USS Yorktown (CV-5) v. HMS Illustrious v. Soryu?

You still are avoiding answering the question. How would you propose to control the seas around Europe without carriers. In the case of Malta, how would you stop the Germans from steamrolling the whole of North Africa and the Middle East if their logistics networkr is not challenged??? And if you concede that it is going to be challenged, how do you propose to do it without carriers?????

I put it to you and Sys that it cannot be done, at least with the tools available in 1939-43. The role of Carriers in Europe, in my opinion is even more crucial than it is in the Pacific.

Without carriers in the Pacific, what is the worst that can happen....say the US loses at Midway.....Japanese shipping is in such short supply that they simply cannot advance any further than they did. An invasion of Australia would never happen...they dont have the 20 divisions and the 2 million tons of shipping needed to do it. They might be able to rough up Hawaii a little, but their losses over the island will be as catastrophic as they were over Guadacanal. They would consolidate their positions in the Solomons, and might advance as far as Fiji and or Noumea, but I cant see them doing much more than that. The Japanese simply dont have the where withall to progress much further, the major constraint is the availability of shipping.

To defeat Japan, you need carriers, lots of them, and lots of planes on those carriers...unquestionably. To contain Japan, you need virtually nothing, because they could go only a little further than they actually did

Ineurope the equation is fundamentally different. If you leave the European axis alone, and you have tiger that is going to eat you, and by eat you I include North America. And the only way you can contain them in 1939-43 is to maintain your blockade of Europe, and the only way you can do that is to commit your carrier forces to the job

You guys must think the Royal Navy to be an absolute bunch of idiots to have lost so many carriers for no reason, if you believe that the European waters can be controlled without carriers in 1939-43. I am just in utter disbelief at the stance you guys have taken on this.

I believe the Yorktown to be the best of the bunch.
In Swordfish By David Wragg Illustrious was indeed a good carrier but suffered some major problems that only came to light after the Taranto raid during the attacks made against it by the German airforce the amoured flight deck was a two edge sword. Yes it made it a tougher nut to crack be it by bomb or Kamikazi plane but if it was penetrated by a weapon that detonated within the hanger deck the armour acted to confine the damage where as the wooden decks on other carriers would acted as a weak point releasing the energy up rather than containing it also within the hanger deck it had been design with vertical steel fire curtians attached to the flight deck head supports when a bomb entered the hanger aft of the flying control position it exploded turning the fire curtains into vast amounts of shrapnel killing many of the crew having said that the armour had succeeded in saving the vitals of the ship, so as I say it was a two edged sword.
The only reason I choose the Yorktown is that what ever the design the more aircraft you can carry the bigger the punch and the better ability you have to defend youself
One thing that had IMO a significant effect on all carrier designs leading up the start of hostilities was the Washington naval treaty of 1922 which set the upper limit of 27,000 tons on new vessels of any category and upper tonnage limits for type of ship eg: cruisers were limited to a maximum of 10,000 tons. However of more significance was the maximum fleet tonnage both the RN and the USN had a maximum of 525,000 tons within this the treaty allowed each navy a maximum carrier force of 135,000 tons so each navy had a different approach to the way in which this tonnage was incorperated into the respective designs. A more obscure part of the treaty also limited carrier gun calibre to a maximum of 8".

Actually, it is beside the point whether carriers were more important in the ETO or PTO. The debate is about which class of carrier was more effective and I will continue to support Yorktown class. On the question of importance of carriers in the PTO. If the US had had no carriers, after the first strikes by Nagumo at Pearl Harbor had destroyed the battle fleet, Nagumo would have then launched strikes to destroy the dock, repair facilities and tank farm for fuel. Hawaii would have been no further use to the US and the USN would have been scoured from the Pacific since it could not fight the IJN with no carriers. That would be the beginning!

renrich said:

Most of the major ships belonging to the Axis in the ETO were sunk by naval gunfire or torpedoes not from aircraft. Taranto would be the exception..

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I think I have to disagree with you on this. If you look at the losses of Heavy Cruisers on up even while ignoring Taranto Germany and Italy lost more ships (either sunk or knocked out of the war) by air then by gun.

