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).
Letter detailing test results of various brake linings and discussing solutions for squeaking issues.
| Identifier | ExFiles\Box 141\3\ scan0339 | |
| Date | 10th December 1934 | |
| -2- Hs{Lord Ernest Hives - Chair}/FJH.{Fred J. Hardy - Chief Dev. Engineer}4/KW.10.12.34. Halo 1119 (Ground). Very constant coefficient of friction. "Running in" required not unduly long. Unsuitable because of very violent squeaking. Mintex N.M.S. (Ground). Irregular coefficient of friction; 0.44 cold rising to 0.53 at 180°F.{Mr Friese} and falling to 0.39 at 330°F.{Mr Friese} Running in period short. Unsuitable because of violent squeaking and irregular u. Mintex ZS. (Wet Ground). Reasonably constant coefficient of friction. "Running in" period short. Unsuitable because of squeaking. As you can see from the above, squeaking is the principal trouble, and we were wondering whether a different material for our servo drum would eliminate or reduce this. At present our material is 3% Nickel Steel. Do you think that a cast-iron material, such as Millenite, would cause an improvement ? If your experience suggests that this would be so, we will try a drum in this material. If you have any further linings to offer, we should be glad to try them. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||