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 9-leaf parallel spring, detailing Brinell hardness and crack analysis after a timed run.
| Identifier | ExFiles\Box 80\2\ scan0321 | |
| Date | 19th August 1920 | |
| X.3981 R.K. X.3981 X.1331 SPRING F.391 - parallel leaves, without tie clips no nibs and slots, ground all over, consisting of 9 leaves. Fitted to N.S. Bump chassis 10.8.20. (2286 lbs.) No. of leaves 9. Brinell. Remarks. Time run. 1 444 Small cracked ## under front clip. 42 hrs. 30 mins. 2 415 Broken under rear clip and cracked under front clip 3 415 Cracked under front clip and rear of clip. 4 444 Cracked under front clip. 5 444 Cracked front of front clip. 6 416 O.K. 7 444 O.K. 8 444 Cracked under front clip. 9 444 O.K. Spring taken off 19.8.20. R.{Sir Henry Royce} R.{Sir Henry Royce} 235a. (100 T) (S. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 643. 13-2-20) G 2618 | ||