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



## Lucky13 (Jun 14, 2009)

Which was the better design?


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## syscom3 (Jun 14, 2009)

After reading about the quality of the Japanese carriers, and the supremacy of the US designs; there can be only one conclusion.

The Yorktown Class was the best.


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## Amsel (Jun 14, 2009)

The IJN Soryu was built for speed, basically a fast carrier and it paid the price at Midway. It was basically a firetrap. I think alot of the safety features that the allied carriers had to dispell fumes and protect the aviation fuel, the IJN Soryu lacked. 

The HMS Illustrious was an armored carrier, so that greatly reduced the amount of aircraft it could carry( up to 52). The armored deck may not make up for its strike capability. But it was a great design.

CV-5 USS Yorktown could carry up to 90 aircraft using three elevators and three catapults. That makes it the superior strike carrier of the three. It also had more range then the Illustrious as well as speed but not as fast as the Soryu.


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## Ferdinand Foch (Jun 14, 2009)

I'm gonna have to go with the Yorktown class. Wooden flight decks aren't the safest compared to armored ones, but between the additional aircraft and great DC teams, that should make up for it.


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## Vassili Zaitzev (Jun 14, 2009)

The soryu had the greater speed, but lack the defense and DC quality of the other two. Illustrious, did not have many planes, but it's armored deck offered greater protection. The Yorktown had the larger number of aircraft, and while the flight deck was wooden, it had better protection and DC teams then the Soryu. Overall, I have to say the Yorktown.


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## Catch22 (Jun 14, 2009)

If I was on a destroyer or a non-carrier on a carrier task force, I'd want to have a Yorktown defending me. If I was on the carrier itself, I'd want to be on the Illustrious due to the armored deck. A kamikaze hit that would put an American carrier out of action indefinitely would only put a British carrier out of action for an hour.


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## syscom3 (Jun 14, 2009)

Catch22 said:


> If I was on a destroyer or a non-carrier on a carrier task force, I'd want to have a Yorktown defending me. If I was on the carrier itself, I'd want to be on the Illustrious due to the armored deck. A kamikaze hit that would put an American carrier out of action indefinitely would only put a British carrier out of action for an hour.



But you end up needing two RN carriers to provide the striking power of one US carriers.

The USN was proven to be correct in its assessment that the primary purpose of an aircraft carrier is to carry airplanes. The RN showed that armored flight decks are quite a usefull design characteristic, but it cant be at the expense of AC capacity.


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## vikingBerserker (Jun 14, 2009)

Interesting enough the Midway Class of US Carriers were inspired by British Carriers _Conways All the Worlds Fighting Ships 1922-1946_ so kinda the best of both worlds. I had to go with the Yorktowns as well.


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## Catch22 (Jun 14, 2009)

syscom3 said:


> But you end up needing two RN carriers to provide the striking power of one US carriers.
> 
> The USN was proven to be correct in its assessment that the primary purpose of an aircraft carrier is to carry airplanes. The RN showed that armored flight decks are quite a usefull design characteristic, but it cant be at the expense of AC capacity.



Apologies, I wasn't very clear.

What I meant was, I would want a Yorktown as it's more capable, but the RN vessels were safer for crews. So I'd go with the Yorktown.


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## Vassili Zaitzev (Jun 14, 2009)

If I can recall Catch, when the RN came into the Pacific in '45, a few kamikazes hit their flight decks with little or moderate damage, compared to a US carrier. However, the Yorktown class's capability to launch more planes is the better choice, on a strategical level.


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## Catch22 (Jun 14, 2009)

Vassili Zaitzev said:


> If I can recall Catch, when the RN came into the Pacific in '45, a few kamikazes hit their flight decks with little or moderate damage, compared to a US carrier. However, the Yorktown class's capability to launch more planes is the better choice, on a strategical level.



Yes, agreed.


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## syscom3 (Jun 14, 2009)

Vassili Zaitzev said:


> If I can recall Catch, when the RN came into the Pacific in '45, a few kamikazes hit their flight decks with little or moderate damage, compared to a US carrier. However, the Yorktown class's capability to launch more planes is the better choice, on a strategical level.




Strategic and defensive level.


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## Vassili Zaitzev (Jun 14, 2009)

Syscom- for the Yorktown? I'd say for Strategic and offensive level, for the number of planes. Or did you mean the Illustrious?


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## Von Frag (Jun 15, 2009)

One of the British flat tops that was hit by a kamikaze had her armored box warped out of shape so badly that the RN deemed her unrepairable and she was scrapped soon after the war. True she continued flight ops to the end but could barely make 24 knots. I can't remember which carrier it was, nor can I remember which book I read it in. 

USS Franklin suffered severe damage off the coast of Japan from a conventional attack, but was repaired. This probably has to do with economics, and the resource and cash strapped RN probably thought it more expediant to do away with her.


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## syscom3 (Jun 15, 2009)

Vassili Zaitzev said:


> Syscom- for the Yorktown? I'd say for Strategic and offensive level, for the number of planes. Or did you mean the Illustrious?



Yorktown.

The more planes the better.


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## Vassili Zaitzev (Jun 15, 2009)

True. You read Shattered Sword right? I'm starting it right now( have two or three other books I'm working on too.) Is it true that the IJN had more carriers, but the US had more planes?


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## syscom3 (Jun 15, 2009)

Vassili Zaitzev said:


> True. You read Shattered Sword right? I'm starting it right now( have two or three other books I'm working on too.) Is it true that the IJN had more carriers, but the US had more planes?



Brilliant book. Once you start reading, you wont be able to put it down.

And yes, the three US carriers had as many AC as the four IJN carriers. Plus they had AC from Midway to help.


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## Glider (Jun 15, 2009)

Of the three chosen the Yorktown has to be the winner.


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## davparlr (Jun 15, 2009)

Aircraft count is overpowering thus the Yorktown would always be the selection. Even though the wooden decks were vunerable, the Yorktown class carriers were tough nuts and didn't die easily.
(I am sure DC is also a key)

*Hornet*

5 bombs
2 torpedoes
Val crashing on deck
9 US scuttling torpedoes
4 24" Japanese torpedoes
sank

*Yorktown*

Coral Sea
1 bomb
Midway
3 bombs
4 torpedoes
USS Hammann exploding along side
Sank

*Enterprise*

2 bombs
2 kamakazes 
survived war


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## Juha (Jun 15, 2009)

Yorktown

Juha


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## diddyriddick (Jun 15, 2009)

As alluded to earlier, both British and American designs proved the shape of things to come, so the Essex and moreso the Midway class incorporated features from each.

I'd have to give the nod to the Yorktown. The strike capability was tremendous!


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## fastmongrel (Jun 16, 2009)

As an all round balanced design the Yorktown has to be the best. Though the Soryu does look kind of cool and mean.

I did a bit of reading on HMS Illustrious and wow she took a beating. In various actions she was hit time and time again. In the Pacific she was hit by 2 kamikaze but carried on flying operations after repairs at sea. She was finally knocked out of action by a Kamikaze near miss that caused serious hull damage. Even then she was able to sail back to Australia for repairs. I imagine if the war had continued she would have been patched up and carried on the fight to the bitter end what a ship. 

HMS Illustrious (87) - Wikipedia, the free encyclopedia


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## Amsel (Jun 16, 2009)

fastmongrel said:


> As an all round balanced design the Yorktown has to be the best. Though the Soryu does look kind of cool and mean.
> 
> I did a bit of reading on HMS Illustrious and wow she took a beating. In various actions she was hit time and time again. In the Pacific she was hit by 2 kamikaze but carried on flying operations after repairs at sea. She was finally knocked out of action by a Kamikaze near miss that caused serious hull damage. Even then she was able to sail back to Australia for repairs. I imagine if the war had continued she would have been patched up and carried on the fight to the bitter end what a ship.
> 
> HMS Illustrious (87) - Wikipedia, the free encyclopedia


I think the HMS Illustrious was a great vessel. Those ships sure did take a beating in WWII.


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## comiso90 (Jun 16, 2009)

A wood deck has to be easier to repair especially away from skilled labor.

Somebody who has more time than i do....
Please go through the American carrier battle damage and ask the question if an armored deck would have helped... escort carriers included.
An armored deck wont protect against torpedoes...
could in some cases an armored deck be worse?... containing the explosion below the deck instead of venting outward?

.


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## Amsel (Jun 16, 2009)

The USS Arizona had a well armored deck and it didn't help her. She repelled most of the bombs but one penetrated and that was all it took. If a heavily armored Battleship can go down then a carrier with all its ava fuel is most vulnerable.


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## Messy1 (Jun 16, 2009)

I would have to go with Yorktown as well. I think her greater number of aircraft more than makes up for not having a armored flight deck. The Yorktown and her sister ships were plenty tough everywhere else.


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## R Leonard (Jun 16, 2009)

Yorktown, hands down.

Rich


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## vikingBerserker (Jun 16, 2009)

I think an amoured deck would have helped the USS Franklin.


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## syscom3 (Jun 16, 2009)

vikingBerserker said:


> I think an amoured deck would have helped the USS Franklin.



Its impossible to prove .... but more than a few US carriers were probably saved by having a large air contingent on board.


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## parsifal (Jun 17, 2009)

Whilst the Yorktown had a theoretical total of 90 aircraft, her operational maximum was in fact closer to 72. The Soryu had a theoretical maximum of 72, but an operational maximum of 63 aircraft. 

Contrary to either the Japanese or the US, the Illustrious had a theoretical maximum of only 40, and this was the number she fought most of the war with. However, in 1944, it was found that by maintaining a permanent deck park, she could operate up to 52. This was the CAG that the Illustrious class carried into the final battles in the Pacific

So in the end, the operational maximums of the three classes are: Yorktown 72, Soryu 63, and Illustrious 52. 

In terms of defensive capability there is no comparison. The Illustrious class, and the light fleet carriers that followed them and adopted the same closed hangar system, were far superior to anything the US possessed, including the Essex classes until long after the war. There were reasons why most post war minor navies went for British Carriers and US aircraft after in their postwar navies

Had Soryu survived the Midway debacle, her defensive capabilities would have been significantly improved as were all the Japanese carriers. though never as well protected as either the US or the british carriers, the Japanese after Midway were quick to adopt CO2 gas lines, and other damage control measures that significantly reduced the risk of fires that had so badly devastated all the carriers at Midway. In 1944 this problem returned when the Japanese were forced to utilise highly volatile unrefined crude from Balipapaan and Tarakan. This fuel was apparently much more volatile than refined fuel, and the result was the repeat debacle at Phillipines Sea. 

Given also that the Brit Carriers could operate in weather conditions that the other nationalities could not, and that she was equipped and her air group trained to operate at night, ther is really no issue for me....the illustrious wins hands down.....in a fight under the right conditions, she would make a meal out of either of the other two. 

In 1940 her Fulmars and Swordfish, operating at night, or in the soupy conditions of the North Atlantic are going to outclass the F2as, the TBDs and the Vindicators then available to the USN by a wide margin. In 1941 and '42, the US Carrier achieves a notable superiority because of the wing folding SBDs, Avengers and Wildcats she was carrying. In 1943, the advantage swings slightly back in favour of the Brit carrier, because of her Corsairs that she now has embarked


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## Glider (Jun 17, 2009)

I think its worth mentioning that the last of the Illustrious Class the Implacable and Indefatigable operated 72 aircraft during the war as they had an extra half halger deck.


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## fastmongrel (Jun 17, 2009)

How about comparing light fleet carriers The US Independence class, Japanese Taiyo, British Colosuss. They were all compromises to get flat tops in service quickly and all carried nearly the same numbers of aircraft.


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## Lucky13 (Jun 17, 2009)

Think that I'll put my money on the Independence class...


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## Amsel (Jun 17, 2009)

parsifal said:


> Whilst the Yorktown had a theoretical total of 90 aircraft, her operational maximum was in fact closer to 72. The Soryu had a theoretical maximum of 72, but an operational maximum of 63 aircraft.
> *The number of aircraft the Yorktown carried into Midway was 75*
> 
> Contrary to either the Japanese or the US, the Illustrious had a theoretical maximum of only 40, and this was the number she fought most of the war with. However, in 1944, it was found that by maintaining a permanent deck park, she could operate up to 52. This was the CAG that the Illustrious class carried into the final battles in the Pacific
> ...



The Illustrious proved that the RN was not up to speed in naval air combat which WWII proved was the new age of naval warfare.


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## comiso90 (Jun 17, 2009)

parsifal said:


> Contrary to either the Japanese or the US, the Illustrious had a theoretical maximum of only 40, and this was the number she fought most of the war with. However, in 1944, it was found that by maintaining a permanent deck park, she could operate up to 52. This was the CAG that the Illustrious class carried into the final battles in the Pacific
> 
> So in the end, the operational maximums of the three classes are: Yorktown 72, Soryu 63, and Illustrious 52.



Launch, recovery and re-arm times with a permanent (read "cluttered") flight deck.... less elevators and catapults..

yikes... By the time the got the last plane in the air, the first would be ready for refueling....

An exaggeration of course but they had to have some pretty low turn around times. A second strike can be decisive in a fleet battle. 

.


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## Glider (Jun 17, 2009)

Amsel said:


> The Illustrious proved that the RN was not up to speed in naval air combat which WWII proved was the new age of naval warfare.



This is a little missleading. I do not disagree with you when you say that going from two hanger deck (Ark Royal) to one (Illustrious) was a mistake, but they did get a lot right Heavy AA guns, Multiple directors, a significant number of Light AA guns, increased protection of the hanger area. One plus of the Illustrious is that she could take the extra weight of the changes needed for war better than the Yorktown class. The Enterprise was topheavy and needed to ahve a bulge fitted to maintain stability.
The RN operated at night and in very poor conditions before any other navy but in aircraft design and fleet tactics the USN and IJN were ahead of the RN. 

As mentioned earlier the later versions of the Illustrious did operate more aircraft the Implacable operating 81 aircraft during the war which was a good number by any standards. 
Personally I could never work out why they designed the Illustrious class, a modified version of the Ark Royal would have been cheaper and available sooner, plus of course she carried more aircraft than the Illustrious.


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## Amsel (Jun 17, 2009)

Hello Glider, I think alot of it comes down to doctorine at the time. I am in no way disparaging the RN but the early war RN doctorine was not conducive to great results for the sea battles of the Pacific. I am not being misleading, but that is my belief. And neither was the USN, but the amount of sorties deployed by the Yorktown , Hornet, and Enterprise dealt a decisive blow to the IJN that they could never recover from. A trade of the Yorktown and a destroyer for four IJN carriers and a heavy cruiser. That is a victory of epic proportions that opened the worlds eyes to the new frontier of naval combat.


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## Amsel (Jun 17, 2009)

Glider said:


> This is a little missleading. I do not disagree with you when you say that going from two hanger deck (Ark Royal) to one (Illustrious) was a mistake, but they did get a lot right Heavy AA guns, Multiple directors, a significant number of Light AA guns, increased protection of the hanger area.
> 
> 
> > The Yorktown could not be refitted for obvious reasons but the Enterprise by wars end was fitted with 8-5 3/8's guns, 40-40mm Bofors, and 50- 20mm Orlikon's as her hanger defense. The Bofors are arguably the best AA of the war for ship protection.


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## renrich (Jun 17, 2009)

CV5 was not a Midway class carrier. Those came later. The Yorktown class were the pick of the litter, at that time, particularly in the PTO. The British carriers were not well fitted for the Pacific and they needed armored flight decks because they had no fighters that could defend them until they got them from the US, thanks to the RAF. The Japanese carriers were not designed as well as the Yorktown class as far as getting strikes into the air. That acted as a force multiplier for the Yorktown class.


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## syscom3 (Jun 17, 2009)

renrich said:


> CV5 was not a Midway class carrier. Those came later. The Yorktown class were the pick of the litter, at that time, particularly in the PTO. The British carriers were not well fitted for the Pacific and they needed armored flight decks because they had no fighters that could defend them until they got them from the US, thanks to the RAF. The Japanese carriers were not designed as well as the Yorktown class as far as getting strikes into the air. That acted as a force multiplier for the Yorktown class.




Theres also the intangibles that really add to a carriers quality, like its ability to maintain and repair the air wing far from its base, ability for the carrier to stay at sea, etc.

That further add's to the Yorktown class's reputation.


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## Amsel (Jun 17, 2009)

renrich said:


> CV5 was not a Midway class carrier. Those came later. The Yorktown class were the pick of the litter, at that time, particularly in the PTO. The British carriers were not well fitted for the Pacific and they needed armored flight decks because they had no fighters that could defend them until they got them from the US, thanks to the RAF. The Japanese carriers were not designed as well as the Yorktown class as far as getting strikes into the air. That acted as a force multiplier for the Yorktown class.


Thanks Renrich, but if your refering to my comments about the Midway class being laid down as an open hanger carrier, I was refering to the choice being made after Midway to not go to the armored box hanger on the newer vessels. I agree about the force multiplier of more sorties faster. 

The Illustrious was more suited for the North Atlantic where rough weather and more darkness made it superior. But in the massive naval campaign of the South Pacific it wouldv'e been at a disadvantage. I know there was better RN CV's then the Illustrious.


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## Glider (Jun 17, 2009)

Amsel said:


> Glider said:
> 
> 
> > This is a little missleading. I do not disagree with you when you say that going from two hanger deck (Ark Royal) to one (Illustrious) was a mistake, but they did get a lot right Heavy AA guns, Multiple directors, a significant number of Light AA guns, increased protection of the hanger area.
> ...


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## Glider (Jun 17, 2009)

Can anyone tell me why I get 8 when typing an eight?


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## Glider (Jun 17, 2009)

Amsel said:


> Glider said:
> 
> 
> > This is a little missleading. I do not disagree with you when you say that going from two hanger deck (Ark Royal) to one (Illustrious) was a mistake, but they did get a lot right Heavy AA guns, Multiple directors, a significant number of Light AA guns, increased protection of the hanger area.
> ...


