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).
Analysis of increasing shaft stiffness and its effect on the critical period.
| Identifier | ExFiles\Box 6\1\ 01-page142 | |
| Date | 11th July 1928 guessed | |
| -2- If the stiffness of the shaft were increase 40% without any increase in inertia, the period, which varies as the √ of the stiffness, would be raised 20%. Therefore we can state that the effect of stiffening the shaft by attacking the big ends is to raise the period by one half the amount that would be gained by incorporating the same increase in over-all stiffness in the journals.√ Thus attacking the pins, besides saving the main bearings, does push the critical period up appreciably. HS{Lord Ernest Hives - Chair}/Rs.{Sir Henry Royce's Secretary} | ||