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).
Bumper test report on a 10-leaf spring (F.5629), detailing Brinell hardness and failures after a timed run.
| Identifier | ExFiles\Box 119\2\ scan0133 | |
| Date | 16th October 1920 | |
| C X/331 X/331/ OCT 16 1920 RECEIVED BUMPER TEST. X.2628 % S.C.FC. F.5629 Spring consisting of 10 leaves, tapered ends, with nibs and slots and tie clips. Fitted to chassis 29.9.20. Table: | No. of leaves. | Brinell. | Remarks. | Time run. | |----------------|----------|---------------------------|-----------------| | 1 | 477 | O.K. | | | 2 | 415 | O.K. | | | 3 | 415 | O.K. | | | 4 | 363 | O.K. | 33 hrs. 55 mins.| | 5 | 415 | O.K. | | | 6 | 429 | O.K. | | | 7 | 444 | Broken under front clip. | | | 8 | 429 | " " " " " | | | 9 | 444 | Borken under rear clip. | | | 10 | 429 | " " " " " | | Taken off 7.10.20 | ||