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).
Experimenting with various materials for iron brake drums on Phantom III and Bentley models.
| Identifier | ExFiles\Box 120\1\ scan0158 | |
| Date | 18th January 1937 | |
| To HPS.{Horace Percy Smith - Experimental Factory Mgr} from Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} 1028 Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale}19/AP.18.1.37. IRON BRAKE DRUMS - PHANTOM III. AND BENTLEY. We have been told to experiment with various materials for brake drums, and we have ordered the material necessary for the drums to be made. The first new material is 0.5% carbon steel. When the rough forgings arrive they should be heat treated to give a Brinnell of 350 and machined to drawings G.84797/8. The second new material is "Chromidium" Iron, this being only 75% the price of "Millenite". These castings should be machined to drawings G.85154/5. The third new material for Ph.III. drums is "Lepaz" iron. We do not yet know in what form the castings will arrive and so cannot quote drawing numbers. We want to run a set of ordinary Bentley drums only in a cheaper iron on the car to go for its 10,000 miles test after 3.B.1V., which may be quite soon. We have ordered "Chromidium" castings; we want a set machining to drawings G.100981 and GB.1988. Material enough for two complete sets (if there is no scrap) will arrive in each case, but we only want one set of each type completing. We want to use existing hubs and end plates where possible. The car these drums are to go on will be decided when they are nearing completion. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} | ||