From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Examination of gun installations on various British aircraft.
| Identifier | ExFiles\Box 175\3\ img112 | |
| Date | 18th January 1940 | |
| -2- Ve/NP.2/CB.18.1.40. Installations examined were :- Spitfire. The space available in the wing is governed by the rectangle formed by the leading edge, two adjacent ribs and the spar. The ammunition is carried in the next similar compartment, the belt passing through an opening in the intervening rib. Ejection of cartridges and cases takes place downwards through openings in the wing. A swinging arm at the back end of the gun provides adjustment in two directions. This appeared to be the easiest installation with which to deal. Hawker Hurricane. In this plane, each wing carries four guns, side by side in a single compartment and in staggered formation to allow two guns to take left hand feed and two guns to take right hand feed. The available space is governed by diagonal ribs and width available is more restricted than in the case of the Spitfire. The four guns are at six inch centres. Westland Whirlwind. The installation examined, comprised four 20 mm. cannon mounted in the nose, but was very tight for room. It should be possible to install in this machine five or six 15 mm. guns or one R.R. 40 mm. gun. Vickers Wellington & Armstrong Whitworth Whitley, with Nash & Thompson two and four gun turrets fore and aft. These are difficult propositions due to the fact that the guns have to elevate and depress through 60°; the belt feed has to accommodate this angular movement in a very restricted space. Boulton & Paul Defiant. This was the only example examined of a turret mid-way down the fuselage. The four Browning guns are here mounted continued. | ||