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## syscom3 (Jun 17, 2009)

Amsel said:


> .... The Bofors are arguably the best AA of the war for ship protection.



The 5"/38's with proximity fuses turned out to be the best.

The Midway class after the war ended had nothing but 5".


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## R Leonard (Jun 17, 2009)

parsifal said:


> Whilst the Yorktown had a theoretical total of 90 aircraft, her operational maximum was in fact closer to 72. The Soryu had a theoretical maximum of 72, but an operational maximum of 63 aircraft.
> 
> Contrary to either the Japanese or the US, the Illustrious had a theoretical maximum of only 40, and this was the number she fought most of the war with. However, in 1944, it was found that by maintaining a permanent deck park, she could operate up to 52. This was the CAG that the Illustrious class carried into the final battles in the Pacific
> 
> So in the end, the operational maximums of the three classes are: Yorktown 72, Soryu 63, and Illustrious 52.



If you’re going to reach into 1945, let us look to USS Enterprise, the only Yorktown class carrier to survive the war. Drawing from USN aircraft location reports:

Average Jan – Dec 1942 Air Group
27	VF
36	VSB
14	VT
77	Total

Average Jan – Dec 1943 Air Group
36	VF
34	VSB
17	VT
87	Total

Average Jan – Nov 1944 Air Group 
40	VF
28	VSB
18	VT
86	Total

Average Dec 1944 – Aug 1945 Night Air Group
35	VF
25	VT
60	Total

Average Jan 1942 – Nov 1944 Day Air Group
34	VF
33	VSB
16	VT
83	Total

Overall Average Air Group
33	VF
32	VSB
18	VT
83	Total

Operating as a regular day fleet carrier, a Yorktown class could operate quite a bit more than your noted 72. Note also that the USN carriers were already using a deck park as standard doctrine, they always had. RN carriers had to adopt the deck park in order to significantly enlarge their air group complements. Any other increases in air group complements were driven by the aircraft themselves

You are, then, IMO, mixing apples and oranges in the same basket; capacity goes down with non folding wing SBD’s and F4F-3’s. TBD’s, with their wings folded, are pretty much even width-wise with TBF/TBM’s with theirs folded. 

Average Air Group with F4F-3’s, TBD’s, and SBD’s (roughly Dec 41 through Apr 42)
18	VF
36	VSB
18	VT
72	Total

Average Air Group with F4F-4’s, TBD’s, and SBD’s(roughly May 42 through Jul 42)
28	VF
33	VSB
16	VT
77	Total

Average Air Group with F4F-4’s, TBF’s, and SBD’s (roughly Aug 42 through Apr 43)
36	VF
35	VSB
12	VT
88	Total

Average Air Group with F4U’s, TBF’s, and SBD’s (May Jun 1943)
39	VF
38	VSB
20	VT
97	Total

Average Air Group with F6Fs, TBFs, and SBDs (roughly Jul 1943 to Jul 1944)
37	VF
30	VSB
18	VT
85	Total

Average Air Group with F6F’s, TBF’s, and SB2C’s (roughly Aug 1944 through Nov 1944)
43	VF
32	VSB
19	VT
94	Total

Average Air Group as Night Operations carrier, F6F’s and TBM’s (Dec 1944 through Aug 1945 – does not include subtractions for aircraft lost incidental to damage to ship nor yard time with no air group assigned)
35	VF
25	VT
60	Total

And, of course the reduced strength CVG(N) was still larger than the deck-parked Illustrious’ air group of 52 in 1945.




> In terms of defensive capability there is no comparison. The Illustrious class, and the light fleet carriers that followed them and adopted the same closed hangar system, were far superior to anything the US possessed, including the Essex classes until long after the war. There were reasons why most post war minor navies went for British Carriers and US aircraft after in their postwar navies



Two different theories of ship defense. One, protect against the inevitable bomb hit, the other, try to prevent the bomb hit. Yorktown, I’d point out, did pretty well, DC wise, even when hit by bombs at Coral Sea and at Midway. Again, apples and oranges. Also that after WWII I think you would find that a few navies acquired US built carriers as well. Most of the RN carriers exported went to Commonwealth nations, most of the other nations picked up USN carriers, albeit none of the CV's as the US was not about to let them go. You don’t suppose there were any economic and political issues involved in Commonwealth carrier decisions, do you?



> Had Soryu survived the Midway debacle, her defensive capabilities would have been significantly improved as were all the Japanese carriers. though never as well protected as either the US or the british carriers, the Japanese after Midway were quick to adopt CO2 gas lines, and other damage control measures that significantly reduced the risk of fires that had so badly devastated all the carriers at Midway. In 1944 this problem returned when the Japanese were forced to utilise highly volatile unrefined crude from Balipapaan and Tarakan. This fuel was apparently much more volatile than refined fuel, and the result was the repeat debacle at Phillipines Sea.



Based on her construction, design and materials, to attempt to retrofit Soryu to meet RN or USN DC standards would be huge, time consuming project that would severely cramp operational realities, especially if Soryu was the sole survivor of the Midway Four. Makes me wonder if the IJN would even waste their time. In historical fact, the Japanese never raised the DC capability of their carriers to a RN or USN standard, both in terms of design and machinery or, just as importantly, overall personnel training. “Significantly improved” is subjective. Just about any improvement to Soryu’s DC capability would be “significant.”



> Given also that the Brit Carriers could operate in weather conditions that the other nationalities could not, and that she was equipped and her air group trained to operate at night, ther is really no issue for me....the illustrious wins hands down.....in a fight under the right conditions, she would make a meal out of either of the other two.



I was not aware that either the Japanese or the Americans kept their carriers in port when threatened by foul weather. Learn something new every day. Your last sentence, though, is telling “. . . under the right conditions . . .” which means, of course, that any other conditions might just preclude the possibility of success. I’d suggest, from your own phrasing, that the suite of conditions under which a Yorktown carrier might typically expect success in an unlikely engagement with an Illustrious might have a trifle more options to it than the suite possessed by an Illustrious.



> In 1940 her Fulmars and Swordfish, operating at night, or in the soupy conditions of the North Atlantic are going to outclass the F2as, the TBDs and the Vindicators then available to the USN by a wide margin. In 1941 and '42, the US Carrier achieves a notable superiority because of the wing folding SBDs, Avengers and Wildcats she was carrying. In 1943, the advantage swings slightly back in favour of the Brit carrier, because of her Corsairs that she now has embarked



Their only advantage is at night and that only works when you know where the enemy is, like a nice snug Italian harbor. Night searches are a whole different game. You are aware, are you not, that night operations from US carriers were not all that unusual during the same time period? For both the RN and the USN night operations were an operational capability, sort of a “we can do this” as opposed to “this is the way we prefer to do business.” Also SBDs did not have folding wings and, with the exception of the XF4F-4, folding winged F4F’s did not reach the fleet until early May 1942. The RN had F4Fs in action long before the USN (G-36A’s from the French Navy order which became Martlet I’s)and their first load of F4Fs with folding wings (F4F-4B/Martlet IV’s) left Norfolk aboard (well, what do you know?) HMS Illustrious on 12 December 1941. Illustrious had been in the Norfolk Navy Yard for the previous *eleven* months recuperating from various indignities inflicted by enemy bombs, which impacted in the daytime.

Any advantage you might perceive in an Illustrious air group operating F4Us, and in summer of 1945 we’re talking about 1830 Squadron (LCDR(A) A M Tritton, DSC +2 Bars RNVR) and 1833 Squadron (LCDR(A) N S Hansen, DSC, RNVR), together amassing about 36 F4U’s, might be somewhat optimistic. Against a typical contemporary USN carrier, those 36 would have to contend, discounting the strike TBM’s and SB2C’s, and depending on which US carrier, some 73 F6F-5’s, such as VF-87(LCDR C E Ingalls, Jr) and VBF-87 (CDR P W Maxwell), USS Ticonderoga; or a mix of 32 FG-1D’s and 18 F4U-1C’s (not to mention the air group night fighter section of 6 F6F-5N or the photo section of 2 F6F-5P’s), such as VF-85 (LCDR W W Ford) and VBF-85 (LCDR S B Strong), USS Shangri La; or a mix of 36 F6F-5’s and 37 FG-1D’s, such as VF-88 (LCDR R G Crommelin) and VBF-88 (LCDR J E Hart), USS Yorktown. Yup, I’d say that was a little optimistic.

Regards,

Rich


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## syscom3 (Jun 17, 2009)

As usual, Leonard has a ton of good stuff.


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## parsifal (Jun 18, 2009)

From the posts in reply to by Post number XX I can see that I need to explain a few terms I have used. “Operational Maximum” to me is not a theoretical total or a total that can be embarked when the carrier is being used in a non-battle situation. It is the maximum carried into battle , and when a carrier is used in more than one battle, one should look into the maximums carried into as many of those battles as one has reliable information for.

In the case of the british, however, I would draw a distinction for the period 1939-41. In that period British carriers routinely carried into battle far less aircraft than they were designed for, primarily because of the chronic pilot shortages that plagued the FAA at that time.

The other thing that needs to be noted is that the operational maximums for the Yorktown (the focus of this debate) were not the same as those for her two sisters. I am not sure why that is the case, but it just is. 

Unfortunately I don’t have sufficiently accurate enough information to apply the same rigour to the Illustrious. This has meant, unfortunately that I have had to group all the Illustrious class together to try and get meaningful figures on the operational maximum for that class of ship, rather than the particular ship we are looking at.

So, what were the operational maximums of the carriers in question at comparable times in the war??? Turning first Yorktown and her sisters, I found the following:

31-12-41 (just prior to the Wake operation)
Enterprise:	72, Yorktown:	69

April ’32 (Raids to the Marshalls)
Enterprise:	81, Hornet: 65

May ’42 (Coral Sea)
Yorktown:	71

June ’42 (Midway)
Enterprise:	78, Yorktown:	75, Hornet: 79

August ’42 (Watchtower)
Enterprise:	84

October ’42 (Santa Cruz)
Enterprise:	84, Hornet: 87

November 1942 (Rennell Is)
Enterprise:	78

June 44 (Saipan)
Enterprise:	69

Average (Class): 76.3
Average (Yorktown):	71.7

Illustrious CAG (prior to selected operations

Aug-40: 30 a/c 
Nov-40: 39 a/c 
Nov-42: 45 a/c 
Aug-45: 54 a/c 

Selected Illustrious Class CAGs 

April ’42:	
Indomitable:	45
Formidable:	38

11/42 (Torch)
Formidable:	42, Victorious:	47

January “44 (raids on Tirpitz)
Victorious:	48

Average (Class): 43.2
Average (Ilustrious):	42

Now, looking at the damage needed to sink each of the classes, well none of the Illustrious class were ever sunk, although the name ship herself came close to spoiling that record, in January 1941, when she suffered no less than 6 hits, (5 x 1000 lbs, and one 500 lbs), a stuka crashing into her upper deck, and a further hit later that day. Whilst in port undergoing emergency repairs she suffered a further 3 hits. The damage to her was extensive, and included , in summary 


1. Hit and destroyed the starboard S2 pom-pom, killing most of the crew; 
2. Penetrated the forward end of the flight deck and passed overboard, exploding above the water. Caused extensive splinter damage to several compartments and started a fire in one; 
3. Exploded in the after lift-well, 10-20 ft below the flight deck, severely damaging the lift and destroying a Fulmar on the lift; 
4. Penetrated the armored flight deck and exploded just above the hangar deck, damaging the forward lift and surrounding structure, and starting a fire on the hangar deck. Several aircraft in the hangar deck were destroyed; 
5. Hit the after end of the after lift, adding to the damage of bomb #3; 
6. Penetrated a pom-pom platform, passed through the shipand went overboard without detonating. A fire was started on two mess decks. 
7. Also hit the after lift, completing its destruction. 
8. A near-miss off the starboard side caused slight structural damage and minor flooding. 


Casualties amounted to 126 dead in that attack. The ship had been attacked by a force of about 50 Stukas, which in the following days expanded to an average daily attack of over 70 aircraft

But it is worth noting that despite this terrible pounding the Ilustrious never lost power, and remained underway at all times. At no time was she forced to hoist an NUC (not under command) signal. Within 14 days she made good her escape, able to make more than 20 knots in her run out of the central basin 


In comparison, the Yorktown suffered damage sufficient to knock her out of action from three 500 lb hits and 2 x 18 inch aerial torpedoes. 

The following is a brief summary of the hits that led to her loss

Despite the barrage, though, three Vals scored hits with 250 kg bombs. The bombs hit just abaft number two elevator on the starboard side, exploding on contact and blasting a hole about 10 feet square in the flight deck. Splinters from the exploding bomb decimated the crews of the two 1.1-inch gun mounts aft of the island and on the flight deck below. Fragments piercing the flight deck hit three planes on the hangar deck, starting fires. One of the aircraft, a Yorktown Dauntless, was fully fueled and carrying a 1,000-pound bomb. Prompt action by Lt. A. C. Emerson, the hangar deck officer, prevented a serious conflagration by releasing the sprinkler system and quickly extinguishing the fire. 
The second bomb to hit the ship came from the port side, pierced the flight deck, and exploded in the lower part of the funnel. It ruptured the uptakes for three boilers, disabled two boilers themselves, and extinguished the fires in five boilers. Smoke and gases began filling the firerooms of six boilers. The men at number one boiler, however, remained at their post despite their danger and discomfort and kept its fire going, maintaining enough steam pressure to allow the auxiliary steam systems to function. 
A third bomb hit the carrier from the starboard side pierced the side of number one elevator and exploded on the fourth deck, starting a persistent fire in the rag storage space, adjacent to the forward gasoline stowage and the magazines. The prior precaution of smothering the gasoline system with CO2, undoubtedly prevented the gasoline's igniting. 
While the ship recovered from the damage inflicted by the dive-bombing attack, her speed dropped to six knots; and then, at 1440, about 20 minutes after the bomb hit that had shut down most of the boilers, Yorktown slowed to a stop, dead in the water. 
At about 1540, Yorktown prepared to get underway again; and, at 1550, the engine room force reported that they were ready to make 20 knots or better. The ship was not yet out of the fight. \
Simultaneously, with the fires controlled sufficiently to warrant the resumption of fueling operations, Yorktown began fueling the gasoline tanks of the fighters then on deck. Fueling had just commenced when the ship's radar picked up an incoming air group at a distance of 33 miles away. While the ship prepared for battle — again smothering gasoline systems and stopping the fueling of the planes on her flight deck — she vectored four of the six fighters of the CAP in the air to intercept the incoming raiders. Of the 10 fighters on board, eight had as much as 23 gallons of fuel in their tanks. They accordingly were launched as the remaining pair of fighters of the CAP headed out to intercept the Japanese planes. 
At 1600, Yorktown churned forward, making 20 knots. The fighters she had launched and vectored out to intercept had meanwhile made contact, Yorktown received reports that the planes were Kates. The Wildcats downed at least three of the attacking torpedo planes, but the rest began their approach in the teeth of a heavy antiaircraft barrage from the carrier and her escorts.
Yorktown maneuvered radically, avoiding at least two torpedoes before two "fish" tore into her port side within minutes of each other. The first hit at 1620. The carrier had been mortally wounded; she lost power and went dead in the water with a jammed rudder and an increasing list to port. 
As the list progressed, Cmdr. C. E. Aldrich, the damage control officer, reported from central station that, without power, controlling the flooding looked impossible. The engineering officer, Lt. Cmdr. J. F. Delaney, soon reported that all fires were out; all power was lost; and. worse yet, it was impossible to correct the list. Faced with that situation, Capt. Buckmaster ordered Aldrich, Delaney, and their men to secure and lay up on deck to put on life jackets. 
The list, meanwhile, continued to increase. When it reached 26 degrees, Buckmaster and Aldrich agreed that the ship's capsizing was only a matter of minutes. "In order to save as many of the ship's company as possible," the captain wrote later, he "ordered the ship to be abandoned." 

Interestingly, the amount of damage needed to immobilize (and eventually cause the loos) of Hornet, was remarkably similar to the amount of damage needed to do the same to Yorktown. Hornet was immobilized by three bomb hits, two torpedo hits, and a Kate crashed into the superstructure

In my opinion the damage firepower needed to knock the Yorktown out was about one third to half that expended on the Illustrious. In terms of the ordinance weight, the Illustrious had absorbed about 8500 lbs of explosive, whilst Yorktown and Hornet had each absorbed about 2200 lbs of explosives. Unquestionably the torpedoes had the potential to cause greater levels of damage than the bombs falling on the Illustrious, but still, the weight of bombs is still a rough, but still valuable measure of the amount of damage each ship could absorb


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## renrich (Jun 18, 2009)

Bombs let air in, torpedoes let water in. Torpedoes were far more damaging to ships in WW2. Enterprise was hit often by bombs and always survived.


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## Glider (Jun 18, 2009)

I have some information on the Aircraft carried by the Illustrious at various times during the war if that will help.

Sept 1940 15 Fulmars and 18 Swordfish
May 1942 20 Wildcats and 20 Swordfish
Sept 1943 26 Wildcats, 10 Seafires and 10 Barracudas
May 1944 28 Corsairs and 21 Avengers
March 1945 36 Corsairs and 16 Avengers


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## Amsel (Jun 18, 2009)

Torpedos could not be protected against.


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## parsifal (Jun 18, 2009)

As a rough generalization, bombs were more effective at closing down flight operations, and were more conducive at propagating fire, however topredoes were more dangerous to the propulsion and flotation systems of a ship. There were effective defences against both forms of attack....

Wiki has the following article with respect to anti-torpedo bulges....

_Essentially, the bulge is a lateral compartment at the waterline level that is isolated from the ship's internal volume. It is part air-filled, and part free-flooding. In theory, a torpedo strike will rupture and flood the air-filled component of the bulge and the water-filled part will dissipate the shock and absorb explosive fragments, leaving the ship's main hull structurally intact. Transverse bulkheads within the bulge limit flooding throughout the entirety of the structure.

