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).
Bump test of a 40/50 chassis fitted with front wheel brake parts and springs.
| Identifier | Morton\M20.2\ img007 | |
| Date | 1st April 1924 | |
| R.R. 493A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} EXPERIMENTAL REPORT. ORIGINAL Expl. No. REF: Hs.{Lord Ernest Hives - Chair}/102.4.24. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. HC. c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c. to HY.{Tom Haldenby - Plant Engineer} WOR{Arthur Wormald - General Works Manager} SECRET X1331 X9940 BUMP TEST - 40/50 FRONT BRAKES. Attached herewith is a report on the bumping of the front of a 40/50 chassis fitted with front wheel brake parts and 43" springs anchored at the rear end. We have completed 125 hours running. The sheet metal brackets at the rear end of the front springs have stood up remarkably well. There is however, a slight crack started on one of them now. The average life of the front springs is higher on this test than on previous tests - Previous test 12 hrs. average. Above test 18 hrs. The failures of the front springs have all occurred on the top leaf. 75% of them are approx. 2" from the centre bolt. This is the point where the sheath ends. We recommend that we try and modify the design so that there cannot be any concentration of stress at this point. Failures of the springs occur equally to the front and rear of the centre bolt. We have not been able to repeat the failure of the frame in the same place as the first one, which went very early on. We have had another frame failure but it occurred through the bolt holes which fix the radiator bracket. This is a place where we have had failures before on the std. 40/50 H.P. Hs.{Lord Ernest Hives - Chair} | ||