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).
Comparative table of performance characteristics for various servo lining materials.
| Identifier | ExFiles\Box 105\4\ scan0148 | |
| Date | 26th October 1934 | |
| -4- Hs{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer}7/KW.26.10.34. | Type of Servo Lining. | Average µ when cold | Decrease in µ when hot per cent | Remarks. | |---|---|---|---| | Cast Iron | - | - | "Picks up" immediately. | | Mintex Rubber | 0.40 | 25 | Objectionable smell. | | Ferodo SS{S. Smith}042 | - | - | Plastic when warm. Judders and breaks up. | | Ferodo VM.30 | 0.45 | 22 | Long life. Silent. | | Ferodo Special B.Z. | 0.43 | 34 | Long life. Silent. | | Duron | 0.52 | 37 | Silent. | | Ferodo SS{S. Smith}060 | 0.44 | 30 | Silent. | Hs{Lord Ernest Hives - Chair}/F.J.Hardy. | ||