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).
Log of failures recorded during a bumping test on the rear of a 40/50 chassis.
| Identifier | ExFiles\Box 119\2\ scan0160 | |
| Date | 15th December 1921 guessed | |
| 40/50 CHASSIS. BUMPING TEST ON REAR OF CHASSIS. Total hours run. | Remarks. --- | --- 30 | Bolt fixing stay for centre bracket for cantilever spring broken. 42 | Stay broken on centre bracket of rear spring. 53 | Rear spring second leaf broken O.{Mr Oldham} S. 87 | Flange on cross member at centre bearing broken. 89 | Rear spring 3rd. and 4th. leaves broken N. S. 100 | O.K. | ||