The bulge was developed by the British Director of Naval Construction, Eustace Tennyson-D'Eyncourt, who had four old Edgar-class protected cruisers so fitted in 1914. These ships were used for shore bombardment duties, and so were exposed to inshore submarine and torpedo boat attack. Grafton was torpedoed in 1917, and apart from a few minor splinter holes, the damage was confined to the bulge and the ship safely made port. Edgar was hit in 1918, this time damage to the elderly hull was confined to dented plating. The Royal Navy had all new construction fitted with bulges from 1914, beginning with the Revenge-class battleships. Older ships also had bulges incorporated during refits. The Royal Navy had its large monitors fitted with enormous bulges. This was fortuitous for Terror, which survived 3 torpedoes striking the hull forwards and her sister Erebus, which survived a direct hit from a remotely-controlled explosive motor boat that ripped off 50 feet (15.25 m) of her bulge.

Later designs of bulges incorporated various combinations of air and water filled compartments and packing of wood and sealed tubes. As bulges increased a ship's beam, they caused a reduction in speed, which is a function of the length to beam ratio. Therefore, various combinations of narrow and internal bulges appeared throughout the 1920s and into the 1930s. The bulge had disappeared from construction in the 1930s, being replaced by internal arrangements of compartments with a similar function

Anti-torpedo bulges were still added as retrofits to older ships, such as HMS Renown and USS Enterprise_

As a rough generalization, British carrier design was thought to be ahead of the USN in terms of its underwater protection, as well as the extent of its deck protection. However, it has to be conceded that the Ark Royal came up short when it came to the crunch. Whilst her loss can be attributed somewhat to poor damage control of the particular event . As the sole modern carrier in more or less continous service from the very beginning of the war, she had never the opportunity to rectify some of the more glaring design faults that were clearly evident, even before her loss. As part of a very modest pre-war re-arrmament program, her designers had taken the shortcut of routing the boiler room uptakes directly beneath the lower hangar, and this proved to be a very vulnerable aspect, as the flooding of the port boiler room generated a modest list of only 19 degrees, but this was sufficient to block the furnace emissions, with a resultant fire contributing greatly to her eventual loss. If the uptakes had been routed further up in the hull, it would have increased the angle of heel needed to close off the funnel exhausts, but in turn would have restricted the aircraft complement she could carry on such a restricted displacement. Another option would have been to armour the funnel uptakes, but this would have increased her displacement above 22000 tons, which for political reasons was unnacceptable to the pacifist pre-war British governments.

But whilst at least these passive defence measures were considered, and ultiimately quite successfully tackled in British carrier design, in the prewar US carriers it was not well tackled, with the result that US Carriers were not well protected, as built, with passive design features. Their internal anti-toprepdo protection was quite weak, and this showed in their relative inability to withstand much punishment, particularly from torpedoes. Small wonder that some of you are saying that there was no effective torpedo defences. In the US experience this was quite true until the arrival of the Essex class. As previously pointed out by a number of the Americans in this forum, the US carriers relied primarily on their ability to carry large numbers of aircraft. That is not to say thet they did not incorporate some good defensive features, but the Enterprise class, like the Ark Royal were major exercises in design compromise, and for the Americans a great deal was sacrificed so as to get as many planes to sea as possible...not the one hundred as is often claimed for them, but operationally more about the 70-80 number, but still an impressive number


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## parsifal (Jun 18, 2009)

Ther is one other variable to consider in this debate....the displacements of the ships being compared. In the pre-war treaty driven navies, the displacement of the ship was paramount....basically the heavier the ship, the less numbers of that ship were going to be available.

The Illustrious class were the heaviest of the three, using deep load displacements as a gude (I cannot rememeber if the treaties used deep load or standard). She had a displacement of 29000 tons.

The Yorktowns were next, at 27000 tons

Ther was some variation between the Soryu and the Hiryu, but the Soryu was lightweight, she had a deep load displacement of only 18500 tons.

This means that for every three Yorktowns, you could have 4.5 Soryus (roughly). Using this favourite argument of aircraft numbers being the all important criteria, and based on operational maximums of 76 (for the Yorktowns) versus 63 (for the Soryus, the Soryus represent the better value....the tonnages spent on the Yorktowns allowed 228 aircraft to be taken to sea, whilst the erquivalent tonnage for the Japanese carriers allowed 284 aircraft to be taken to sea. 

Of course the Soryus were more vulnerable, than the Yorktowns, but just how vulnerable becomes a little more problematic, if the Japanese can field 50% more hulls on the same displacement


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## vikingBerserker (Jun 18, 2009)

With regards to the Yorktown I think you left out the final blows being 2 torpedoes from the I-168 (a 3rd had blown the USS Hammann (DD-412) in half).

Also, you have to keep in mind that at Coral Sea she had been hit by a Val and had been temprarily repaired in 4 days before Midway.


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## parsifal (Jun 18, 2009)

vikingBerserker said:


> With regards to the Yorktown I think you left out the final blows being 2 torpedoes from the I-168 (a 3rd had blown the USS Hammann (DD-412) in half).
> 
> Also, you have to keep in mind that at Coral Sea she had been hit by a Val and had been temprarily repaired in 4 days before Midway.




All true, but the ship was totally knocked out by the airstrikes. She was dead in the water and no lnger contributing to the battle. The sub torpedo from I-168 did the actual sinking, By comparison the Illustrious was never removed as a functional unit of the fleet throughout her ordeal. 

The object of the game, in the first instance is to remove the threat, which, if that can be achieved without actually sinking the hull is all the better. 

Remember also that Hoirnet suffered nearly identical levels of damage when she was lost


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## R Leonard (Jun 18, 2009)

parsifal said:


> All true, but the ship was totally knocked out by the airstrikes. She was dead in the water and no lnger contributing to the battle.




Nope, you need to read up a little more on Midway.


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## parsifal (Jun 18, 2009)

R Leonard said:


> Nope, you need to read up a little more on Midway.



Okay, are you suggesting the ship could undertake independant action of any kind after the second strike by the kates hit her????


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## R Leonard (Jun 19, 2009)

parsifal said:


> From the posts in reply to by Post number XX I can see that I need to explain a few terms I have used. “Operational Maximum” to me is not a theoretical total or a total that can be embarked when the carrier is being used in a non-battle situation. It is the maximum carried into battle , and when a carrier is used in more than one battle, one should look into the maximums carried into as many of those battles as one has reliable information for.



You must have missed the source of the aircraft complements noted in my last, to wit, the actual USN aircraft location reports which were submitted to BuAer on a weekly basis noting the number of aircraft present in a given squadron. Not theoretical, drawn from the actual number of aircraft present in squadrons as reported through channels to BuAer.



> . . . less aircraft than they were designed for, primarily because of the chronic pilot shortages that plagued the FAA at that time.



I have never heard of this explanation for smaller complements aboard RN fleet carriers. Do you have some official source which explains this?



> . . . operational maximums for the Yorktown . . . were not the same as those for her two sisters. I am not sure why that is the case, but it just is.



Yorktown was lower due to the aircraft carried, as I pointed out in my previous. F4F-3’s and SBD’s did not have folding wings and, therefore, took up more room. Yorktown did not embark folding wing F4F-4’s until 28 May 42 as she deployed for Midway. One might note that the number of fighters aboard Yorktown jumped from the VF-42 F4F-3 complement of 18 up to the VF-3 complement of 27. 

I find it interesting that you want to explain smaller RN air groups by a lack of pilots/crew when you fail to recognize the effects of an overall USN shortage of TBD’s in the Pacific limiting the number that could be assigned to a given carrier. The three Yorktown class carriers were, in fact, rated for 18 TBD’s. 



> Unfortunately . . . the particular ship we are looking at.



Which is exactly why I used Enterprise data as it encompassed the entire war rather than just the first 6 months.



> So, what were the operational maximums of the carriers in question at comparable times in the war??? Turning first Yorktown and her sisters, I found the following:
> 
> 31-12-41 (just prior to the Wake operation)
> Enterprise:	72, Yorktown:	69



Wake operation was in 24 February 1942. On 31 December 42, Yorktown had arrived at San Diego, Hornet was at Norfolk, and Enterprise was at sea. Your count is a little off:

Yorktown
VT-5 - 14 TBD-1
VS-5 - 19 SBD-3
VS-5 - 2 SNJ-3
VF-42 - 18 F4F-3
VB-5 - 19 SBD-3
CYAG - 1 SBD-3
CV-5 - 2 JRF-5
CV-5 - 1 SOC-1
Subtotal 71 combat aircraft
Total 76 aircraft

Enterprise
VT-6 - 1 SNJ-3
VT-6 - 18 TBD-1
VS-6 - 10 SBD-2
VS-6 - 8 SBD-3
VF-6 - 3 F4F-3
VF-6 - 17 F4F-3A
VB-6 - 18 SBD-2
CV-6 - 2 JRF-2
CV-6 - 2 SBD-2
CV-6 - 2 SBD-3
CV-6 - 2 SOC-3
CV-6 - 4 TBD-1
CEAG - 1 SBD-2
Subtotal 83 combat aircraft
Total 88 aircraft

Hornet
VT-8 - 7 SNB-1
VT-8 - 8 TBD-1
VS-8 - 20 SBC-4
VF-8 - 19 F4F-3
VF-8 - 2 F4F-3A
VF-8 - 2 SNJ-3
VB-8 - 19 SBC-4
CV-8 - 2 JRF-5
CV-8 - 2 OS2U-2
Subtotal 68 combat aircraft
Total 81 aircraft



> April ’32 (Raids to the Marshalls)
> Enterprise:	81, Hornet: 65



Marshalls-Gilberts raids were 1-2 February 1942, not in April. Hornet was no where near the action. These raids were carried out by Enterprise and Yorktown.

YAG had lost 3 VF-42 F4F-3’s in take off accidents between 8 Jan 42 and 14 Jan 42. The ship was at sea, on her way to Samoa. There was no where to get replacement aircraft. So, on the eve of the 1 Feb 42 Jaluit/Makin strikes, VF-42 had but 15 aircraft and that the YAG total combat complement available was 68 out of the 71 it had on 31 December. It did not mean that 15 F4F-3’s were all that could be operated, nor that 68 was the maximum operational complement. It does not mean, no matter how much you want it to, that 68 aircraft was the maximum Yorktown could carry into battle, it only means this was the number on hand.

Enterprise started out with on 31 Dec 41 with 83 combat aircraft. That day VF-6 lost b/n 3907 in a landing accident. The ship arrived at Pearl Harbor on 7 Jan 42 and the lost F4F-3 was replaced by a pool spare so this did not result in a complement change; so Enterprise and the EAG left for the north Marshalls on 11 Jan 42 with a full combat complement of 83 aircraft. On 16 Jan, an SBD was lost in a landing accident and a TBD-1 disappeared altogether. This reduced available, not rated, aircraft to your noted 81.



> May ’42 (Coral Sea)
> Yorktown:	71



I count 69 VF/VSB/VT aboard. VF-42 lost two F4F-3’s on 4 May 42 and VT-5 lost a TBD-1, so that does not quite explain the difference. In any case, availability does not always equal routine operating capacity and does not mean that capacity is lowered.



> June ’42 (Midway)
> Enterprise:	78, Yorktown:	75, Hornet: 79



Enterprise lost one TBD, b/n 370, in a landing accident on 28 May, reducing its available TBD strength to 14. VF-6 had 27 F4F-4’s; VB-6, 19 SBD’s (1 GC); and VS-6, 18 SBD; giving us, indeed, a total on the eve of the battle of 78, but they started with 79. VT-6 had previously lost TBD’s b/n’s 0335 (see above) and, later, 0274, in the Marshall’s strikes; neither had been replaced, so with 18 on hand on 31 Dec 41 and these three losses, none of which were replaced as there was naught with which to replace them, that should have left us with 15 TBD’s, but alas, it appears as one seems to have escaped my notice as there were but 14 left after Lindsey’s crash. Again, though, your subtraction out of losses does not give an accurate picture of routine operating complements.

Yorktown’s VT-3 had 16 TBD’s on hand for the deployment, one, b/n 1517, was a dud and was left behind at Pearl; there were no spares not already earmarked for other duty to replace it (same problem VT-6 had). That does not equate to the ship not being able to operate 16 vs 15 TBD’s, especially when 18 was considered a full complement. Generously not counting that one missing TBD into account, the YAG had 79 aircraft aboard on the eve of the battle, 27 F4F-4 (25 operational), 37 SBD (18 VB-5, 18 VB-3, 1 GC), and 15 TBD’s. VT-3’s two early TBD operating losses on 8 Jan 42 and 10 Jan 42 had not been replaced. So, counting the 15 TBD’s aboard Yorktown, plus the one dud left at Pearl, plus the two lost operationally in January and never replaced, VT-3’s routine operating complement was 18. Had all 18 been available, they would have been aboard Yorktown.

HAG had a total of 80 aircraft assigned on the eve of the Midway deployment. VT-8 lost a TBD in a landing crash at Pearl in the days before departure, reducing available TBD’s to 15. VF-8 had 27 F4F-4’s; VB-8, 9 (including the GC’s); VS-8 started with 18 SBD’s, 1 SBD was a dud and left behind at Pearl Harbor and another was lost operationally on 29 May. This left the HAG with 77 from a routine operating complement of 81. 



> August ’42 (Watchtower)
> Enterprise:	84



I see the BuAer location returns as Enterprise with 88. Hornet complement in the same report is 87.

It’s tedious to go through all these instances where you seem to confuse availability with rated and routine operating complements. 

Snipping the remaining actions you listed (And, gee, if you really want me to go through them, I will, but I’m searching for a little brevity here. I have a life, and a job, and family responsibilities and really cannot devote hours and hours to this stuff. I have already provided in my previous posts the average returns from the aircraft location reports; followers of the thread can note the differences between your numbers and mine and draw their own conclusions.) 

Let us move on . . . 



> Illustrious CAG (prior to selected operations



I have no problem with your Illustrious complement numbers, but I wonder if you give them the same availability versus routine complement short shrift. Not having any data to challenge same, I believe you.

I am going to snip portions of your post regarding how tough the Illustrious was versus Yorktown class complete with recitations of damaged inflicted on each where you point out that the Illustrious was not sunk. Well, good. How many torpedoes did Illustrious take?

My point would be that no US fleet carrier was lost to bombs, nor Kamikazes, alone. That the US fleet carriers that were lost over the course of the war, Lexington, Yorktown, Hornet, and, being generous, Wasp, were all torpedoed. So to trot out Illustrious with her armored deck and claim some sort of superiority by comparison to non-armored deck ships lost to torpedoes is IMO somewhat disingenuous.

How about this, Illustrious was under repair at Norfolk Navy Yard for eleven months after her adventures in the Mediterranean. Eleven months. And is there a guess on how long the average USN CV spent in the yard after being hit by a bomb(s) or Kamikaze(s)? Looks like about 52 days on average, slightly less than 2 months and that includes almost a year for USS Franklin. 

If you want to sink a ship, letting water in is much more efficient than letting daylight in. You compare apples and oranges.

Regards,

Rich


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## parsifal (Jun 19, 2009)

If you want to sink a ship, letting water in is much more efficient than letting daylight in. You compare apples and oranges.

[/QUOTE]

Hi Rich

Thanks for the comprhensive reply, much appreciated. In regards to this point, would you not agree that the greatest single danger to a carrier was the risk of fire. And while torpedoes can cause fires, I think bombs are far more likley to cause a fire. Moreover, if the ship is provided with adequate torpedo protection a torpedo is going to let in a relatively small amount of water. This would have been the case for the Ark Royal, if not for her inherent design flaw that failed her in the end. A Japanese air launched torpedo only has 331 lbs of warhead I might add, whereas a 1000lb bomb actually1100 lbs if german) has explosive charge in excess of 650 lbs) 

I did rather get my operations dates mixed up for which I am embarrased about. 31-12-41 was a strength date given by Brown and carries the note that this was the strength before the cancelled opersation to Wake....it carries the further note that Yorktown arrived 6th Jan....I dont know what I was thiniking when I wrote that up.....

Talking about losses is missing the main object of a carrier strike. It is not, in fact, the primary aim of the airstrike to sink the carrier, although that is admittedly a big bonus if it can be achieved. The aim is primarily to prevent it from operating aircraft, in the first instance, and secondly to immobilize it. Bombs are far more potent and capable at disabling the flight deck of a carrier. and hence removing it as a threat.

Moreover, I think you need to consider that in the main the US carriers were being hit with 250kg bombs, being the main armament of the Val. The British Carriers were being mostly hit by 1100 lbs capacity, which I can assure you are far more powerful pieces of ordinance. Your assessment is akin to saying an 8" shell is equival;ent to a 16" shell in terms of its damage capabilities. 

Torpedoes tend to work on the hull integrity and the propulsion systems, whilst bombs work on the flight deck and and superstructure. Bombs can do a lot of damage if they penetrate the armoured box (sometimes referred to as the citadel). As far as I know this did not happen to any US carrier, but I think this was because the US defences were designed to withstand a 500lb impact, but not a 1000 lb bomb. 

Your reference to the long repair times for the Illustrious is indeed a major flaw in the armoured deck concept....once the bombs pentrated the armoured deck the amount of damage went up exponentially. It was a bit like putting a stick of dynamite inside a sardine tin.....not pretty. 

My figures for operational aircraft were based on ajust a quick look at David Browns "Carrier Operations of wwii". 

I finished up not drawing any distinctions about aircraft shortages in 1940 for the RN. You are right, that would probably just skew the dataset. However I can assure you that the RN throughout 1940 struggled with an acute numbers shortage. For the whole of 1940, they received the grand total of just 16 pilots, which is no way to run a war, surely you would agree.

If you adopt my rough method for determining the amount of damage a ship can absorb before being renedered inoperable (or you can simply look at how much it took to sink a ship), I think you are going to find an intersting consistency in the tonnage of explosives needed to destroy a target. 

Anyway, dont let me keep you from your more important things to do like your family and the like.....


