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).
Bump test results for Firths road springs, comparing 43' and 42' springs and discussing standardisation.
| Identifier | ExFiles\Box 171\3\ img233 | |
| Date | 9th April 1924 | |
| 9.4.24. FIRTHS ROAD SPRINGS. The bump test results show that the 43" springs made by Firths with the Woodhead type clips are running on the average 30% longer than the 42" springs, either Woodheads or Firths. There is no very wide variation in the life of different springs. The standardisation sheet is for Firths springs for the 40/50 HP. car. We have for some time now been fitting them as standard on 20 HP. cars. Hs.{Lord Ernest Hives - Chair} | ||