In perfect Hindsight: Build Japan's Carrier Force beginning 1933

Would it have mattered if Japan had a very "Flat" navy? Say scrap the Yamato project in favor of 3-4 modern fleet carriers. Also, build a lot of light carriers from old and new heavy cruisers.

Could a development program for carrier-based fighters have produced consistently superior fighter aircraft compared with those of the Americans for at least 5 years of conflict? Could they have matched the US' monthly output of of newly-trained navy pilots?

The rest of the Japanese navy units will become escorts, heavy on anti-submarine and anti-aircraft warfare. Surface combatants would avoid line engagements using battleships and limit themsalves to fast run-in attacks like those in the slot.

Last question, not related to the thread question: was there ever a single-engine, carrier based bomber capable of both dive and torpedo bombing?

 

The Japanese were still under treaty restrictions until they left in 1936. As such, the simply could not start laying down or converting carriers in 1933.

The Japanese needed more heavy & light cruisers - not less. The lack of these warships hampered and constrained their historical actions.

No, the Japanese could not match US fighter design & production. Just look at the A7M Reppu(Sam), the Zero replacement. What started out as a superior fighter, lingered in development hell, as Mitsubishi designers were switched to other tasks. Thus, only a few were produced when the war ended & none were operational.

Matching US pilot graduations, also requires Japan to substantially increase airframe production. More pilots is meaningless without more aircraft. Then there is the AVGAS problem.

There were very few traditional line engagements in the Pacific War, with most occurring very early or late in the war. Thus, this is also meaningless.

Yes, the SB2C could divebomb & carry a torpedo, but it was never used to conduct a combat torpedo drop. There were also some US aircraft in development that could do both, but they did not enter production. As an aside, the TBF/TBM could glide bomb as well, and late in the war was usually carrying bombs instead of torpedoes.

 

...I thought the US had a lot more pilots pre-WW2 ..so, not only more people, but more that were experienced in flying = US could produce more and ''better'' pilots ...same with mechanics to service the aircraft [ and truck/auto mechanics ] ...so we see an exponential advantage for the US

 

As to carrier qualified pilots, they were roughly equal. Japan had more carriers, but they were smaller and mostly carried less aircraft.

 

..the question was pilot future '''monthly output'''--not how many on hand
..I don't know what your post has to do with the reply

 

Your reply

Does not concern "future 'monthly output'", but concerns itself with pilots "on hand" prior to WW2.


As to future monthly output, both sides were already ramping up output. But, the pilots did not have the experience of the older pilots. We see this in the attack on Pearl Harbor, where the Shokaku and Zuikaku torpedo bombers are tasked with high altitude bombing, because they lack the necessary torpedo training, and with USS Hornet pilots at Midway with the infamous flight to nowhere & all 10 Hornet fighter pilots flying away from Hornet to ditch because they thought she was Japanese.

Japan also did not have the manpower resources of the US to draw on, as they had the smaller population, and they maintained the strict pilot requirements for far too long.

 

OK, let's imagine that in the early 1930s the Japanese have an inspiration that no one else does, that aircraft carriers are likely to displace battleships as the arbiters of sea power. Navies, including the Japanese, recognized that carriers were an important component of a navy, as were cruisers, destroyers, submarines and the like, but no one disputed that the battleships were the heart of the fleet.

Or, we might hypothesize that the "Yamato people" (in both senses of the term) accepted that they could not match their rivals in the conventional way and chose to focus on what a later generation would call "asymmetrical warfare". They did invest in night tactics, long-range torpedos, midget submarines, and other unconventional options.

Historically they gave the required notice of withdrawal from the treaty system in 1934, were free of its restrictions in 1936, and laid down their first non-treaty ships in 1937, Yamato and Shokaku, followed by Musashi and and Zuikaku in 1938. From a ship construction point of view, these could all have been carrriers, and one or two more would not seem impossible.

I'm inclined to agree that they should not have torn up existing heavy cruisers. There was a valid need for surface combatants, and reconstructing existing ships - all of which had had extensive work in the past few years already - would be a wasteful strain on Japanese resources.. If we are talking 1933 it might have been possible to order Tone and Chikuma as carriers similar to Hiryu; they were almost as large and had the same 152,000 hp propulsion plant. Ironically, the key feature of their design was to carry a few additional aircraft to supplement the reconnaissance capability of the carrier force.

Seaplane carriers Chitose and Chiyoda could support 24 aircraft and were eventually converted to aircraft carriers - more tearing up of operational ships - given that treaty limits were no longer a factor, one wonders why the IJN didn't just finish them as carriers to start with.

Side note - the submarine support ships Takasaki and Tsurugisaki were converted to light carriers Zuiho and Shoho. They originally had diesel engine plants (consistent with subs) of 56,000hp and speed of 29 knots. Their conversion included ripping the engines out and replacing them with destroyer-type turbines of 52,000hp for 28 knots. I'm completely perplexed at the purpose of this.