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## Glider (Jun 19, 2009)

R Leonard said:


> My point would be that no US fleet carrier was lost to bombs, nor Kamikazes, alone. That the US fleet carriers that were lost over the course of the war, Lexington, Yorktown, Hornet, and, being generous, Wasp, were all torpedoed. So to trot out Illustrious with her armored deck and claim some sort of superiority by comparison to non-armored deck ships lost to torpedoes is IMO somewhat disingenuous.
> 
> How about this, Illustrious was under repair at Norfolk Navy Yard for eleven months after her adventures in the Mediterranean. Eleven months. And is there a guess on how long the average USN CV spent in the yard after being hit by a bomb(s) or Kamikaze(s)? Looks like about 52 days on average, slightly less than 2 months and that includes almost a year for USS Franklin.
> 
> ...



The comment about torpedo's is valid as the Illustrious was not hit by any however the comment about repair times is a little unfair. No other carrier in the world would have taken the pounding that the Illustrious received that is certain, so its only to be expected that she would take some time to repair. However there are plusses and minus's in anything and that goes for the armoured box on the Illlustrious.

The Minus side
- If you have a major fire inside the hanger Box then the hanger acts like a pressure cooker increasing the temperatures and structural buckling

The Plus side 
- You are far less likely to have a fire in the hanger as the armoured deck reduces the chances of this happening. 
- The fires are more likely to be contained within the Hanger due to the extra rigidity/strength of the hanger
- The US carrriers were almost certain to have to spend time in dock after a hit on the deck. In similar circumstances a similar hit on an armoured deck will normally cause a dent in the flight deck easily fixed with quick drying cement. A simple easy and effective repair.
So yes when the damaged Illustrious did have to spend longer in dock but the chances of her having to go in for repair are less


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## fastmongrel (Jun 19, 2009)

> How about this, Illustrious was under repair at Norfolk Navy Yard for eleven months after her adventures in the Mediterranean. Eleven months. And is there a guess on how long the average USN CV spent in the yard after being hit by a bomb(s) or Kamikaze(s)? Looks like about 52 days on average, slightly less than 2 months and that includes almost a year for USS Franklin.



I am not sure that is a fair comparison all Royal Navy ships that were repaired in US yards seem to have taken a long time. After all the dockyard was working on an unfamiliar ship with completely different equipment. Even things like thread sizes, pipe fittings and electrical fittings would have been different plus I bet a lot of that 11 months was waiting for parts to come across the Atlantic.


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## Juha (Jun 19, 2009)

One short notice more on the repair time of Illustrious. It was a foreign warship in repairs in peace-time USA, USN CVs were repaired in war-time USA. In war-time the repairs of important ships were made much faster than in peace time, an extreme example is the repairs/patching up of Yorktown after the Battle of Coral Sea

Juha


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## parsifal (Jun 19, 2009)

The repair time issue is a mixture of all these factors I would venture to say.....the bombs being dropped on the british carriers were about twice the size of those being dropped on the USN Carriers, which were big enough to penetrate the armoured box....the armoured box acted like an amplifier once the bombs had penetrated, but it is also true that the open hangars of the US carriers were inherently easier to fix and repairable. 

If the tables had been turned, and it was British Carriers being torpedoed, and USN Carriers being bombed by really big bombs, I am willing to bet that the Brit carriers would still have faired better i withstanding the damage. Their underwater protection systems were simply more extensive than their US counterparts, and 5 or 6 1000 ilb Bombs on a Yorktown class (perhaps more likley the Wasp) would have reduced them to sinking condition, in my opinion, primarily because their defences were not designed to stand up to that size of ordinance....The British carriers underwater protection, whilst fairly conventional, was still more extensive and in my opinion abale to withstand damage better, than the US underwater protection.

The US carriers were designed to a displacement lower than the Illustrious class, but they carried a greater larger air component. I do not believe that in terms of naval design generally, that the US was more advanced in underwater protection (and certainly not in the above the waterline protection. So it should be no surprise or denigration of the US type to claim the Brit Carrier was better protected. Thats what the British carriers were renowned for, and it was that reputation, I believe, that led to their ability to offload thir carriers after the war to the smaller navies of the world. I believe the post war verdict of the smaler navies was to use US aircraft on British carriers, because that was seen as the best value for money at the time


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## renrich (Jun 19, 2009)

I suspect that they bought them a lot cheaper also because the British, right after the war ended were short of money and could not afford to operate them. The British carriers that I see that were sold to foreign navies after WW2 were almost all Colossus class, around 13000 tons, 25 knots with 48 AC. Probably bought because they were cheap to operate and met the needs of the small navies. I doubt if the US had anything similar to sell.


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## parsifal (Jun 19, 2009)

In the case of Australia, two carriers were purchased, the Terrible and the Majestic. They were renamed Sydney and Melbourne. 

Sydney was purchased unmodified for 2.75 million pounds, for the equivalent of 40 million dollars (in 2007 dollars). Melbourne was extensively modified to incorporate the latest aircraft handling and safety features including angled deck and mirror landing system. Melbourne as modified was not a cheap purchase....she cost the equivalent of 120 million Dollars (in 2007 terms) exclusive of aircraft and some spares. 

There is not much comparison between the Majestic class and the armoured Illustrious class. The Majestic class were unarmoured, and built to mercantile standards, and only incorporated a speed of 26 knots (which later years was a theoretical rather than actual speed). They were termed "trade protection" carriers, and had been designed as a result of Admiralty investigations in the war as to how to reduce the cost of getting carriers to sea. 

Within the limits of their design and displacement they represented a highly survivable unit. The ships wre unarmoured, but the macheinery spaces were placed en echelon, and the internal partitioning designed to allow counterflooding that could allow up to two torpedo hits and not sink the ships. this makes them very survivable for their size (remember, the yorktowns only needed about 2-4 torpedo hits to be reduced to sinking condition). They included a number of internal fire curtains and of course C02 drenchers in the hangars. The Hangar itself was the standard admiralty closed box system, again as a fire retardant measure. 

When I served on her, I do recall seeing a document (classified at the time....but I dont think we are getting any problem now, she was scrapped thirty years ago) that estmated the ship could absorb up to two torps and about 3-4000 lbs of conventional bombs before being reduced to a sinking condition. It is not fair to compare that to the wartime experiences, because safety features were vastly improved in both the USN and the RN systems in the latter part of the war, and in the post war period (though not enough, as the Falklands experiences showed in 1982). Nevertheless, this shows that despite their small size and lack of armour, their general design was quite good, and able to withstand considerable punishment (however, that same report, incidentally conceded their vulnerability to plunging cruise missiles such as the exocet or Harpoon, which may have sunk them with just a single hit.....these things were greatly feared at the time).

I have heard, but concede that I cannot confirm that at the end of the war Australia was offered its choice of US carriers as well, including an unmodified Essex class and either one or two Independance class carriers. I dont know if they were offered free or at a cost, but they were rejected on the basis of the manning costs and the costs of modernizing them. The advantages offered by the Melbourne was that she was purchased incompolete, thereby allowing the opportunity to retrofit the more modern concepts which could not have been done with a completed US Hull. 

Nevertheless the Americans did sell a Light carrier to the Spanish (the Dedalo). I dont know th cost of this purchase, but the Dedalo did not operate fixed wig aircraft as such (she did operate AV8s after the the wooden deck was sheathed with a steel heat shield).

Have not been able to locate the cost of the Indian Carrier Vikrant. The Brazilians purchased their Colossus class in 1956 for the equivalent of about 60 million dollars (in 2007 dollars), but the ship required a lot of money spent on her (the amount I have been unable to determine) to allow her to operate S-2s and Skyhawks. I have not been able to track down the costs of the british carriers supplied to other nations.

There were a number of reasons why the Colossus were adopted by the RAN, and I suspect by the other small navies (based on that Australian experience). Firstly, they were relatively cheap as you say, but certainly not bargain basement. Secondly, some were purchased incomplete, allowing modifications to be built into them during construction. They were relatively low in terms of manning costs. But lastly, they represented a very sound design in terms of survivability, which I believe was at least a partial legacy to their forebears


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## Hunter368 (Jun 19, 2009)

syscom3 said:


> After reading about the quality of the Japanese carriers, and the supremacy of the US designs; there can be only one conclusion.
> 
> The Yorktown Class was the best.



I could not agree more.


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## R Leonard (Jun 19, 2009)

parsifal said:


> In regards to this point, would you not agree that the greatest single danger to a carrier was the risk of fire.



I entered this thread because of some obvious, to me anyway, errors in describing air group complements for Yorktown class carriers. I still cannot for the life of me see how one can present available aircraft on the eve of some event (and frankly, some of what you posed as such was not even an accurate presentation of what was available) and decide that is a “maximum operating strength”. That plain and simply is not so. If you want to say XYZ carrier had an available strength of ABC, that’s fine and we can debate those numbers, but for what you’ve presented as available to somehow morph into “maximum operating strength” is demonstrably incorrect.

I, frankly, don’t really give a hoot about the great armored flight deck versus wood flight deck argument. Most of the more vociferous proponents of one side or the other conveniently leave out the parts that would tend to reduce their argument and I find that to be somewhat disappointing. I see the advantages and the disadvantages to either design. They all go back to operating doctrine, which is driven, in part, by the operating environment and expectations. The RN presumed their carriers would be operating within range of major land based air formations and armored their carriers accordingly and based their air defensive response from there. USN doctrine from the 1930’s (and really always aimed towards a war with Japan, not against a continental Europe adversary, whether they admitted it or not) was to avoid facing off against major land based air and concentrate on naval adversaries, be they carriers or not, and restrict land strikes to those places with limited air based defenses. Illustrious’s adventures in the Med are an example. I have my doubts of a contemporary US carrier being able to absorbing the same beating. It was not until late 1943 that the USN was comfortable bringing carriers within range of major enemy land based air facilities, a function of numbers, equipment, and a noted decline in enemy capabilities. As such, the armored flight deck was not a major consideration in US carrier design and the armored deck was the main deck, not the flight deck. The USN doctrine, against both land and sea based air, was to depend on CAP and maneuverability, avoid the hits rather than absorb them. The Battle of the Philippine Sea is the classic fleet defense example. Plain and simple, that’s in a nut shell. Different paths to doctrine lead to different designs. 



> And while torpedoes can cause fires, I think bombs are far more likley to cause a fire. Moreover, if the ship is provided with adequate torpedo protection a torpedo is going to let in a relatively small amount of water. This would have been the case for the Ark Royal, if not for her inherent design flaw that failed her in the end. A Japanese air launched torpedo only has 331 lbs of warhead I might add, whereas a 1000lb bomb actually1100 lbs if german) has explosive charge in excess of 650 lbs)



Torpedoes in sufficient quantities or in the right places sink ships. Fire on any ship, carrier or no, will ruin your day, and if you let your damage control get away from you, and especially if it is inadequate in the first place (Akagi, Kaga, Soryu, Hiryu, and Mikuma all come to mind), sure bombs can sink ships. Torpedoes, on the other hand, are much more efficient (such as Lexington CV-2, Yorktown, Wasp, Hornet, Shokaku, Yamato, Musashi Shinano) although unlike Taiho, the “just one probably won’t do the trick” category include Saratoga X 2, Lexington CV-16, Intrepid, Pennsylvania. 



> Talking about losses is missing the main object of a carrier strike.



My reference to losses, operational and combat goes to the heart of the “maximum operating strength” question. Your drawing, apparently from Brown’s reporting, of a conclusion on maximum operating strength based on available capacity, that is what was available on the eve of an action, leads to an error in reality as to what would be the real maximum operating strength. Sure, as you reported, CVG-10 aboard Enterprise at Saipan fielded 69 aircraft, but 21 of them were space robbing SBD-5’s, and the 69 did not even come close to Enterprise’s “maximum operating strength,” it only represented what Enterprise had aboard, available, at the time. By the end of the July 1944, CVG-10 had rotated back to NAS Alameda and CVG-20 was about to go aboard Enterprise with 37 F6F, 35 SB2C, and 19 TBM-1C, a total of 91. It cannot be said that Enterprises “maximum operating strength” then is 69 when one month later she takes aboard and operates an air group that is 32% larger. My earlier post shows these differences which are directly related to aircraft types.



> Moreover, I think you need to consider that in the main the US carriers were being hit with 250kg bombs, being the main armament of the Val. The British Carriers were being mostly hit by 1100 lbs capacity, which I can assure you are far more powerful pieces of ordinance.



Gee, 1100 lbs is more than 550 lbs. I never would have guessed. Pretty hefty tomes of laws to be carting around. On the other hand, as long as we’re playing ordnance apples and oranges, what do you suppose has a greater damage effect, a 550 lb GP, such as the Japanese Type 99/25/1 on a wood flight deck/open hangar deck or an 1100 lb GP, such as the German SC 500/III on an armored flight deck/closed hangar deck? Do we have any explosives experts who can make those calculations or will we be reduced to, really, uninformed opinion? Note, I said “we," if it's just "me" then feel free to post the calculations. And even with someone making the calculations for us, I’d like to see their work, too.



> Your assessment is akin to saying an 8" shell is equival;ent to a 16" shell in terms of its damage capabilities.



I do not believe I made any such statement that could even be construed as such.



> Torpedoes tend to work on the hull integrity and the propulsion systems, whilst bombs work on the flight deck and and superstructure. Bombs can do a lot of damage if they penetrate the armoured box (sometimes referred to as the citadel). As far as I know this did not happen to any US carrier, but I think this was because the US defences were designed to withstand a 500lb impact, but not a 1000 lb bomb.



No hot new information here, but I’d be interested in your source for the 500 lb impact design. Would not surprise me, though; Yorktown class design work started around 1930 . . . design work that was framed by US operational expectations and doctrine (see above). Since I don’t know, was the reverse true for Illustrious? Was that class’ armored deck portion designed to withstand a 1000 lb bomb hit? Just GP’s? What about SAP’s and AP’s? Inquiring minds.

What was the purpose of the year Illustrious spent in the yard after war? Was that modernization or repair of accumulated war damage that “could wait?” Both? I don’t know, I’m asking.



> Your reference to the long repair times for the Illustrious is indeed a major flaw in the armoured deck concept....once the bombs pentrated the armoured deck the amount of damage went up exponentially. It was a bit like putting a stick of dynamite inside a sardine tin.....not pretty.



Having seen the effects of explosions in confined spaces, I can imagine. 



> My figures for operational aircraft were based on ajust a quick look at David Browns "Carrier Operations of wwii".



I looked at Brown once as a potential purchase, but was not sufficiently convinced to take the plunge, mostly because I tend to avoid the sweeping histories (too many opportunities for mistakes), preferring the more concentrated efforts. Perhaps you have some disinterested third party review you could give us.



> For the whole of 1940, they received the grand total of just 16 pilots



Now that is an interesting number. Geez, there were more than that in my father’s class a Pensacola (rec’d his wings in Nov 40). The USN winged, combined, some 708 USN/USMC/USCG naval aviators or USN/USMC/USCG naval aviation pilots in 1940; after that the number jumps to multiple thousands, then by orders of magnitude; the peak being 1944 with 21,067.



> . . . which is no way to run a war, surely you would agree.



Yup, perhaps the last vestiges on RAF control?



> Anyway, dont let me keep you from your more important things to do like your family and the like...



It’s the weekend, don’t worry, I won’t, someone probably already has their plan for my time . . . rumor has it I moving the piano . . . oh joy.

Regards,

Rich


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## vikingBerserker (Jun 19, 2009)

IIRC, the Britsh considered the Illustrious class as almost being too amoured, esp the sides. That was the reason why the newer British carriers were different.


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## R Leonard (Jun 19, 2009)

parsifal said:


> Okay, are you suggesting the ship could undertake independant action of any kind after the second strike by the kates hit her????



After the hits scored by Hiryu's D3A's which brought her to a halt, Yorktown DC snuffed out most of the fires and made emergency repairs to the flight deck. Engineering brought power back on line, enough to generate about 23 knots, enough to launch six fighters which accounted for a goodly number the incoming torpedo planes, but not quite enough, all before she was struck by the two torpedoes which brought her to a halt. Absent the torpedo hits Yorktown could have resumed full operations despite the bomb hits.


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## parsifal (Jun 19, 2009)

R Leonard said:


> After the hits scored by Hiryu's D3A's which brought her to a halt, Yorktown DC snuffed out most of the fires and made emergency repairs to the flight deck. Engineering brought power back on line, enough to generate about 23 knots, enough to launch six fighters which accounted for a goodly number the incoming torpedo planes, but not quite enough, all before she was struck by the two torpedoes which brought her to a halt. Absent the torpedo hits Yorktown could have resumed full operations despite the bomb hits.



The question asked was whether after the hits by the Kates she was still operational. Simple question should get a simple answer. i suspect you dont want to answer this question, so you avoid it by describing the damage caused by the Vals, with only the shortest of oblique referrals to the damage caused by the torpedo strikes

So, I am interested to hear your rebuttal on whether thw Yorktown was operational after the second strike


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## Glider (Jun 19, 2009)

vikingBerserker said:


> IIRC, the Britsh considered the Illustrious class as almost being too amoured, esp the sides. That was the reason why the newer British carriers were different.



A very accurate summary


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## syscom3 (Jun 20, 2009)

parsifal said:


> The question asked was whether after the hits by the Kates she was still operational. Simple question should get a simple answer. i suspect you dont want to answer this question, so you avoid it by describing the damage caused by the Vals, with only the shortest of oblique referrals to the damage caused by the torpedo strikes
> 
> So, I am interested to hear your rebuttal on whether thw Yorktown was operational after the second strike



Like he said, the Yorktown was operational after the bomb hits. The fact it launched fighters is proof.

It was the torpedo hits that caused the listing and loss of headway. That's when its fate was sealed. And even then, the carrier was under tow when it was hit by the final (sub launched) torpedo which doomed it.


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## parsifal (Jun 20, 2009)

"Maximum Operating" and "Operational Maximum" are referring to two completely different issues. You are aware of that I am sure.....

