Aircraft Carrier Capacity

[herwin]

Again, this is a 1970s study. Cum grano salis.

The controlling factor in WWII aircraft carrier operations was space. It took about 400 feet to land and 150 to take off, and to maintain a CAP that much deck had to be kept clear. A strike required only 150 feet at the front to take off, but required the whole 400 feet to land. This meant some of the smaller carriers were basically useless. For example, the Ryujo, despite hanger space for 36 aircraft plus 12 in reserve, could launch only 9 aircraft in a strike and could not maintain a continuous CAP.

Assume the following points of deck space were occupied by 9 aircraft (with wings folded if possible):
3: F4U, F6F, F4F4, FM2, F8F, Ju87T (?)
4: Kate and Jill
5: everything else

Then the following classes had the following space (CAP/Strike/Hanger/Reserve):

Hornet 12/20/32/5
Kaiser class CVE 3/5/13/0
Kaga 15/20/28/15
Akagi 15/20/28/15
Hiryu 10/15/20/15
Saratoga 12/20/30/10
Essex 15/24/40/0
Midway 20/36/50/25
Shinano 10/25/15/5
Audacious 12/24/50/0
Graf Zeppelin 15/23/22/0
Illustrious 10/16/20/0 (operated just the hanger initially)
Implacable 10/16/40/0
Shokaku 15/20/25/8
Taiho 15/20/25/8
Junyo 10/15/17/5
Ark Royal 12/20/40/0
Albion 10/18/20/0
Courageous 6/16/24/0
Furious 0/6/15/5 (no CAP!)
Eagle I 5/12/20/0
Wasp 10/16/30/5
Ranger 12/15/25/5
Unryu 10/15/20/5
Unicorn 0/8/20/0
Taiyo 5/5/12/0 (as AVT 30)
Soryu 10/15/20/10
Saipan 5/10/25/0
Joffre 5/10/20/6
Colossus 7/13/20/8
Hercules 7/13/15/0
Argus 0/6/15/0
Independence 3/6/11/0 (designed to operate 22, but that was excessive)
Shoho 5/10/9/0
Chiyoda 5/10/9/0
Ryuho 5/10/9/4
Hermes 3/10/10/0 (not even a full squadron on CAP)
Ryujo 0/5/17/5 (can you spell AVT?)
Hosho 0/5/12/0
Sangamon CVE 6/10/10/0

The operational capacity of a WWII carrier was the CAP plus the hanger. The reserve space held disassembled spares. Strike was the strength of a deckload strike. A carrier would typically launch a reinforced CAP and then launch the strike. The strike would form up before departing. Search aircraft shared the CAP space.

In addition to the standard causes of loss, CVs could be lost or damaged by fire. Damage to frames and structural elements would seriously reduce the strength of the ship. For example, the Zuikaku was damaged this way at the Battle of the Philippine Sea and was regarded as expendable in preference to losing ships in the new Unryu class at Leyte Gulf.

[Sneer]

extremally interesting
if implemented in witp there would be no uber battles and cap would be also reasonable

[tsimmonds]

PBEMers interested in realism should always consider a CAP % limitation -- max of 30-50%. Big potential advantage here for ships with air-search radar.

[castor troy]

ORIGINAL: irrelevant

PBEMers interested in realism should always consider a CAP % limitation -- max of 30-50%. Big potential advantage here for ships with air-search radar.

I thouhgt ship based air search radar was broken? [&:]

[Speedysteve]

I think just the Japanese Type 13 radar is not assigned as an air-search radar IIRC

[tsimmonds]

ORIGINAL: Speedy

I think just the Japanese Type 13 radar is not assigned as an air-search radar IIRC

Not that that makes any difference since none of the IJN CVs get radar until too late to matter.

[wild_Willie2]

Not that that makes any difference since none of the IJN CVs get radar until too late to matter

But you CAN assing a ship to a CV TF which HAS radar (kitamukai and OI to start with)

[tsimmonds]

But you CAN assing a ship to a CV TF which HAS radar (kitamukai and OI to start with)

You can do that, but it won't do you any good.[;)]

I believe that these ships should not have this radar until much later.

[Sardaukar]

It'll do good in scenarios where Oi/Kitakami radar has been corrected to have right class (air search). In stock scenarios it was wrongly classed as surface search and thus didn't help with air search. It's corrected in CHS (don't know about NikMod).

[Nikademus]

corrected.

[Iridium]

Nik mod looks more and more inviting...[8D]

[tsimmonds]

ORIGINAL: Nikademus

corrected.

Does it make a difference that you have noticed in how much CAP is available?

[el cid again]

I think just the Japanese Type 13 radar is not assigned as an air-search radar IIRC

In WITP a radar must be EITHER air search or surface search - it cannot be both. So a dual function radar must be given one or the other. This can be fixed however. Just assign an air search radar to do the other function. Pick the right range. All are short for Japan - so it matters only a little.

[el cid again]

But you CAN assing a ship to a CV TF which HAS radar (kitamukai and OI to start with)

That is wrong. The first radar went to battleships. Old, slow battleships - not nice fast Kongos either. But there is radar on most surface ships eventually - and many submarines - and on aircraft. This is not well done in the game so far but will be in RHS. [I began life as a USN Radar ET - and went on to pioneer what one day would be called EW - a sort of anti-radar specialty. I collect radar data and I also understand it.]

