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).
The design and installation of .500 guns and ammunition boxes in Spitfire wings.
| Identifier | ExFiles\Box 176\1\ img189 | |
| Date | 20th May 1941 | |
| To Rm.{William Robotham - Chief Engineer} from Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} c.c. [redacted] c.c. [redacted] c.c. [redacted] EV{Ivan Evernden - coachwork}/JD.{J. Draper - Frames}6/SW.20.5.41. .500 Guns in Spitfire. We attach to Rm{William Robotham - Chief Engineer}/HH's copy the originals of :- QPL.189 Ammunition Box and Feed Neck .500 Type A.A. Gun in Spitfire Wing. QPL.190 Ammunition Box Lid{A. J. Lidsey} for use with .500 Type A.A. Gun in Spitfire Wing. The above scheme QPL.189, shows an ammunition box fitted in the Spitfire Wing, the box is produced in three pieces riveted together by angle pieces, the feed neck which is fabricated, is to be made in Mild Steel. The box is a permanent fixture in the wing, and will take approx 300 rounds, this we believe is the same capacity as the .500 Browning ammunition box. Access to the ammunition box is by a hole in the top of the wing, the particulars of the lid{A. J. Lidsey} are shown on QPL.190, the lid{A. J. Lidsey} being held in position by DZUS fasteners. We believe the intention is to fit one of these boxes in the actual wing at Sinfin, unfortunately the wing in our possession is a 'port side' wing, whereas our designs are for a 'starboard' wing, this was done to tally with the R.R. type A.A. - .500 gun shown on QPL.182. Will Rm{William Robotham - Chief Engineer}/HH therefore kindly detail these schemes for both the Port and Starboard sides. We should mention that these ammunition boxes have been designed to suit the wing at Sinfin and may require minor modifications to suit the later type of Spitfire wings in production. The feed necks for the .303 guns were flexibly mounted, but as the .500 Browning have gone to a fixed feed neck, we have done likewise as we have no room for an adjustable feed, it is not necessary to have a feed neck on the gun as shown on QS.232. The chutes for the discharge of the empty cases and belt links, will be designed by Ve. Original to Rm{William Robotham - Chief Engineer}/HH. Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} [signature] Prints to Ev.{Ivan Evernden - coachwork} Ve. Rm{William Robotham - Chief Engineer}/HH. & Ashby. | ||