Junyo: 21 F, 18 DB, 18 TB

For a total of 162 Zeroes, 171 Vals and 180 Kates. Adding on the 10% increase, we need 180 Zeroes, 189 Vals and 198 Kates. I think this is dooable, given the production numbers you have suggested. Additionally, the IJNAS had 2000 extra pilots coming up for mid-1942, IIRC. I don't think it would be beyond possibility that, with war imminent, the training of the best 120 or so is accelerated to equip these here Hawks.

I think the Hiyo and Junyo would go to Pearl, though. This is Yamamoto's love child we are talking about; the operation that, if all goes well, can win the Pacific War from the get go. It is worth avoiding the mistakes of Midway here and applying maximum force at the point of contact.

The only light carrier that really matters early war is the Ryujo. She only needs 27-33 planes, so I don't think that big a difference will be made.

 

[Kantai Kessen]

One thing the IJN absolutely must do is lower their standards. So few men were accepted into the schools and many flunked out for trivial reasons. Admittely the pilots won't be quite the elite they were IRL but there will be more of them. And going up against the USN and RN they're going to need every pilot and aircrew member they can get.

I agree more aircraft are possible but they're going to have to displace something else like "Nell" or "Betty" bombers. And that's going to have a ripple effect...

This conversion might actually be a small driving factor for that, which would be interesting.

 

[Kantai Kessen]

I wonder if the conversion of the Nagato's to carriers would delay the Yamato's entry into service to any serious degree.

Probably not, and that was the intention. No slipways taken up, little armor plate consumed, no need to manufacture big turrets and the hull is mostly there. Machinery upgrades could call upon the industry used to construct the ocean liner conversions of OTL.

 

[Athelstane]

In the post I said 57 aircraft per ship. With the peacetime losses taken into account that means about 63 planes assigned per ship.

Ah. Sorry, I missed that.

I don't think it would be beyond possibility that, with war imminent, the training of the best 120 or so is accelerated to equip these here Hawks.

Yeah, I can't disagree with that. We are not talking huge numbers here.

I think the Hiyo and Junyo would go to Pearl, though. This is Yamamoto's love child we are talking about; the operation that, if all goes well, can win the Pacific War from the get go. It is worth avoiding the mistakes of Midway here and applying maximum force at the point of contact.

There is another way to look at this: Having another carrier division that *isn't* conscripted for this operation may make it easier for Yamamoto to get his way with the General Staff to back Genda's plan. Now not everything is being risked on one throw; now, something *is* available for the southern operation; and then there is the refueling situation, too. Now, obviously Yamamoto got his way in the end anyway; but in the summer of 1941 he wouldn't know that, and it was only by the hardest road that he got his way in the end. (For one thing, it was the success of tests in the Eleventh Air Fleet in September which demonstrated that engine adjustments to the Zero fighters based on Formosa made them operational for flights to and from the Philippines, thus providing adequate air cover for Homma's invasion through use of land-based assets.)

This is not to say an 8 carrier attack on Pearl is not interesting to think about. But it opens up other possibilities, too.

I think it would have considerably bigger butterflies for Phase II of the IJN's conquest plans. For one thing, I think it will significantly increase the chances that Japan can secure Port Moresby and the Solomons by the summer.

 

[Kantai Kessen]

There is another way to look at this: Having another carrier division that *isn't* conscripted for this operation may make it easier for Yamamoto to get his way with the General Staff to back Genda's plan. Now not everything is being risked on one throw; now, something *is* available for the southern operation; and then there is the refueling situation, too. Now, obviously Yamamoto got his way in the end anyway; but in the summer of 1941 he wouldn't know that, and it was only by the hardest road that he got his way in the end. (For one thing, it was the success of tests in the Eleventh Air Fleet in September which demonstrated that engine adjustments to the Zero fighters based on Formosa made them operational for flights to and from the Philippines, thus providing adequate air cover for Homma's invasion through use of land-based assets.)

This is not to say an 8 carrier attack on Pearl is not interesting to think about. But it opens up other possibilities, too.

I think it would have considerably bigger butterflies for Phase II of the IJN's conquest plans. For one thing, I think it will significantly increase the chances that Japan can secure Port Moresby and the Solomons by the summer.

Now this is interesting, and I see where that logic is coming from. D'ye think we could see a situation in which one of those extra Ark Royals is escorting Force Z, and gets into a duel with Carrier Division 6? Unlikely, I grant, because LB air will probably do the job beforehand, but who knonws?

For your last point - that was the intention...

Poor USMC.

 

[Athelstane]

Now this is interesting, and I see where that logic is coming from. D'ye think we could see a situation in which one of those extra Ark Royals is escorting Force Z, and gets into a duel with Carrier Division 6? Unlikely, I grant, because LB air will probably do the job beforehand, but who knonws?

Probably . . . not.

As I understand it, the variant that was initially wargamed on October 13 was detailing Akagi, Soryu, and Hiryu to cover Homma's invasion of the Philippines, not Malaya (I was in error talking about that earlier). Only Kaga, Zuikaku, and Shokaku were used for the Pearl Harbor attack, because they all had greater range, and thus did not have refueling difficulties to address.

What is your notional range for these Hiyo and Junyo conversions, BTW?

Anyway, if Carrier Division 6 gets detailed south, it is going to be hanging around Luzon, not Malaya. Now, if somehow Philips has an Ark Royal or an Illustrious with him, and manages to venture further north intact, that would jeopardize the whole Malaya operation, and it is not impossible that CarDiv 6 might get ordered south to deal with him. . . though in all likelihood, one Brit carrier like we are talking about probably is not really going to improve Tom Phillips' survivability against the Genzan Air and Kanoya Air Groups by an adequate margin . . . of course, if my idea about additional Hurricane squadrons in Malaya got executed, that would require some additional consideration. That might possibly give him enough air cover to push back the attacks out of Saigon, if they get used that way.

