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).
Hand-drawn graph comparing frame stiffness and resonance against frequency and amplitude.
| Identifier | ExFiles\Box 170\2\ img282 | |
| Date | 3rd July 1935 | |
| Amplitude A: original frame B: first stiffening. much worse. C: further stiffening. Equal to original. D: improved frame. Frequency wheel hop frequency - 540 v/min Frame Stiffness & Resonance Olley July 3/35 | ||