With regard to your statement about the US concentrating on a possible war with Japan, I thought the US had contingency plans for all manner of attacks....the so-called rainbow war plans. 

The scenario that eventuated was about the worst possible that could arise....a simultaneous war on two fronts. 


_Torpedoes in sufficient quantities or in the right places sink ships. Fire on any ship, carrier or no, will ruin your day, and if you let your damage control get away from you, and especially if it is inadequate in the first place (Akagi, Kaga, Soryu, Hiryu, and Mikuma all come to mind), sure bombs can sink ships. Torpedoes, on the other hand, are much more efficient (such as Lexington CV-2, Yorktown, Wasp, Hornet, Shokaku, Yamato, Musashi Shinano) although unlike Taiho, the “just one probably won’t do the trick” category include Saratoga X 2, Lexington CV-16, Intrepid, Pennsylvania. _

err, can I ask if you have any training or experience in DC? Torpedoes will affect hull integrity, and the cumulative damage may well lead to fire, but as a general rule of thumb they will not lead to a spontaneous combustion, unless they penetrate the underweater defences too badly, or hit a vital, like a fuel line or a magazine. 

Bombs are much more likley to cause fire in an immediate sense, you neither acknowlwedged or questioned that statement, so for now I will assume you are not disputiong it 

You say that it was the torpedoes that led to the loss of Yorktown, Lexington and Hornet, but didnt all three ships also suffer catastrophic fires that made the damage control exercise impossible. So what, in reality led to their loss....the holes in the side (as you contend), or the fires that prevented the ships damage and flooding being stabilized?


The "real" operating strength is not the "maximum operating strength", unless that is also the the same as the "Operational Strength". There is a difference, and I know you know what that is. For the record, the Operational Maximum is the number of aircraft the ship can bring to battle, whilst the Maximum operating strength is the number of aircraft that can practically be operated normall from the carrier. 

We have a disgreement, I can see...is the maximum that can operationally be carried into battle more relevant than the numbers that were actually carried into battle. I happen to think the latter is more important. Incidentally, the numbers I gave you concerning the Illustrious are, to the best of my knowledge the numbers she carried into battle at those times...so the numbers I gave are comparing apples to apples 

_On the other hand, as long as we’re playing ordnance apples and oranges, what do you suppose has a greater damage effect, a 550 lb GP, such as the Japanese Type 99/25/1 on a wood flight deck/open hangar deck or an 1100 lb GP, such as the German SC 500/III on an armored flight deck/closed hangar deck? Do we have any explosives experts who can make those calculations or will we be reduced to, really, uninformed opinion? Note, I said “we," if it's just "me" then feel free to post the calculations. And even with someone making the calculations for us, I’d like to see their work, too._

So I see you have selected a piece of Japanese ordinance (the type 99/25/1) that was a rocket accelarated bomb with a side fuze that was not adopted until 1944. Thats reall representative of Japanese ordinance for most of the war. A rocket assisted bomb able to penetrate 150mm of hardened armour plate. I know you think me comparing bombs and torpedoes is somehow unfair, somehow not comparing "apples to apples", but at least I dont try and cheat in the debate by introducing ordinance that was not used until the very end of the war.

The facts are these....British carriers were generally at risk from torpedoes (sub and air launched) and big bombs. The Americans in the Pacific were at risk from torpedoes (air and somewhat less so from Subs) and smaller bombs of the 250 kg. History shows that the Illustrious was never tested against topredoes, but by the same token the Yorktowns were not tested against the the "big" bombs 

The more representative Japanese 250 kg bomb was the Type 2, number 50 Modell 1 SAP . The former had a theoretical armour penetration of 80 mm when dropped at 10000 feet, but in reality was dropped at much lower altitudes, and tended, typically to penetrate about 40-60 mm of deck armour (very roughly). 

Compare that to the typical German 1100 lb bomb (but please note the Germans also routinely had access from early in the war to a 1400 lb bomb that could also be deleivered by a Ju87)..... Both these types were available from very early in the war, so I think can be considered representative of german ordinance. The smaller bomb in its AP form could penetrate about 80mm of armour, whilst the larger bomb could penetrate about 140mm at what i would call "normal" or "typical" release altitudes of about 5000 feet.

The problem with using AP is that it restricts the size of the bursting charge and therefore needs to hit a vital to do lethal damage. This is why, except when attacking battleships, most attacks were with SAP. This meant that armour penetrations were less, generally, but damage from the blast effects was greater....much greater. Generally, it can be assumed that against carriers SAP (someimes even GP) 

My estimation is that typically, the 250kg SAP bombs being dropped at "normal altitudes" by the Japanese could penetrate about 50mm of armour, whilst the 1100 SAP bombs could penetrate about 80mm, and the bigger 1400 lb version about 140mm.

To get some idea of the relative effects on each of their respective targets, one has to look briefly at the armouring scheme of the respective targets....in the case of the Japanese thats the Yorktowns, whilst in the case of the Germans thats the Ilustrious.

The Yorktowns had an armoured deck, below the Hangar (I believe) of 1.5 inches, or about 38 mm. The internal bulkheads were protected to almost 4 inches, though I dont know how extensive this was.

This means that a good proportion of the 250kg bombs dropped on a Yorktown are not going to penetrate the armoured "deck" and those that do are more likely to be contained by the bulkhead protection. In other words, it is reasonable to summarise by saying that the Yorktowns were designed to withstand hits from bombs up to 250 kg in size.

Now what would happen if the Yorktowns had been subjected to bombing by aircraft with 500 and 650kg bombs. Their armour protections systems are going to fail, no question. With bombs capable, on average of penetrating 80-120mm, and only 35mm in protection, the Yorktowns defences have simply no chance of withstanding such weight of bombs. The result, the bombs will penetrate to the vitals of the ship, and the ship will sink (thereby challenging your notion that only torpedoes can sink ships). 

Now in terms of horizontal protection, I am not as sure of the characteristics, but my conways talks about an "STS" protection (not sure, but I think that is a reference to side armouring). The extent of armouring is very minimal, and the thickness is 0.75 inches. If those numbers are correct, they will offer no side impact protection from any torpedo of any size. The result is that the torpedo will penetrate very quickly to the vitals, and it wont take many to cause lethal damage. This conforms to the known facts....it only takes about two or there small torpdoes to sink a Yorktown class carrier

Comparing this now to the Illustrious protective scheme. She was protected immediately below the flight deck by 75 mm, and a further armoured deck below the hangar (Not sure of its thickness, but I think it was about 30-50 mm). Against bombs of 250kg, it could easily repel most hits, with little or no damage. A 500 kg bomb has about the same probability as a 250kg bomb has of penetrating the yorktown, but then the vitals below that are further protected. Historically this is what happened. of the 6 bombs that hit her (totalling 6000 lbs of exposive, only 2 bombs, or 1500 lbs of explosive , penetrated to the hangar deck, and none penetrated through to the vitals as such. It can be stated that the Ilustrious was designed to withstand hitsd from bombs of up to 500 kg in size.

What would happen if the Illustrious was torpedoes instead of bombed. Well, that too can be pretty well estimated I am afraid...its not the voodoo you believe it to be.

Illustrious had sandwich type underwater protection with 40mm bulkheads, extended a point 5 metres above the waterline. this was important, because it meant that it would need to ship a great deal of water before the protective bulkheads would be overcome. The bulkheads themselves, coupled with the modern sandwich style protection system, meant that the the underwater protection was good to warheads of up to 750 kg capacity. That means that an 18 inch torpedo of the type used to dispatch the US carriers, would have little or no effect on the carriers hull integrity. Of course things could, and often did go wrong, as the bismarcks experience clearly demonstrates.

Obviously the generalization about protection are just that...a lucky hit, or a hit that is dropped higher than usual, will upset this summary.of these bomb of 3 in


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## Amsel (Jun 20, 2009)

It seems that all the USN CVs in 1942 were lost to torpedos. And I don't think the Illustrious would have survived what the Hornet went through either, look at the Ark Royal. The main reason why the Illustrious survived _its_ ordeal was the proximity to Malta. Imagine it being in the oceans instead. The mauling of the Illustrious in October of 41' showed that the ABH failed in most aspects, and the Illustrious suffered from severe fires.

One of the issues you brought up earlier in the thread was the "greatness" of the design of the Illustrious or other RN carriers so other countries bought them after the war. They probably did not take into consideration that the Illustrious was unfit for future use due to its small elevators and most of all the small ABH which could not accomodate the later generation aircraft. The hanger cieling was too low and the elevators could not lift non-wing folding aircraft.

1942 was the most important year for the allies in the Pacific. Due to the speed of the IJN carriers the USN needed a large contingent of aircraft to be able to dash within range of the IJN fleet , send a strike with escort and also CAP over the friendlys. Also in the Guadacanal campaign aircraft were needed for ASW as well as scouting striking, CAP, and escorts. The small contingent of aircraft, maintanance capability and the fuel carried by the Illustrious doesn't bode well for her. I think that she was suited well for the Med but not for such a formidable opponant as the IJN was in 1942 in the Pacific. If the USN used the Illustrious class at Coral Sea, Midway, and Guadalcanal, I really can't see her surviving let alone winning the battles.

It all comes down to defensive vs. offensive operation doctorine. Could the smaller number of aircraft win the massive battles, protect the fleets, prep and give airsupport to invasion forces, and defend against the massive kamikaze onslaught? Is it better to protect the carrier only slightly better but have a much smaller range, sortie capability, maintanance capability? You can't use the ABH and expect to be able to have the same characteristics that gave the USN its successes in the PTO. It's all a trade off. Armor for everything else.


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## parsifal (Jun 20, 2009)

_It seems that all the USN CVs in 1942 were lost to torpedos. And I don't think the Illustrious would have survived what the Hornet went through either, look at the Ark Royal. The main reason why the Illustrious survived its ordeal was the proximity to Malta. Imagine it being in the oceans instead. The mauling of the Illustrious in October of 41' showed that the ABH failed in most aspects, and the Illustrious suffered from severe fires_.


What Mauling did the Illustrious suffer in October 1941. My understanding is that she was in the US at that time under repair. Perhaps you were referring to another ship, or another date, but you will need to clarify before I can respond. 

Actually, the Illustrious would be likley to shrug off with little or no damage to her operational efficiency all except the sub launched 21 in torpedo delivered by the I-168, if it had been her rather than Yorktown that had suffered the damage at Midway. Her underwater protection systems were designed to withstand detonations from warheads of up to 750 lbs, and since the 18 inch torps that hit the Yorktown (and all the other carriers lost in 1942, except Wasp) had warheads of only 331 lbs, the Illustrious should have been able to withstand those hits fairly easily. Of course, like anything in life, nothing is certain. 

Moreover, the Illustrious differed from the Ark Royal, in that the funnel uptakes were not routed under the hangar deck, and the transverse bulkheads reached higher up into the hull. This meant that she would not suffer the same catastrophic fires as the Ark Royal, and could also withstand a greater level of heel and flooding. Chances are, she could have survived the attacks that disabled the Yorktown with little or no impact.

With regard to Malta providing a great deal of assistance, well there was some help and shelter provided, but not nearly as much as you might expect. She could not be docked, and instead had to rely on divers to patch her hull so as to make her partially seaworthy. Whilst it would have been risky for her to go to sea in that condition, she probably coud have. She remained effectively in combat for the 13 days she was in the grand harbour, suffering a further three heavy bomb hits during that ordeal. No other carrier before or since has absorbed as much punishment as the Illustrous in January 1941.

The severe fires were indeed real enough, but at no stage did they spread outside the hangar. The heavy bombs dropped on her had ben sufficient to penetrate the 1st armoured deck below the flight deck, but not the second, below the hangar. If it had been the yorktown instead, the bombs would have passed clean through the armoured deck (of the yorktown) and into her vitals. My opinion is that she may have lasted seconds, not days, because there is every chance that an uncontrollabe fire or explosion would have occurred in her machinery spaces or her magazines....likley that she would have blown up and sunk in the same way as the Hood in other words.... 

_One of the issues you brought up earlier in the thread was the "greatness" of the design of the Illustrious or other RN carriers so other countries bought them after the war. They probably did not take into consideration that the Illustrious was unfit for future use due to its small elevators and most of all the small ABH which could not accomodate the later generation aircraft. The hanger cieling was too low and the elevators could not lift non-wing folding aircraft._


Illustrious remained in service postwar, but her wartime service was never fully rectified and she remained a training carrier in the postwar era. her sister ship Victorious was fully refitted, however, and provided frontline service she was fully refitted and served quite successfully as a front line carrier until 1968. I would point out that the wartime Essex class carriers also required extensive modifcations to render them suitable for frontline operations so i fail to see the distinction here. 


_1942 was the most important year for the allies in the Pacific. Due to the speed of the IJN carriers the USN needed a large contingent of aircraft to be able to dash within range of the IJN fleet , send a strike with escort and also CAP over the friendlys. Also in the Guadacanal campaign aircraft were needed for ASW as well as scouting striking, CAP, and escorts. The small contingent of aircraft, maintanance capability and the fuel carried by the Illustrious doesn't bode well for her. I think that she was suited well for the Med but not for such a formidable opponant as the IJN was in 1942 in the Pacific. If the USN used the Illustrious class at Coral Sea, Midway, and Guadalcanal, I really can't see her surviving let alone winning the battles._

I agree with most of what you say here....the British carriers did not have the legs to operate well in the Pacific....but you seem to imply that the Germans (and to a lesser extent their Italian allies) seem in some way to lack the ferocity of the Japanese. Whilst the Japanese were indeed ferocious, and I might say fanatical, the Germans were technically more proficient, and their sheer weight of ordinance made them very dangerous. In exactly the same way as you criticise the British carriers, one could level exactly the same criticism of US carriers if they had operated on aprolonged basis in the confined waters of the North Atlantic or the Med.

And there should be one other postscript added into this. Of the the two allied powers, only the British could effectively deliver night strikes against moving targets before 1943, and the main burden for carrier operations in areas north of the Arctic Circle remained firmly the responsibility of the RN. If you look for any major US carrier operations such as the Arctic convoys, you will not find any US carriers present. I believe that is because they sucked at rough weather operations

_ It all comes down to defensive vs. offensive operational doctorine. Could the smaller number of aircraft win the massive battles, protect the fleets, prep and give airsupport to invasion forces, and defend against the massive kamikaze onslaught? Is it better to protect the carrier only slightly better but have a much smaller range, sortie capability, maintanance capability? You can't use the ABH and expect to be able to have the same characteristics that gave the USN its successes in the PTO. It's all a trade off. Armor for everything else._
Err, the British did things with their carriers that the US did not as well, plus, I really am at a loss as to how this is at all relevant to the issue of Illustrious vs Yorktown. The US fast carriers were Essex class, werent they, and wasnt the British production base just a fraction of that commanded by the US??? In short, I fail to see the relevance of this line of argument.


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## Amsel (Jun 20, 2009)

Err, the Kreigsmarine were not even 1/4 as ferocious as the IJN. What became the biggest threat to ships in WWII, and made the battleship obselete? I'll answer for you; airpower! What you are failing to admit, and what has historically made the Illustrious a failed design was its force projection. If the Yamato, and Tirpitz could be sunk by airpower then what of the puny armor of the Illustrious. You fail to grasp the idea that the USN carriers were designed to be force projectors and not warships. The doctorine of the ABH which restricted the range, deck length, hanger space, speed, and elevators for what? A little more armor. There is a huge difference betweeen the strike capability of the Yorktown class over the Illustrious. Airpower was what it was all about.


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## parsifal (Jun 20, 2009)

Amsel said:


> Err, the Kreigsmarine were not even 1/4 as ferocious as the IJN. What became the biggest threat to ships in WWII, and made the battleship obselete? I'll answer for you; airpower! What you are failing to admit, and what has historically made the Illustrious a failed design was its force projection. If the Yamato, and Tirpitz could be sunk by airpower then what of the puny armor of the Illustrious. You fail to grasp the idea that the USN carriers were designed to be force projectors and not warships. The doctorine of the ABH which restricted the range, deck length, hanger space, speed, and elevators for what? A little more armor. There is a huge difference betweeen the strike capability of the Yorktown class over the Illustrious. Airpower was what it was all about.



You have not factored into this equation of yours the effects of the Luftwaffe, or the U-Boats. The U-Boats alone sank over 80% of all allied shipping and came closest of all axis forces to actually defeating the Allied navies. 

So your initial answer that airpower alone rendered battleships obsolete is in itself inherently and fundamentally mistaken. Airpower was a very important factor in changing the nature of warfare, it was not the only factor, n some would argue not even the most important factor. More than anything, Battleships were designed and built to fight the conventional surface battle....the decisive surface action, Jutland style battles if you will, but the nature of warfare had changed so much that such battle concepts were largely obsolete. Battleships meeting battleships became a relatively rare occurrence, and with that the very reasoning for having batleships in the first place was no longer there....

Even in the context of the Pacific war, battleships and their poorer cousins, cruiseres and destroyers, nevetheless played a critical part in the outcome of the war. The battles in the Pacific were fought in part with surface ships, ground forces, aircraft , and most importantly, with submarines. so this notion that carriers, and air power were singularly responsible for the obsolesence of battleships (and by extension, the outcome of the war) is just patently mistaken. Airpower, and carriers played their parts, but they are just part of the whole picture, a complex combination of supporting factors that led to their demise.

The problem with battleships was not so much their obsolesence, as their inflexibility. They could not protect against submarines, were vulnerable to airpower (as you say) were so expensive that nobody dared risk them in open battle. In most instances their many and varied roles could be accomplished far more cheaply and efficiently by lesser systems, like submarines and the like.