I was not clear on that but was trying to say that not many Axis, in ETO, heavy ships were lost to air strikes by carrier aviation. Off the top of my head. Oran, to keep French ships to become German, Italian cruisers at Matapan, Graf Spee, Bismarck, Scharnhorst, all sunk by RN ships although Bismarck was damaged by Swordfish torpedo. The only "major ship" German, I can find sunk by carrier AC is Leipzig. The only Italian are Conte Di Cavour and Trento. This from Janes 1944-45, war losses.

renrich said:

Actually, it is beside the point whether carriers were more important in the ETO or PTO. The debate is about which class of carrier was more effective and I will continue to support Yorktown class. On the question of importance of carriers in the PTO. If the US had had no carriers, after the first strikes by Nagumo at Pearl Harbor had destroyed the battle fleet, Nagumo would have then launched strikes to destroy the dock, repair facilities and tank farm for fuel. Hawaii would have been no further use to the US and the USN would have been scoured from the Pacific since it could not fight the IJN with no carriers. That would be the beginning!

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I think it relevant, because as Rich pointed out, the Illustrious class were built for a certain environment. I think you are unwilling to explore the possibility because it will show up the design faults of the yorktowns.

Dont quite follow your supposition about a war without carriers in the Pacific.....are you suggesting that the japanese Carriers after woud return to Pearl after Midway (lets say the tables were turned and the Japanese had jumped the US carriers, sinklng all three for the loss of say one of their own, but relaistically with losses of about 250 aircraft....are you satisfied that I have supposed a reasonable post Midway scenario???)

In that circumstance, the Japanese will take at least 3 months to replace the losses to their CAGs. They were receiving about 40-60 aircrew per month in the post Midway months, although they could accelarate this if they chose to sacrifice quality for quantity....so lets say they are able to mount their offensive against Hawaii in say September. By then you have Wasp and Saratoga operating off Hawaai, and I believe at least 500 land based air to support them. The Japanese are never going to penetrate that sort of defence, Even if you take out the carriers completely, what are they going to do. If they carry out raids against Pearl, they may well be successful (in a pyrrhic sense), but surely each time they do this, at the very least they are going to lose massive numbers of aircraft. Pearl would essentially become the American Malta, even though the Axi might pound the bejeesus out of it, they cant take it, and they cannot destroy it. For the duration of this battle the fleet falls back to San Diego, and runs supplies into the beleagured island as required.....and uinlike the Germans, the Japanese have no depth to sustain that kind of fight. It will be allover by christmas, just like the historical Guadacanal scenario was the end for Japan,

renrich said:

I was not clear on that but was trying to say that not many Axis, in ETO, heavy ships were lost to air strikes by carrier aviation. Off the top of my head. Oran, to keep French ships to become German, Italian cruisers at Matapan, Graf Spee, Bismarck, Scharnhorst, all sunk by RN ships although Bismarck was damaged by Swordfish torpedo. The only "major ship" German, I can find sunk by carrier AC is Leipzig. The only Italian are Conte Di Cavour and Trento. This from Janes 1944-45, war losses.

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I think this is being more than a little disingenuous

Axis losses to carrier aircraft amounted to the following in the Meditteranean alone (1940-43)

290 Merchant ships totalling approximately 490000 tons of shipping and amounting to 37% of all losses in that period. Addionally the following ships were lost, or heavily damaged as a result of action by the FAA. BBs Cavour, Veneto (twice) Littorio (twice) Duillo

Cruisers Fiume, Zara Pola, San Giorgio were lost as a result of action by the FAA British carrier doctrine was fundamentally different ( and perhaps less well developed than US operations, in that the British still saw the FAA as undertaking a spotting role mostly, however these ships would not have been lost or damaged without assistance by the FAA).

In addition the Italians are known to have lost twenty three destroyers to the FAA, and approximately 14 submarines.

All this was achieved with an average of about two carriers in the theatre at any given time, and an average operational strength not exceeding 100 aircraft.

