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).
Comparison of weight and moment of inertia for two clutch types, a Double Plate and a Single Plate, trialled on the Spectre.
| Identifier | ExFiles\Box 93\3\ scan0059 | |
| Date | 22th August 1935 | |
| X 312 22.8.35. SpectreCodename for Phantom III Clutch. We have determined the following figures for the two types of clutch tried on the SpectreCodename for Phantom III :- Double Plate Clutch - G.81430. Weight - 74.38 lbs. Moment of inertia - 2200 lbs.in.sq. Single Plate Clutch - N.Sch.4229. Weight - 71.75 lbs. Moment of inertia - 2340 lbs.in.sq. HS{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} | ||