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 cracks and breaks after a runtime test.
| Identifier | ExFiles\Box 80\2\ scan0193 | |
| Date | 19th August 1920 | |
| HS{Lord Ernest Hives - Chair} X2628 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. 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. Time run: 42 hrs. 30 mins. 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. 19-2-20) G 2618 | ||