But the most significant achievement of the FAA at this time was not the sinking of ships, but the maintenance of a blockade, incorporating Malta as part of that strategy, but also including direct raids allover the central basin. Without the assistance of the FAA there could well have been upsets at several signifcant engagements, including Calabria and again off Sardinia, each time the presence of carriers alerting the british of the approaching Italians and the italians in turn being spooked by the presence of aircraft

More importantly still perhaps, was the ability of the carriers to enable convoys to be run into Malta, thereby keeping the Italian supply routes under direct and sustained pressure from aircraft surface ships and submarines. Without the efforts of the carriers none of this would be possible

We do know this:

The small size and endurance of the Illustrious made it hard to say that it would have any success in the Pacific. Even if it was in company with other USN fleet carriers, the logistics issues regarding this class preclude it from being usefull except in limited roles.

The Yorktown class would have been punished by the LW had it been caught by a large air group. But, thats offset by the Yorktown to put up a large fight and make the attackers pay dearly.

And as I said before, in the PTO, fleet carrriers were integral in the victory in this theater. In the ETO/MTO, fleet carriers were not (and whether Malta falls or not, the results are the same).

End result, the Yorktown class were superior because they could bring more planes to the fight and stay at sea longer.

The Yorktown would not only be able to stay at sea longer but if the British carriers were typical of most of the rest of their Navy, they were not as fuel efficient as the US ships and would not be able share out bunker fuel to the DDs in their escort. It is a ridiculous assumption to make but if the US Navy had had no carriers at the onset of war, like Germany and Italy, Nagumo would have stayed near Pearl Harbor in December 1941 and pounded the military bases there to pieces. He cleared out without launching any further strikes because he feared the two missing US carriers. Without carriers, the US would have been in the Pacific like Germany was in the Atlantic, reduced to sneaking out surface raiders and submarine warfare. Without the British carriers in the Atlantic, Britain would have been as successful prosecuting the war, although it would probably have taken longer, as they were in WW1 without carriers. I, frankly, don't care for the tone of this debate. Consequently, not being disingenuous at all, I will close with saying, I examined Jane's war losses for major German and Italian warships sunk by all carrier aircraft and found the three mentioned. In looking at Japan's war losses, it is no longer worth my time to enumerate all the major and minor IJN warships sunk by carrier AC. And the Allied major units sunk by IJN carrier AC.

I agree Renrich.

Too much is being made of the ships damage "bomb proof" decks, and not the other intangibles that make a carrier a great ship or a bad ship.

The Yorktown is superior in two extremely important regards:
1) Aircraft capacity
2) Logistics

QUOTE=syscom3;518282]We do know this:

The small size and endurance of the Illustrious made it hard to say that it would have any success in the Pacific. Even if it was in company with other USN fleet carriers, the logistics issues regarding this class preclude it from being usefull except in limited roles.

The Yorktown class would have been punished by the LW had it been caught by a large air group. But, thats offset by the Yorktown to put up a large fight and make the attackers pay dearly.

And as I said before, in the PTO, fleet carrriers were integral in the victory in this theater. In the ETO/MTO, fleet carriers were not (and whether Malta falls or not, the results are the same).

End result, the Yorktown class were superior because they could bring more planes to the fight and stay at sea longer.[/QUOTE]

Agree with the first tweo paragraphs, except that you omit to assess the damage effects if Yorktown were subjected to attacks similar to the Illustrious or Formidable. Or the Eagle for that matter.

Yorktown was designed to withstand bombs of up to 500 lb capacity, and had some protection against torpedoes. As a rough generalization, she could absorb about 3 x 18 inch torpedoes, give or take.

What would happen if she absorbed 5 x 1000 lb bombs plus a further 1 x 500 lb bomb plus a German "kamiklaze" crashing into her island superstructure , or was hit by 2 x 2200 lb bombs down the centreline, or was hit by 4 x 21 inch torpedoes. My opinion is that she would not survive.

Now, in 1941, when these attacks occurred, she had a fighter component of 18 fighters, compared to illustrious's fighter component of 12 fighters. In 1941, the yorktown was not fitted with early warning radar, so her CAP will be far less effcient. In the raids mnounted against the Illustrious in January 1941, the illustrious shot down about 10 Axis attackers, out of 70 attackers. The Yorktown without radar, but more fighters would be forced to mount continuous patrols, and might not place her fighters at the correct altitude (the same thing happened to the illustrious, even with fighter controllers directing them). One might expect with 50% more CAP and better fighters but no radar, the yorktown could shoot down 50% more attackers, and that is being generous. So that means that realistically the Yorktown might shoot down 15 or so of the attackers, compared to the 10 that the illustrious was able to drive away. This might mean that instead of suffering 6 hits, as the British carrier suffered, the Yorktown might be likley to suffer four or five. Could she survive four or five hits by heavy bombs?. My previous thumbnail analysis of her defensve capabilities suggests not. The 1000 pounders are simply too powerful for her to withstand....they would penetrate to her vitals and she would suffer catastrophic fires and damage to her engines and possibly hits to her magazine. My opinion is that she would sink in minutes as aresult of this attack.