Failure of the Illustrious class as a force prohector???? are you kidding??? have you even bothered to read about the accomplishments of this ship on even the most rudimentary levels. Are you aware of the accomplishments of these ships?? ever heard of battles like taranto the loss of the Bismarck, the near total domination of the meditteranean in 1940-42, the landings in Sicily, Salerno and southern France, the invasions of Madagascar, the escort carrier operations in the north Atlantic (oh and by the way, this was done by RN CVEs, the USN carriers were concentrated in the south and central Atlantic, the convoys to Russia wre an RN responsibility. If that is not a case of force projection I'll be a monkey uncle...its just that it wasnt done with 38% of the worlds industrial potential to back it up that makes it look puny in comparsion to the great drives across the central pacific. 

However there is a fundamental difference between the conditions the British carriers were expected to fight under, and those that the USN expected to fight. The USN was into the crossing of vast stretches of open ocean, like the pacific (but it could also have been across the Atlantic as the various rainbow plans demonstrate), and therefore designed its carriers, as you say with a maximised number of aircraft in mind. For the prewar carriers, like the Yorktown this meant that sacrifices had to be made, and you guessed it, the sacrifices were in the levels of protection they had worked into their designs.

In the case of the Illustrious class, the idea was still force projection ( I am sorry to be rude about this, but fair d*nkum, you need to get out more, force projection was drummed into me at Naval college until I ate drank and slept the stuff, its actually quite humourous to me that you would even suggest that) but more attention had to be paid to the protection issues because the ships would be operating within the range of large numbers of enemy land based planes, and the fighter defences available to the RN at the time of design were very weak. But even that aside, the RN carriers were simply designed to a higher standard of protection than their USN counterparts. Put crudely, they were designed to withstand bombs of up to 1000lbs, and torpedoes of up to 18 in calibre. The Yorktowns essentially were designed to withstand bombs of up to 500 lbs only, with limited protection against torpedoes.

Now the loss of the battleships that you mention demonstrate that protection systems are not fullproof, but what they fail to take into account are all the times that protection systems do work. I can assure you that for every time they dont work, there are other times that they do. And the examples you quote...the loss of the Tirpitz and the Yamato are somewhat strange as choices of the vulnerability of Battleships. Yamato needed the attentions of over 500 aircraft to be sunk, whilst tirpitz was not finally sunk until attacked by heavy bombers carrying special ordinance of over 12000 lb weight (the so-called "tallboy" bombs) Bismarck withstood the torpedo attacks made against her that hit her belt (it was a n exceptionally lucky hit on the rudders that disabled her) the Italians adopted a failed system of underwater protection, whilst the US losses at Pearl were with ships lacking proper torpedo and deck protection. Compared to all these systems (except the Bismarck and Yamato) the Illustrius was a properly designed defensive system, far in advance of any of them. It was not just an accident of fate that the only modern British Carrier lost in the war was the Ark Royal, and she was lost due to a design fault. Propely designed ships, like the Illustrious dont sink easily. You are just sadly mistaken to describe them as "lightly protected"....I suggest before you try saying that again you read up about the RN operations off Crete Malta, and Japan to determine just how tough these armoured carriers really were. If you did, you wouldnt say such inanely dumb things


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## Amsel (Jun 20, 2009)

parsifal said:


> You have not factored into this equation of yours the effects of the Luftwaffe, or the U-Boats. The U-Boats alone sank over 80% of all allied shipping and came closest of all axis forces to actually defeating the Allied navies.
> *I actually did take into consideration the u-boats and LW, and still believe that if the Illustrious class was used at Coral Sea, Midway, and Guadalcanal; the battles would have been lost which would give the IJN a strong hold of the Pacific. I again reiterate that the Illustrious was better suited for the Med then the massive naval campaign in the Pacific. You are mistakenly, just as the RN was in 1936 putting more into armor then sinking enemy fleets. Trading force projection for armor. Not to be rude but I don't think you will admit to 91 aircraft being better then 40-60 aircraft. But you admit that the RN reluctantly went to the permanent deck park of the USN doctorine. Why? Because the poor design of the Illustrious in the offensive role. The ABH really cut down on the capabilities to engage the aggressive IJN. How was the Kreigsmarine a threat to anyone besides the u-boats? They were essentially always on the defensive due to their lack of carriers.*
> 
> So your initial answer that airpower alone rendered battleships obsolete is in itself inherently and fundamentally mistaken. Airpower was a very important factor in changing the nature of warfare, it was not the only factor, n some would argue not even the most important factor. More than anything, Battleships were designed and built to fight the conventional surface battle....the decisive surface action, Jutland style battles if you will, but the nature of warfare had changed so much that such battle concepts were largely obsolete. Battleships meeting battleships became a relatively rare occurrence, and with that the very reasoning for having batleships in the first place was no longer there....
> ...



I would take the capabilities of the Yorktown class over the Illustrious design for the same reasons the USN did. You might study the USN doctorine vs. the RN doctorine in carriers to realize that the RN had to adopt the USN doctorine eventually. That tells me that the USN design was much better then the Illustrious design.


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## Glider (Jun 20, 2009)

_*You keep putting too much into the armor of the Illustrious, when it has been proven that the armor only barely helped it and in one instance actually showed the structural flaw besides the armor. The Ark Royal was not lost due to a design fault, but to a torpedo which has been proven time again that ships could only be theoretically protected by its armor below the waterline to a torpedo hit.*_ 

An observation about the loss of the Ark Royal. A number of years ago I had a conversation with a Priest who was a TAG on the Ark Royal when she was lost and he was adament that the reason the ship was lost was down to the Captain. Yes there was a design fault but the flooding could and should have been contained.

In essence the torpedo struck and immediately most of the crew were told to abandon ship, the No 1 wanted to keep the crew on board and help save the ship. It was some hours after the torpedo hit that the water reached the boiler rooms and later before power was lost. Effective damage control didn't start until nearly an hour after the ship was hit, in his eyes an unforgivable delay. His summary was the the Ark was a happy shiip and achieved a number of successes but that this was down to the No1 not the Captain

I have looked up a number of sites and they seem to back up what I was told but I would like one day to get hold of the official investigation. 

With this in mind I would temper any negative comments on the design of the Ark. It wasn't perfect but no ship was perfect


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## Amsel (Jun 20, 2009)

I didn't make a negative comment about the Ark Royal but a nuetral comment. The Ark was a much better carrier then the Illustrious.


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## Glider (Jun 20, 2009)

Amsel said:


> I didn't make a negative comment about the Ark Royal but a nuetral comment. The Ark was a much better carrier then the Illustrious.



I don't disagree with you about the Ark being a better all round carrier than the Illustrious and was just giving some background to the loss of the Ark Royal. 

People tend to jump to the design element and sometimes for get the human element.


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## parsifal (Jun 20, 2009)

I note that your position changed from Post 76 to Post 78. Post 76 was basically that the Illustrious was a failed design in that it could not project its force. Post 78 abandons that position and says that it was better in the constricted waters around Europe and had difficulty in the Pacific. You then throw into the mix some comments about the inability of armouring schemes to stop torpedoes. 

Well, before I respond, please clarify to me what your actual and final position is on this.....are you stil saying that the illustrious class are a failure because thay cannot project force, or are you simply saying that they were better suited to operations in Europe.

The difference forme is critical. I totally agree with one position, and totally disagree with the other. I would like you to clarify what exactly is your position on this.


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## parsifal (Jun 20, 2009)

Glider said:


> I don't disagree with you about the Ark being a better all round carrier than the Illustrious and was just giving some background to the loss of the Ark Royal.
> 
> People tend to jump to the design element and sometimes for get the human element.



So, you think the results of the official enquiry into her loss are wrong?????? Her loss was attributed to a minor extent on poor DC procedures....pilot error if you like, but mostly to faults in her design


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## Glider (Jun 20, 2009)

parsifal said:


> So, you think the results of the official enquiry into her loss are wrong?????? Her loss was attributed to a minor extent on poor DC procedures....pilot error if you like, but mostly to faults in her design



I have not read the results of the official enquiry so cannot be precise, if you have and have a link to it I would more than welome it. I understood that the inquiry put a lot of the blame onto the Captain only lowering its level of blame on the basis that he wanted to save the crew.
It is true I believe that after the ship had been abandoned due to the level of flooding and loss of power the crew went back on board the ship, restarted one of the boilers and regained some power. There must be a suspicion that the crew were ordered off the ship before they needed to have been and that the flooding had not been the cause at that time. After all if it was underwater when they left, its more than unlikely that the flooding had reduced so that they could restart the boiler rooms again between 30 - 60 minutes later when they reboarded the ship. Differing sources give differing times. 

I am not saying that the design of the Ark Royal was without fault, but it would be wrong to concentrate on that aspect. All parts need to be considered.


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## parsifal (Jun 20, 2009)

_You keep putting too much into the armor of the Illustrious, when it has been proven that the armor only barely helped it and in one instance actually showed the structural flaw besides the armor. The Ark Royal was not lost due to a design fault, but to a torpedo which has been proven time again that ships could only be theoretically protected by its armor below the waterline to a torpedo hit. It is a good thing that the Illustrious was never hit by a torpedo, especially a Japanese torpedo. If a kamikaze hit below the waterline could put her out of service then imagine a Long Lance hit. I brought up those battleships because of their armored capability. The armor of the Illustrious could not even compare to that of the Yamato and its counterparts. Thus i am saying that the trade off of armored hangers for speed, range, strike capability, maintanence capabilities proves precisely what the advantage the Illustrious had. Slightly better passive protection then the Yorktown class, and much worse strike, ASW, escort, and CAP capabilities._

Please show me where it was proven that armouring schemes only barely helped these carriers survive. Where is it proven that time and again torpedoes could not be defended against? In fact there are many instances that torpedoes dont have much effect. I can go through plenty, but cant be bothered writing them up to be honest, so I will just cut and paste and article from wiki instead....its relating to wwi, but it does illustrate what I am talking about....

_"Essentially, the bulge is a lateral compartment at the waterline level that is isolated from the ship's internal volume. It is part air-filled, and part free-flooding. In theory, a torpedo strike will rupture and flood the air-filled component of the bulge and the water-filled part will dissipate the shock and absorb explosive fragments, leaving the ship's main hull structurally intact. Transverse bulkheads within the bulge limit flooding throughout the entirety of the structure.

The bulge was developed by the British Director of Naval Construction, Eustace Tennyson-D'Eyncourt, who had four old Edgar-class protected cruisers so fitted in 1914. These ships were used for shore bombardment duties, and so were exposed to inshore submarine and torpedo boat attack. Grafton was torpedoed in 1917, and apart from a few minor splinter holes, the damage was confined to the bulge and the ship safely made port. Edgar was hit in 1918, this time damage to the elderly hull was confined to dented plating. The Royal Navy had all new construction fitted with bulges from 1914, beginning with the Revenge-class battleships. Older ships also had bulges incorporated during refits. The Royal Navy had its large monitors fitted with enormous bulges. This was fortuitous for Terror, which survived 3 torpedoes striking the hull forwards and her sister Erebus, which survived a direct hit from a remotely-controlled explosive motor boat that ripped off 50 feet (15.25 m) of her bulge.

Later designs of bulges incorporated various combinations of air and water filled compartments and packing of wood and sealed tubes. As bulges increased a ship's beam, they caused a reduction in speed, which is a function of the length to beam ratio. Therefore, various combinations of narrow and internal bulges appeared throughout the 1920s and into the 1930s. The bulge had disappeared from construction in the 1930s, being replaced by internal arrangements of compartments with a similar function."_
My understanding regarding the Kamikaze hit b in April 1945 was that it had little or no effect on the ship....are you saying she was knocked out at that time???? if so its news to me...

You also mention the Long Lance torpedo. I never ever said that the Illustrious class were safe against these weapons. A Long Lance is a destroyer launched, 24 inch weapon with a practical range of 15000 yards, a warhead size approaching 1500 lbs, and a speed in excess of 40 knots. What I said was that she was designed to withstand torpedoes of up to 18 inch capacity, which typically had a warhead of 350 lbs, and a range of about 2000 yards. there were no air launched Japanese Long Lance torpedoes that I know of. All of a sudden we have jumped from the sublime to the ridiculous

I never even claimed that the Illustrious were proofed against 21 inch torpedoes. Whilst on this subject, I also never made any claims about the protection of the rudder, the driveshafts, or the miniing effects of magnetic exploders. My claim is simply that they were designed to withstand against a contact hit on the torpedo protection belts. If the hit occurred where it was expected (and likely) to hit, the Illustrious would have little difficulty in defeating an 18 inch torpedo with a contact exploder. 

I also never said that putting more aircraft was not a good idea, in fact was at pains to say that the illustrious was able to increase her air groups to respectable number as at the end of the war (it was actually a max operating total of 57 to use the vernacular of the other guy, in my vernacular, the operational maximum was 52). What I did take to task was the actual numbers carried into battle by the Yorktowns, and I see that once again we are touting numbers of around 91. Before we get into this myth once again....please tell me exactly which battles these ships carried into battle 91 (and I anticipate 91+ )aircraft into battle. The answer, in fact is less than 80. They had max operating capacity of just over 80, apparently, and an Operational maximum of about 75 (in my book) maybe 80 (according to others), but not 91...so lets keep the numbers to what they actually should be, and not what we would like them to be. The Operational maximum for the Illustrious was 42-52, to the Yorktowns 71-83 . But what the RN needed was survivability over numbers....and it got that with the illustrious. You are at pains to tell me the vulnerbility of the Illustrious class generally, and then make up spurious arguments about Long Lance torpedoes in the 18 inch category. In terms of its general strength and durability, I rest on the war record of the class as a whole....not one loss despite the most ferocious attacks made against them.....in terms of torpedo protection, unproven, no claims about protection against Long Lance, but in design terms has a theoretical protection up to 18 inch torpedoes.

Your claims about much worse ASW protection???? how did you arrive at that conclusion. My understanding is that training for aircrews in asw training was never formalized for the squadrons on the USN fleet carriers (at least not until very late in the war), and that asw weaponary on the fleet carriers was pretty basic. The efforts of the British fleet carriers were also pretty ordinary at the beginning of the war but by 1941 had been lifted to repectable levels. Crews had been trained on how to search for u-Boats, the strike aircraft were carrying ASV radar able to detect a surfaced or partially surfaced U-Boat, and weapons had been developed to allow some airborne attacks to be made. This is a genuine question...what information do you have on confirmed or likley kills of U-Boats and submarines by US Yorktown class carriers. I know of none....they certainly dont appear on any of the class's battle honours....but perhaps you some additional information that I have not seen.


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## parsifal (Jun 20, 2009)

Glider said:


> I have not read the results of the official enquiry so cannot be precise, if you have and have a link to it I would more than welome it. I understood that the inquiry put a lot of the blame onto the Captain only lowering its level of blame on the basis that he wanted to save the crew.
> It is true I believe that after the ship had been abandoned due to the level of flooding and loss of power the crew went back on board the ship, restarted one of the boilers and regained some power. There must be a suspicion that the crew were ordered off the ship before they needed to have been and that the flooding had not been the cause at that time. After all if it was underwater when they left, its more than unlikely that the flooding had reduced so that they could restart the boiler rooms again between 30 - 60 minutes later when they reboarded the ship. Differing sources give differing times.
> 
> I am not saying that the design of the Ark Royal was without fault, but it would be wrong to concentrate on that aspect. All parts need to be considered.




Beofore I reply, I need to post a correction. The official admiralty board of enquiry attributed her loss partly to the shortcomings in damage control measures taken (Barnett, page 373, "Engage the Enmey more closely"). However barnet also mentions another technical report that went into the technical shortcomings of the ship. You can apply for a copy of that report through your national archives.....the title to request is 

DM 234/508, BR 2055 Technical Report Of Loss and Damage to HMS ARK ROYAL (1942)

This assessment places a much greater emphasis on the technical shortcomings of the ship. 

Hope this clarifies things a bit


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## Glider (Jun 20, 2009)

parsifal said:


> Beofore I reply, I need to post a correction. The official admiralty board of enquiry attributed her loss partly to the shortcomings in damage control measures taken (Barnett, page 373, "Engage the Enmey more closely"). However barnet also mentions another technical report that went into the technical shortcomings of the ship. You can apply for a copy of that report through your national archives.....the title to request is
> 
> DM 234/508, BR 2055 Technical Report Of Loss and Damage to HMS ARK ROYAL (1942)
> 
> ...



Thanks for the link, I was there today looking at other items but will order it next time I go


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## parsifal (Jun 20, 2009)

Glider said:


> Thanks for the link, I was there today looking at other items but will order it next time I go




No worries, hope it is intersting and helps.


Just a quick note. With regard to the Ark Royal, her underwater protection systems were similar to the Illustrious, though less extensive. In particular the transverse bulkheads were not as thick, and were not passed up into the hull as high as they were on the Illustrious class.

It is worth noting, incidentally, that the Ark Royal was hit by a 21 inch torpedo carrying a 661 lb warhead. The underwater defenses of the ship failed against this warhead, because the warhead exceeded the design parameters of the underwater protection system. The poor DC efforts combined with the inherent weaknesses in the design did the rest.

If the Illustrious had been hit by a 21 inch torpedo, it would have penetrated her underwater protection as well. If the crew were caught napping as the Ark Royals had, the result is likley to have been the same (although the redesigned funnel lines may have given them more time in which to react). 

Italian torpedo bombers such as the S-79 carried up to 4x 18 inch torps or 1 or 2 21 inch torps. inevitably they chose to arm with the larger weapon, because I believe they knew that the 18 inch was not good at penetrating properly prepared underwater defences (they needed a lucky hit to be efective) . To be considered "proper" I believe you needed a mixture of armour plate and other measures to contain the extent of blast and contain flooding. It was much harder to protect against a bigger warhead, and even harder still to protect against a propely functioning magnetic exploder. But for that matter, plunging fire was much more damgerous than flat trajectory fire, and larger bombs much more dangerous than smaller ones....but thats another story I guess.