As @Takao reminded us, ships are only part of the picture. The carriers in service as of Dec 7, 1941 carried about 500 planes. Recently completed Shokaku and Zuikaku and their air groups were not up to par. Some of the lesser carriers had incomplete air groups as late as Coral Sea and Midway, including obsolescent planes like B4Ys and A5Ms. Junyo, Hiyo, and Ryuho would have needed another 130 or so. The additional carriers contemplated here could need 3-400 more. Even if the Japanese had gone "all in" on carriers in 1933, were their training or production systems up to the task?

 

One cannot just decide to produce better aircraft than one's rivals. Every nation is trying to build the best planes, train the best pilots, and develop the best tactics.

Japanese tactics, reflected in their designs, stressed performance - range, speed, maneuverability - while Americans, and practically everyone else, balanced those against survivability and rugged construction. I expect Japanese designers like Horikoshi Jiro could have produced whatever the establishment asked for.

 

I thought 6 years would be more than enough time to design and stockpile weapons (subject to your available resources of course). But the lead time helped Japan at best during the first six months of the war. For Germany, maybe 2 years. Beyond that, it was a war of production capacity.

Regarding new pilots, the situation becomes critical when the enemy begins to outpace you in terms of aircraft production and combat performance. Saburo Sakai mentioned some American pilots were so inexperienced they were no better than those he was desperately trying to train, but it didn't seem to matter to the Americans back in 1944. Japan's educational system was far behind that of the US to develop a comparable pool of trainable recruits. That, coupled with old-fashioned structures, like limiting admittees to the naval academy to those of samurai stock, made Japan's naval aviation good for two years of fighting.

 

That's a valid point, but Japan was already devoting an unusually large proportion of her economy to military and particularly naval production. Canceling the Yamatos and their massive armor, armament, and ammunition would free up resources for other items. I assume your scheme would also mean ordering Zuikaku type carriers in place of Shinano or #111, the fourth Yamato which was canceled in December 1941 when about 30% complete..

The rest of the Japanese navy units will become escorts, heavy on anti-submarine and anti-aircraft warfare. This seems a lot like the Akizuki class destroyer which began joining the fleet in 1942, designed for carrier escort. A large number were planned but only twelve completed. They carried eight of the excellent Type 98 100mm dual-purpose guns with half the torpedo armament of conventional destroyers and more depth charges. Type 98 indicates that it dates from 1938 (Japanese year 2598), so someone was thinking along the same lines you are.

We should also consider how other nations, particularly the US, would react. They might just write it off as Orientals having a strange idea of how to structure a navy, but more likely we would add at least a few more carriers. We had built up to the treaty limit with Wasp, but when the Japanese dropped out of the treaty we ordered Hornet and Essex, and by 1940 we had a massive program of both carriers and battleships (and everything else). Britain laid down no fewer than six fleet carriers in 1937-39, in addition to new battleships.

 

Nope. If you begin your buildup in 1933, your only stockpiling aircraft that will be shortly out-of-date by 1940. Remember, the Kate only comes along in 1937, and the Val & Zero in 1940(while the Val was earlier, it only began large scale production at this time.) Further, more decks means more aircraft to replace, and production remained low until after the war began. You seem to forget that the IJAAF was also undergoing a massive build up at the time.

Also gun production was lagging behind orders - Japanese warships with the older 4.7-inch AA guns retained them, while new production was getting the new 5-inch ones. High-angle fire control sets were also similarly behind schedule. So, it is not just resources, but production capacity too.

 

here's the OP:
''''' Could they have matched the US' monthly output of of newly-trained navy pilots?'''

 

A few more thoughts about this....

The Tone class cruisers were designed to provide reconnaissance for the carrier force, so apparently the need was recognized. If carriers were built in lieu of these ships, would a portion of their aircraft be tasked for recon? That would certainly be desirable, but it would be a change in the IJN's operational philosophy.

In 1933, Soryu and Tone were being designed for construction in 1934. Chikuma was laid down in November 1935, after the Fourth Fleet incident and while the improved Soryu design (Hiryu) was being finalized. Would "Chikyu" be built to the existing Soryu design or the new one? Aesthetically and perhaps operationally, I think matched pairs have a certain appeal.

If Japan built more carriers, the US would likely respond and assign most of the added carriers to the Pacific Fleet, so some might well be in Pearl Harbor on Dec 7. Enterprise and Lexington were absent on specific missions, delivering aircraft to Wake and Midway, but carriers with no such tasks would likely be in home port.

