Somewhat based on earlier comments, I'm going with better aircraft but with some caveats:
Countries start building battleships 1st when they start rearmament because battleships take the longest to construct, fit out and commission (in theory)
No. Countries start building a new class of battleships in the 1930s because it was a battleship centric world and Admirals around the world were expecting to fight the next Jutland style action. It was 1942 before things began to change. 10 Dec 1941 was the first time that a major warship, battleship or aircraft carrier, had been sunk
at sea, by any aircraft. Interwar the role of the TB in the RN was to inflict enough damage on an enemy warship to slow it down for the big guns of the fleet to sink. The USN virtually gave up on the TB in the early 1930s only ressurecting it with the TBD Devastor (service entry late 1937). The intended target for its dive-bombers were an enemy's carriers not its battleships.
New construction battleships (by dates laid down):-
France - Dunkerque 12/32; Richelieu 10/35
Italy - Littorio & VV 10/34
Britain - 2xKGV 1/1/37 + 3 more 5-7/37
USA - North Carolina 10/37
Japan - Yamato 11/37
And no it doesn't necessarily follow that a battleship willl take significantly longer than a carrier to build. Both types took 3-4 years at peacetime build rates. Many of the ships ordered for the RN were delayed during construction for a variety of reasons. KGV contractual build time was 43 months (actual 48 months). Carriers of whatever navy took similar times to build (Ark Royal 39 months, Illustrious 36 months, USS Yorktown 40 months, Enterprise 46 months, IJN Hiryu 36 months). CV-8 Hornet was an exception at 25 months. The contractual build times for the Essex class when ordered was c36 months.
But even in 1945 the battleship was not dead in the eyes of the Admirals.
France's battleship programme ground to a halt in June 1940 with the escape of the Jean Bart from its builders yard. But postwar they completed her to a modified design.
Italy continued her battleship programme to April 1943 with completion of the Roma in June 1942 and work continuing on the fourth ship, Impero until April 1943 albeit at a slow rate..
Britain's planned Lion class were put on hold at the outbreak of WW2 but weren't cancelled until 1945. BUt design work on a new battleship went on into the postwar years.
The US suspended the Montana class in 1942 because it had higher priorities in the construction programmes. But it didn't cancel them until July 1943. The USN pursued construction of 2 more Iowas in 1945 and while suspending them at the end of the war began work on a redesign.
For the IJN work continued until July 1942 when it was decided to convert her to a carrier following the Midway disaster. Work on the fourth ship had ceased in March 1942 due to a shortage of materials to comlete her.
So just how do you intend to change the attitudes of every navy the world over to abandon the tried & tested battleship for the completely untested aircraft carrier?
And navies didn't start building battleships before carriers. They were being built simultaneously. Britain laid down 5 KGV in 1937 & 4 Illustrious class carriers.
But if we explain (sell) to treasury, that aircraft carrier take even longer than battleships to construct, fit out, commission and train air group, therefore we get them started 1st
See above re build times.
RN plans called for a new carrier's air group to assemble about 6 months prior to the completion of the carrier itself. The RN training programmes were designed to fit that schedule. So 18-24 months to train a pilot. Less tme than it takes to build the carrier they will operate from.
But then we begin to hit the problems of the conflict between the RN and the RAF. Provision of at least 50% of the pilots and all the maintenance personnel and the training thereof was an RAF matter. In the early 1930s the RN had to go out and prove to them that a carrier could operate effectively more aircraft than the RAF thought possible. Until then the RAF wouldn't buy any more even though the RN was paying for them.
Inskip reported in late 1937 with the recommendation that the FAA be transferred from the RAF to the RN, but it didn't become fully effective until May 1939. Meanwhile the RN had to set up an entire system of control from scratch and begin recruiting personnel to man those aircraft. The RAF agreed to supply a number of pilots in the interim, but then failed to deliver due to its own expansion. And it was decided during 1938 that training of FAA personnel (pilots & maintenance crews) should remain with the RAF.
The 2nd part - aircraft designers need a higher minimum landing requirement.
Yes. But with the RN banned from talking to the aviation companies and having lost virtually all of its aviation experts in the RNAS to the RAF on 1 April 1918, it lost touch with what was possible in aircraft terms. And as the relationship with the RAF deteriorated in the early 1930s the Air Ministry technical advisory committees met infrequently, and they limited the RN contribution to relatively junior officers.
RN needs to get rid (mothball) Hermes, Argus and Eagle and build 3 Ark Royals. This allows better aircraft - minimum landing speed may increase 10 knots because all the carrier in the fleet can turn 30kn (versus some <20), landing distances may be extended with longer decks.
Under the Treaties mothballing was not an option. They either had to be somehow reclassified (Argus & USS Langley for example) or scrapped within certain time limits of the completion of the new tonnage (6 months to strip & 18 to completely scrap IIRC).
Argus was in reserve from April 1930 until converted 1936-38 as a Queen Bee carrier, allowing her reclassification as an auxiliary and freeing up her Treaty tonnage to build Ark Royal.
Eagle & Hermes rotated on the China Station from 1930 to 1939, returning to Britain to refit (no Singapore Dockyard until 1938), so really only one in commission at a time. But they could be kept until new ships appear.
