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How much can a carrier take? USN carriers were noted for their exceptional damage control. the Brits had armor decked carriers. What is the most damage a carrier had recieved and still survived? I remember reading about the Franklin with the photos of Kamikaze attacks. What about the IJN? Their carriers seemed to go down quickly. Was it solely due to theeir poorly developed damage control?

Interesting Question....I seem to remember a very long thread on this subject over at the WiTP forum....I'll go and see if I can dig it up.

Ok ! I found it ! FIGJAM!

showthread.php?s=&threadid=19349&highlight=Carriers

And there is also this one:-

showthread.php?s=&threadid=17070

Excellent references Raverdave. I had read that the tradeoff that the Brits made for the armored decks was the weight factor which limited their capacity. HMS Victorius sizes up as a CVL to US standards. Sounds like WitP will take all this into account. The Japanese never did address the gas fume problem I guess.

Also a limiting factor on the RN in pre war design was the international disarmament treaty limits on the total tonnage of aircraft carriers. The RN could have built 5 carriers upto 27,000 tons and still been within the treaty limits but wanted 6 carriers and so the tonnage was reduced to 23,000 tons....once you factor in the armoured deck, (acually the deck was not armoured so much as the hanger itself) you only have space for 36 aircraft.

This problem of small aircraft capacity was later addressed in the war by using the USN system of deck parks and outriggers. So by 1944 both the Indefatigable and Impacable were able to operate upto 80 aircraft.

I have some interest in this subject so please forgive me if I jump in.

The differences in carrier design between the Royal Navy and the US and Japanese Navies derives from two major concepts.

First, the British considered an Aircraft Carrier to be primarily a warship whereas the US and Japanese considered them to be primarily aircraft operating vessels. A very significant difference in viewpoint.

To the British, the aircraft handling and arming/fueling areas of a carrier were considered to be magazines and were to be so protected. This meant that aircraft handling arrangements were comprised for protection. The armoring of the hanger and flight decks brought not only reduced aircraft complement but reduced aircraft handling ability as well.

The sides of the hanger deck were armored, with minimum openings, which reduced airflow throughout the hanger and severely limited operation of aircraft engines on the flight deck. Unlike US/Japanese carriers, British carriers could not warm up large numbers of aircraft while on the flight deck – they had to be moved to the flight deck before starting the engines. This slowed aircraft operations appreciably, because of both the inherent warm-up delays and the problems with aircraft that would not start. British carriers took longer to launch smaller strikes.

The weight of the hanger “armor box”, carried high on the ship, was a problem for stability. To reduce the weight the hanger had to be reduced in size. The limited hanger deck height of British Carriers was a constant problem. There were problems with storing some modern U.S. carrier aircraft and others had problems folding their wings within the hanger.


Second, the British expected to operate their carriers in European waters – within range of enemy airbases. They had to expect frequent and heavy land-based attacks – which increased the pressure for defensive armor and also heavy AA batteries. In fact early British practice when under air attack was to strike down all aircraft and defend solely with AA guns from the carrier and her escorts.

This also affected their air group makeup. British carriers carried less fighters and more attack aircraft (the Royal Navy also lacked a quality naval fighter at the beginning of the war).


The US and Japanese Navies both designed their carriers to two major criteria:

• The were primarily aircraft operating vessels and needed to operate the largest possible number of aircraft with the greatest possible efficiency.
• They were expected to operate in the Pacific, generally out of the range of large numbers of land based aircraft (or so it was thought in the 1930s).

They were designed for efficient aircraft handling and operations – with large open hangers and convenient access to fuel and servicing facilities. Armor was applied thinly and locally over the most sensitive areas. Other protective measures were devised – including the ability to drain fuel lines and pressurize them with inert gas and extensive fire-fighting equipment.

The war exposed the strengths and weaknesses of both design theories.

The modern British carriers shook off Kamikaze damage that put U.S. carriers out of action (and sometimes at risk for their survival). But the aircraft operating ability of these ships was so low that they were considered (by US fleet commanders) not worth the replenishment effort to keep them on station.

The US and Japanese carriers proved themselves to be effective offensive weapons but much more susceptible to battle damage. They could launch large, coordinated air strikes. They could also defend themselves with their own fighters – which partly hid their susceptibility to battle damage. Until the Kamikazes that is.

