US vs UK Carriers ?

Hah! Now what do you suppose that means? It means (well, in a way), that US carriers are better! Or, maybe not. :lol:

 

No, it means that the two Navies had different design philosophies and built accordingly.

US carriers were bigger and there were more of them.

For the record, no (zero) British armoured carriers were sunk during WW2, although HMS Illustroius came close. So, in percentage terms, the armoured carriers have a better survival rate than the non-armoured ones.

Tom

 

"So, in percentage terms, the armoured carriers have a better survival rate than the non-armoured ones."
By my calculations, 25% of carriers with flight deck armor sank during the war, while 19.4% of carriers without flight deck armor sank.
A more instructive analysis would differentiate these sinkings by cause. How many carriers succumbed to bombs or gunfire? How many sank primarily from torpedo damage?

 

Which ones came into each type?

I was considering the British "I" class as the only armoured deck CVs -- which ones did I miss?

 

The Japanese Taiho and Shinano both had armored flight decks. That makes a total of eight ships, two being lost. Not much of a sample pool.
But in any case, I am a notorious hater of statistics as they so easily lend themselves to misunderstanding and distortion. How about a quick survey of carrier losses? This would be a good way to get past the stats.
British: Courageous torpedoed, Glorious shelled, Eagle torpedoed, Hermes bombed, Ark Royal torpedoed, Avenger torpedoed, Dasher accident
American: Lexington torpedoed, Wasp torpedoed, Hornet torpedoed, Yorktown torpedoed, St Lo kamikazed, Gambier Bay shelled, Liscome Bay torpedoed, Bismarck Sea kamikazed, Ommaney Bay kamikazed, Block Island torpedoed, Princeton bombed
Japanese: Akagi bombed, Kaga bombed, Shoho torpedoed, Hiryu bombed, Soryu bombed, Ryujo bombed, Shokaku torpedoed, Zuikaku torpedoed, Zuiho bombed, Hiyo torpedoed, Chitose torpedoed, Chiyoda bombed, Taiyo torpedoed, Unyo torpedoed, Chuyo torpedoed, Shinyo torpedoed, Unryu torpedoed, Amagi bombed
Note that I have listed only the primary agent in each ship's loss.
As regards our discussion of flight deck armor, we can dismiss all the escort carriers and light carriers as there was no option of fitting them with armored flight decks.
Would Glorious have been saved by an armored flight deck? No. Would Hermes? No. Obviously all the ships lost to torpedoes would not have benefited from armored flight decks, so we have no American ships to discuss. So in the end, if we're looking for ships to benefit from flight deck armor, we're left with the four Japanese victims at Midway. All of these ships were lost to fires in their hangars, and given the inability of 75mm armor to keep out modern bombs, there is not a good case for the armor.
As for the British ships, I think the Navweaps article covers them well enough. Would Illustrious have survived without her flight deck armor? I'm totally on the fence here. It's possible that the hangar deck armor (not the flight deck armor) stopped enough splinter damage to ensure the ship maintained power. It was the ship's ability to keep steaming that figured most prominently in her survival. The fact that she had no CAP overhead at the time figures most prominently in her getting so badly battered.

 

Nice wrap up Tiornu.

 

Except the three that were kamikazied...

 

CVE + armored flight deck = really big turtle

 

Tiornu, I assume you would have read Washington Treaty Re-evaluated on the battlecruisers page (sorry everyone no direct link to the article and its not mine to give away).

There is a section in it stating..

The RN’s new aircraft carrier design: not an armoured girder

i. The Illustrious class has been criticised (Slade, S. and Worth, R., 2000) for the design failure of the concept of the armoured box, the structural loading of which rendered the hull design vulnerable to irrepairable distortion after bomb damage.

ii. One of the weight saving concepts which lead to this was that the armour plate was used both for protection and longitudinal strength. No backing was used for the armour. The 3” flight deck armour and 4½” hangar side armour was worked structurally with riveted and rabbited laps and butts.

iii. The armour was thus the load girder, both horizontally (the deck) and vertically (the hangar walls). This lack of specific structural support for the armour was the design weakness in the armoured carrier. But without the limitations on displacement, the armoured box becomes simply an armoured box mounted upon structural supports, not an-inverted U-shaped girder. If the Illustrious class had been built to a displacement limit of say, 24,500 tons, they would probably not have had the structural problems resulting from heavy bomb hits, because the armour would have had structural backing.


