R Leonard
Staff Sergeant
I did think R (and Im sure you will be able to verifie or deny it) that the USS Ranger was the first US purpose built carrier of any size, as I believe all the ones previous to this where based on other vessels or hulls. Also have you any info on UK carrier categories as all mine say that HMS Hermes 10,750 tons was the first and smallest Fleet carrier operated by the RN where I believe in the US it has to be over 20,000 tons and carry over a set number of aircraft before it is rated as a fleet carrier. This appears to be quite a grey area especially prior too 1930.
Yes, Ranger was the first designed for purpose US aircraft carrier, fleet or otherwise. Langley was converted from the collier USS Jupiter. Lexington and Saratoga were converted from battle cruisers as a result of the naval limitation treaties. Yorktown, Wasp and Essex class were designed for purpose. The Independence class light carriers were converted from light cruisers. Saipan class light carriers were designed for purpose.
There is no hard and fast tonnage rule that divides fleet carriers from light carriers. That being said, we can look at how the USN made its distinctions in the WW2 era.
Lexington Class (2) – fleet carrier, 33000 tons, 34 knots speed, 80-120 aircraft
Ranger Class (1) – fleet carrier, 14500 tons, 29.5 knots speed, 80 aircraft
Yorktown Class (3) – fleet carrier, 19900-20000 tons, 34 knots speed, 80-100 aircraft
Wasp Class (1) – fleet carrier, 14700 tons, 29.5 knots speed, 80 aircraft
Essex Class (24) – fleet carrier, 27100 tons (average), 32.7 knots speed, 110 aircraft
Independence Class (9) – light carrier, 11000 tons, 31.6 knots speed, 45 aircraft
Midway Class (3) – fleet carrier, 45000 tons, 33 knots speed, 137 aircraft
Saipan Class (2) – light carrier, 14500 tons, 32.5 knots speed, 50 aircraft
The distinction appears to be based more on aircraft complement than tonnage. Note that displacement for the Saipan class is the same as for Ranger, yet they carried 30 less airplanes, thus falling into the CVL classification. Confirming the aircraft complement theory of distinction, note the Altamaha class, Sangamon class and Commencement Bay class CVEs. These classes of escort carriers all displaced more than the Independence class CVLs, but carried only 18, 35, and 35 aircraft, respectively. The rated speed of the CVLs when compared to CVs and CVEs also serves to distinguish the CVLs from the CVEs in that the CVLs could keep pace with the CVs and the CVEs could not. The deciding factors, then, are an ability to keep station with the CVs and the size of the aircraft complement.
Early Japanese carriers were conversions, Hosho from a hull that started as a tanker; Akagi, from a battle cruiser; and Kaga from a battleship. Shoho class carriers were converted from submarine tenders as was Ryuho. Hiyo class was converted from liners that were designed with the conversion in mind. Chitose class were seaplane tender conversions. And, of course, Shinano was converted from the Yamato class battleship. Hosho remains an oddity. Considered to be a fleet carrier when built, its primary purpose was as an experimental platform. It remained, despite small tonnage and aircraft complement on the Japanese books as a fleet carrier even though, in practice it was smaller than most escort carriers and carried even less aircraft. Had Hosho been built in 1943 it would have been considered a CVE.
Hosho Class (1) – fleet carrier, 7470 tons, 25 knots speed, 21 aircraft
Akagi Class (1) – fleet carrier, 36500 tons, 31.5 knots speed, 90 aircraft
Kaga Class (1) – fleet carrier, 38200 tons, 28.3 knots speed, 90 aircraft
Ryujo Class (1) – light carrier, 10600 tons, 29 knots speed, 48 aircraft
Soryu Class (1) – fleet carrier, 15900 tons, 34.5 knots speed, 73 aircraft
Hiryu Class (1) – fleet carrier, 17300 tons, 34.3 knots speed, 73 aircraft
Shokaku Class (2) – fleet carrier, 25675 tons, 34.2 knots speed, 84 aircraft
Shoho Class (2) – light carrier, 11262 tons, 28 knots speed, 30 aircraft
Hiyo Class (2) – fleet carrier, 24140 tons, 25.5 knots speed, 53 aircraft
Ryuho Class (1) – light carrier, 13360 tons, 26.5 knots speed, 31 aircraft
Chitose Class (2) – light carrier, 11190 tons, 29 knots speed, 30 aircraft
Taiho Class (1) – fleet carrier, 29300 tons, 33.3 knots speed, 53 aircraft
Shinano Class (1) – aircraft transport, 64800 tons, 27 knots speed, 47 aircraft
Unryu Class (3) – fleet carrier, 17150 to 17460 tons, 32 knots speed, 65 aircraft
Japanese CVEs of the Chuyo class had a displacement of 17830 tons, a speed of 21 knots and an aircraft complement of 27. Kaiyo class was 13000 tons, 23.75 knots, and 24 aircraft. Shinyo class was 17500 tons, 22 knots, and 31 aircraft. The primary distinction, then, for the Japanese, if you ignore Hosho, appears to be, as with the USN, speed first, then aircraft complement.