Who was right? The best answer to this can be seen in the late war carrier designs of the US and British – US and Japanese vessels were moving toward better armor and protection and British vessels toward increased aircraft abilities. If the war had lasted longer they might well have met somewhere near the middle.

For references I recommend:
US Aircraft Carriers – An Illustrated Design History by Norman Friedman (ISBN 0-87021-739-9)
British and Empire Warships of the Second World War by H.T. Lenton (ISBN1-85367-277-7)
The Hybrid Warship – The Amalgamation of Big Guns and Aircraft by R.D. Layman and Stephen McLaughlin (ISBN 1-55750-374-5)

Originally posted by Don Bowen
I have some interest in this subject so please forgive me if I jump in.

Great post, Don, thank you very much for the information.

A few years ago, I was dabbling at study of the roots of aircraft carrier design in the pre-WWII period, and remember some informative discussion of the differences between American and Japanese approaches to damage control. The Japanese ships, being primarily conversions of surface capital ships, were rather haphazard and ineffective in this area (except for Shokaku and Zuikaku, which were laid down as carriers), while the American Yorktown design built damage control into the ship as a basic feature (Saratoga and Lexington, if I remember right, suffered from some of the same problems the Japanese conversion ships did). Wasp was a good damage control ship as well, although a little fragile due to her small size and light construction.

I think there was a doctrinal problem with the Japanese approach to damage control, most famously represented in their failure to fill fuel hoses in aircraft handling areas with CO2 when not in use.

Those who have studied the matter more seriously can straighten out my misconceptions and faulty memory, of course.

Posted by Don Bowen

Unlike US/Japanese carriers, British carriers could not warm up large numbers of aircraft while on the flight deck – they had to be moved to the flight deck before starting the engines. This slowed aircraft operations appreciably, because of both the inherent warm-up delays and the problems with aircraft that would not start.

Don,

I thought there was a difference between the IJN and USN CVs in this area as well, in that most of the IJN CVs lacked the ability to sufficiently "vent" their hanger decks to allow engines to be warmed up. I was positive that I saw it mentioned as fact in a discussion on how long it took the IJN CVs to prepare a strike at Midway.

Was this the case?

Originally posted by Drongo

I thought there was a difference between the IJN and USN CVs in this area as well, in that most of the IJN CVs lacked the ability to sufficiently "vent" their hanger decks to allow engines to be warmed up. I was positive that I saw it mentioned as fact in a discussion on how long it took the IJN CVs to prepare a strike at Midway.

Was this the case?

A good point, but I don't know. My library is much weaker on Japanese carriers (and Japanese vessels in general) than on US/British.

A quick scan of design diagrams and photographs does indicate that the Japanese CVs did not have as many side openings as the U.S. designs. Also many Japanese carriers had two-story hangers so the lower one would have venting problems.

In the old Hosho "the spaces abrest the hanger were open, apart from right aft where the hull plating was carried up to flight deck level". **

In Kaga, the 1930s reconstruction increased aircraft capacity "by extending both hangers forward and enclosing them". Enclosing of hanger spaces is also mentioned in the Akagi rebuild. **

Shokaku and Zuikaku had hangers that were "totally enclosed yet unprotected" **

Junyo/Hiyo, being merantile conversions, were too lightly built to support a large hanger and had a severly restricted hanger deck height (10'6" - barely enought for a Zero). **

Can you guide me to any additional references??

Don

** Aircraft Carriers of the World, 1914 - Present (present being 1984) ISBN 0-87021-902-2

Here are a couple more references that may be of interest:

Operation Pacific by Edwyn Gray (ISBN 1-55750-650-7) - a history of the British Eastern and Pacific fleets, contains a good summary of the strenghts and weaknesses of British Carriers in operations off Japan in 1945.

Allied Escort Carriers of World War II by Kenneth Poolman ((ISBN 0-87021-005-X) - primarily covers escort carrier operations from a British viewpoint but has some interesting information on the differences in US/British practices.


Neither Conway's Warships nor Morrison's History of U.S. Naval Operations in World War II shed any light on the subject.

Don

Posted by Don Bowen

Can you guide me to any additional references??

This is an extract from the 2 online articles I was thinking of.

