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 showing spring rating tests, one for shackle angle and the other for pad width.
| Identifier | ExFiles\Box 67a\1\ scan0215 | |
| Date | 27th May 1925 guessed | |
| GRAPH 2: SPRING RATING TESTS. (δ) AND (€). EFFECT OF SHACKLE ANGLE NARROW PADS. Y-AXIS: RATING LBS/IN X-AXIS: TOTAL SPRING LOAD. LBS. LEGEND: δ = 21° FORWARD SHACKLE. € = VERTICAL SHACKLE. GRAPH ANNOTATIONS: WORKING RANGE GRAPH 3: SPRING RATING TESTS (B) AND (€). EFFECT OF PAD WIDTH. VERTICAL SHACKLE. Y-AXIS: RATING LBS/IN X-AXIS: TOTAL SPRING LOAD. LBS. LEGEND: B · WIDE PAD. € · NARROW PAD. GRAPH ANNOTATIONS: WORKING RANGE, 1100 LBS. | ||