The material change of plugs for the Wraith II gearbox.
| Identifier | ExFiles\Box 8\11\ 11-page053 | |
| Date | 14th January 1937 | |
| SECRET. 1049 628 BY. {R.W. Bailey - Chief Engineer} c. Ds. Rm. {William Robotham - Chief Engineer} HPS. {Horace Percy Smith - Experimental Factory Mgr} W/Lid. {A. J. Lidsey} E {Mr Elliott - Chief Engineer} /HDY. {William Hardy} 3/HP.14.1.37. Wraith II Gearbox. With reference to the two special plugs on this car GW.583 and 616, the filling plug and the drain and observation plugs respectively, it is intended that these should be used on all gearboxes in due course. The filling plug is shorter than the plug at present in use on the other cars but is otherwise the same. The drain plug which is also used for plugging the holes for observing the meshing of the gears, is of mild steel instead of brass, but is otherwise the same. In both cases it is turned from hexagon bar. The change was made to secure the reduced cost of steel as compared with brass. We also suggest that the filling plug for the damper governor unit should be made of steel instead of brass. E {Mr Elliott - Chief Engineer} /HDY. {William Hardy} | ||
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).