Japanese carrier design is also notable for its use of enclosed hangar decks. In contrast to U.S. carriers, whose hangars could be opened to the elements by rolling up metal screens along their sides, Japanese hangars were fully enclosed by storerooms, workshops, and crew spaces, with no natural ventilation. This meant that aircraft engines were never warmed up below. This is in direct contrast to American practice, where aircraft commonly were warmed up in the hangars, brought to deck, and immediately launched. These factors had important ramifications during the battle of Midway and imposed severe restrictions on Japanese operational tempos.

I've listed them below (hope they work).
Article 1 attempts to show how lack of communication between Yamamoto and Nagumo was the real failing at Midway and that Nagumo's decision making was generally good in the circumstances, with the exception of the re-arming of the Kates for the second strike at Midway. The article covers in great detail the deck and hanger operations of the Kido Butai on the day.

Article 2 was written in response to articles 1's claim that the Japanese could have got a good strike off at the USN CVs had their high level communications been better. It also goes into a lot of detail on Japanese CV operations, specifically the how long (and why) the Japanese would take to get their strike ready.

Article 1 "The Battle of Midway: Why the Japanese Lost" by Dallas Isom for the Naval War College Review.
http://www.nwc.navy.mil/press/Review/20 ... t3-Su0.htm


Article 2 "Doctrine matters : Why the Japanese lost at Midway" by Jonathon Parshall et al for the Naval War College Review.
http://www.nwc.navy.mil/press/Review/20 ... d1-su1.htm

Can't vouch for all the writers' credentials but they certainly sound smart.

Originally posted by Drongo
Can't vouch for all the writers' credentials but they certainly sound smart.

Thank you Drongo. Your point is excellent. These are both interesting and authoritative articles and well supplied with references. Thank you for guiding me to them.

I'm going to see if I can find a copy of:

"ATIG Report 2, p. 3, and ATIG Report 5, p. 3. This was due to the inability of the forced-air ventilation systems used in the hangars to cope with the exhaust from multiple aircraft. NavTech Report A-11, p. 9. "

I have gone back over the various reviews of carrier design in my library (old fashioned books I must admit) and I have obviously extended a generality. Although several other design features are compared to both US and Japanese designs, the hangar deck venting is specifically compared only to US designs. My apologies to all for the error.

Don

Japanese hangers were enclosed (but not armored) which while not precluding warming up of engines in the hanger deck completely, did create potential damage control situations for the Japanese similar to that experienced by the British. (blast pressure created by enclosed spaces) The enclosed nature of the IJN hangers exaserbated blast effects, particularily in conjunction with 1000LB GP bombs which resulted in large portions of the wooden flight deck being destroyed and greater damage to equipment contained on the hanger deck (such as firefighting equipment, of which IJN carriers were lavishly equipped.)

Shokaku's experience at Coral Sea and Santa Cruz are good examples of this. While hull and machinery were not affected, a good number of 1000LB bomb hits destroyed her ability to operate aircraft. and fire hazzards often proved difficult to extinquish. American carriers often were able to repair their flight decks both because of the Japanese mix of SAP and GP bombs as well as their smaller size. If a bomb penetrated deep though, it could cause grave damage to the internals of the carrier.

At Midway, what hurt the Japanese was their air ops policy of first striking all aircraft to the hanger deck for refueling and re-bombing whereas USN policy was to rearm and rebomb on the flight deck (in a hurried situation) This slowed IJN reactions and created a hazzard in the hanger deck once orders came in to restrike and rearm aircraft leading to a litter of unsecured ordinance on that deck.

Another key difference was the Japanese did not at that time employ such damage control precautions as draining fuel lines and filling them with CO gas prior to an incoming attack

Posted by Don Bowen

My apologies to all for the error.

And don't let me catch you doing that again. :p

I don't see any need for an apology. The articles give the impression that most of the Western language texts all assume Japanese methods of aircraft handling on carriers were similar to those used by the Allies.

The book that the authors of the second article are writing (have written?) could well be the first detailed english language one on the subject and may also cause some of the standard texts to be revised. Or it could be condemned from all sides and have no impact what so ever.

I remember finding a link with the specs for all carriers used in WW2...can't remember where.
Interestingly, from memory, many of the Jap carriers had three inch deck armour compared to one and a half inches for the US carriers.

Oh no, I hope this won't cause a ruckus.