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).
Page stating the weight of a twin system and a single system.
| Identifier | ExFiles\Box 123\1\ scan0012 | |
| Date | 27th December 1939 | |
| -3- Rm{William Robotham - Chief Engineer}/ym.2/JH.27.12.39. The weight of the twin system is 77 lbs. and the single system 60 lbs. Rm{William Robotham - Chief Engineer}/ym. | ||