[Nikademus]

can't say with authority. havn't tested it extensively. I have seen radar make a difference in other battles on the Allied side

[tsimmonds]

ORIGINAL: el cid again

But you CAN assing a ship to a CV TF which HAS radar (kitamukai and OI to start with)

That is wrong. The first radar went to battleships.

And not in 12/41, it was several months later.

[Feinder]

It's an interesting analysis. Some questions tho...

Code: Select all

 Class	CAP	Strike	Hanger	Reserve
 Saratoga	12	20	30	10 
 

I'm gonna zero in on the Lexington (Saratoga class), since I can more easily dig up data.

a. If Operation Capacity = CAP + Hanger, then are you saying that the "operational capacity" of the Lex was 42? I guess a definition of "operational capacity" is in order. She and her sisters certainly carried and launched more planes than that. But again, I'm probably misunderstanding.

b. Within what time frame are you talking about? A 24-hour period? A twelve hour period? See deck logs to follow from Lex.

c. Or do you mean that 12 are on CAP and 20 are on strike (damn unions) and 30 are in the Hanger (to do with whatever you want)?

d. Some more data from another thread, I pulled these numbers from the deck log of the air-boss on Lex at Coral Sea:

Taken from the debrief report of Commanding Air Officer of USS Lexington:

Lexington - CAPT Frederick Sherman
Lexington Air Group - CDR William B. Ault - 1 SBD-3
VF-2: 21 F4F-3/-3A - LT CDR Paul H. Ramsey
VB-2: 18 SBD-2/-3 - LT CDR William L. Hamilton
VS-2: 17 SBD-3 - LT CDR Robert E. Dixon
VT-2: 13 TBD-1 - LT CDR James H. Brett, Jr.

Therefore, Lex has:
21 F4F3
36 SBD
13 TBD

CAP
VF-2 : (4 + 4 - 3(?) + 5) = 10 of 21
0700 : 4 F4F launched as CAP at start of day's flight operations
0820 : 4 more F4F launched as CAP
0928 : "Commenced landing CAP". It is not specific how many were landed (I believe the number landed to be 3. discussion in a minute).
1012 : 10 SBDs launched to suppliment CAP vs. torpedo planes (cannot be handled in WitP, so we'll discount it). Some of these were returned scouts, some were from Yorktown.
1106 : 5 F4F launched and 5 SBD luanched as CAP. There is a note in the log that 19 (of 21 F4F are airborn). Since we know that 9 F4F on the inital strike, we must have 10 CAP currently flying, and 3 must have landed at 0928.



NavSearch
VB-2 : 6 of 18
VS-2 : 12 of 17

Initial Strike
VF-2 : 9 of 21
VB-2 : 11 of 18
VS-2 : 4 of 17
VT-2 : 12 of 13

This accounts for
VF-2 : 19 of 21
VB-2 : 17 of 18
VS-2 : 16 of 17
VT-2 : 12 of 13


If I had to make a call, I'd say Lex's WitP settings were as follows:

VF-2 : Escort, 50% CAP
VB-2 : NavAtk, 30% Search
VS-2 : NavAtk, 70% Search
VT-2 : NavAtk, 0% Search

===

Granted, Coral Sea was certainly a learning experience for both sides. It was shown the SDBs weren't particularly effective vs. enemy bombers, and more fighters, MORE FIGHTERS, MORE FIGHTERS, etc. etc. etc. Naturally, this shouldn't be used as "the rule" for what was standard USN CAP doctrine in WW2. It'll take me a wil to read thru the AARs of the other carriers and battles.

Still, it's interesting. I never bothered to do the math.

There's more information there, than you actually need, but I thought I'd put in the whole post, in case it's interesting.

Lex ends up with

CAP
10 F4F3 = Substantiates your data.

Strike
9 F4F3
15 SBD
12 TBD
===
36 planes.

And there are 18 of 36 planes on search (from I've read, usually begin launching about an hour before dawn, so as many as possible up by the time the sun comes up).

Not sure where the reconcile is. If I understand your numbers correctly (I might very well not), you indicate that Lex could not launch more than 20 planes on a strike? However, at Coral Sea, her initial strike comprised of 36 planes, and there were 10 Wilcats on CAP.

What am I missing?

Don't get me wrong. Obviously, you've done your homework. But I'm obvioulsy missing something, in order to reconcile your analysis to the historical record.

-F-

[el cid again]

This entire discussion omits a terribly important factor: plane size.
Bigger capacities may exist if you use smaller planes, and vice versa.
And some planes are simply too big for some carriers. The Zero was turned into a fighter bomber because late war carrier bombers were too big for smaller carriers in IJN. Some of the too big carrier ratings ARE historical - for older generation planes. In a more complex simulation, carriers are rated for the size of the planes, and putting bigger ones on board comes at a penalty even when it is possible.

[Hipper]

Class CAP Strike Hanger Reserve
Saratoga 12 20 30 10

I think these numbers refer to aircraft spaces 5 spaces = 9 aircraft
or 3 spaces = 9 aircraft for Wildcats, hellcats and corsairs

so strike 20 would seem to equal 36 bombers your numbers exactly

cap 12 would equal 36 fighters !

cheers

we can use this stuff it's very good !

[Fishbed]

That's it!! You got it Hipper, thank you! Now I suddenly feel a lot cleverer thanks to you - Herwin's data's very nice, but still in many way too brillant for my little brain sometimes [:D]