Introduction
I made so many changes, that I decided to abandon the original thread, and start a new one. I intend to follow up this post with one explaining the history of the Royal Navy's aircraft carrier force ITTL and follow that up with one post about each navy that bought Audacious class ships in place of the light fleet carriers purchased IOTL.
ITTL the 6 aircraft carriers laid down 1936-39 were built with hangars 17½ feet high. IOTL they were:
- 16 feet for Formidable, Illustrious and Victorious;
- 14 feet for the main hangar and 16 feet for the lower half-length in Indomitable;
- 14 feet for the main hangar and 14 feet for the lower half-hangar in Implacable and Indefatigable
They were also given bigger lifts. This was because the people who set the staff requirements they were designed to meet had more foresight and made more allowance for the growth of naval aircraft over their service lives which were projected to be 20 years.
The increase in hangar height increased the depth of the hull, in case of Implacable and Indefatigable, from 71 to 77 feet. The hull would have to be longer and beamier too in order to maintain stability. That would in turn push up the displacement to over 23,000 breaking the OTL 1936 London Treaty. However, IOTL it was the British who wanted the limit reduced from 27,000 tons (under the Washington and 1930 London Treaties) to 22,000 tons in the first place, but they were only able to get a reduction to 23,000 tons. ITTL the 1936 Treaty keeps the aircraft carrier displacement limit at 27,000 tons.
Changes to RN Building Programmes 1941-45
Additions
- 14 Audacious class fleet carriers laid down 1941-44. All of them were completed between the end of 1944 and the middle of the 1950s. IOTL 3 ships of this class were laid down 1942-44. The original Eagle, laid down in 1944 was cancelled in 1946 even though she was 26% complete. The other two were completed in 1951 and 1955;
- 40 Battle class destroyers laid down as OTL. All of them would be launched and 36 completed 1944-48 instead 33 launched and 24 completed IOTL.
Deletions
- The 16 light fleet carriers of the Colossus and Majestic classes laid down 1942-43. IOTL all 16 ships were launched 1943-45 and 15 were completed between the end of 1944 and 1961;
- The 4 Centaur class light fleet carriers laid down 1944-45 and completed 1953-59;
- The battleship Vanguard laid down in 1941, launched in 1944 and completed in 1946;
- The 8 Swiftsure class cruisers laid down 1941-44. IOTL 6 were launched 1943-45 and 3 completed 1944-45. At the end of the war the 2 ships that had not been launched were cancelled and the other 3 were suspended. In 1951 it was decided to complete the suspended ships as the Tiger class, but work did not resume until 1954 and they were completed 1959-61;
- The 20 Weapon class ordered. IOTL 4 were cancelled before the war ended. Of the remainder 13 were laid down before the end of the war, 6 were launched and 4 completed 1947-48;
- The 16 Daring class destroyers ordered. IOTL 8 were cancelled at the end of the war, 8 were laid down 1945-49 and completed 1952-54;
- The 16 G class destroyers planned. IOTL only 8 were actually ordered and they were all cancelled at the end of the war before they were laid down.
Or put another way:
- ITTL an aircraft carrier named Vanguard was built instead of the battleship Vanguard. She was laid down at the same time as Vanguard, but took less time to build and was completed in November 1944 instead of May 1946;
- ITTL 10 Audacious class aircraft carriers were laid down 1941-43 and completed 1944-48 using the resources used to build the 2 Audacious class, 10 Colossus, 6 Majestic class and 8 Swiftsure class cruisers laid down 1941-44 IOTL;
- ITTL 3 Audacious class aircraft carriers were laid down in 1944 and completed in the early 1950s using the resources used to build the one Audacious class laid down 1944 and 4 Centaur class laid down 1944-45;
- ITTL 40 Battle class destroyers laid down as OTL, but the resources put into the Weapon class IOTL were used to completed 36 of them by 1948 (plus 4 suspended ships in reserve) instead of 24 completed by 1948 (plus 4 suspended ships in reserve);
- The 8 Daring class cost a total of £20 million to build and ITTL the money saved by not building them is used to complete more aircraft carriers.
