Aircraft Carrier and Aircraft Limits

[cherry blossom]

It is quite clear that whatever these are, they cannot be sensibly used to lift two aircraft at the same time How the carrier double elevator might have been used.. Eugen Pinak suggests that these are "elevator covers" designed so that aircraft could land on them without a risk of breaking the elevator Elevator covers, NOT double elevators on Akagi, Kaga & Ryujo.

 

[Admiral Beez]

It is quite clear....

Nice.

The website you linked to is referring to drawings that non-members cannot see, and the matter seems hardly settled there. Either way, it is surprising to me that this is even a point of contention. IJNS Akagi and Kaga are not ancient history, and are both less than a hundred years old. I'm surprised IJN personnel, pilots or records from her builder Kawasaki Heavy Industries haven't revealed the lift arrangement. If it is a protective cover, the IJN has done it better than the hinged covers on the French carrier Bearn.

 

[Peter Gunn]

Re: Admiral Beez's post #7, I don't know about anyone else but I think I'd be a little concerned over a situation where a KG V is cracking off main battery rounds a couple hundred yards astern of my carrier.

So, what gives in that photo?

 

[Zipper730]

All these factors existed. For the RN FAA, maximum carrier aircraft design dimensions were length = 40ft, folding wing dimensions = 19ft and parked height = 14ft. These dimensions were dictated by elevator dimensions and hangar height. Several carriers had larger elevators and could accommodate unfolded wings of up to ~40ft width, but in general, these were aircraft adapted from RAF types.

The RN had several carrier classes (some single ship designs) which included the following overall (as far as I know)

1. Fleet Carrier
   • Argus Class: 18 A/C
   • Hermes Class: 20 A/C
   • Eagle Class: 21 A/C
   • Courageous Class: 36-48 A/C
   • Ark Royal Class: 54 A/C
   • Illustrious Class: 36-57 A/C
   • Implacable Class: 54 A/C
   • Colossus Class: 48
2. Light Carrier
   • Unicorn Class: 35 A/C
3. Escort Carrier
   • Audacity Class: 8 A/C
   • Avenger Class: 15 A/C
   • Attacker Class: 24 A/C

They all were fitted to at least 40'?

TO weight was dictated by carrier flight deck length and carrier speed (hence the use of the Swordfish and Albacore) and by catapult weight limits. Similarly landing speed was dictated by arrestor hook strength limits. I don't have exact numbers for these handy, but catapult limits initially were 11000lb to 66 knots for the armoured carriers, and 7000lb to 56knots for the earlier carriers. Higher weights could be accommodated but with lower terminal speeds.

That's why I was curious about that variable. I figure WOD partially corrects for the speed limitations (56 knots + 25 knots WOD = up to 81 knots)?

 

[36feet10inches]

I was just thinking about this very question as I looked at this image of what must be near the limits of what a British carrier can spot on the deck. HMS Formidable in Far East 1944. THE FLEET AIR ARM AT SEA, JULY 1944

View attachment 582777

What a picture that is!

 

[RCAFson]

The RN had several carrier classes (some single ship designs) which included the following overall (as far as I know)

1. Fleet Carrier
   • Argus Class: 18 A/C
   • Hermes Class: 20 A/C
   • Eagle Class: 21 A/C
   • Courageous Class: 36-48 A/C
   • Ark Royal Class: 54 A/C
   • Illustrious Class: 36-57 A/C
   • Implacable Class: 54 A/C
   • Colossus Class: 48
2. Light Carrier
   • Unicorn Class: 35 A/C
3. Escort Carrier
   • Audacity Class: 8 A/C
   • Avenger Class: 15 A/C
   • Attacker Class: 24 A/C

They all were fitted to at least 40'?
That's why I was curious about that variable. I figure WOD partially corrects for the speed limitations (56 knots + 25 knots WOD = up to 81 knots)?

Hermes was the odd carrier out and it's lifts (elevators) were only 36ft x 36.6ft. The others up to Ark Royal were large enough to fit a Sea Hurricane. Standard lift dimensions were 25x45ft from Ark Royal onward, but Indomitable and the Implacable's forward lift was 36 x 45ft and thus could accommodate most fixed wing fighters of the day.

The problem the RN faced was that most older carriers, prior to Ark Royal, had flight decks that were shorter than 600ft and Eagle's was only 652ft and she was only good for 22-24 knots. This meant that their aircraft had to have very good STOL characteristics and thus the Swordfish and Albacore were chosen as the FAA's standard torpedo/divebomber design pending the development of higher power engines which would make the Barracuda viable. The USN's TBD and the IJN B5N1, for example, were not practicably operable from any RN carrier prior to Ark Royal (1938). The Albacore doesn't get much love but, in fact, it had better STOL characteristics than the Swordfish.

Yes, you add WOD to catapult terminal speed.

 

[Admiral Beez]

Re: Admiral Beez's post #7, I don't know about anyone else but I think I'd be a little concerned over a situation where a KG V is cracking off main battery rounds a couple hundred yards astern of my carrier.

