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).
Comparing vehicle acceleration times and braking distances.
| Identifier | ExFiles\Box 69\4\ scan0310 | |
| Date | 14th December 1925 | |
| R.R. 498A (50 H) (D.D. 31, 12-6-25) J.H.D. EXPERIMENTAL REPORT. -5- Expl. No. REF Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}/L.C14.12.25 Expressing the time to accelerate in m.p.h. and seconds, instead of as in Graph 1. - we have :- | Increase in speed. | Time taken secs. | |---|---|---| | | 117-MC. | Standard. | | 10 - 20 | -- | 4.9 | | 20 - 30 | 5.0 | 5.3 | | 30 - 40 | 5.4 | 6.4 | | 40 - 50 | 6.1 | 7.7 | | 50 - 60 | 7.4 | 11.1 | And comparing the distances to rest instead of the retardation produced by the brakes :- | Road speed m.p.h. | Distance to rest. ft. | |---|---|---| | | 117-MC. | Standard. | | 60 | 150 | 270 | | 50 | 94 | 170 | | 40 | 70 | 108 | | 30 | 40 | 60 | Hs{Lord Ernest Hives - Chair}/W.A.Robotham. | ||