With all that in mind, we can take on the Royal Navy's distinctions between CVs, CVLs, and CVEs. Furious began life as a battle cruiser, first with the flight deck forward, then extended aft and finally converted to flush decl. Vindictive was built on light cruiser Canvandish with a forward flightdeck, not really an aircraft carrier. Argus was converted from an Italian liner. Argus was rated as CV, and for the period in which it was built, was indeed so. By later standards of speed and complement she was closer to a CVE then anything else. Eagle started as a dreadnought battleship. Another early carrier rated CV, 20 years later, on speed and aircraft complement, she would probably be rated a large CVE. Hermes, since the Japanese Hosho started as a tanker, is generally regarded as the first designed and built for purpose aircraft carrier. Courageous class carriers were converted from battle cruisers. All CVs and CVLs that followed were also designed and built as carriers.
Furious Class (1) – Not Typed, 22450 tons, 32.5 knots speed, 33 aircraft
Vindictive Class (1) – Not Typed, 9750 tons, 29 knots speed, 6 aircraft
Argus Class (1) – fleet carrier, 15775 tons, 20.75 knots speed, 20 aircraft
Eagle (I) Class (1) – fleet carrier, 22600 tons, 24 knots speed, 21 aircraft
Hermes Class (1) – fleet carrier, 10850 tons, 25 knots speed, 25 aircraft
Courageous Class (2) – fleet carrier, 22500 tons, 32 knots speed, 48 aircraft
Ark Royal Class (1) – fleet carrier, 22000 tons, 31.5 knots speed, 72 aircraft
Illustrious Class (4) – fleet carrier, 23000 tons, 31 knots speed, 36 aircraft
Implacable Class (2) – fleet carrier, 23000 tons, 32 knots speed, 72 aircraft
Eagle (II) Class (2) – fleet carrier, 36800 tons, 31.5 knots speed, 100 aircraft
Unicorn Class (1) – light carrier, 14750 tons, 24 knots speed, 35 aircraft
Colossus Class (10) – light carrier, 13190 to 13350 tons, 25 knots speed, 48 aircraft
A quick look at RN CVEs leads us to:
Audacity, a conversion from merchant vessel, 5537 tons, 15 knots, 6 aircraft.
Pretoria Castle, merchant conversion, displaced 17392 tons, speed 17 knots, and 15 aircraft.
Activity, merchant conversion, displaced 11800 tons, speed 18 knots, and 15 aircraft.
Campamia, merchant conversion, displaced 12450 tons, speed 17 knots, and 15 aircraft.
Vindex, merchant conversion, displaced 13455 tons, speed 17 knots, and 15 aircraft.
Nairana, merchant conversion, displaced 14500 tons, speed 17 knots, and 15 aircraft.
and then the Tracker class (26), merchant hulls, 11420 tons, speed 17 knots, 24 aircraft.
It would appear that for the RN the distinction, generally based on speed, CVL speeds vary from 24 to 25 knots. The CVEs are all at 17 and lower knots except for HMS Activity at 18 knots. Separation from CVs is a little more difficult due to the specifications of some of the early carriers. And then there's the fact that none of the CVLs of the Unicorn and Colossus, were completed during the war. Looking at the data, it would appear that speed was the determining factor. If your carrier had a top speed over 20 knots you were either a CV or a CVL without regard to aircraft complement. Tonnage wise, Unicorn and Collossus classes displace somewhat less than the contemporary CVs. If I had to make the call, I'd say the RN looked at speed. Less than 20 knots and it is a CVE. More than 20 knots, but less than 15000 ton displacement then, if you do not count pre 1925 carriers, would seem to define the CVL.
As a youngster and I do mean young, I spent a little time on aircraft carriers. Spent about a week on USS Ranger (CVA-61) back in 1961. I was all of nine years old. In 1965 I went out for a day on USS Enterprise for a dog and pony show. And in 1966 I went out on USS Wasp (CVS-18) a couple of times, once on a two day equipment check and then again for about a week or so for one of the Gemini recoveries. Being a kid on a carrier . . . good duty if you can get it.
Regards,
Rich