Do you agree that if the Illustrious were to 24,500 tons then they wouldn't necessarily have had these structural problems.

 

How about the approach taken by the Japanese with Taiho - armoured flight deck and enclosed sides, though not armoured from what i've read.

 

Something to remember when talking about flight deck armour, we are not talking about armour from bows to stern, its a case of an armoured box surrounding the hanger so there are substantial parts of the flight deck that are unarmoured particularly the lifts which Illustrious' history showed gave bombs access to the hanger where they could explode and their blast contained inside the hanger by the armoured sides.

As Tironu's article states, more aircraft might prevent a bomber from dropping a bomb on the plane in the first place and an armoured box is useless against a torpedo bomber.

 

Agreed, that and keeping the aviation fuel from going up.

It would be intresting to see what would have happened to Lexington, Wasp, Akagi, Hiryu, Shokaku, Zuikaku, Taiho etc if the US and Japan had been as paranoid (with good reason as it turns out) about the dangers from aviation fuel as the RN was.

 

various

"Agreed, that and keeping the aviation fuel from going up."
It's also easier to avoid a severe avgas fire when you don't carry very much avgas.

"How about the approach taken by the Japanese with Taiho"
In this context, Taiho makes a lot more sense than Midway. What good is keeping out the bombs if any old plane can come by and strafe your hangar?

"Do you agree that if the Illustrious were to 24,500 tons then they wouldn't necessarily have had these structural problems."
I should note that, while my essay is on the same page as Stuart's, I can't necessarily verify all his remarks. My impression is that he has overstated the severity of the hull problems in the damaged ships. I asked DK Brown specifically about Illustrious, and his impression is that she could have been made right without extraordinary efforts. I personally don't feel capable of addressing a specific displacement that would have allowed the protection of the armor without the structural complications of the armor.

 

Re: various

Very true, IIRC, Friedman says the aviation fuel load of Illustrious was being considered low right from the moment she hit the water.

How did the RN system differ from USN and IJN aviation fuel systems, was it simply a case of less fuel in RN carriers?

The only thing I've been able to find is that the RN system made the tanks independent of the hull so reducing the effect of whiplash.

 

Re: various

Well, the Midways did have their AA guns and crews as 'padding'.........

:smok:

 

Re: various

Ohhh for London to have kept the 27,000 ton limit........whether the RN would have built to 27,000 tons is debaltable but......

 

Re: various

"How did the RN system differ from USN and IJN aviation fuel systems, was it simply a case of less fuel in RN carriers?"
Extrapolating from the Dasher case, I assume the British system involved more fool-proof equipment while the American system involved more crew training. I have no info on the specifics of the hardware.

"Well, the Midways did have their AA guns and crews as 'padding'."
I've always found that quite amusing. Who wouldn't love to find himself aboard a ship where he's considered part of the armor scheme?

 

About this famous WTRE: I've seen many people refer to it but yet I haven't personally been able to read it. It isn't available online, I believe. Or is it?

 

No link i'm afraid, but you could ask on the Battlecruisers page, like I said its not mine to hand out.

http://pub57.ezboard.com/falltheworldsb ... uisersfrm1

 

"By my calculations, 25% of carriers with flight deck armor sank during the war, while 19.4% of carriers without flight deck armor sank."
--------------------
But some of those armored deck carriers were sunk by U.S. Fleetboats, not by hits on the flightdecks.

U.S.S. Princeton CVL and one Judy dive-bomber.

HMS Formidable back in action within the hour after Kamikaze hit.