Moreover the British carriers provided support for something like 18 of these operations ( I will check this statistic a bit later) , so the chances of the Yorktown being sunk on one of these occasions is very high. In the case of the British carriers they were able to survive without being sunk on all but two occasions

Survivability in the European context was critical. Without it, Carriers were high risk items, and a carrier the size and importance of the Yorktown would have particularly at risk....a bomb magnet waiting to be sunk

In relation to your last paragrapgh about the outcome being the same....I suggest you have another look at the importance of malta. Carriers were vital to the re-supply of malta, and without Malta, the adfvantage of the land campaigns in North Africa swing firmaly in favour of the Axis. The most likley outcome of that is the loss of the Suez, the middle east, and ultimately the war itself.

renrich said:

I was not clear on that but was trying to say that not many Axis, in ETO, heavy ships were lost to air strikes by carrier aviation. Off the top of my head. Oran, to keep French ships to become German, Italian cruisers at Matapan, Graf Spee, Bismarck, Scharnhorst, all sunk by RN ships although Bismarck was damaged by Swordfish torpedo. The only "major ship" German, I can find sunk by carrier AC is Leipzig. The only Italian are Conte Di Cavour and Trento. This from Janes 1944-45, war losses.

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Ok now I follow you.

Currently finishing a book,"Retribution," by Max Hastings, a Brit who has some interesting things to say about the RN and FAA in the last days of the Pacific War. These remarks have some relevance in the discussion about the relative qualities of British and American CVs. Apparently, according to Hastings, the British effort in the latter part of the PTO war was so that Churchill could say that the UK contributed to the defeat of Japan. Admiral King was hostile to a British presence but FDR convinced him to cooperate. The British effort was called TF 57 and contained CVs, BBs, CAS, CLs and escorts.
"Thereafter, in the first months of 1945 it proved embarrassingly hard to muster a British fleet for Pacific service." The RN, like it's parent nation was overstretched and war-weary. Australia's shameless dock labour unions delayed the deployment of both warships and the fleet train of supply ships. When Rawling's ships finally joined Spruance, they were hampered by design unfitness for tropical conditions, which inflicted chronic hardship on crews. British Seafires and Firefly aircraft were too delicate for heavy labor, and British carriers embarked far fewer planes than their American counterparts." " In an early series of air strikes, the British lost 41 aircraft in 378 sorties, a casualty rate which would have been deemed disastrous even by Bomber Command." " Sir Bruce fraser wrote later in his dispatch: " There can be little doubt that the Americans are much quicker than we are at learning the lessons of war and applying them to their ships and tactics....As a result the British fleet is seldom spectacular, never really modern......." A British war correspondent who had spent some time on USS Lexington and watched refueling and resupplying at sea in winds up to Force Six, watched similar efforts on KGV with dismay. "Replinishment operations at sea remained an embarrasment for the British." "Flying mishaps inflicted an alarming rate of attrition-- in their first 12 strike days, 19 British planes were lost to flak, 28 in accidents." The armored flight decks of the British CVs did stand them in good stead during Kamaikaze attacks. Another fly in the buttermilk was when the Canadian government announced that only those of it's citizens who chose to do so need continue to serve against the Japanese once the war with Germany was over. " Despite offers of increased pay, 605 ratings of Rawling's Canadian-crewed cruiser, Uganda insisted upon exercising their right to go home." TF 57 with drew at the end of May to Sydney. They claimed 57 enemy AC shot down for the loss of 203: 32 to suicide attacks, 30 in a hangar fire, 33 to enemy flak or fighters, 61 in deck landing accidents and 47 to other causes. "A British squadron returned to Halsey's command only in the last days of July." During the battle for Okinawa, because of the Kamikazes, the USN lost 4907 killed,the US Army, 4675 killed and the Marines, 2928. Startling figures to me. Anyway some of these revelations surprised me. I find that the more I read and know, the fact dawns on me that I know very little and often things are not what we have been led to believe.

