Test results from a bumping rig comparing different types of rear springs based on hours run until fracture.
| Identifier | ExFiles\Box 80\2\ scan0189 | |
| Date | 19th February 1920 | |
| E. {Mr Elliott - Chief Engineer} W. 255A (100 T) (S.G. 642, 19-2-20) G 2618 TESTS ON BUMPING RIG - 2" CAMS. SET AT X.1331. 180° - DRUMS REVOLVING AT 105 R.P.M. | | No. | Hours run | Fracture. | |---|---|---|---| | Pre-war rear springs. | 1 | 61.75 | 3 leaves cracked through centre bolt. | | | 2 | 29.1 | Bottom leaf broken 6" from eye. | | | 3 | 36.75 | 2 leaves cracked through centre bolt. | | Average. | | 42.5 | | | Modified rear springd. | 1 | 17.25 | 3 leaves cracked under clip. | | | 2 & G | 17.25 | 1 leaf broken. | | | 3 | 14.1 | 4 leaves cracked under clip. | | | 4 | 8.5 | 2 leaves broken under clip. | | | 5 | 9.25 | 2 leaves broken under clip. | | Average. | | 13.2 | | | Present standard type rear spgs. | 1 | 2.75 | 2 leaves cracked under clip. | | | 2 | 21.75 | 3 leaves cracked under clip. | | | 3 | 30.2 | 2 leaves broken under clip. | | | 4 | 31.5 | 3 leaves cracked under clip. | | Average. | | 26.3 | | MADE AT CROXLEY | ||
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).