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).
Letter to British Power Boat Co. Ltd. detailing the specifications for a new power-driven mounting for a 40mm gun.
| Identifier | ExFiles\Box 175\3\ img196 | |
| Date | 1st October 1940 | |
| c. to Rm.{William Robotham - Chief Engineer} e.{Mr Elliott - Chief Engineer} to Rm{William Robotham - Chief Engineer}/GTS. Ev.{Ivan Evernden - coachwork}3/JH. 1st. October, 1940. SECRET. British Power Boat Co.Ltd., Hythe, Southampton. For the attention of G.S.Selman Esq. Dear Sirs, re Power Mounting of Type BD.{Mr Berend} Gun. We believe you are aware that we are developing experimentally a power driven mounting for the 40 m.m. Gun. The gun will be automatic and will be fired by a gunner on a seat rotating with the gun. We have been asked to state angles of rotation and elevation for which a firing cut-out should be provided, as the firing cut-out is in the process of being designed. The height of the trunnion above the deck is 5.000 ins. The gun will go in the same position on the boat as the present type BD{Mr Berend} gun, and will have the same bolt circle. The maximum angle of depression is 12° and the maximum angle of elevation is 70°. From the above particulars we believe it will be possible for you to give us an angle of rotation in plan in which the elevation must be restricted to above a certain angle. It will be possible to interchange this power mounting with a pedestal mounting with the minimum of difficulty for test purposes when the occasion arises. Yours faithfully, H.I.F.Evernden, | ||