It must be a training volley, or they loaded the 14" guns in preparation to shoot in anger, and then changed their minds. AIUI, it's diffcult to draw out the charges and projectile once loaded, so better off shooting. The carrier and aircraft seem safely distant though.

 

[ThomasP]

Hey guys, the following are taken from various USN Action Reports quoted in post-war studies:

USS Yorktown [Yorktown class] carried 53 operational aircraft (14x F4F-3, 30x SBD, 9x TBD) during the battle of Coral Sea, although she set sale from Pearl Harbor with 79 aircraft total. As re-organized after Coral Sea the Yorktown carried 88 aircraft, but only 66 were operational (27x F4F, 27x SBD, 12x TBF) with 33/33/12 pilots. The remainder were in a "broken-down" state and/or suspended as spares from the hangar ceiling. It was thought that the number of TBF might be increased to 18 operational if space allowed. [As far as I can find, space/operations did not allow it?]

In late-1943, the Enterprise [Yorktown class] CO considered a total airgroup of 91 aircraft (36x F6F, 36x SBD, 19x TBF) to be too large for efficient operation, and recommended a maximum number of 74 folding-wing aircraft embarked (36x F6F, 20x SB2C, 18x TBF).

The much bigger USS Lexington [Essex class] submitted an Action Report for September 1943 in which the crew recommended doing away with spares stowage in the overheads and crated, and warned that its total complement of 99 aircraft (36x F6F, 35x SBD, 18x TBF) presented dangerous overcrowding difficulties.

The late-1944 standard mixed airgroup [Essex class] was set at 90 aircraft (36x F6F/F4U, 36x SB2C, 18x TBF).

At the height of the Kamikaze period, some Essex class carried upto 102 aircraft total (36x F4U, 36x F6F, 15x SB2C, 15x TBF). The extra large number of fighters was to allow sustained CAP and escort fighter/bomber operations during which it was probable that routine maintenance and repair of damaged aircraft would not be possible (in effect the extra fighters, although assembled and maintained ready for combat to the start of the operation, were treated as spares when not being used and were tightly packed in the hangar until needed).

Words in [ ] are my edits.

 

[ThomasP]

Addition to the above:

The Enterprise and Saratoga operated as night fighter carriers in 1945. Both airgroups were composed of 60 aircraft total (16x F6F, 17x F6F(N), 27x TBF). The small airgroups were partly a reflection of the greater difficulty of operations at night vs daytime.

 

[RCAFson]

It must be a training volley, or they loaded the 14" guns in preparation to shoot in anger, and then changed their minds. AIUI, it's diffcult to draw out the charges and projectile once loaded, so better off shooting. The carrier and aircraft seem safely distant though.

The above image shows HMS Valiant practise firing her 15in guns in August/Sept 1942 probably during Operation TOUCHSTONE . The carrier is HMS Illustrious. Carrier Operations of WWII list her complement as 23 Marlets, 6 Fulmars, and 18 Swordfish.

Note the bomb racks on the foreground Fulmar's starboard wing, and what appears to be a bomb, on the flight deck, under the wing while the aircraft directly aft of it also appears to have bomb racks fitted. Also note the centre-line 60IG drop tank beneath the left hand, foreground Fulmar. The Fulmar on the portside, aft, also appears to have a 60IG DT.

In June 1942, Fulmars had been cleared to carry a 500lb bomb on the centre-line attachment point, in lieu of the DT.

 

[Zipper730]

USS Yorktown [Yorktown class] carried 53 operational aircraft (14x F4F-3, 30x SBD, 9x TBD) during the battle of Coral Sea, although she set sale from Pearl Harbor with 79 aircraft total.

Based on operational aircraft, it's interesting they had more bombers than fighters. That said, I don't know what the remaining 26 planes were.

In late-1943, the Enterprise [Yorktown class] CO considered a total airgroup of 91 aircraft (36x F6F, 36x SBD, 19x TBF) to be too large for efficient operation, and recommended a maximum number of 74 folding-wing aircraft embarked (36x F6F, 20x SB2C, 18x TBF).

At least the number of fighters eclipses the number of each bomber category. They're on the right track.

At the height of the Kamikaze period, some Essex class carried upto 102 aircraft total (36x F4U, 36x F6F, 15x SB2C, 15x TBF).

Now that's what I'm talking about: 72 fighters escorting 30 bombers. Generally I would favor a ratio of around 2:1 for fighters to bombers.

 

[SaparotRob]

As long as we're on the topic of flight decks, some pictures I've seen had aircraft parked forward. Of course not the shots during active air operations but a few. It seems a counter intuitive thing to do.

 

[Zipper730]

SaparotRob

That was common practice: For landings, you'd move all the aircraft forward (or move things under deck) to make room in the rear deck; For takeoffs, you'd move everything aft to make room on the forward deck.

 

[SaparotRob]

SaparotRob

That was common practice: For landings, you'd move all the aircraft forward (or move things under deck) to make room in the rear deck; For takeoffs, you'd move everything aft to make room on the forward deck.

I thought that might be the case. Launching I can see. Landing, however, seems risky. If a plane bolts (?) or, after one landing too many, the tail separates and the plane plows into those ahead.
I guess there was a barrier of some kind?

