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).
Visit to Ferodos to discuss brake linings, specifically regarding high temperatures and squeaking.
| Identifier | ExFiles\Box 111\3\ scan0232 | |
| Date | 8th January 1941 | |
| To Rm.{William Robotham - Chief Engineer} from Rm{William Robotham - Chief Engineer}/MHR.{M. H. Rigby} 806 8.1.41. VISIT TO FERODOS We discussed brake linings with Mr. Longley, with special reference to high temperatures and squeak. It had been our impression that Martindale's theory was as yet unproven and, from Mr. Shilton's letter in November, we gathered that he was willing to fit up the squeal rig which had been dismantled on the installation of their new testing machinery. Mr. Longley's attitude, however, was that the theory had been proved to his satisfaction and that VG.91 was the only satisfactory material showing the required non-squeal characteristics, with increasing with rubbing speed. He also recommended this material for resistance to high temperatures. VG.91 was developed for use on Norton T.T. motor cycles where the drums were actually getting red hot, and it will, he said, stand up to temperatures of 700° and 800° F.{Mr Friese} Its is rather low, although Longley puts it higher than VG.90 at 0.36. We had some in 1938, but we do not know why it was discarded, apart from Martindale's temperature curves, some of which were rather erratic. In certain temperatures ranges on these curves, the lining was noisy. Another good non-squeal lining was S.7732, but this fades very badly after 600° F.{Mr Friese}, and Martindale's curves show a squeak characteristic at low temperatures. We have therefore ordered 16 linings in VG.91 material to fit two cars. One set can be fitted to 3.B.50, which requires relining, and an impression can be formed of this lining. Rm{William Robotham - Chief Engineer}/MHR.{M. H. Rigby} | ||