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 causing frame fractures and front spring failures.
| Identifier | WestWitteringFiles\L\Jan1924-March1924\ Scan161 | |
| Date | 12th July 1923 | |
| R.R. 493A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} EXPERIMENTAL REPORT. ORIGINAL EAC BUMP TEST - FRAME FRACTURES Expl. No. X1331 X2628 REF: H62/AMO/B.24 BUMPING TEST ON FRONT SPRINGS AND REAR ANCHORAGE. N.SCH.1706. EAC To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. Rg.{Mr Rowledge} c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} Wor.{Arthur Wormald - General Works Manager} We have been running a chassis on the bump test with the proposed standard fixed anchorage at the rear end of the front springs. We have broken two front springs; both failed after approximately 14 hours running. One fracture occurred 2" to the rear of the centre bolt and the other one 2" to the front of the centre bolt. This is an average life for front springs. After 24 hours running the N.S. frame member cracked in the position shewn on the attached sketch. On our previous test when we anchored the rear end of the front springs, the frame broke in a similar position. It is only when we have fixed the rear end of the front spring that we have failures of this portion of the frame. It would appear necessary for us to strengthen the frame at this point. When the car is on the road it will get braking stresses which we do not get on the bump test. We are replacing the side member and continuing the tests. We are sending the section of the frame showing the crack to W.W. Hs.{Lord Ernest Hives - Chair} | ||