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).
Two graphs illustrating spring rating tests, one for the effect of pad width and another comparing different spring systems.
| Identifier | WestWitteringFiles\O\2April1926-June1926\ Scan165 | |
| Date | 27th May 1926 guessed | |
| TOP GRAPH: (4) SPRING RATING TESTS. (δ) AND (α) EFFECT OF PAD WIDTH. 21° SHACKLE RATING LBS/IN. TOTAL LOAD. LBS. α = WIDE PAD. δ = NARROW PAD. WORKING RANGE 1100 LBS. Y-Axis Scale: 250, 300, 350, 400, 450, 500 X-Axis Scale: 0, 300, 600, 900, 1200, 1500, 1800 BOTTOM GRAPH: (6) SPRING RATING TESTS. (α) AND (ϵ) COMPARISON OF SPRING SYSTEMS. RATING LBS/IN. TOTAL SPRING LOAD. LBS. α = WIDE PAD. 21° SHACKLE. ϵ = NARROW PAD. VERTICAL SHACKLE. WORKING RANGE 1100 LBS. Y-Axis Scale: 250, 300, 350, 400, 450, 500 X-Axis Scale: 0, 300, 600, 900, 1200, 1500, 1800 | ||