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).
Requirement for cranks to have a specific type of balance weights.
| Identifier | ExFiles\Box 123\5\ scan0308 | |
| Date | 20th February 1939 | |
| -2- Rm{William Robotham - Chief Engineer}/Cwdl.5/JH.20.2.39. type of damper. The cranks should have the R.R. type of balance weights. Rm{William Robotham - Chief Engineer}/Cwdl. | ||