Early RN Escort Carriers

[Mike Snyder]

Interesting but wiki makes no mention of carriers, but with a tonnage limit for the RN on heavy cruisers with 8" guns, gives them more of an incentive, to convert and replace with 8" gun armed heavy cruisers rather than 7.5". But besides which, who knows the conversions may have been accomplished before 1930!!
https://en.wikipedia.org/wiki/London_Naval_Treaty

http://www.navweaps.com/index_tech/tech-089_London_Treaty_1930.htm Here is the Treaty as signed. I am wrong (and you are right) in that the Treaty prohibited ANY carriers under 10,000 tons, but the actual result was that there was no attempt to build an aircraft carrier of that size. The IJNS Ryujo ended up over 10,000 tons and the Vindictive if fitted as a carrier with arresting wires, a full flight deck and elevators and bulged for stability would certainly displace more than 10,000 tons at standard displacement and have to be counted under the Treaties after 1930 (she would probably have been included in the experimental clause in the 1922 Treaty) until 1936. Also, I do believe the Treaty of 1930 prohibited the building of auxiliaries and merchant ships fitted to land on and launch aircraft, auxiliaries being limited to no more than 3 aircraft.

 

[Mike Snyder]

Using Raven and Roberts and the breakdown of the weights for the "Elizabethan" class cruisers and then Freidman's British Carrier Aviation's breakdown of weights for Furious, Eagle and Hermes after the addition of arresting wires, and the Naval Weapons by Campbell, nominal standard displacement was 9,850 tons. Removing the main guns, ammunition and the superstructure would remove 640 tons. Flight deck, elevators (aircraft and ordnance), arresting wires, closed hanger with integral fire fighting system, additional AA guns (4" or 4.7"), ordnance for aircraft, aircraft, aviation fuel storage and distribution would weigh 880 tons. This would bring displacement to 10,090 tons. The stability acceptable for cruiser operations would not be acceptable for flight operations and bulges would be needed. This would add around 230 tons, bringing displacement to 10,340 tons unless additional weights, such as armor is removed. Full load would be around 13,700 tons and sustained sea speed would be 28 knots. The hanger was the limiting factor for air groups for the RN so it looks like a maximum of 12 aircraft. She would probably be used as a "fighter" carrier in direct support of the Battle Line, so by 1939, she would carry Sea Gladiators or Skuas, though her flight deck length might limit the operation of Skuas to fighter missions only.
As an addendum to my other post, RN doctrine kept the carriers close to the Battle Line even in 1939, where the USN and IJN had released the carriers to operate independently against their opposite numbers.

 

[Mike Snyder]

In 1930, the experimental clause of the Washington Treaty was lifted adding Furious, Eagle, Argus and Hermes to British carrier tonnage. That represented 70,000 tons to the 42,000 represented by Courageous and Glorious. That was 112,000 tons of 135,000 tons allowed. This left enough to lay down Ark Royal. If Vindictive was in service, she would have precluded laying down a new fleet carrier unless she or one of the other older carriers was scrapped or hulked. Converting additional "Elizabethans" before 1930 would have been financially impossible with the funds needed to convert Courageous and Glorious and upgrade Furious. Between 1930 and 1936, the RN wouldn't have the tonnage and with the 1936 Treaty, while the "Elizabethans" could have been converted, the priority was the armored carriers for the Fleet, given the limited ability of British industry to provide the necessary aviation accessories.

 

[jsb]

In 1930, the experimental clause of the Washington Treaty was lifted adding Furious, Eagle, Argus and Hermes to British carrier tonnage.

I'm not sure I think they haven't changed they count but can be replaced at any time (if you have the money fro HMG).

 

[Mike Snyder]

I'm not sure I think they haven't changed they count but can be replaced at any time (if you have the money fro HMG).

If you look at the language of the Washington Treaty (http://www.navweaps.com/index_tech/tech-089_Washington_Naval_Limitation_Treaty_1922.htm), the experimental carriers did not count towards the total tonnage limit, but their replacements would. In 1930, the London Treaty eliminated that category and the existing "experimental" carriers were added to the total tonnage. This is why the USN reduced the USS Langley from a carrier to a seaplane tender, removing part of her flight deck to meet the terms of the treaty regarding auxiliaries with flight decks being banned.