But if there is a carrier battle, the Brits are toast, unless Phillips can run away. The Fulmars will get eaten alive against the A6M's.

For your last point - that was the intention...

Poor USMC.

There are all sorts of possibilities here. But my chief thought was that the Japanese secure these before King even gets a chance to try something like WATCHTOWER. The real victims here would be the green Aussie troops at Port Moresby.

 

[Kantai Kessen]

Probably . . . not.

As I understand it, the variant that was initially wargamed on October 13 was detailing Akagi, Soryu, and Hiryu to cover Homma's invasion of the Philippines, not Malaya (I was in error talking about that earlier). Only Kaga, Zuikaku, and Shokaku were used for the Pearl Harbor attack, because they all had greater range, and thus did not have refueling difficulties to address.

What is your notional range for these Hiyo and Junyo conversions, BTW?

Anyway, if Carrier Division 6 gets detailed south, it is going to be hanging around Luzon, not Malaya. Now, if somehow Philips has an Ark Royal or an Illustrious with him, and manages to venture further north intact, that would jeopardize the whole Malaya operation, and it is not impossible that CarDiv 6 might get ordered south to deal with him. . . though in all likelihood, one Brit carrier like we are talking about probably is not really going to improve Tom Phillips' survivability against the Genzan Air and Kanoya Air Groups by an adequate margin . . . of course, if my idea about additional Hurricane squadrons in Malaya got executed, that would require some additional consideration. That might possibly give him enough air cover to push back the attacks out of Saigon, if they get used that way.

But if there is a carrier battle, the Brits are toast, unless Phillips can run away. The Fulmars will get eaten alive against the A6M's.



There are all sorts of possibilities here. But my chief thought was that the Japanese secure these before King even gets a chance to try something like WATCHTOWER. The real victims here would be the green Aussie troops at Port Moresby.

Range of these girls would be similar to Kaga, so around 10,000 nautical miles at a cruising speed of 15 knots. Nice and long.

This may be beyond realistic, but - possibly - the threat of the IJNAS causes better FAA fighter development, so instead of Fulmars, it's Sea Hurricanes being deployed against the Zeroes, which stand a somewhat better chance of survival. Still, it's 2-1, and things aren't going well for the small British air groups.

In this mini-timeline I am writing, Hiyo and Junyo were sent to Pearl Harbor, so that entire consideration is kind of pointless anyway. However, the butterflies in Port Moresby will certainly be intriguing and far-reaching.

 

[Athelstane]

Range of these girls would be similar to Kaga, so around 10,000 nautical miles at a cruising speed of 15 knots. Nice and long.

That is very useful. (And plausible.)

This may be beyond realistic, but - possibly - the threat of the IJNAS causes better FAA fighter development, so instead of Fulmars, it's Sea Hurricanes being deployed against the Zeroes, which stand a somewhat better chance of survival. Still, it's 2-1, and things aren't going well for the small British air groups.

That would be higly desirable, but (I fear) unlikely. My read of RN/RAF politics at that point is that you'd need a bigger prod to make it happen. Alas.

In this mini-timeline I am writing, Hiyo and Junyo were sent to Pearl Harbor, so that entire consideration is kind of pointless anyway. However, the butterflies in Port Moresby will certainly be intriguing and far-reaching.

I don't want to mess with your timeline, but here is another consideration that would militate against bringing Hiyo and Junyo: In OTL, Zuikaku and Shokaku's air groups were dedicated to air field attacks and fighter cover, because, it was felt by Genda and the planners, the CARDIV 5 pilots simply were not experienced enough to entrust with the shipping attacks. As it turned out, of course, they did brilliantly, and the CARDIV 1 and 2 actually underperformed somewhat . . . but the point is, given the 1941 commissioning dates, Hiyo and Junyo are going to be viewed in much the same light. And working over the airfields even more is going to be overkill. It was the battleships Yamamoto wanted taken out.

Not impossible that Yamamoto might shift to a higher risk mindset on attack planning; but I think it's another factor that would push the odds against an 8 carrier strike.

 

[Cryhavoc101]

April `1940.

Motor Torpedo Boats manned by reservists do enough to delay the German forces invading Norway to allow the British to arrive in time to drive them off. Ironically Norway had bought the 36 M.T.B's from Germany between 1936 and 1939.

View attachment 655586

Love this idea

Scrap or decommission the 2 coastal defence ships - freeing up at least 400 officers and men for other tasks (the Norge navy numbered just over 1000 officers and men in April 1940)
Turn the 3 older Draug class DDs into fast minelayers
Build the 6 Sleipner class as modern versions of a fast DD minelayer
6 B class (US L class) of OTL
And then have 7 Squadrons of 6 Boats each based around a major Norwegian port each supported by a 'mothership' allowing for crew mess, training, spares and local ship upkeep etc

 

[Cryhavoc101]

One needs spare pilots and planes. There is a 10% loss of plane and pilot per quarter factor built into "peacetime" operations.

And 6 months operational in peacetime an aircraft is going to have to be given a major overhaul or replaced with a new plane - in war time the burden on airframe and components is far worse if not mitigated by a looser margin of acceptable issues allowing a given plane to remain in service - and that's before we factor in battle losses.

One of the issues they had at Midway with the IJN air groups was the large number of 'Pearl Harbour' airframes they were obliged to keep in use that were at the extreme of service life and the air groups were as a result understrength over what they should have been due to the inability of Japanese industry to provide enough replacements.