I remember reading a book on TF57 and it supported a lot of what you say. I am going from memory but if I remember right TF57 were a more independent command given their own areas of operations by the USN which were away from the American Fleet.
The only other comment I would make is the reference to the Fifely being fragile. That goes against everything that I have heard about that aircraft.

To anyone who is interested in a well written(maybe the best) book on all the facets of Guadalcanal, IJN and USN both; check out Guadalcanal: The Definative Account of the Landmark Battle by Richard B. Frank. I cannot praise this book enough. It has all the orders of battle for both sides as well as very researched casualty lists for men, aircraft, and ships. It is also quite readable.

I'll check it out Amsel, sounds like Shattered Sword.

don't know quite why this came up in my unread items. Its been a while, but an interesting thread. The reality is that the US produced more carriers with far higher complements, but in the post war, most of the smaller navies opted for surplus British carriers over US types, even though many ex-USN carriers were available. The British at the end of the war convened an investigation as to what was essential and what was not in carrier design. The armoured box was seen in the finish as an expensive "nice to have" option, but not essential. not so the closed hangar system. Armour plating was seen as another non-essential element of carrier design, and excessive speeds as a positive waste of time. Speeds of around 25 knots were plenty good enough, as the fuel consumption above that speed were just not sustainable and the power demands for fleet speeds of 33 knots were just prohibitive. A/C handling rates were essential, but contrary to what someone said earlier about how much faster US carriers were at their "spot rates", my experience aboard WWII designed Light fleet carriers, ships with all the benefits of that committee I referred to earlier, were as good or better than the USN at getting planes off the deck. During Korea for example the carrier CVL HMAS Sydney managed 2300 sorties during her deployment of roughly 2.5 months with the peak daily sortie rate of 89 sorties on the 11 October 1951 with a complement of just 34 a/c.

other essentials that appear supported by events were the design and positioning of fuel storage tanks, design and protection of fuel lines including avgas lines, better LSO control procedures (to reduce accidents). A small but still significant issue was the design and placement of the island, always on the starboard side and aerodynamically designed to reduce turbulence. Brit Carriers were always better in all these respects until the big US supercariers came to be, and these come at such cost

with all the heat in this discussion there were a lot of things said I wish hadnt, and some issues that we allowed to slide that were perhaps worth taking in. Cant do much about the acrimonius debate, but probably can say a few words about the things I wish had been raised at the time.

We were presented with a discussion topic on which carrier out of three choices were superior .....ILLUSTRIOUS, YORKTOWN or SORYU. The first point we failed to consider is that each of these ships were designed to treaty limits. This meant there were limits on the total tonnage of carriers that could be built, and the second was that limits were placed on the size and characteristics of individual ships. Rather more restricted limits were placed on the IJN total tonnages compared to the two major navies....the so called 5: 5 : 3 ratios. The Japanese made efforts to circumvent by packing as much firepower as they could into all their ships. This was the philosophy they used in ships like the Yamatos and even their destroyers. In the case of their carriers, the Japanese rightly concluded they needed as many carrier borne planes as they could muster, and this meant they cut protection to the bone for the Soryu class. With the abandonment of the treaties they were able to field far more well rounded ships in the Zuikaku class.

A comparison of the tonnages of the ships is revealing. The ILLUSTRIOUS had a nominal displacement of 23500 tons, which grew to 29500 by the end of the war, soaked up mostly by additional AA, increased aircraft capacity and increased fuel storage. The ILLUSTRIOUS was the heaviest of the three.

The YORKTOWN was sunk before her displacement was much affected, but in 1942 she had a nominal displacement of 25900 tons. There has been a lot of debate about aircraft capacities, but in 1938 her listed aircraft complement was 91 aircraft, 18 fighters, 36 torpedo bombers and 37 divebombers. We should just leave it at that. Her listed fuel capacity at that time was 177000 US gallons or 5500 tons (according to Conways in 1938 the ILLUSTRIOUS had a fuel capacity of 4500 tons and the SORYU 3800 tons, which had been increased to 4400 tons by December 1941).