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## parsifal (Jun 20, 2009)

A further note about Japanese aerial torpedoes. There were quite a number available, however in 1941 there were two main types, the Type 91(1931) Model 1 and the Type 91 (1931) model 2. The two types differed in two areas, warhead size and overall weight. The model 2 was used by Kates at ranges below about 180 NM, and the Model 1 for ranges above that. Both types were used in the attacks against the Prince Of Wales and Repulse, whilst it was the Model 2 that was used by the 40 torpedo carrying Kates at Pearl. I am uncertain what types were being used at Midway, but I suspect Model 1s given the ranges of the strikes.....

The warhead size and overall weight of these types are 331/1728 lbs for the Model 1 and 452/1929 lbs for the model 2 

Repulse had anti-torpedo protection far less extensive than that used in the Illustrious. Her last major reconstruction was in 1923 where among other things she had early type bulges fitted. The She had some transverse bulkheads in the hull, but nowhere near as extensive as those that existed in the Illustrious

PoW was a thoroughly modern warship, with underwater protection superior to that of the Illustrious - around the citadel....around the screws and the rudders she suffered from the same problems, namely a vulnerable spot that if hit was likley to cause severe problems.

Prince Of Wales was hit by at least 4 x Type 91 Mod 2 torps of which two hit the shafts and or their housings. one hit and broke off the "A" Bracket to the port outer shaft. The second torpedo hit the outer shaft housing on the starborad side. What caused the loss of the ship was the continued rotation under power of the bent shafts, which caused massive and catastrophic flooding of the engine spaces to occur. The remaining hits caused no damage to the torpedo protection system. There are unconfimred reports of other hits to the underwater belt, perhaps as many as four additional, so in a sense it may have taken up to about 8 torpedo hits to sink this ship. 

Japanese aerial torps are admittedly surpisingly heavy for their size, thereby making them that much more dangerous, however they are not Long Lance, and their success in sinking ships is not guranteed.


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## syscom3 (Jun 20, 2009)

OK, Parsifal has proven that the Illustrious had the better protection of the three carriers. But all he proved was the Illustrious had increased protection from damage, but *NOT IMMUNITY FROM*. And then part of that argument goes back to the original question, on whether the Illustrious sacrificed too much AC capacity to provide that protection.

Leonard proved beyond a doubt that the Yorktown class could carry 90 AC, even if air groups were going to battle with less than a full compliment.

Too me, the small air group for the Illustrious would cause serious operational issues in the Pacific where three of these ships would be needed to provide the same striking power of two Yorktown carriers. You can also say that one Illustrious carrier was simply too small to be usefull even for a single ship raiding mission.

Ultimately, the carriers were there to provide striking power, and anything that detracts from that is undermining the rationale for its existence, unless its only for escort duties and not offensive operations. In that case, the Illustrious should be compared to the Independence class carriers.

Finally, the Yorktown had far better endurance and logistical support for its air group. That meant it was going to stay at sea longer and do what it was supposed to do, and not be in dock.


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## Amsel (Jun 20, 2009)

parsifal said:


> I note that your position changed from Post 76 to Post 78. Post 76 was basically that the Illustrious was a failed design in that it could not project its force. Post 78 abandons that position and says that it was better in the constricted waters around Europe and had difficulty in the Pacific. You then throw into the mix some comments about the inability of armouring schemes to stop torpedoes.
> 
> Well, before I respond, please clarify to me what your actual and final position is on this.....are you stil saying that the illustrious class are a failure because thay cannot project force, or are you simply saying that they were better suited to operations in Europe.
> 
> The difference forme is critical. I totally agree with one position, and totally disagree with the other. I would like you to clarify what exactly is your position on this.



My position hasn't changed. The Illustrious was a mistake and was not repeated. It is not even in the same class as the Yorktown class. I have stated all the reasons why I think this. The Yorktown class CV-6 USS Enterprise was a huge success for the USN. Like I have stated before; it is about two different doctorines. Many agree the doctorine of the RN when they laid down the Illustrious was flawed, recognized, and not repeated. We could go on and on about this but it comes down to armor or more aircraft, range, speed, deck size, elevator size, and maintanance capability.


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## vikingBerserker (Jun 21, 2009)

This might have been said before and I apoligize for the repeat, but the reason why the "Indomitable" (which was supposed to be the 4th ship of the Illustrious Class) was changed to accomidate more aircraft and less armour was due to the short comings of the Illustrious Class.


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## parsifal (Jun 21, 2009)

The Illustrious class was three ships, that were developed into a a fourth half sister, the Indomitable with the same armoured flight deck (but eith less side armour....wartime experience had shown that the principal reasoning to justify the side armour of the hangar deck - the supposed threat from surface attack was just not going to ever eventuate, so weight could be saved by reducing the side armouring. ), in exchange for an increased air capacity. Still the same basic design, and the same closed hangar system

Following the Indomitable came the two Impacable class carriers, that squeezed two full hangars into the same basic hull. Oh and yes it retained the same armoured box principal and to quote Conways, was "a further development of the Illustrious class" These two ships expanded the air air capacity to over 80, but retained the the same principals of armoured protection (on a slightly reduced scale, again to reduce the side armouring mostly which had been found to be unnecessary from wartime experience).

After that the hull design was changed, but the same basic philiospophy encompassing the armoured deck and closed hangar was retained in the next two (and final) classes designed for the RN. Only one of these classes was actually completed to a different postwar design, but within the context of the war, both of them once again retained the armoured box principal, the closed hangar system and oh yes, the superior underwater protection. One was of course the Eagle Class, the other was the cancelled Malta class. To be completely fair, the Malta class were eventually altered to incorporaporate an American style open hangar system, because it was quicker and less expensive to build the ships that way, not because it offered a superior method of construction.

That was the end of the British heavy carrier construction, and whilst it was not feasible to build an armoured carrier on anything smaller, the ubiquitous post war Light Fleet carriers carriers, which proved so popular with all the foreign navies except the USN, also were largely based on the experiences of the Illustrious class. though they could not be armoured, they did retain the same type of underwater protection, retained the same closed hangar systems, but did introduce the unit machinery system. 

So it is not true that the Illustrious class were not repeated. they were in fact the basis of every class that followed them (not including of course the Invincible class, or the new cariers under construction).


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## parsifal (Jun 21, 2009)

syscom3 said:


> OK, Parsifal has proven that the Illustrious had the better protection of the three carriers. But all he proved was the Illustrious had increased protection from damage, but *NOT IMMUNITY FROM*. And then part of that argument goes back to the original question, on whether the Illustrious sacrificed too much AC capacity to provide that protection.
> 
> Leonard proved beyond a doubt that the Yorktown class could carry 90 AC, even if air groups were going to battle with less than a full compliment.
> 
> ...



That about sums it up...for once we are pretty much in agreement....but there is just the little issue of the european thetre....were the Yorktown as suited to the operating environment there as well


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## renrich (Jun 21, 2009)

Since Germany and Italy had rather insignificant navies and no aircraft carriers, why doe it need to be proved that the Yorktown class was suited to the operating environment in the ETO?


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## parsifal (Jun 21, 2009)

Between them the two axis powers commissioned 15 Battleships, Battlecruisers and armoured ships. They commissioned 10 heavy cruisers 21 Light cruisers, and approximately 150 destroyers. They did not commission any carriers, but they did field specially trained antishipping units. The Luftwaffe in 1942 was about three times the size of the Japanese air arms, and deployed about 1200 aircraft to the southern front in the meditteraanean. 

In the north, more than 50% of materiel sent to Russia in the critical years of 1942-3 went via the northern route. 

In the south the the progress of DAK was directly linked to the ability of the Allies to keep just one small island supplied and the airbases thereon stocked with aircrraft. In the event of a Soviet Collapse on the eastern front the allies at short notice needed to be able to mount an emergency invasion somewhere on the continent, to try and draw pressure off the Russians. And finally, of course, the allies had to protect the convoys operating in the North Atlantic and the Carribean. All of this needed carriers , fleet carriers to support the actions at sea....without carriers none of what was achieved could have been achieved

I would say that there are some pretty good reasons to want to maintain control of the oceans in the western hemisphere in amongst all of that.....I would further say that I agree with the joint chiefs when they essentially identified the pacific as a secondary front, and the battles in and around Europe as the critical one to decide the war. The naval battles were the essential precursors to any other battle you care to name in Europe and North America. If the battles of the seas had been lost, even lost by reason of non-participation, the whole war was going to be lost. the same cannot be said for the battles in the Pacific. You think about it...which theatre was more important, and which theatre was less dependant on seapower for its outcome


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## syscom3 (Jun 21, 2009)

parsifal said:


> That about sums it up...for once we are pretty much in agreement....but there is just the little issue of the european thetre....were the Yorktown as suited to the operating environment there as well



The war in the ETO was not going to be effected by fleet carriers since that theater (MTO included) was a continental war. The escort carriers in the ASW and anti-bomber roles is what was vitally important.

The PTO on the other hand, the fleet carrier was integral in the successfull prosecution of the war. Since the Illustrious was a fleet carrier, we have to compare it to similar types. And in this regard, it was second fiddle in an all around capacity.


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## renrich (Jun 21, 2009)

Sys, I concur. The Allies could maintain control of the seas in the ETO without carriers. If they had not had carriers in the Pacific, they might have been speaking Japanese in Australia today. The Allies did not need carriers for air support in landings on defended beaches in the ETO either. 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. An interesting point. " On November 26, 1944, a Navv conference in San Francisco finalizes the decision to put a 73 fighter-per-carrier complement on fleet aircraft carriers." They pretty well could not have done that without the large capacity for AC of US carriers.


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## parsifal (Jun 21, 2009)

Unbelievable. So you think that the control of the seas around europe can be achieved with a few CVEs, and rowboats. I am staggered to read that.

I dont know where to start, but just to take one option....lets look at Malta as an issue. Ther are two possible scenrios that can arise from your comments....either it was not nercessary to retain it as a viable forward base, or, you believe it can be maintained with a minimum of trouble, and not require the intervention of fleet carriers.

Lets just have a quick look at the implications of either opinion. 

If Malta is not kept supplied, it ceases to function as a forward airbase, and in fact either surrenders, or literally starves to death. With Malta not available as a base, the supplies and troops pour into North Africa, and Egypt falls, After that it is not possible to hold the Middle East, and Iran and Iraq fall, which isolates Turkey and forces her into the Axis camp. With the southern front secure, and turkey quite possibly now either a member of the axis, or at minimum allowing rights of passage to the axis forces, the whole of the caucasus is now at risk. If I were in charge of the Nazis, I would pour troops into that potential front with the idea of captuing the caucasus oilfields. that in turn is going to bring Russia to its knees allowing the German in 1943 (approximately) to turn its attentions to the remainder of the western alliance. They are now in an unassailable position, and the allies have effectively lost the war.....all because the american commander in charge of this hypothetical scenario dosent have the sense to relaize the importance of Malta.

Lets be more charitable, and assume that after all you do see the importance of Malta, but are unwiling to pour the carrier strength into hoilding it. you say you will try and undertake this task with escort carriers, but ther is just one small problem with this approach...escort carriers were not built or developed in any numbers until the latter part of 1942-3, and in any event were needed to win the battle of the atlantic until early 1944. So in the critical period of 1940-42, there will be no air cover for the relief convoys trying to reach the island. 

The Italian fleet will be much stionger and far more confident than it was, because it has not suffered the defeats at Taranto, Matapan, or even the total domination of the central basin that the one or two carriers gave the allies (until the arrival of the germans in 1941). The Italians are able to mount effective attacks because their air force, is not being hacked out of the sky by defending allied fighters. If and when the Germans do arrive they are going to absolutely massacre the unprotected warships and merchant shipping trying to reach the island.....the allies meanwhile are being forced to divert major amounts of warships to containing the German battle squadron at brest, which now include s an undamaged Bismarck and Prinz Eugen. They dont have any carriers to attack these ships, and they cannot sink them with their own BBs (Bismarck is effectively an unsinkable Battleship in 1941 IMO), .....so ...do i need to go further

A war without carriers in Europe is a war lost. Trying to say you will control its seas without carriers, or with carriers that you dont have access to until the latter part of 1943 is about the stupidest thing I have ever heard. You guys should know better.

And remember, these are just two scenarios. There are many others that I have not even bothered yet to explore for you.


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## renrich (Jun 22, 2009)

I think that saying the war in the ETO would have been lost without Allied aircraft carriers except for ASW uses is, undoubtedly an overstatement. I would not go so far as to label it stupid, however.


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## parsifal (Jun 22, 2009)

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.


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## trackend (Jun 22, 2009)

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".


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## renrich (Jun 22, 2009)

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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## vikingBerserker (Jun 22, 2009)

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..



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.


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## renrich (Jun 23, 2009)

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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## parsifal (Jun 23, 2009)

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!



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,


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## parsifal (Jun 23, 2009)

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.



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


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## syscom3 (Jun 23, 2009)

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.


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## renrich (Jun 23, 2009)

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.


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## syscom3 (Jun 23, 2009)

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


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## parsifal (Jun 23, 2009)

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.


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## vikingBerserker (Jun 23, 2009)

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.



Ok now I follow you.


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## renrich (Jul 9, 2009)

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.


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## Glider (Jul 9, 2009)

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.


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## Amsel (Jul 9, 2009)

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.


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## Vassili Zaitzev (Jul 9, 2009)

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


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## parsifal (Mar 14, 2016)

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


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## parsifal (Mar 14, 2016)

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


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## cherry blossom (Mar 31, 2016)

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.

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## Glider (Apr 3, 2016)

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


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## nuuumannn (Apr 3, 2016)

Ultimately, the value of an asset is how its used (look at the Blackburn Skua - wholly inadequate fighting machine, but still sank a cruiser). Both the Lusty and Yorktown were constructed with different philosophies and roles/theatres in mind; would the British have gotten as much valuable service out of the Yorktown and they did with the Lusty and vice versa with the Americans? If either side had no other option, then yes, I believe so, despite each ship's limitations in the different theatres they operated in. I believe the Yorktown might have been more vulnerable in the ETO and in the Med it would have been subjected to heavy attacks, which it's likely it might not have survived, whereas the Lusty, if it were in US hands, in the Pacific its limitations are well documented - Max Hastings' book, which Renrich quotes from is excellent and well worth reading and gives an eye opening view of this all-important aspect of the war in the Pacific; The British really couldn't match US numerical assets, nor operational experience in theatre, but if the US had Illustrious Class carriers they would still have gotten what was asked of the carriers from the outset, despite their limitations of small aircraft numbers and shorter range.

The Royal Navy was hampered considerably post WW1 in terms of aviation for a few reasons; in a fiscally lean post-war environment, followed by nationwide calls for peace and disarmament, carriers were an expensive symbol of militarism and the RN clung desperately onto what it had at the end of the Great War despite the ships' inadequacies - Courageous and Glorious were slated for conversion to carriers as early as 1917 and conversion of Furious into a full flat top only made sense. Also, the RAF took over all naval air operations in 1918, combined with peacetime reduction of capabilities hindered naval aviation growth in Britain after a bright start leading the field during the Great War. It wasn't until 1939 that the FAA gained complete autonomy from the RAF.

So at the outbreak of war Britain's naval aviation is hindered with inadequate aircraft, small budgets and carriers, which are of variable value in a high threat environment, that are restricted in size owing to cost and original design constraints. Yet, the RN and FAA gave astonishingly good service with the equipment they had in extraordinarily trying circumstances, despite all this. So, in conclusion, it's very hard to state which was better in my opinion; both ships had their merits, but would each one have been as effective as the other in the environments that the other was used in by the forces in those theatres?


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## RCAFson (Apr 8, 2016)

cherry blossom said:


> 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).
> 
> 
> 
> .


Indomitable and the two Implacables had a 45 x 33ft forward elevator that could accommodate most fixed wing fighters of the day.

The RN did occasionally use deck parks in the early war period. Illustrious, for example carried about 9 aircraft in a deck park during the Taranto mission.


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## parsifal (Apr 8, 2016)

I wonder if we could examine this issue from a slightly different perspective. Say the Japanese were building Yorktowns instead of the Soryus, and the US had to build Soryus instead of Yorktowns. Assume the other classes are built with perhaps some minor tweaking where necessary, and money is not the problem, just the tonnages set by the treaty.

There were four Yorktowns with a total tonnage of around 100000 tons. They could have had 6 Soryus with an a/c capacity of 378 a/c and a reserve capacity of 54. Individually each hull is more vulnerable but there are 6 of them, carrying more a/c. Combine that with the known US superiority in damage control and I think the US may have been better off with the Soryus. The problem of course is their fragility, though it took more bombs to knock out Hiryu than Yorktown at Midway. probably a fluke I would concede.

Conversely The Japanese had 34000 tons for the hiryus and they also had 8000 tons for the Ryujo. It creates an awkward tonnage issue for them, with 40000, they just don't have the tonnage to build 2 Yorktowns whichever way they cut it.

If they retain the Ryujo, they could build one Yorktown and another Ryujo, but probably better to cheat a bit and build another shoho class. So, in exchange fior their two Soryus, they could get 1 Yorktown and 1 Shoho, and even then have to lie a bit (Shoho had a displacement of 11000 tons). 

For the British, there are four alternative scenarios that I can see. 

1) Build 3 Ark Royal repeats instead of the 4 Illustrious option. If they scrap or demilitarise the Argus, they could build the 4th Problem here is that these carriers would never be more than 50% full and carried inherent and serious design flaws. The Bucknill Committee, which had been set up to investigate the loss of the Ark Royal produced a report that concluded the lack of backup power sources was a major design failure, which contributed to the loss: Ark Royal depended on electricity for much of her operation, and once the boilers and steam dynamos were knocked out, the loss of power made damage control difficult. Moreover the strakes protecting engine spaces were not of sufficient height to protect the engine spaces from uncontrolled flooding and the two design issues fed off each other in a vicious way. The committee recommended the design of the bulkheads and boiler intakes be improved to decrease the risk of widespread flooding in boiler rooms and machine spaces, while the uninterrupted boiler room flat was criticised. The design flaws were rectified in the Illustrious and later the implacable classes, but these solutions took time.

