The 1960 RN aircraft carrier

[uk 75]

CVA01 was even disliked by its designer as a compromise too far. The RN wanted its own version of the US Forrestal class so borrowed the US initials.
The 1952 carrier looks as if it would have been too small for the F4 Phantom.
The RN ordered 2 assault ships with steam boilers for the 1960s.
Had the nettle been grasped around 1960 the RN could have designed an improved version of Eagle for delivery at the end of the decade.
This ship would have replaced Victorious and Ark Royal.
A second ship would follow her in the 70s to replace Eagle.
Hermes would stay in service in the ASW/Commando role but retaining her catapults to operate Buccaneers and Gannet COD/AEW.
This apprpach would have allowed F4s to enter service on Eagle and the new ship by 1970.

 

[EwenS]

The design of Eagle can be traced back to 1938 and the Implacable class but was redrawn in 1942. If you can't do something much much better on the same tonnage by 1960 other than updating the machinery there is something far wrong.

For example the underwater protection system of CVA-01 benefitted from USN experience and was far superior to that of the Audacious class.. It was estimated to be able to withstand 1500-1800lb of TNT while it was doubtful if Eagle's could have withstood a 1000lb charge.

The double hangar is great in a WW2 armoured hangar with a 4" flight deck as it helps minimise the armoured area and armour weight. But it leads to a tall ship with generally less flight deck area than an equivalent unarmoured open hangar deck carrier. Postwar flight deck space became more important. Look at all the extra add on areas in Ark Royal and Midway. And 4" of structural armour forming the hangar sides is a complete waste of tonnage in 1960. CVA-01 had 50% more flight deck space than Eagle.

Saving all that weight can then be used to build a better more voluminous hull better able to take the vastly increased amount of electronics and improve crew accomodation.

Eagle's flight deck was capable of taking a static load of 45000lbs. CVA-01 70000lb and a correspondingly higher load from aircraft landing on its decks. Aircraft at the time were growing in weight. It is hindsight to say we dont need to design to those parameters.

CVA-01 was going to have much longer catapults allowing Phantom launches without reheat. Less stress on ship and aircraft.

I could go on. But there are just too many major structural changes required in a then modern carrier design when compared to Eagle that you need to start with a clean sheet of paper anyway.

Whichever way you look at it CVA-01 as designed may not have been perfect but it was a huge step forward in its ability to operate the then modern generation of naval aircraft.

 

[zen]

1. CVA-01 is fine, compromises are not compromising. Most of it's systems were built.
a) Structure informed Invincible design.
b) Catapult elements incorporated into Ark Royal's modernisation.
c) Scissors lift on Invincible.
d) Broomstick by the Dutch.
e) Sea Dart.
f) Ikara.
g) ADAWS
Etc....
Major element not built was the boiler and machinery.

2. 1952 CV handles static loads of 60,000lb aircraft.
a) Catapults rated for similar results to later Ark Royal modernisation.
b) Recovery zone, rated for heavier aircraft.
c) Speed equal or higher than Audacious class.
d) Endurance greater.
e) Magazine depth deeper.
f) Aviation fuel greater.
F4K would be fine. Better than from Ark Royal.

3. Medium Fleet Carrier studies based on same characteristics for aircraft as 1952 effort.
Essentially F4K on lighter, cheaper to run ship.

4. There was a 50,000ton study presented to the Minister I think 1960 and he told the Admiralty to go away and think bigger. CVA-01 resulted.
Probably in full knowledge that this and other military projects were unsustainable as group. Deferring the inevitable to either someone else in the Cabinet or the Opposition.

5. Lower end study of the 1960 comparison for 42,000tons, 31 Buccaneer sized aircraft and later 18 OR.346 aircraftto succeed Buccaneer sized aircraft, Tartar type SAM system.

 

[uk 75]

Another example of a thread teasing out useful information. Thanks.

 

[NOMISYRRUC]

What @EwenS and @zen said. Plus an Improved Eagle is unlikely to have been significantly cheaper to build than a CVA.01. "Steel is cheap and air is free." The "expensive stuff" which is the steam catapults, arrester gear, lifts, electronics (radars, sonars and ADAWS), flagship facilities and fixed armament would be common to both ships.

I doubt that it would have been significantly cheaper to run than a CVA.01. The "Phantomised" Ark Royal had a crew of 2,640 and the reference books quote CVA.01's crew as between 2,700 and 3,200 which is probably determined by the size of the air group so I suspect that an Improved Eagle and a CVA.01 carrying the same air group as Ark Royal in the 1970s would have had crews of similar size.

 

[starviking]

CVA01 was even disliked by its designer as a compromise too far.

I think that extrapolates too far from Prof Rydel’s unguarded remark in 1966, that cancellation was the happiest day of his life. The project had a lot of new features - that bring risk to a build, but the project was also understaffed and under resourced. I think the latter two project features are likely to be the source of his relief.

 

[NOMISYRRUC]

CVA-01 was going to have much longer catapults allowing Phantom launches without reheat. Less stress on ship and aircraft.

To reinforce the above.

Ark Royal (after her 1967-70 refit) and Eagle (after her 1959-64 refit) had one BS.5 catapult in the bow with a stroke of 151 feet and one BS.5 catapult in the waist with a stroke of 199 feet.

CVA.01 was to have a pair of BS.6 catapults (one bow and one waist) both with a stroke of 250 feet. Its waist catapult was 25% longer than the waist catapult in Ark Royal and Eagle. Its bow catapult was 65% longer than the bow catapult in Ark Royal and Eagle.

Norman Friedman's British Carrier Aviation says the 199ft version of BS.5 could launch a 50,000lb aircraft at 105 knots. Friedman didn't say what the 151ft version of BS.5 could do. However, @Riain on Alternatehistory.com said it could launch a 50,000lb aircraft at 91 knots. Friedman also wrote that the BS.6 was designed to launch a 60,000lb aircraft at 150 knots. (Whether that specification would have been met is another matter.)

It it true that the bow BS.5 on Ark Royal needed more wind-over-deck to launch a Phantom than the longer waist catapult?