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).
The failure of three split rear springs during testing on a bumping rig.
| Identifier | ExFiles\Box 80\2\ scan0072 | |
| Date | 16th February 1920 | |
| R.R 235 A (100 T) (S.F. 846. 6 8-19) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2460. X 2628 b To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to Bn.{W.O. Bentley / Mr Barrington} c. to E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to EP.{G. Eric Platford - Chief Quality Engineer} Hs{Lord Ernest Hives - Chair}2/LG16.2.20. X.1295. SPLIT REAR SPRINGS ON BUMPING RIG. X.3461. X.1331. X.2628. We have had two more split springs commence to break on the bumping rig, making a total of three. One of them is a new spring which was put on to replace the first spring which broke. The failures have occurred - 1. N.S. Rear. One portion of split leaf broke off after 8 1/4 hours running - 20 minutes of this with-out clips. 2. N.S. Rear. Crack .75" long after 7 hours running. 3. O.S. Rear. Crack 1" long after 15 1/4 hours running - 20 minutes of this without clips. Except for 20 minutes run, the chassis had shock absorbers fitted the whole time. We are sending a portion of the bottom leaf to Mr. Royce, which shows where the frac-tures start. We think there is no doubt that apart from any-thing to do with the riding of the car we shall have to make some modification to split springs to make them reliable. The cantilever springs we used before the war which were not split, the two bottom plates ran back past the rollers. In the case of those springs it would not have been serious if the bottom leaf had broken because the second leaf would have taken the load but with the present springs, if it Contd. | ||