2) Build the Illustrious class with these design solutions in place, but otherwise to the original design. I think this is the least feasible of the alternatives, because there simply aren’t that many advantages to doing that. The Illustriousclass was designed within the restrictions of the London Naval treaty in place, were built to an to an upper limit of 23,000 tons. They were different in conception to the RNs only modern carrier at the time, their predecessor Ark Royal and what may be described as their nearest American contemporaries, the Yorktowns class carriers.

Where other designs emphasised large air groups as the primary means of defence, the Illustrious class relied on their AA and the passive defence provided by an armoured flight deck. This latter aspect has often been thought to been the cause of her small CAG, but this in fact is a furphy Other carriers had armour carried on lower decks (e.g. the hangar deck or main deck); the unprotected flight deck and the hangar below it formed part of the superstructure and were unprotected against even small bombs. However, the hangar could be made larger and thus more aircraft could be carried, but the differences in aircraft capacity between these carriers and their United States Navy (USN) counterparts is largely due to the USN's operational doctrine, which allowed for a permanent deck park of aircraft to augment their hangar capacity. Illustrious's hangar was 82% as large as the Yorktown design. but the US carrier typically carried 30% of her aircraft capacity in her deck park. That equates to 23 a/c, and effectively reduces the air capacity if used as the Illustrious was uses to 51 a/c in the hangar. Indomitable's two hangars were actually larger than _Enterprise's_ but she carried fewer aircraft because she did not have a large permanent deck park. In 1944/45 RN carriers began to carry a permanent deck park of similar size to their USN counterparts and this increased their aircraft complement to an eventual 57 aircraft in the single hangar carriers and up to 81 in the double hangared carriers.

In the Illustrious class, armour was carried at the flight deck level—which became the strength deck—and formed an armoured box-like hangar that was an integral part of the ship's structure. However, to make this possible without increasing the displacement it was necessary to significantly reduce the headroom of the hangar. The later three vessels, _Indomitable_, _Indefatigable_ and _Implacable_, had re-designed two-level hangars which enabled them to carry larger air groups than the original design. The size of the air wings was also increased by using outriggers and deck parks. The original design was for 36 aircraft, but eventually the vessels operated with a complement of up to 72 aircraft. However, the smaller overhead height of the hangars (16 ft (4.88 m) in the upper hangars and 14 ft (4.27 m) in the later ships with lower hangars) compared unfavourably to the 17 feet 3 inches (5.3 m) of the _Essex_ class, 17 ft 6 inches (5.38 m) in _Enterprise_ and 20 ft (6.10 m) in _Saratoga_. This restricted operations with larger aircraft designs, particularly post-war.
This armour scheme was designed to withstand 1,000 pound bombs (and heavier bombs which struck at an angle); in the ETO and MTO it was likely that the carriers would operate within the range of shore-based aircraft, which could carry heavier bombs than their carrier-based equivalents. The flight deck had an armoured thickness of 3 inches, closed by 4.5-inch sides and bulkheads. There were 3-inch strakes on either side extending from the box sides to the top edge of the main side belt, which was of 4.5 inches. The main belt protected the machinery, petrol stowage, magazines and aerial weapon stores. The lifts were placed outside the hangar, at either end, with access through sliding armoured doors in the end bulkheads.
Later in the war it was found that bombs which penetrated and detonated inside the armoured hangar could cause structural deformation, as the latter was an integral part of the ship's structure.
Pre-war doctrine held that the ship's own firepower, rather than its aircraft, were to be relied upon for protection, since in the absence of radar, fighters were unlikely to intercept incoming attackers before they could release their weapons. Accordingly, the Illustrious class was given an extremely heavy Anti-Aircraft armament. The armament was similar to _Ark Royal_ with twin 4.5 inch turrets (in a new "between-decks" or countersunk design) arranged on the points of a quadrant. The guns were mounted sufficiently high so that they could fire across the decks; de-fuelled aircraft would be stowed in the hangar for protection during aerial attack. The _Illustrious Class_ were fitted with four HACS controlled High Angle Director Towers, for fire control of her 4.5" guns.

Bottom line is that without armour scheme, you might get another 10 a/c per carrier. Build to the later Indomitable design, and you might get 1 less carrier and a capacity 20 more a/c across the class

3) Build to the new concepts embodied in the slightly later Unicorn. At 16000 tons, you get 6 carriers instead of 4 with a carrying capacity of 35 instead of a design capacity of 36 (but practical of 53). The air capacity is near as dammit the same, but againwe are at the conundrum of hull numbers versus design strength. Hard to know which strategy is better, but coming from a background of the post war light fleet carriers that came from the unicorn, I tend to favour the unicorn option.


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## Peter Gunn (Apr 8, 2016)

Interesting thought to swap Yorktowns for Soryus, I don't see how that could have really happened unless we're just doing a total what if scenario. I believe the USN already knew that they wanted larger fleet carriers, that's why they built the three Yorktowns, with the spare 15k odd tons left over they built the Wasp, roughly the same size as Soryu and she was no bargain. Some of her problems may have been design flaws but she was only brought to the Pacific (read hotter war zone for CV's) after the early losses, and didn't last long then.

Wasp would be the equivalent of what you're proposing and I'm not sure I see the USN following that path, after Lexington/Saratoga and the Ranger experiment, I don't see the USN going smaller. The Wasp wasn't a Yorktown, 5 grand lighter and 3 knots slower with less than optimal design features (like no armor) although it could be called a modified Yorktown I suppose.

As I said, interesting but after the Fleet Problems of the twenties and thirties, I just don't see the USN going with smaller, less capable flat tops.


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## parsifal (Apr 8, 2016)

The nearest "real life" equivalent" might be to assume repeats of the Wasp, with a couple of thousand tons of displacement added, to be used for whatever purpose might be most appropriate.

Point i was making isnt that the USN would be that much better off, but that the IJN would be much worse off if they tried to replace their Soryus with something equivalent to the Yorktowns. They just dont have the tonnage under the treaties to even consider that .

Some will say that the Japanese were not bound by treaties after 1936, since they did not sign the 2nd london naval treaty. It still greatly influenced their behaviour because of the various escalator clauses contained in the treaty. if Japan was found to be in breach of the treaty, the treaty powers could invoke their escalator clauses. At the time this applied mostly to battleship armament, but if the Japanese broke other parts of the treaty, such as the limits on class tonnages, the other powers could be released from the limits applying to them as well. 

This is the main reason the Japanese became so secretive in their naval builds from 1935-41. They wanted to avoid other powers simply increasing their builds and thereby cancel any advantage the Japanese might derive from cheating the system. The Japanese only had enough tonnage to build the two Hiryu/Soryu class. They didnt embark on outright carrier construction until after 1939, with the Shokaku and Zuikaku. Soryu and Hiryu were the last true carriers they could build and not be seen to breach the treaty. Thus they could keep the allies restricted to the treaty whilst doing their best to circumvent it themselves. They did this with their merchant conversion carriers Hiyo and Junyo, which were built as merchant vessels, but designed for easy conversion from their initial design. They did similar expedients with the Shoho class, the Ryuho, the Chitose Chiyoda, Nishin and Mizuho. All of these were built as auxiliaries, but with an easy conversion to carriers always in mind. The US also considered this approach but rejected it until the quick CVE lash ups were insisted upon by Roosevelt. 

As carriers these Japanese conversions were not as good as the USN purpose built types, but it also meant the japanese could at least count on parity, and not be swamped for a while at least. If they had not suffered a number of defeats in 1942, it might have worked.

As a generalisation the USN considered these socalled "trade protection carriers" and mercantile conversions, but rejected them as unnecessary. That should not, in the longer term, be seen as a smart design choice. After 1943, the issue became largely academic as vast numbers of Essex class became available. They still were limited in numbers of these big carriers until the latter part of 1944, and had to make do with their own conversions for a while, the Independance Class. They also embarked on their CVE conversions, which by the early part of 1944 were playing a decisive role, although not in pure fleet work (for the USN)

The British convened a committee in 1942 to examine the carrier needs. Though they already had plans to build super carriers, mostly for prestige reasons, the RN was more in favour of the "light fleet carrier" concept, and in this they were absolutely on the money. These trade protection carriers found the key issues were still the closed hangar protection system, not armour as such, good endurance and fuel stowage, back up systems for DC, unitised machinery and a sustained fleet speed of about 24 knots. These led to a series of designs that had they been available earlier, might well have been decisive. As it was, these designs proved far more useful to most of the post war navies over the big and unwieldy USN designs. I refer of course to the Colossus, Majestic, and Centaur classes, which completely dominated the post war small navy carrier market post war, and whose design philospophies continue to dominate over the more traditional US types to this day. In the RANs case, post war, we were offered a fully functional Essex, but went for two Majestics instead, one of which was converted to an angled deck carrier whilst building and not retired until 1983. Even then its service was not done. Purchased at scrap prices by the Chinese, they secretly (and unlawfully) removed the entire upper deck and used that for carrier deck landings and take offs until 2004. They painstakingly reverse engineered the steam catapult and intently studied the unitised machinery spaces and compartment segmentation of the ship. That should at least give an idea of just how far ahead of their time these ideas actually were in 1942.


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## Peter Gunn (Apr 11, 2016)

parsifal - Ahh, now I see, I wasn't getting it before, sorry. For what it's worth I agree, well thought out explanation, thanks.


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## parsifal (Apr 11, 2016)

On a ship for ship basis, its pretty clear that the Yorktown is the winner, but there is more than one way to skin a cat. On a ton for ton basis, I think Id argue the Soryus, and on a man for man probably the Illustrious


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## Glider (Apr 12, 2016)

Replace the Illustrious with the Ark Royal and then you have a different winner, as the main problem with the Illustrious ie the no of aircraft is increased significantly.


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## parsifal (Apr 13, 2016)

i have to respectfully disagree. you do get a significantly increased air capacity, and Ark Royal was a good ship, but she suffered some damning design flaws that the RN was never keen to publicise. Quoting my post 123...."_The Bucknill Committee, which had been set up to investigate the loss of the Ark Royal produced a report that concluded the lack of backup power sources was a major design failure, which contributed to the loss: Ark Royal depended on electricity for much of her operation, and once the boilers and steam dynamos were knocked out, the loss of power made damage control difficult. Moreover the strakes protecting engine spaces were not of sufficient height to protect the engine spaces from uncontrolled flooding and the two design issues fed off each other in a vicious way. The committee recommended the design of the bulkheads and boiler intakes be improved to decrease the risk of widespread flooding in boiler rooms and machine spaces, while the uninterrupted boiler room flat was criticised. The design flaws were rectified in the Illustrious and later the implacable classes, but these solutions took time_"

moreover, the limited air capacity of the illustrious was as much about the RN operations philiosphy as it was the limits of the design. illustrious had 83% the hangar space of the yorktown, and unlike the USN, the RN at the beginning of the war refused to accept large permanent deck parks in the same way that the USN did. Fully 23 of the quoted 75 a/c capacity of the yorktowns was due to that deck park. The illustrious, once she also took on a deck park, had a real air capacity of 57 and not the 36 she is often quoted as capable of. We will never know about the max carrying capacity of the ark royal, but i imagine her smaller deck area might limit her to about 80 a/c with a deck park


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## Glider (Apr 13, 2016)

I certainly agree that the report did make those statements (what else could I say) but the changes were for the most part easy to make. Back up generators were more widely issued to the fleet and I do loath the memories I have of lugging back up diesel powered pumps up and down the ship during damage control exercises.
I don't know the changes needed to increase the height of the strakes but its also worth remembering that poor leadership was a major factor, indeed the primary factor in the loss of the Ark Royal.
The changes were probably not included in the design of the Illustrious as she would have been too far down the design build path by the time the report came out.
When war broke out the Ark Royal although not perfect had first class AA defences, good protection and an aircraft establishment few carriers could match. I have always believed that a fine tuning of the Ark Royal design and a mass production of that design would have resulted in a better earlier carrier fleet and probably for less cost, that the Illustrious and associated classes.


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## RCAFson (Apr 22, 2016)

A great website about RN armoured aircraft carriers and their aircraft:

Home


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## Wurger (Apr 22, 2016)




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## fastmongrel (Apr 24, 2016)

The RN must have known about some of the flaws in the Arks when they were designing the Illustrious. What would an Illustrious look like if she had been designed with aircraft capacity rather than armour as the main defence iirc 1,000 tons of flight deck armour was fitted plus all the extra steel needed for the structure to take the weight. If we say 4,000 tons went to the defence how much length, beam and flight deck height above the waterline can you get without all that weight high up and an extra 4,000 tons to play with in the hull.


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## Glider (Apr 24, 2016)

First of all why would the RN be aware of the flaws in the Ark Royal, she hadn't been tested in combat so the flaws wouldn't have been known. As to what the Illustrious would look like who knows. 
if the RN went for the armoured deck then she would have looked like the Implacable which had a second hanger deck.
If they didn't and went for capacity, then they would have looked a lot like the Ark Royal with a better lift layout and a slightly wider deck


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## parsifal (Apr 25, 2016)

The design flaws of the Ark Royal were not known at the time the illustrious was built, though there were misgivings abiout the machinery arrangements , lack of horizontal protection, limited deck area and the known inability of the vertical strakes around the engine room to stem uncontrolled flooding. 

The Illustrious class were meant to be repeat Ark Royals, but pretty quickly the RN reconsidered this option. The RN had such limited crew numbers for the Fleet Air Arm that it made no sense to repeat the Ark Royal. They also wanted a carrier that could withstand up to a 1000 lb bomb dropped from below 10000 feet (might be 5000), and this required a much heavier armouring scheme, basically reducing the number of decks by 1 and limiting the headroom of the hangar severely. The AA suite was the primary air defence weapon and was redesigned in the Illustrious class.

Whilst undergoing this redesign process the Illustrious were modified to adopt better machinery layouts and address the flood vulnerability issues. More tonnage could be devoted to damage control back up systems, so the Illustrious, despite suffering catastrophic damage on a much greater scale than that suffered by the Ark, was able to keep steaming and able to fight the fires that nearly sank her. Illustrious class design was in fact a response to the expected or anticipated flaws of the Ark Royal, coupled with a realistic appraisal about the slow rate the FAA would expand 1938-42.


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## Glider (Apr 26, 2016)

My understanding is a little different. Once the decision was taken that the new carriers had t withstand a 1000lb bomb any thought of the Illustrious being a follow on from the Ark Royal was discarded, we were automatically in for a totally different design.
No one could deny that the Ark Royal had for its time an exceptional AA defence, but the demand for an overwhelming priority for the AA defence led to the extreme demand that the 4.5in guns could fire across the deck, hence the raised gun turrets. I believe this was the only major difference in the AA protection
Even before completion the significantly reduced aircraft capacity of the Illustrious was subject to criticism so the fourth ship had a second hanger deck that could only be half the length of the ship. The final pair having two full hanger decks. 

From this my take is that the Illustrious with one hanger deck was a mistake. The RN moving as fast as it could without disrupting production to increase the aircraft capability back to that carried in the Ark Royal. 

So when comparing the immediate pre war carriers the Ark Royal was in my mind a better balanced design than the Illustrious.


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## parsifal (Apr 26, 2016)

The big advantage about just churning out repeat Ark Royals in my opinion is that they would have been available far sooner than the Illustrious. Probably reasonable to assume a 3 carrier delivery 1939-40, instead of the 4 carrier delivery (although 6 were originally planned) hard to argue that the later Implacables were any sort of variation of the Illustruious. Its worth noting this earlier delivery as a tangible advantage to going down the path of repeat Ark Royals, but only three in the short term is really limiting your egg baskets in my opinion. In my book the following Implacables were so different from Illustrious as to be more correctly thought of as a new design

It is true that the illustrious class raised misgivings about their limited air capacity from the start, but then again the RN felt no urgency to adopt US methods of a permanent deck park until the very end of 1943. Overnight this raised the carrying capacity for all 4 of the class to a respectable 57 a/c. Then something strange happened. Indomitable, the last of the class and theoretically designed so as to accommodate 45 a/c in its redesigned hangars, had trouble accepting the increased CAGs of 57 being operated by the others and for the '45 deployment dropped her capacity dropped back to 48 a/c. The revised internal layout had increased hangar space, but at the cost of eating into the machinery spaces, such that her engines were limited to a ten year life span because of excessive overheating. She was refitted 1948-51 to try and address this, but it was useless, and in 1955 she was scrapped, just two years behind the Formidable, which was scrapped in 1953 because of her poor condition.

The two remaining carriers in the class were Illustrious and Victorious. Illustrious went through two refits and served as a training carrier until 1957. Despite having been heavily damaged in 1941 (something she never fully recovered from), the superiority of the design over the later designs is that despite obvious limitations brought about by her wartime service, she was retained longer than either of the two Implacables, both of which were gone by 1955. Their hangars were far too constricted and the machinery spaces so poorly designed as to preclude their effective postwar use, and had they been subjected to really rigorous service, this would have been shown during wartime service.

Victorious was the only wartime fleet carrier in the UK to be considered as having sufficiently good conditions and inherent design advantages to warrant full modernisation. Like most of these wartime completions, modification to angled deck, redesign of the engine spaces and modernisation of the defensive systems meant it took over 8 years to complete the modernisation, but at least her design was good enough in the first place to warrant that effort. The so-called "better" Implacables were not, and really were of such poor design as to preclude any attempt to re-use them


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## fastmongrel (Apr 27, 2016)

What the RN really needed were bigger dry docks so they could have built longer carriers. A longer single hanger Illustrious would be a better ship than an Implacable which as Parsifal says were a quart in a pint pot. The Yorktowns were 60 feet longer waterline and an extra 60 foot longer in an Illustrious type hangar is about 3,000 sq feet extra still not as big as a Yorktown (iirc 33,000sq ft) but probably give space for 50 aircraft struck below if the Yorktown can fit 60.

An extra 60 feet also possibly allow another lift or 2 of a bigger size plus the engine rooms and accomodation get some much needed elbow room.


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