Aeroplane Monthly 1991-12
??? - Spitfire Notebook (14)
No, not XXX depth-charges, but beer barrels attached to the bomb carriers of Spitfire IX MJ329, done mostly for propaganda purposes.
Spitfire IX AB505 fitted with a Merlin 77 and a Rotol six-bladed contra rotating propeller. Ballast had to be carried in the tail to counter the additional weight.
The Spitfire IXC MK210 fitted with Mustang underwing tanks at Wright Field, Ohio, prior to its non-stop Atlantic crossing from Newfoundland, via Iceland, in September 20, 1944.