On this displacement, under the treaty, the US was allowed to build 4 Yorktowns, and a slightly smaller carrier (the WASP). She went to war with the two LEXINGTONS, the RANGER, the WASP and the 4 YORKTOWNs. They had also commissioned the LONG ISLAND CVE which they did not include in their treaty toatals because they classified this ship as an a/c transport. They had four ships that I know of in the US slated for quick conversion to carriers, the SANGAMON class CVEs(completion of this conversion was delayed until 1943). Individually, the 4 YORKTOWNs were better than the Japanese carriers, but the smaller displacement of the Japanese carriers meant they had more hulls to work with. I dont know which was the better strategy really, more hulls of less well protected ships, or a lesser number of better larger ships.

The SORYU and her half sister the HIRYU had treaty displacements just 15900 tons. This displacement increased to about 18800 tons for wartime service. For that, the Japanese got a carrier with a prewar aircraft capacity of 72 a/c. They could have had 6.5 Soryus (say 7 if they played the same game as the Americans and "converted" HOSHO to other duties). 7 carriers @ 72 a/c is 504 a/c. Compared to 364 aboard the YORKTOWNs. No wonder the Japanese opted for the solution that they did. What wrecked this thinking was the very limited industrial base that the Japanese had. They simply didnt have the ability to build that many carriers 1938-41. The US did.

The British had some capacity to build carriers at a higher rate than the Japanese, but their problem was threefold. Firstly, they lacked the carrier trained pilots and a/c to field large CAGs the same as the US and Japanese could. Building carriers with a capacity of 80-100 was a waste of time for the RN.

Which brings me to the second challenge facing the RN. The US and IJN battle problems were relatively straight forward, each for different reasons, and this allowed them in their pre-war plans to assume vast concentrations of carriers in the expected operations. Not so the british. they had a vast, worldwide empire to defend, long shipping lanes and an enemy who was wedded to mercantile warfare. The British needed a lot of carriers, with a relatively few number of aircraft (which was theiur third problem) . Aircraft numbers were not important to the British. mostly because didnt have many in the FAA. As war approached, the British started to design carriers with relatively low CAGs, but high levels of survivability. This was the basis for the ILLUSTRIOUS class, which carried over into the so called "trade protection" light carriers built (or building) towards the end of the war. As far as survivability was concerned, the ILLUSTRIOUS was the best of the three types but far worse in terms of the vital aircraft capacity

I am coming to this thread a little time after it started, so I expect that most points have been made by earlier posters.

However, I do agree strongly with Parsifal that Soryu, whilst a close contemporary of Yorktown and Enterprise, was a creation of the Washington and London Treaties. Under the treaties, Japan could lay down two 15,000 standard ton carriers or one larger ship of up to 23,000 tons standard dispacement. Soryu's real American equivalent was USS Wasp, laid down two years later to use the last of the available tonnage, and, like Wasp, Soryu had almost no armour or defence against torpedoes. As the weakness of her hull as designed became apparent, Soryu was strengthened during construction but no armour was added. Soryu's "half sister" Hiryu started to have some, still fairly weak, armour because, with Japan's withdrawal from the Treaties, it was possible to bulge the design. Finally, Shokaku was a contemporary of Illustrious and Hornet and much more representative of a design unconstrained by the Treaties.

Wasp 14,700 long tons (standard); 19,116 long tons (full load)
Yorktown Class 19,800 tons Standard, 25,500 full load (original) 32,060 full load (Enterprise after adding bulges in 1943).

Soryu 15,900 tons (standard); 18,448 tons (trials); 19,800 tons full load
Hiryu 17,300 tons (standard); 20,250 tons (trials); 21,900 tons full load
Shokaku 25,675 tons standard, 29,800 tons trials, 32,105 tons deep load.

