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).
Test results for 20 HP front and rear main leaf springs, including load, camber, and stress data.
| Identifier | ExFiles\Box 106\1\ scan0248 | |
| Date | 13th May 1931 guessed | |
| FILES. Sent to R.{Sir Henry Royce} and Ds. only. F.56511. 20 HP. FRONT SPRING MAIN LEAF TEST. Free Camber of Main Leaf without plates = 3.000" " " " with " = 2.712" } Set .112 " " " with " = 2.600" } After Test " " " without " = 2.875" } Free Camber of Complete Spring = 4.525" With Plates Load lb Camber ins 0 2.712 42 2.0 87 1.0 137 0 190 -1.0 210 -1.375 244 -2.0 Spring Length Flat 38" Stress approaching 145,000 lbs/sq.in. F.57192. 20 HP. REAR SPRING MAIN LEAF TEST. Free Camber of Complete Spring = 6.1" } " " Main Leaf " = 4.525" } Set .350" " " " after plate test= 4.175" } Main Leaf Rating Without Plates With Plates Load lb Camber ins Load lb Camber ins 53 +2.0 87 +1.0 83 +1.0 123 0 109 0 161 -1.0 143 -1.050 205 -2.0 173 -2.0 Spring Length Flat 56" Stress approaching 100,000 lbs/sq.in. Plates referred to are spring clip plates. Tested with shackle at corect angle in each case. | ||