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).
Specification sheet detailing leaf spring dimensions and requesting design modifications and testing.
| Identifier | ExFiles\Box 110\3\ scan0038 | |
| Date | 13th January 1941 | |
| Rm{William Robotham - Chief Engineer}/GB.8/ET.13.1.41. - 3 - | Leaf No. | Thickness | Length of leaves when flat | Free radius | |---|---|---|---| | 1 | .254" | * 44" | 53.6" | | 2 | .231 | 41 | 41.6 | | 3 | " | 35.875 | " | | 4 | " | 30.79 | " | | 5 | " | 25.71 | " | | 6 | .208 | 20.63 | 34.1 | | 7 | " | 16.03 | " | | 8 | " | 11.43 | " | | 9 | " | 7.00 | " | * Eye centres. The leaves are tapered in thickness for 2.25" at the ends. The spring thickness is increased to 2.160" (leaves 2.010", and 5 liners at .020") from 1.625. Will Rm{William Robotham - Chief Engineer}/HH. please increase the shock absorber link length shown on PL.370 by .53". Will Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} please advise as to the necessity of a rebound stop. The estimated weight of the spring is 24 lb. It is hoped that it will be possible to obtain sample springs so that the suspension rate etc.. could be checked on the improvised spring test machine. Following this the fatigue life of the springs could be checked on some sort of cranking rig. Rm{William Robotham - Chief Engineer}/GB. | ||