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).
Modifications required for fitting a 40 m/m gun in a Beaufighter aircraft.
| Identifier | ExFiles\Box 176\1\ img143 | |
| Date | 28th February 1941 | |
| To [redacted]. from EV{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} c. to Rn.{Mr Robinson} c. [redacted] Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames}1/SW.28.2.41. 40 m/m Gun in Beaufighter. In fitting the 40 m/m vertical feed automatic guns in the beaufighter, the following modifications will be necessary to the plane. (1) The front fuselage will require modifying by removing the four blast tubes for the Hispano 20 m/m guns (two each side) and replacing them by two blast tubes (one each side) to suit the 40 m/m gun. This also modifies the front bulk head. (2) The four support plates and spherical mountings attaching the Hispano guns to the main spars (two each side), will be replaced by two support plates and spherical mountings (one each side), to take the recoil load of the 40 m/m gun. We have completed the design of the front gun mounting, and find that three castings will be required, two for the spherical housing and one bridge piece to stiffen the front end of the cradle of the gun. (3) The cross tubes and rear gun mountings for the Hispano guns, will require removing, and the gun mounting of the stirrup type will be added to suit the 40 m/m gun, providing both vertical and horizontal adjustment to permit of gun alignment. (4) Shutes will have to be provided to prevent the empty shell cases from damaging the interior of the plane. (5) The position of the pneumatic feed pipes to fire the gun, will require altering to suit the 40 m/m gun. (6) Provision for shell racks in the interior of the plane, will also be required. EV{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} | ||