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 the results of tests on 'Safeguard' brake lining material.
| Identifier | ExFiles\Box 140\4\ scan0122 | |
| Date | 3rd January 1938 | |
| 1181 --- 2424 January 3rd.1938. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale}2/AP. The Gandy Belt Manufacturing Co.Ltd., Seacombe, WALLASEY, Cheshire. For the attention of Mr.Ikin Dear Sirs, Tests on 'Safeguard' Material. We have obtained the following information from tests:- (1) The servo linings on the Bentley we took to Birkenhead started to squeak on the return journey. The squeak became steadily worse so we removed them. These linings ran approximately 1,500 miles. (2) We fitted your 400 G.M. linings to another Bentley, and after about 100 miles they started to squeak. Moreover, the car dived to one side very badly, and the fierce brake wore out its lining at an excessive rate, .030" of lining being used as against .006" on the other brakes. We noticed that the linings swelled on first heating by an unusual amount, but this is not of any importance provided one is expecting it. (3) We have tested the 400 G.M.2 on a rig and the extra graphite is not sufficient to prevent squeaking. As regards (2) you remember that we said we were not going to fit 400 G.M. to a car. We received the impression, however, that you were disappointed and that you did not consider that we were testing your linings fairly, therefore we fitted it and you notice that our predictions were correct, the lining being bad for squeaks. We consider that your 400 M.{Mr Moon / Mr Moore} is not as good in the natural state for curing squeaks as Ferodo B.Z., therefore the task of freeing it from this characteristic is harder. We think that the maximum amount of graphite will be necessary. continued | ||