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).
Installation of a .500 bore Type A.A. gun in a Spitfire wing.
| Identifier | ExFiles\Box 176\1\ img156 | |
| Date | 31th March 1941 | |
| To Rm.{William Robotham - Chief Engineer} from Ev.{Ivan Evernden - coachwork} c. to Ve. c. to HPS.{Horace Percy Smith - Experimental Factory Mgr} c. to Rm{William Robotham - Chief Engineer}/HH. SECRET. Ev.{Ivan Evernden - coachwork}6/JH.31.3.41. .500 bore Type A.A. Gun in Spitfire Wing. On CPL.182 (original attached to Rm{William Robotham - Chief Engineer}/HH's copy of this memo.) we shew the fore and aft mountings for the .500 bore, type A.A. gun in the Spitfire Wing. The intention is to fit one gun only per wing in the bay closest to the fuselage. The drawing shews the mounting in the port wing, but identical pieces can be used for the star'd wing with the exception of the plate gussets rivetted to the rib structures to carry the rear stirrup. These should be detailed for both hands. Both mountings follow closely the schemes used by Supermarine for mounting the .500 Browning Gun. We have made no structural alteration to the ribs or spars of the wing which for some while has been at the Clan Exptl. and is now at Sinfin. We are not sure of the materials used by Supermarine for the for'd and aft stirrups of the .500 Browning suspension but on the .303 gun they appear to be made as steel forgings. For the purpose of this test we suggest that our pieces should be Alum bronze castings, and finally for production Dural Forgings. Designs are in hand for the ammunition box and the chutes for the clips and spent cases. For the rig test at Sinfin we presume that the modifications to the wing skin and doors will be made by merely cutting away to suit. For the flight test these modifications we presume will be made by Hucknall. Ev.{Ivan Evernden - coachwork} Original to Rm{William Robotham - Chief Engineer}/HH. Prints to Ve. Rm{William Robotham - Chief Engineer}/HH. Ev.{Ivan Evernden - coachwork} Ashby | ||