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).
Main leaf test results for the 20 HP front and rear springs.
| Identifier | ExFiles\Box 17\1\ Scan033 | |
| Date | 19th May 1931 guessed | |
| FILES. Sent to R.{Sir Henry Royce} and Da.{Bernard Day - Chassis Design} 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 0 108 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. | ||