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).
Laboratory report comparing a failed and an unbroken Bentley III front shock damper.
| Identifier | ExFiles\Box 99\3\ scan0096 | |
| Date | 31th August 1938 | |
| M.1,667. Laboratory. To Rm{William Robotham - Chief Engineer} from Hl/EJW.✓ c. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} Hl/EJW. 1/JM.{Mr Morley} 31.8.38. Bentley III Front Shock Damper. 4 1/2. Your ref. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} 4/JH. 18.8.38. We have compared this failed shock damper with an unbroken one, and have found the following differences. HARDNESS. Failed shock damper. Unbroken shock damper. 194 Brinell. 231 Brinell. Micro Structure. Photomicrograph M.1,667/1 shows the graphite in the failed damper to be coarser than in the unbroken one (photomicrograph M.1,667/3). The failed damper also had a much greater amount of ferrite than the unbroken one. (Compare photomicrographs M.1,667/2 and M.1,667/4). Fracture. The failed damper gave a coarsely crystalline fracture as compared with the unbroken casting, which gave a finer-grained fracture which we should consider satisfactory. (See photomacrograph M.1,667/5.) Hl/EJW [Signature] | ||