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Allied passenger liners to CV conversions?
Posted: Sat Sep 07, 2013 2:15 am
by Jorge_Stanbury
Question on CV conversions
Was there any Allied attempt to convert passenger liners to carriers? Japan was relatively succesful with the Hiyô class.
a passenger liner CVE would be almost as fast as a fleet carrier and could carry more planes than a CVL. Between December 1941 and the end of 1942, they could had helped a lot.
My guess is that liners were badly needed for the invasion of Europe and/ or conversion would had taken so long that it was better to wait to the superior Independence/ Essex
RE: Allied passenger liners to CV conversions?
Posted: Sat Sep 07, 2013 2:25 am
by warspite1
I understood there were plans drawn up to convert both Queens - Elizabeth and Mary - into carriers early in the war, but they were too important as troopships to be spared.
RE: Allied passenger liners to CV conversions?
Posted: Sat Sep 07, 2013 2:42 am
by wdolson
The fastest passenger ships were only about 22-24 knots top speed. With the added weight topside for the deck and hanger, they may have been even slower. That's too slow for a fleet carrier and a conversion would lack much in the way of armor. Another drawback for being a fleet carrier. These were problems with the Hiyo and Junyo as well ass the other passenger ship conversions.
Most of the Japanese conversions were originally built with conversion in mind. The Allied passenger ships didn't have the "hooks" built in to convert them to carriers quickly, so it would have taken more effort to do the conversions.
Among the first CVEs built by the US were converted tankers. They were quite good carriers with capabilities approaching the Independence CVLs. However, the hulls were too valuable as tankers to make a lot of conversions. In the end making CVEs out of more common merchant hulls made a lot more sense. For invasion support a larger carrier might have been more useful, but for convoy escort the smaller CVEs proved to be very good.
Converting large passenger ships would have been costly, taken quite a while, and may not have been as useful as the CVEs that were built. In the end I think the Allied CVEs were a more successful production strategy.
Bill
RE: Allied passenger liners to CV conversions?
Posted: Sat Sep 07, 2013 3:13 am
by Capt Cliff
With all the CVE's and CVL's the Allies get it's not worth it, IMHO. Like the Japanese conversions they would carry a small air group anyway and be slow not 30 knots. Anyway a proper conversion would most like take as long as building a new CVL from scratch. The Allies had such vast shipyard capacity and the Japanese such limited capacity conversion of passenger liners was a must for Japan. Besides carving out a hanger deck and getting cg just right on a liner would have been a pain. You'd have to blue print the liner to be sure. No the allies needed those liners, but for some strange reason the allies don't need them in WitP. Most of my allied liners have been sitting in San Francisco since 12/7/41, I don't need them. So I think the load capacity of troopship might not be modeled properly.
RE: Allied passenger liners to CV conversions?
Posted: Sat Sep 07, 2013 7:27 am
by Jorge_Stanbury
Yes, I was not taking into account the "sneaky" factor...Japanese were able to convert liners and auxiliaries quite easy because their design was dual purpose
RE: Allied passenger liners to CV conversions?
Posted: Sat Sep 07, 2013 8:56 am
by dr.hal
The key is, as stated above, that the liners were built with conversion in mind. The British did the same thing but with "troop ships" in mind. The put "hard points" in their liners for gun emplacements and other things (ammo storage) that would make the ship very easy to convert. It's much like our airliners today where the seats are made to take out at a moment's notice!
RE: Allied passenger liners to CV conversions?
Posted: Sat Sep 07, 2013 10:20 am
by btbw
Why need convert if can build?
RE: Allied passenger liners to CV conversions?
Posted: Sat Sep 07, 2013 12:16 pm
by DuckofTindalos
The Hiyos were in no way successful. As for the Allies, their passenger liners were far too useful for troop transport duties to waste time converting. The MAC ship programme and later CVE classes fulfilled their needs adequately.
RE: Allied passenger liners to CV conversions?
Posted: Sat Sep 07, 2013 6:05 pm
by geofflambert
ORIGINAL: wdolson
The fastest passenger ships were only about 22-24 knots top speed. With the added weight topside for the deck and hanger, they may have been even slower. That's too slow for a fleet carrier and a conversion would lack much in the way of armor. Another drawback for being a fleet carrier. These were problems with the Hiyo and Junyo as well ass the other passenger ship conversions.
Most of the Japanese conversions were originally built with conversion in mind. The Allied passenger ships didn't have the "hooks" built in to convert them to carriers quickly, so it would have taken more effort to do the conversions.
Among the first CVEs built by the US were converted tankers. They were quite good carriers with capabilities approaching the Independence CVLs. However, the hulls were too valuable as tankers to make a lot of conversions. In the end making CVEs out of more common merchant hulls made a lot more sense. For invasion support a larger carrier might have been more useful, but for convoy escort the smaller CVEs proved to be very good.
Converting large passenger ships would have been costly, taken quite a while, and may not have been as useful as the CVEs that were built. In the end I think the Allied CVEs were a more successful production strategy.
Bill
Bill, c'mon, you're the flippin' moderator
RE: Allied passenger liners to CV conversions?
