3. When did the Seafire's adopt the 89 US gallon P-40 tank? I know it was definitely in place by 1945 (and that might very well be the year it was adapted to the aircraft, for all I know).
When the British Pacific Fleet formed in Nov 1944, Indefatigable was the only carrier with Seafires as its main fighter type. The others three were using Corsairs and Hellcats. Due to its short range and good performance at lower levels Indefatigable's Seafire squadrons were initially used to provide CAP for the Fleet. At that time only the 30 & 45 gal slipper tanks seem to have been available to them. However in June 1945 it became apparent that both Indefatigable and the newly arrived Implacable, also with Seafires, would need to play a far greater offensive role in upcoming operations over Japan itself. Why? Because Seafires would form a much greater proportion of the fighters on the carriers (Indomitable with Hellcats was in refit so it was going to be 2 with Corsairs and 2 with Seafires). Both ships then began looking for a solution to increase the range of their Seafire III.
Indefatigable, being in Australia at the time, after operation Iceberg, talked to the RAAF, and obtained a supply of 90 gal slipper tanks from them.
Implacable was in Manus in the Admiralty Is at the beginning of June 1945. Her Seafire squadrons experimented with the 30, 45 and 90 gal slipper tanks but they experienced problems with the connections on them. After talking to the Americans, it was discovered that there was a supply of 89 or 90 imp gal drop tanks (sources vary on the exact size) at a base in New Guinea that looked, from the drawings they were able to obtain, like they might prove suitable. A deal was done (currency changed hands - 2 "crates" of Johnny Walker whisky according to Commander Mike Crosley, the 880 squadron CO on Implacable) and a destroyer despatched to collect them. 100 "rusty" P-40 drop tanks were put aboard the carrier on her return to Manus on 17 June from Operation Inmate to Truk. The Seafire bomb racks were then modified by the ship's engineering staff to allow these tanks to be carried. That work was complete by the time she sailed for Japanese waters with the rest of the Fleet on 28 June 1945. And very successful they proved in July/Aug operations off Japan. But there was never an official clearance for the use of these tanks.
That is not to say that they
45 90 gal slipper tanks did not prove equally successful in these operations. Implacable was, by all accounts, a very happy and efficient ship. It is just that her air group has attracted much more attention. She carried official photographers and a film crew so there is much more coverage of her July/Aug operations off japan than probably any of the other RN carriers. And of course Mike Crosley and others who were serving aboard her have written their autobiographies covering the period.
While I thought the lines making the Mk.VII & VIII were converted to the Mk.XIV/XVIII, what happened to the lines that produced the Mk.VII?
Supermarine was solely responsible for production of the Mk.VII, VIII, XIV and XVIII. A couple of points:-
1. There was a war on. While stating the obvious it affected production in Britain in ways that the US was not affected by, which necessitated a different approach to aircraft production in many cases. After its factory in Southampton was bombed in 1940 Supermarine used a system of dispersed production. There was then not a single Supermarine production line / factory. Sub-assemblies were built all over the south of England and then brought together at a number of airfield sites to create complete Spitfires to be test flown. You will find much information about the production of Spitfires by Supermarine here:-
The name “Supermarine” is inextricably linked to “The Spitfire”, the iconic aircraft that symbolised British defiance during World War II, but the name masks a more complex …
supermariners.wordpress.com
The shadow Castle Bromwich Aircraft Factory was an entirely different kettle of fish. It was set up for mass production, which took some time to achieve. But it only built a limited number of Marks. (Mk.II/V/IX/XVI/XXI)
2. There was not a clean movement from one mark to another at Supermarine as happened with most US types (e.g. P-51 to P-51A to P-51B/C to P-51D/K to P-51H). Supermarine produced various marks in parallel. So the various marks and their production periods were as follows:-
Mk.VII - 140 produced between August 1942 and May 1944. Final assembly for all was at Eastleigh
Mk.VIII - 1,654 produced Nov 1942 and Dec 1944. Final assembly was at a number of sites starting at Eastleigh and then expanding to places like Chattis Hill, Keevil etc
Mk.XIV - 957 produced Oct 1943 to Dec 1945. Final assembly started at Eastleigh then expanded to other sites like Chattis Hill, Keevil & Aldermaston
Mk.XVIII - 300 produced June 1945 to Jan 1946. Final assembly at Eastleigh, Keevil & Aldermaston
The XV's flight manual indicates 9-3/4 imperial gallons per wing not 19.5 per wing.
Where did I say 19.5gal in "
each" tank? What I said was "....
19.5gals in wing-root tanks...." Note the use of the plural. 2x9-3/4 = 19.5 total per my maths.