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).
40/50 chassis bumping test, its setup, and a comparison of results to pre-war tests.
| Identifier | ExFiles\Box 38\1\ Scan046 | |
| Date | 18th August 1919 | |
| R.R. 535. 100 T/S/P. 274. 16-4-19. C. 2581 To R.{Sir Henry Royce} from EH. c. Co. c to Bn.{W.O. Bentley / Mr Barrington} c to E.{Mr Elliott - Chief Engineer} c to Da.{Bernard Day - Chassis Design} X.3465 EH2/LG18.8.19. RE 40/50 chassis bumping test X. 1331. The bumping rig is rigged up in the same way as we used it before the war. We are using a 3" cam on each drum - the cams are fitted 180° from each other. The drums revolve from 100 to 103 R.P.M. This was the standard arrangement for bumping tests before the war. The only modification we have made is that we now hold the stationary wheels of the car very firmly in shocks cemented to the floor; previously, we have had temporary chocks which always allowed the stationary wheels to move slightly. We attach herewith a list of a number of parts which we have broken on the chassis after just under 10 hours running. We have had more than the average number of failures compared with bumping tests before the war. We feel that the different method of holding the back of the car may be making the test more severe. We think that we might reproduce bad road conditions better if we had smaller cams and ran the drums faster, if we do this, however, it would make it impossible to compare with records of previous tests taken on the bumping rig. EH. | ||