Posted: Sat Sep 07, 2013 7:30 pm
by warspite1
ORIGINAL: geofflambert
ORIGINAL: wdolson
The fastest passenger ships were only about 22-24 knots top speed. With the added weight topside for the deck and hanger, they may have been even slower. That's too slow for a fleet carrier and a conversion would lack much in the way of armor. Another drawback for being a fleet carrier. These were problems with the Hiyo and Junyo as well ass the other passenger ship conversions.
Most of the Japanese conversions were originally built with conversion in mind. The Allied passenger ships didn't have the "hooks" built in to convert them to carriers quickly, so it would have taken more effort to do the conversions.
Among the first CVEs built by the US were converted tankers. They were quite good carriers with capabilities approaching the Independence CVLs. However, the hulls were too valuable as tankers to make a lot of conversions. In the end making CVEs out of more common merchant hulls made a lot more sense. For invasion support a larger carrier might have been more useful, but for convoy escort the smaller CVEs proved to be very good.
Converting large passenger ships would have been costly, taken quite a while, and may not have been as useful as the CVEs that were built. In the end I think the Allied CVEs were a more successful production strategy.
Bill
Bill, c'mon, you're the flippin' moderator
warspite1
Agreed. That sort of language is just completely out of place here Mr Potty Mouth [:-]
RE: Allied passenger liners to CV conversions?
Posted: Sat Sep 07, 2013 7:32 pm
by msieving1
The US gave some thought to converting passenger liners to auxiliary fleet carriers. It was decided that the ships were more valuable as troop carriers. See
http://www.hazegray.org/navhist/carriers/us_auxil.htm
It might be something to consider, at least as an option, for an alt-history mod. Another possible conversion to consider would be the British MAC ships, or merchant aircraft carriers. These were cargo carriers with a flight deck added, but no hanger, and could operate 4 aircraft. IRL they were only used in the Atlantic, but if Japanese subs had been a greater threat to shipping it seems likely there would have been MAC ships in the Indian Ocean or Pacific.
RE: Allied passenger liners to CV conversions?
Posted: Sat Sep 07, 2013 8:13 pm
by wdolson
ORIGINAL: wdolson
The fastest passenger ships were only about 22-24 knots top speed. With the added weight topside for the deck and hanger, they may have been even slower. That's too slow for a fleet carrier and a conversion would lack much in the way of armor. Another drawback for being a fleet carrier. These were problems with the Hiyo and Junyo as well ass the other passenger ship conversions.
[snip]
ORIGINAL: geofflambert
Bill, c'mon, you're the flippin' moderator
warspite1
ORIGINAL: warspite1
Agreed. That sort of language is just completely out of place here Mr Potty Mouth [:-]
I'll go commit sepaku now...
Bill
(Had to look twice to see what you were referring to. Damn typos.)
RE: Allied passenger liners to CV conversions?
Posted: Sat Sep 07, 2013 8:27 pm
by MateDow
There were plans for US conversions of passenger ships. The Navy didn't think that they were going to be worth the effort.
RE: Allied passenger liners to CV conversions?
Posted: Sun Sep 08, 2013 1:43 am
by Lokasenna
60 planes!
But pretty much no protection. And slow. Very slow.
RE: Allied passenger liners to CV conversions?
Posted: Sun Sep 08, 2013 7:57 am
by DuckofTindalos
Even slower than the Hiyos. Good luck operating those with the fleet.
RE: Allied passenger liners to CV conversions?
Posted: Sun Sep 08, 2013 9:48 pm
by Jorge_Stanbury
Yes, not that great; but if available in early or mid 1942, I would had taken them
or maybe use as carrier flag in the Atlantic and move CV-4 Ranger to the Pacific
RE: Allied passenger liners to CV conversions?
Posted: Mon Sep 09, 2013 3:13 pm
by Amoral
Akitsu maru is a passenger liner converted to be a flat-topped amphibious assult ship. In the game it can only carry float planes, but in real life it launched aircraft.
RE: Allied passenger liners to CV conversions?
Posted: Mon Sep 09, 2013 4:10 pm
by String
ORIGINAL: Amoral
Akitsu maru is a passenger liner converted to be a flat-topped amphibious assult ship. In the game it can only carry float planes, but in real life it launched aircraft.
It launched them but IIRC it couldn't recover them. The idea being that the ship carried the aircraft to be flow off on to a newly captured airfield
RE: Allied passenger liners to CV conversions?
Posted: Mon Sep 09, 2013 4:35 pm
by Amoral
ORIGINAL: String
ORIGINAL: Amoral
Akitsu maru is a passenger liner converted to be a flat-topped amphibious assult ship. In the game it can only carry float planes, but in real life it launched aircraft.
It launched them but IIRC it couldn't recover them. The idea being that the ship carried the aircraft to be flow off on to a newly captured airfield
That might be right. Akitsu was operated by the IJA, and didn't have access to trained carrier pilots nor the experience of carrier ops that the IJN would have.
In the game it is valuable because it provides an unload bonus when it is in an amphibious TF. The air capacity is secondary.
RE: Allied passenger liners to CV conversions?
Posted: Mon Sep 09, 2013 5:39 pm
by Bullwinkle58
ORIGINAL: MateDow
There were plans for US conversions of passenger ships. The Navy didn't think that they were going to be worth the effort.
That's one fuggly ship.