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 results for 11 leaves detailing their Brinell hardness and condition after a timed run.
| Identifier | ExFiles\Box 119\2\ scan0137 | |
| Date | 26th November 1920 | |
| S.F.C. X1331 BUMPER TEST. File F.4631 - 11 leaves with tapered ends - nibs,slots and tie clips. Fitted to O.S. Bump. Chassis 29.10.20. 1000 lbs. No. of leaves. Brinell. Remarks. Time run. 1 388 O.K. 2 444 O.K. 3 415 Broken in centre. 4 401 " " " 5 388 " " " 6 415 " " " 7 415 O.K. 8 388 O.K. 9 415 O.K. 10 415 O.K. 11 415 Broken under rear clip. 28 hrs. 20 mins. Date removed 26.11.20. EFC DEC 16 RECEIVED R.{Sir Henry Royce} R.{Sir Henry Royce} 199 (250T) (SD676 19-7-17) MP 180865 | ||