 

One possible constraint could be engineering plants, particularly turbines and reduction gears. Japanese heavy cruisers, battleships, and fleet aircraft carriers in the period all used four-shaft steam plants of 150-160,000 shaft horsepower. From 1931-41 inclusive they laid down fifteen ships with such plants, 6 cruisers, 5 carriers, 4 battleships including the never-completed #111, fourth unit of the Yamato class, 1-2 per year. In 1942 and again in 1943, they started construction of three Amagi class carriers, but only two each year could be given the intended 152,000shp propulsion plant. One ship each year had to make do with a double set of destroyer turbines totaling 104,000shp, reducing speed from 34 to 32 knots. 2/year appears to be an upper limit no matter how much steel and other resources were freed up by not building the Yamatos.

 

Even if Japan built more carriers, they needed to step up the training of airmen and crews. The quality of pilots declined (Great Marianas Island Turkey Chute)

 

A few points on this from a historical perspective. Even forgoing some of the treaty restrictions, the Japanese aren't going to get much further than they did in carrier construction, along with some notes on IJN doctrine.

Japanese light cruisers were doctrinally used as destroyer flotilla leaders. It was felt they were necessary for that to give the admiral leading the flotilla a proper set of command spaces. That left them lightly armed, and like the larger cruisers, having a scout plane capacity.

Japanese heavy cruisers were the primary scouting force for the fleet. They had to carry several reasonably long-ranged scout float planes, have catapults and recovery equipment, and space to store and maintain the planes. The Tone class took this to the extreme, but within Japanese naval doctrine they were seen as what the fleet needed.

As for carriers... Even if the Japanese managed to build more, they'd be forced to retain older, obsolescent, aircraft in service to provide those ships with planes. Japan's aircraft industry was incapable of keeping up with demand, be it in 1934 or in 1944.

Assuming their pilot training program is expanded some to try and provide sufficient crews, Japanese doctrine is going to remain an issue regardless. The IJN doctrine regarding carrier planes was each carrier got allotted the number of planes and reserves the carrier required. These were assigned to the carrier, trained with it, and remained with the ship. Losses were made up with new aircraft and pilots being sent to the ship.
This is distinctly different from the USN doctrine where squadrons were formed, equipped and trained as squadrons. They could then be assigned to any carrier as required. Squadrons that suffered heavy losses were rotated off their carrier or combat airfield to rear areas and refitted, undergoing training out of combat before being recommitted.
Not so with the Japanese. You got assigned to a ship's aircraft complement and stayed with that complement until promoted out to some new command. For enlisted aircrew, you pretty much were going to stay with the ship you got assigned to. This meant that if a carrier went into combat and suffered heavy aircraft losses, it would be pulled from active combat duty to refit with replacements to its airwing, no different than if the ship had suffered damage in combat.
US carriers could suffer heavy aircraft losses, and in a matter of a month or two have worked up a new air wing and been sent back into combat. The old squadrons would now be ashore absorbing replacements and training. Also, US pilot standards remained nearly unchanged during the war. The programs were expanded, but pilots were expected to have about 200 hours flying time before being sent to an operational squadron where they'd get more flying time prior to entering combat.

This means the number of pilots and planes for the Japanese will be limited regardless. And as the war progressed, Japanese pilot standards fell dramatically with them being accepted at lower quality, and having far fewer flying hours entering combat. By 1944 it was common for Japanese pilots to have less than 100 hours flying time and near zero on their operational mount.

I'd also think that if the US really thought the Japanese were going to go carrier heavy, they'd follow suit and had the resources to out produce the Japanese.

As to ASW and anti-air doctrines and equipment:

The Japanese had basic sonar systems available fairly early in the war. Their ASW doctrine in say 1939 was roughly analogous to other navies in terms of equipment and practice. Where they fell apart was they didn't have the means to improve at the rate the US or British did.

As for AA, again, in 1939 the IJN was confident that their existing systems were perfectly adequate and as good as any other navy's. It's when you get into the details that things fall apart for the Japanese. Like every navy of the late 30's--except the USN--they expected each ship to defend itself from air attack with the onboard weapons. Their existing 4", 4.7" and 5" AA guns were as good as any, at least on paper. The 25mm appeared to be perfectly serviceable for dealing with aircraft too.

Their AA shells like 3 shiki (the incendiary one) were mediocre in quality. The 25mm with 10 round magazines was too slow firing and short-ranged. Their 5" AA guns used bagged charges and fixed loading positions giving them half or less the rate of fire of other navy's similar guns. AA doctrine was also poor as was their training regimen.

The US in 1938 made a huge change in their AA training when drones were introduced with live fire drills. These showed current doctrine and training to be terrible and the USN revamped their whole program making AA fire far more effective. The Japanese didn't get that luxury. The US also introduced the circular formation for ASW and AA defense using mutual support tactics. Again, the no other navy pre-war picked up on this so I wouldn't see Japan suddenly switching doctrine there as the effect of this formation was unproven at that point. That is, there was no good reason to introduce it and the Japanese weren't privy to the Naval War College's having gamed and worked its value out.

