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).
Specification memorandum for the Phantom III Over-drive Gearbox.
| Identifier | ExFiles\Box 94\2\ scan0183 | |
| Date | 3rd March 1937 | |
| 828 HPS.{Horace Percy Smith - Experimental Factory Mgr} from Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} P.III OVER-DRIVE GEARBOX. Owing to the fact that By.{R.W. Bailey - Chief Engineer} has not time to detail this, Hs.{Lord Ernest Hives - Chair} has agreed that it can be designed and detailed in this Department. Will you, therefore, please put it in hand to the following specification:- (1) 4.050 shaft centres and gear wheel particulars to Rm.{William Robotham - Chief Engineer}331. (2) Shaft Bearings to EX.25846A and EX.25331. (3) Strengthen side shaft to G.85124. (4) More metal on the boss of the side shaft front three gears. (5) Selector forks to suit new shaft centres. (6) Present mechanism which reverses the motion of the 1st and 2nd speed, deleted so that the gate is thus:- [Diagram of an H-pattern gear gate showing R, 2, and 1 positions] (7) Casting to suit new shaft centres and to allow full length of boss of constant mesh side shaft pinion which was shortened on EX.25846A. (8) 9° Top and third gear cones. (9) 8° Second gear cones. } All to be screw threaded. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} | ||