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).
Report comparing prewar and postwar spring breakages, fractures, and manufacturing processes.
| Identifier | ExFiles\Box 42\3\ Scan148 | |
| Date | 1st November 1923 | |
| BY6-P6.11.23. contd. - 2 - thoroughly well controlled, and in addition worked closely to pyrometer readings. One other point which I discovered early on in the postwar program was that Messrs. Woodheads had always finished their springs by a cross grinding process, this applying to prewar springs as well as postwar. I at once insisted on having this abandoned, and whilst speaking in this connection it is interesting to note that quite a number of the springs which break shew no signs of cross grinding at all. In regard to the fractures themselves they almost invariably occur in the top plate approximately 6" from the front eye, the fracture generally shewing signs of starting from the top corner at the side of the plate and working diagonally across. In regard to the fact that more postwar springs break than prewar, I think this can be accounted for by the fact that owing to the prewar having slightly less maximum deflection and not having the extra flexibility allowances of 50 lbs, deducted from the type of spring the poundage actually demanded, the stress on the postwar spring is approximately 10% higher than the prewar, an increase of stress which could reasonably account for the difference in the number of breakages. contd. | ||