The Akizuki class was mentioned. This started out as a very light cruiser class for that mission of destroyer leader. It was redesignated a destroyer to make up for losses and changes in the conditions of warfare during the war. Had it entered service earlier, it would have been produced in very limited numbers for the original purpose rather than the new one.

 

The USN flight training program produce some 65,900 flyers between January 1939 and December 1945. Of these roughly 12,000 were Marines, 600 Coast Guard, and at least 300 foreign personnel.

Even by the end 1943 there were 20,847 USN and 4898 USMC naval aviators (officers) and 774 USN and 132 USMC naval aviation pilots (enlisted) on active duty.

By the end 1945 there were 49,380 USN and 10,229 USMC naval aviators (officers) and 439 USN and 47 USMC naval aviation pilots (enlisted) on active duty.

In December 1941, the Japanese Navy had some 3500 “front line” pilots (this comparing to some 2500 IJAAF available pilots) of whom about one half were carrier current, that is, assignable to carrier squadrons. The USSBS reports that of the 3500 or so IJN pilots, 600, with about 800 hours each on the average, were assigned to carrier groups. (See USSBS Report No. 62, Japanese Air Power, Pacific War, Military Studies, Military Analysis Division, July 1946, Appendix II, Japanese Air Personnel.) This proportion pretty much correlates with those of the USN/USMC. Just looking at active 1941 USN squadrons yields a similar number of available-right-now aviators. USN carrier squadrons, at the end of 1941 mustered about 580 flying slots in 38 squadrons. Land-based USMC VMF and VMSB squadrons probably accounted for another 200-250 readily available carrier qualified pilots. Certainly, this was not the total pool of available carrier qualified USN/USMC pilots as it does not consider carrier qualified pilots assigned to such mundane activities as training and staff positions, as well as land based squadrons. The same would be true of the IJN, there were undoubtedly many carrier qualified pilots not actually assigned to a carrier squadron and so operating.

During the course of the war the IJN trained some 24,000 pilots of all stripes. Roughly 18,900 of them, and their pre-war compatriots, were killed, either in action, training accidents, or operational losses. Over 2500 of these were killed in suicide attacks. Compare to the above turning out of USN/USMC pilots.

Would not have mattered how many carriers the Japanese had if they could not supply the pilots.

I can wax long on the subject of IJN vs USN training programs, about 20 pages worth.

Picking the carrier airplane of which the Japanese produced the most, the A6M series . . . there were about 10,000 of them. And their primary adversaries? By the end of the war, the F4F series (including the FM’s) – about 7,900; the F4U series – about 11,235; and the F6F series – about 12,210. And most of the F4U and F6F production was not underway until the start of 1943 . . . serious A6M production started in 1940.

Would not have mattered how many carriers the Japanese had if they could not supply the airplanes in sufficient numbers as just in carrier fighters they were out-produced three to one.

And there is always to oil/gasoline problem. Carrier operations, usually requiring higher operating speeds to produce the wind over the deck, are notorious fuel hogs, Extra carriers don’t do you any good if you cannot operate them due to empty bunkers.

And as far as one Japanese pilot’s comment on the quality of USN adversaries (and I’d be interested in a reliable source for that), the USN pilots did not have to be good enough to beat him, they only had to be good enough to beat the children he was training and herding about.

It would not have mattered when the Japanese started building a larger carrier navy at the expense of battleships (but, golly, no, not at the expense of cruisers) all the factors for victory were stacked against them. Not enough trained personnel, no programs to increase trained personnel, no manufacturing base that could compete in the real world, not enough fuel . . . everything you need to win a war, they did not have and going to war was not going to get it for them.

And, last, the F6F was a proven dive bomber that could, if you really wanted to, really wanted to, haul and drop a torpedo. Not that anybody wanted to do so. That was more of a "that's nice boys, why don't you go and figure something useful" thing.

 

I always wonder about what ifs that start with "with perfect hindsight...." Is there anyone out there that actually realize there is no such thing?

 

And the glaring problem with all what ifs . . . suppose, as the OP wishes, the Japanese actually embark on a carriers before all path? Does the rest of the world just stand still?

Besides the problems noted above, and perhaps concurrent with them, what ever makes anyone think that, for example, the US is just going to sit on its hands, firmly mired in an imagined concrete timeline? Anyone remember the pre-War-to-end-all-Wars naval arms race between Great Britain and Germany (with the US slowly jogging on the sidelines)? This you would have seen, and in fact, did see, in the Pacific between Japan and the US.

It had, in fact, already started with the stretch between the Yorktown class of the late 1930s and the soon to be authorized Essex class . . . moving the USN away from a big-gun battle ship navy to a carrier navy.

The Japanese were already behind.