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 tests of Woodhead design road springs, comparing failure rates and deflections with cams at 0° versus the standard 180°.
| Identifier | ExFiles\Box 119\2\ scan0203 | |
| Date | 10th June 1924 | |
| X1331 To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. BJ. c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} Hs{Lord Ernest Hives - Chair}8/LG6.10.24. BUMP TESTS ON ROAD SPRINGS. X1331 We have carried out a test on the bumping rig by setting the cams 0º in relation to each other instead of being fixed at 180º, which is the standard position. Running under this condition, we have broken three Woodheads 12½% springs (Woodhead design). (a) Failed after 9 hrs. 43 mins. - top plate fracture, 2" rear of centre bolt. (b) Failed after 10 hrs. 50 mins. - top plate fracture, 15" rear of centre bolt. (c) Failed after 9 hrs. 28 mins. - 2" to the rear of centre bolt. With the cam set at 180º, similar springs averaged 21½ hrs. The shortest life was approx. 18 hrs. This shews that the springs are breaking in half the time when the cams are set 0º to each other. During this test we measured the max. deflections of the springs. From the normal, the max. compression was 1.55", the max. rebound was 3.100". With the cams set at 180º, the max. compression was 1.93", the max. rebound was 2.58". The buffer clearance during these tests was 2". Hs.{Lord Ernest Hives - Chair} | ||