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).
Technical memo discussing brake system options, drum temperatures, and recommendations for the Wraith model.
| Identifier | ExFiles\Box 85\1\ scan0054 | |
| Date | 27th March 1936 | |
| -2- Hs{Lord Ernest Hives - Chair}/AFM.{Anthony F. Martindale}10/JH.27.3.36 Brake rods when the pedal is within .100" of the end of its travel allowing that the servo has opened to an amount corresponding to 1" of pedal movement. or (2) the use of a "limited equalization" system. We prefer the latter. The use of either of these systems but especially the second, gives us a much greater safety factor than we have on existing cars in the event of brake failure, which our testers have experienced twice recently. We do not think there is anything revolutionary in these suggestions. (b) We have found out that the maximum brake drum temperature/on the road of a 4¼ litre Bentley is /reached 350°C. with standard drums. 150°C. with aluminium drums. We have determined that our aluminium drums will stand 350°C. without failure or distortion. Any heating system that would raise an aluminium drum to 350°C. (such as driving with hand brakes on) would raise a standard drum to 800°C. so that we are satisfied that we have adequate strength in these drums. We recommend using 'Millenite' liners for a start. We would like to see Wraith designed with aluminium drums and one set of shoes in the rear drums only. We hope the above will clear up any doubts that may remain as to the wisdom of doing so. Hs{Lord Ernest Hives - Chair}/AFM.{Anthony F. Martindale} | ||