Ark Royal 22,000 tons standard, 27,720 tons full load.
Illustrious 23000 tons standard; 28661 tons full
Implacable 32,100 tons full load

The next question naturally is how the offensive powers of the carriers compare which brings us to their aircraft facilities. Soryu has the largest total hangar area followed by Yorktown whilst Illustrious have the smallest area. However, Soryu's superiority needs to be qualified. The upper hangar was 4.6 metres high and the lower hangar only 4.3 metres. The Implacables also had two roughly 4.3 metre high hangars and were unable to carry the F4U because its folded wings were too high. Thus the B5N could not be carried in Soryu's or Hiryu's lower hangar. Illustrious together with all the RN carriers from Ark Royal to Implacable had an opposite limitation as the elevators were kept very small to avoid weakening the flight deck which was also the strength deck. Thus those RN carriers could only carry aircraft with folding wings, which prevented them carrying the early Martlets and also prevented them carrying Spitfires to Malta (hence the use of USS Wasp).

The actual number of aircraft carried is complex because it involves the dimensions of the hangars, whether the aircraft have folding wings and how many aircraft formed the deck park, which was partly an issue of doctrine. Several recent threads at other sites have explored the theology of how many aircraft could be stored in the hangars of USN carriers North Cape Dec 1943: What if Tirpitz sails with Scharnhorst in Battleship Vs Battleship Forum and carrier capacity??? - Tullys Port at CombinedFleet.com. The best point made was that it proved possible to fit large numbers of adults into VW Beetles and British Leyland Minis but that there are only four seats available for normal use. In practise, the USN could easily store around half the aircraft complement in the hangar and parked the other half on deck. Thus a Yorktown normally carried around 75 aircraft, using Midway for three examples. The importance of folding wings can be seen by the increase in the number of fighters from 18 to 27 just before Midway when the F4F4 replaced the F4F3.

Soryu normally carried around 60, which could all be stored below. Interestingly, http://www.fischer-tropsch.org/prim...Reports/USNTMJ-200A-0560-0608 Report A-11.pdf reports on page 9 that 12 aircraft were normally carried on deck and that many more securing points were available on the flight deck (presumably of Soryu and Hiryu's descendant Katsuragi which they examined). However, Shattered Sword argues that the IJN was short of aircraft before Midway and clearly they were short of pilots later. Thus the IJN never had a great incentive to use extensive deck parks.

There remains one big puzzle about Soryu. Why did the IJN demand such a high speed when using half of the installed power would have given around 29 knots, equalling the RN Centaur Class and keeping up with almost all the WW2 battleships? I can think of two possible answers:

The first is that Soryu had the same machinery as a Mogami Class cruiser. Those cruisers were to operate together with destroyers to break through the American fleet's screen on the night before the "Decisive Battle" and thus they had destroyer speeds. However, Soryu and Hiryu were initially assigned as part of the 2nd Fleet together with those cruisers and the 1st Air Fleet was only created later over the objections of the CIC 2nd Fleet Koga Mineichi. Could the speed have been specified to allow them to operate with the 2nd Fleet?

The second possible explanation takes us to another thread on IJN carrier based aviation Japanese Carrier Operations where it was noted that IJN carriers adjusted their speed to maintain a wind speed of 15 m/s over the deck. 15 m/s is 34 knots, so Soryu can just give that speed in a dead calm. Was that the origin of the speed requirement?

There may be some weak evidence for the second idea in the words of the only aviator from Soryu whose memoirs are available in English. In "The Miraculous Torpedo Squadron" by Jūzõ Mori we find

"One day, shortly after I was transferred to the Omura Squadron, I was shocked to receive a telegram ordering me to report immediately to the carrier Soryu. This was highly unusual because it was navy policy to always send transfer orders to petty officers by written letter. Something's up, I said to myself. I was filled with a sense of anticipation and foreboding. This was partly because much as I wanted to go to the Soryu, I still hadn't yet landed on the deck of a carrier!"

Thus, unless we are seeing an oversight, it might seem that any well trained IJN pilot was expected to be able to land on a carrier although Mori quickly arranged some training for himself and other pilots of the Omura Squadron. The combination of a constant wind speed and the landing lights might suggest that landing safely was given more priority by the IJN than the USN. We could add the low stall speed specified for the A7M as further evidence for such a mind set.

I also go with the Yorktown. The reasons are simple, the Illustrious had the best protection and AA protection for most of the war, but not enough aircraft. The Soryu had the aircraft but not the protection, the Yorktown had all three