Post by Merlin DorfmanThe escort carriers had around a third to a quarter the manpower on
board and also a third to a quarter the airpower. So there needs to be
30 or more escort carriers added to the fleet, essentially that looks
like more than were available.
The 10 CVs/CVLs (were CVLs still in use in Spring 1945?) had to carry
out ground support and CAPs over themselves and the pickets.
The numbers were given in the first reply,
"The USN reports it had a nominal 18 fleet aircraft carriers by end
April and 20 by end June, along with 8 light fleet carriers. It had
65 escort carriers by end April and 70 by end June. This counts
all ships, including those under repair, refit or still working up.
Some 10 fleet carriers were in operation in April, 9 in May and
8 in June, 6 light fleet carriers were in action in April and May,
and 4 in June. 20 escort carriers were in action in April and May
and 17 in June."
Are you wanting the CVL's more towards the rear as well as the
CV's?
Post by Merlin DorfmanThe CVEs
would only need to provide ground support and perhaps picket CAP so
perhaps fewer than 30 would be needed.
There were CVEs present whose job it was to provide ground support,
just like the CVE's present at Leyte Gulf.
Again from the first reply,
"At the start of the battle the US escort carriers were deployed as
follows, 18 to support the landings, 4 to ferry in USMC air units,
(Marine Air Groups 31 and 33 with 192 F4U and 30 F6F),
2 as protection for the fleet train, 4 as plane transport units to
replace lost carrier aircraft and 2 as anti submarine."
That totals 30 CVE's out of 65 in April and 70 in June.
To replace 10 fleet aircraft carriers you would need 3 to 4 times the
number of escort carriers.
Post by Merlin DorfmanAccording to Wikipedia, the US built 151 aircraft carriers during WW
II, of which 121 were escort carriers (including 50 Casablanca class and
45 Bogue class).
Now deduct the 6 CVE losses, the 1 commissioned in July and
the 1 commissioned in September 1945, and in particular the
number sent to the RN and you end up with 65 in commission at
the end of 1944, by end April 1945 that had gone to 66 despite
2 losses.
Have a look at the percentage of fleet carriers and light fleet carriers
nominally available that were actually present, as well as the escort
carriers. Ships need their maintenance and time out of combat.
Put it another way as of end April 1945 the USN had in commission,
in addition to the carriers mentioned above, 23 battleships, 20 heavy
and 45 light cruisers, 369 modern destroyers, 367 destroyer escorts
and 238 submarines. If nearly all the CVE's can be present at
Okinawa then by the same reasoning so can most of these ships.
Post by Merlin DorfmanBy April/May 1945 the U-boat war was essentially over;
what fighting was still going on in Europe was fully accessible to land-
based air; and I doubt if many CVEs were needed to ferry aircraft to
Europe. Hence presumably all active CVEs could be deployed to the Pacific
if needed.
Except the CVE's were in use in the Atlantic as anti submarine ships
until around mid May, after people were sure the U-boats had
surrendered, and CVE's made good transports for short ranged
aircraft for both Europe and the Pacific.
Next comes the fact the more carriers in action the more carriers
are needed to train pilots and supply replacement aircraft to the
carriers in action. Part of the resupply was the exchange of "flyable
duds" between the combat carriers and the escort carriers assigned
to the fleet train for the purpose. And of course simply replacing
the total losses.
Post by Merlin DorfmanThen add the appearance of the escort carriers going where the fleet
units feared to go.
Wasn't that already the case since the pickets (Destroyers, LCS(L)s,
etc.) were placed along the flight path from Japan to the Fleet and could
be seen as going where the Fleet was afraid to go?
The purpose of the radar pickets was to give advanced warning to
the carriers, and give them time to launch and intercept. It makes
no sense for the carriers to be along side the radar pickets. One
urgent task was sighting a radar station on the highest part of
Okinawa controlled by US forces.
Moving the carriers 100 miles further away increases the chances
of missed interceptions, given the extra distance flown. They would
need fighter controllers in the Okinawa area, with relevant radios
and radars.
Post by Merlin DorfmanAnd isn't it common
for more valuable/more expensive/more difficult-to-replace military units
to be placed where they were less subject to attack, while less valuable
units are placed in a more exposed position?
As I pointed out in the complements, less valuable applies to the
hull, the number of men going in harm's way would be about the
same and they would have significantly less protection built into
the ship, in terms or armour, damage control and AA guns.
Post by Merlin DorfmanIf you look at what sank the escort carriers it is clear they could not
take the damage the fleet carriers could. It is therefore probable an
average hit would kill more sailors. It is also the case the presence
of the fleet drew attacks away from what was more important
strategically, the fighting around Okinawa and the supply system.
Interesting point--could the Kamikazes have done as much damage to
the entire effort if they had been directed against land targets (probably
not) or the supply ships and unloading facilities (maybe so--especially
given that this was a "choke point").