 

[RCAFson]

I thought that might be the case. Launching I can see. Landing, however, seems risky. If a plane bolts (?) or, after one landing too many, the tail separates and the plane plows into those ahead.
I guess there was a barrier of some kind?

Yes, the development of a barrier was key to utilizing a permanent deck park, and in speeding up the landing on of aircraft. Barriers are illustrated in this video in the animation portion during the first couple of minutes:



especially at ~2:00.

 

[SaparotRob]

Yes, the development of a barrier was key to utilizing a permanent deck park, and in speeding up the landing on of aircraft. Barriers are illustrated in this video in the animation portion during the first couple of minutes:



especially at ~2:00.

Great link!! I never saw this stuff before. I read a bunch about carrier actions as well as naval aircraft but this stuff never was brought up. Seeing the RN flight deck layout made the elevator posts much clearer.
Gotta be honest, the dimensions discussions was kinda like school again. I just started daydreaming and drawing airplanes while the teacher was putting up numbers on the blackboard.

 

[Freebird]

Hey guys, the following are taken from various USN Action Reports quoted in post-war studies:

USS Yorktown [Yorktown class] carried 53 operational aircraft (14x F4F-3, 30x SBD, 9x TBD) during the battle of Coral Sea, although she set sale from Pearl Harbor with 79 aircraft total. As re-organized after Coral Sea the Yorktown carried 88 aircraft, but only 66 were operational (27x F4F, 27x SBD, 12x TBF) with 33/33/12 pilots. The remainder were in a "broken-down" state and/or suspended as spares from the hangar ceiling. It was thought that the number of TBF might be increased to 18 operational if space allowed. [As far as I can find, space/operations did not allow it?]

In late-1943, the Enterprise [Yorktown class] CO considered a total airgroup of 91 aircraft (36x F6F, 36x SBD, 19x TBF) to be too large for efficient operation, and recommended a maximum number of 74 folding-wing aircraft embarked (36x F6F, 20x SB2C, 18x TBF).

The much bigger USS Lexington [Essex class] submitted an Action Report for September 1943 in which the crew recommended doing away with spares stowage in the overheads and crated, and warned that its total complement of 99 aircraft (36x F6F, 35x SBD, 18x TBF) presented dangerous overcrowding difficulties.

The late-1944 standard mixed airgroup [Essex class] was set at 90 aircraft (36x F6F/F4U, 36x SB2C, 18x TBF).

At the height of the Kamikaze period, some Essex class carried upto 102 aircraft total (36x F4U, 36x F6F, 15x SB2C, 15x TBF). The extra large number of fighters was to allow sustained CAP and escort fighter/bomber operations during which it was probable that routine maintenance and repair of damaged aircraft would not be possible (in effect the extra fighters, although assembled and maintained ready for combat to the start of the operation, were treated as spares when not being used and were tightly packed in the hangar until needed).

Words in [ ] are my edits.

Excellent post, thanks!

Which post war study did you reference for the info?

 

[Admiral Beez]

1. Maximum allowable aircraft dimensions
2. Maximum takeoff & landing weights

We should also consider the maximum weight capacity of the flight deck, especially on lightly built carriers like a Courageous class. Spot 24 fully loaded Swordfish (7,500 lbs) and a dozen Fulmars (9,700 lbs) on deck and you've put about 148 tons on the flight deck. Do that with 24 Tarpons (15,600 lbs) and a dozen Hellcats (12,600 lbs) and you're now at about 263 tons, an increase in weight on the flight deck of over 77%. And given that the size of CAGs in the RN dramatically increased from 1939 to 1942-45, I would expect the flight deck to see more than double its usual weight of aircraft from 1939. This may have an impact of stability or stress the supports for the flight deck. You can see above in Furious that there isn't a lot of structure here.

 

[RCAFson]

We should also consider the maximum weight capacity of the flight deck, especially on lightly built carriers like a Courageous class. Spot 24 fully loaded Swordfish (7,500 lbs) and a dozen Fulmars (9,700 lbs) on deck and you've put about 148 tons on the flight deck. Do that with 24 Tarpons (15,600 lbs) and a dozen Hellcats (12,600 lbs) and you're now at about 263 tons, an increase in weight on the flight deck of over 77%. And given that the size of CAGs in the RN dramatically increased from 1939 to 1942-45, I would expect the flight deck to see more than double its usual weight of aircraft from 1939. This may have an impact of stability or stress the supports for the flight deck. You can see above in Furious that there isn't a lot of structure here.

It might be a factor on some carriers but the Courageous and Furious classes had a 1in thick HT steel flight deck. In the picture you linked above, the foreground is a bit misleading, but the upper back of the photo shows deep support beams under the flight deck. OTOH, the increase in topweight became substantial, and this led to Enterprise (CV-6) being blistered to increase her stability.

 

[Admiral Beez]

It might be a factor on some carriers but the Courageous and Furious classes had a 1in thick HT steel flight deck.

Good point. Perhaps it's more of an issue on some of the later IJN conversions, such as IJNS Katsuragi below.