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).
Material choices for Bentley main bearings, specifically A.C.7 versus White Metal.
| Identifier | ExFiles\Box 115\3\ scan0101 | |
| Date | 16th November 1937 | |
| Hs.{Lord Ernest Hives - Chair} from Rm.{William Robotham - Chief Engineer} c. Ey. c. RMC. 1020 Rm{William Robotham - Chief Engineer}2/R.16.11.37. BENTLEY MAIN BEARINGS. We agree with you that there is no alternative but to revert to A.C.7 material until we can get the present job straightened out. We have an additional recommendation to make, however, which is outlined in the attached report. We have either got to take a chance and use the White Metal rear main bearing forthwith, or stick to the A.C.7 and put up with service trouble. It seems a strange thing to recommend mixing bearing materials, but we had already come to the conclusion that it was the right thing to do on P.III. The principle resolves itself into fitting Hall's metal bearings only where the bearing loadings preclude the use of white metal. Rm.{William Robotham - Chief Engineer} | ||