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 nine-leaf parallel spring, detailing Brinell hardness and damage after a time run.
| Identifier | ExFiles\Box 80\2\ scan0320 | |
| Date | 18th August 1920 | |
| E.F.C. X 3981 SPRING F.391 - 2324 lbs. - parallel leaves without tie clips, no nibs or slots - ground all over, consisting of nine leaves. X/331 Fitted to Dump Chassis 10.8.20. (O.S.) No. of leaves 9. | Brinell. | Remarks. | Time run. 1 | 444 | Small crack under rear clip. | 39 hrs. 50 mins. 2 | 461 | cracked front of front clip. 3 | 444 | O.K. 4 | 461 | cracked under rear clip. 5 | 461 | cracked front of front clip. 6 | 420 | " " " " " Broken 8" from rear end of leaf 7 | 444 | " " " " " 8 | 444 | cracked under rear clip. 9 | 444 | O.K. Taken off 18.8.20. R.{Sir Henry Royce} R.{Sir Henry Royce} 235A (100 T) S. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 643. 19-2-20 G 2618 | ||