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).
Test report for a 6-leaf spring, detailing failures, hardness, and run times.
| Identifier | ExFiles\Box 119\2\ scan0121 | |
| Date | 2nd August 1920 | |
| X1331 SPRING F.363 - 2212 lbs. parallel - tapered ends X.3981. no nibs and slots - ground all over. X.1331. Fitted on O.S. bump chassis 28.7.20. No of leaves 6. Brinell. Remarks. Time, run. 1 415 cracked 1 1/2" rear of clip. 20 hrs. 45 m 2 444 cracked 1 1/2" rear of clip. 3 415 broken under front clip. 4 415 cracked " " 5 415 " " " 22 hrs. 25 m 6 415 O.K. Spring taken off 2.8.20. | ||