Lastly, you now have 3 carriers * 72 (design) + 3 * 48 (yes, I know Furious is short a couple) aircraft; opening ratios were 50% TSR/50% fighters So, now you are talking 200 fighters/dive bombers + spares (25%) + additional for base protection...more/less equal to the order for RAF's premier fighters, therefore you get the 'A team working the design. Same for the TSR aircraft.*
Therefore, '34 budget gets 3 Ark Royals. We'll put off some other refits to find the money/batch 1 will be 2 KGVs rather than 3 with 2nd BB batch replacing a CV with the 3rd KGV.
It's critical to start before the Abyssinian Crisis - after RN gets cold feet about fighter protection and goes with armoured carriers, the order for planes gets cut in 1/2 and you get the 'C' team working on design.
In 1934, the world is only just coming out of the Depression that started in 1929. Money was tight. That was one cause of the delay from 1931 to 1934 in including a new carrier in the Warship Programmes. Another was technical, while arrester gear trials were carried out in 1933. At that point RN planning was looking at a new carrier in the 1933 Programme (delayed to 1934 - Ark Royal not laid down until Sept 1935 in the end) for completion in 1936, one in 1936 for completion in 1939, one in 1939 for completion in 1942, one in 1942 for completion in 1945, one in 1945 for completion in 1948. That then changed in 1936.
In 1934 both Hermes & Eagle are only 10 years old (from completion as carriers). Money had been spent on them during that time to keep them relatively up to date. The Washington Treaty declared that the life of a carrier was 20 years. How do you persuade a Treasury to replace 2 more ships with new construction against the financial and political background.
As for the large repairs / reconstruction of capital ships from 1933-40, the RN viewed that work as essential to keep its battlefleet effective until such times as new construction came along. It was not a replacement for new construction. Back to the battleship centric world again.
The 1936 RN Programme included
2 KGV (laid down 1 Jan 1937 - the very very very earliest date possible under the Treaties) and 2 Illustrious class carriers. The 1937 Programme included
3 KGV and another 2 Illustrios class carriers. All 9 ships in both programmes were laid down in 1937.
I'll pull in the FAA order for the Griffon by 2 years ('36 start, not '38) dropping Peregrine and Exe to get early Griffon
I doubt that was possible.
Firstly Griffon history. From the RR Buzzard of 1925 through the R series racing engines to the Griffon I of 1933 that was only run on a test rig. But RR then had to concentrate on Merlin development. RR only returned to the "Griffon" in 1938/39 when it was completely redesigned incorporating much learned in Merlin development. That is why the true Griffon Mark nos start with the Griffon II. And that was with an eye to future fighter aircraft, principally for the RAF.
Peregrine was the final development of the Kestrel series of engines using many components therefrom as well as lessons from early Merlin development. So just how much development time did it absorb? They only built 301 Peregrine engines between 1938 & 1942.
The Exe was a new engine design and doesn't seem to have been a bad engine, other than its oil consumption. Being an air cooled X inline layout it held certain advantages especially for a carrier aircraft. Its cancellation forced a major redesign of the Barracuda to take the Merlin and its cooling radiators which formed a major part of its weight growth problem. Whether it could have been developed from its 1,150hp to keep up with the weight growth in the Barracuda for other than engine reasons is another matter.
As the carriers are bigger/faster, the pilot can be seated lower (we might need to put FAA pilots in Spitfire/Buffalo to show <beat them over head> him what he would get for visibility in single seater)
Not a good idea. With long nosed fighters visibility in and around the deck was a huge problem. Hence the adoption of the curved approach to landing a Seafire & Corsair. In the Firebrand they even fitted an extra ASI on the side of the fuselage, outside the cockpit, in the pilot's line of sight to allow him to concentrate on his curved approach. Look to the final generation of piston engined fighters to see how the pilot's seating postion was RAISED to improve his visibility e.g. Spiteful v Spitfire, Fury/Sea Fury v Tempest.
Resulting in the RN gets a Firefly prototype in mid '37, issues sorted and production in '39 (OK, it might be closer to a Griffon power Fulmar, but its still 300+ kn aircraft and we can work on clean up/more powerful Griffons - I'm thinking Typhoon -> Tempest path).
Much as I would like a single seater, until aircraft have VHF/UHF radios and ships have Radar/Fighter control, I can't see giving up the back seater.
*I'm nervous that the 'improved' TSR aircraft is Fairey Barracuda; but the 'early' models won't have armour/self sealing tanks and the other weight increases of the late WWII planes. And the Griffon Barracuda seems to be OK as torpedo/dive bomber.
The Griffon engined Barracuda V was a big disappointment. While power was increased from 1,640hp of the Merlin 32 in the Barracuda II/III to 1,890 or even 2,020 hp in the Barracuda V top speed only rose by 15-20mph and its warload capabilities hardly changed. The earliest Griffon engine, the IIB only produced 1,720hp. The Mark V grew even heavier and a weight reduction programme saw it lose the TAG in the rear cockpit. After 2 years of development 1943-45 it still wasn't considered fit for service with a number of problems still to be overcome (including a noisy cockpit). The major area of improvement was the ability of the Mark V to climb away from an aborted carrier landing even with its flaps & landing gear down, something the Mark II/III struggled to do.