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).
Appendix sheet showing a frequency calculation and comparison for different engine and frame combinations.
| Identifier | ExFiles\Box 100\3\ scan0091 | |
| Date | 30th October 1939 | |
| Appendix Sheet 5. Ev.{Ivan Evernden - coachwork}1/JH.30.10.39. h B.V. / n R = ( (.104 x 26.03 x 8) / (.064 x 40^E x 10) )^1/2 = .600 It will be seen therefore that the Ripplet frame with B.40 engine has approx. 17% higher frequency than that of B.V. and the shortened Rippletto 40% Ev.{Ivan Evernden - coachwork} | ||