Simply put the Japanese war effort would have been more significant
if they had understood how important supply was, the Okinawa
ground forces had to ration their mortar ammunition for most of the
campaign thanks to supply ship losses. More such losses and the
campaign would probably last longer.
No fleet to attack should mean more damage to the supply ships.
Post by Merlin DorfmanPost by Merlin DorfmanMaybe the jeeps could provide close support of ground troops,
with every airplane on board, while the fast carriers, 100 miles or
more away and thus out of range of the kamikazes, could provide the air
cover for the jeeps.
If they are 100 miles from carriers south of Okinawa how far are the
fleet carriers from the radar pickets?
Remember the USN tended to think of 200 miles as its comfortable strike
distance.
Probably another 100 miles or more: within easy range of the CVEs but
not of the Kamikaze bases in Japan. Since the Kamikazes are on a one-way
mission, they can "range" twice as far as planes that are intended to
return to base.
The Japanese aircraft were usually longer ranged than the US ones.
Kagoshima in Southern Kyushu is listed as 412 miles from Okinawa.
Taiwan is actually slightly closer and one of the fleet tasks was to
interdict the supply of Japanese aircraft from China or Taiwan along
the island chain between Taiwan and Okinawa, the British were
assigned to the task, plus some CVE's when the British fleet was
resupplying.
Post by Merlin DorfmanI don't have ready information on strike distances at that point in
the war; my recollection is that during the Guadalcanal campaign, the
preferred location of carriers doing ground support was about 90 miles
from the targets. Of course at that time they were flying F4Fs instead of
F6Fs (and the fighters were the "short-legged" of the types in use).
If you look at the Philippine Sea the closest Japanese ships to
the US fleet when it launched the strike was around 275 miles.
Each fleet carrier launched 30 to 40 aircraft, 206 sorties from the
6 fleet carriers, the 5 CVLs added another 34 aircraft.
Carriers take longer to launch aircraft and even longer to land
them, so lots of the range is taken by forming up or waiting to
land.
Post by Merlin DorfmanThe purpose built warships could take the damage and generate a better
defence in terms of numbers of aircraft and AA guns. Also taking places
like Iwo Jima and Okinawa put more land based airpower with range of
Japan, reducing the importance of the carriers compared to things like
the assaults on the Marianas and Leyte.
Not questioning the need for the invasions of those two islands, just
some of the tactics, specifically tying down the most potent naval
striking force in the history of the world to ground support rather than
attack.
The fleet carriers switched to mainly fighters in 1945, and the strike
aircraft certainly did ground support, in addition to the 18 CVEs
specifically tasked which such operations, but the fleet carriers
main purpose was to provide combat air patrols over the island
and all the shipping present.
Post by Merlin Dorfman(Though I wonder if, knowing how costly Iwo was going to be, that
invasion would still take place, or would take place with vastly different
tactics. A different subject, however.)
Hindsight always gives better options.
Post by Merlin DorfmanIndeed trying to invade Japan itself using only carrier-based air
would be much riskier than having aircraft based on Iwo and Okinawa as
well.
That was never the plan. Think of US strategy in the Pacific as on
arm assuming carrier based airpower was as limited as pre war
theory, so Australia to the Philippines to Japan, and one that the
USN planned for pre war but now relied on carrier based
airpower being more effective than originally assumed.
Post by Merlin DorfmanGiven the expected invasion of Japan there is also the case the fleet
needed to learn how to deal with Kamikaze attacks.
Were any lessons learned that helped blunt the effect of Kamikazes?
I recall that the percent of carrier-based airgroups devoted to fighters
was to be increased.
Lots of fighters, radar pickets, throw out any AA gun under 40 mm,
better fighter control.
Post by Merlin DorfmanI infer from the Wikipedia article that close air support was not a
common mission for the CVEs or one that its pilots were well trained or
practiced in.
Incorrect, look up what the CVE's were doing at Leyte for example,
hence they were not really equipped with the weapons to handle
Japanese battleships and cruisers.
Even earlier were the landings in Hollandia and the Marianas.
The Okinawa fleet included CVE's specifically tasked with ground
support, just like the old USN battleships versus the newer ones
with the carriers. There was nothing stopping an Iowa etc. class
bombarding Okinawa but as far as I know after the invasion only
the specifically tasked bombardment support ships did so.
Post by Merlin DorfmanLeyte may have been the exception in that regard, with the
fast carriers not being under the command of the invasion force and thus
the invasion commander needing to be prepared to provide his own close
support.
No, the USN had the numbers to provide dedicated ground support
carriers, and did so.
Post by Merlin DorfmanThis is all completely speculative and hypothetical, but an
interesting discussion nonetheless.
Look at the numbers.
Geoffrey Sinclair
Remove the nb for email.