In terms of resources:
- The aircraft carrier Vanguard had a displacement of 36,000 tons, boilers producing 152,000 shp and 4-shaft machinery. The battleship Vanguard had a displacement of 44,500 tons, boilers producing 130,000 ships and 4-shaft machinery. They also had similar anti-aircraft armaments. Therefore substituting one Audacious class battleship for one Audacious class carrier is "resource neutral" and the financial cost would be about the same too;
- The 8 Audacious class ships could not be built instead of the 16 Colossus and Majestic class. In terms of displacement 2 Majestic was about 80% of one Audacious (28,000 tons v 36,000 tons), half the power output (80,000 shp v 152,000 ship) and there was no comparison in the gun armament (no guns larger than 40mm v sixteen 4.5"). This was why it was necessary to sacrifice the 8 Swiftsure class cruisers. Each of them had a displacement of 8,800 tons, machinery producing 72,500 ship driving 4 shafts and a gun armament of nine 6" and ten 4". In terms of resources 2 Colossus/Majestic light fleet carriers and one Swiftsure class cruiser equal one Audacious class ship.
- On the other hand the Centaur class was designed to be half an Audacious class fleet carrier. Their displacement has exactly half (18,000 tons v 36,000 tons), their boilers produced half the power (76,000 shp v 152,000 shp) which drove 2 shafts instead of 4 and as designed they carried half as many guns (eight 4.5" v sixteen 4.5"). The cost of a Centaur class ship was about half an Audacious too. Eagle cost £15,795,000 when completed in 1951 and Ark Royal cost £21,428,000 when completed in 1955. By comparison Albion, Bulwark and Centaur cost an average of £10 million each when completed 1953-54. But Hermes which was suspended between 1946 and 1952 cost £37½ million when completed in 1959, nearly double the £20 million it cost to rebuild Victorious 1950-58.
Names of the extra Audacious class aircraft carriers
- The ship built instead of the battleship Vanguard was named Vanguard also;
- The Audacious class ship laid down in 1944 was named Eagle and when she was cancelled in 1946 the sister ship laid down in 1942 took her name. ITTL the ship laid down in 1944 was named Invincible from the start;
- The 8 ships built instead of the Colossus and Majestic class were named Benbow, Cochrane, Collingwood, Dreadnought, Marlborough, Montagu, Russell and St Vincent. They were laid down, launched and completed in that order;
- The 2 ships built instead of the Centaur class were named Inflexible and Irresistible.
The Situation In August 1945:
IOTL6 Colossus class ships had been commissioned before the war ended:
- Colossus, Glory, Venerable and Vengeance were in Australia where they formed the 11th Aircraft Carrier Squadron preparing to join the British Pacific Fleet and depending upon the source each ship had an air group of 39 aircraft (21 Corsairs and 18 Barracudas) or 36 aircraft (24 Corsairs or 12 Barracudas);
- The aircraft maintenance ship Pioneer was also in Australia;
- Ocean was working up in the UK.
ITTL 4 Audacious class ships had been commissioned before the war ended:
- The aircraft carrier Vanguard was completed in November 1944, but instead of being sent to join the British Pacific Fleet she replaced 3 or 4 escort carriers in the East Indies Fleet. Had the war continued she would have taken part in Operation Zipper the projected invasion of Malaya and Operation Mailfist the projected follow-up attack on Singapore;
- Benbow and Cochrane were in Australia where they formed the 11th Aircraft Carrier Squadron. Each ship had 72 or 78 aircraft aboard depending on the source;
- Collingwood (the ship built instead of Glory and Ocean) would have commissioned on 8th August 1945 the same day as Ocean IOTL. However, ITTL she was to be transferred into the RCN in place of Magnificent and Warrior, but IOTL the commissioning of Warrior was delayed until January 1946 because it took the Canadians longer than planned to find the personnel and the end of the war.
There was no aircraft maintenance ship in Australia because Dreadnought, the ship built in place of Perseus and Warrior did not commission until January 1946. ITTL Eagle just missed the war because she commissioned in October 1945 instead of 1951. The next ships to commission were Marlborough in May 1946 (instead of Theseus and Triumph) and Ark Royal which ITTL was completed in May 1946 instead of 1955.
To be continued...