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).
Comparison of initial camber and leaf thickness for satisfactory and unsatisfactory 1150 lbs. Firths springs.
| Identifier | ExFiles\Box 52\2\ Scan117 | |
| Date | 13th December 1924 | |
| To R. {Sir Henry Royce} from Hs. {Lord Ernest Hives - Chair} c. to CJ. BJ. c. to E. {Mr Elliott - Chief Engineer} DA. {Bernard Day - Chassis Design} c. to RG. {Mr Rowledge} BY. {R.W. Bailey - Chief Engineer} c. to Wor. {Arthur Wormald - General Works Manager} X4429 Hs {Lord Ernest Hives - Chair} 3/LG13.12.24. FIRTHS SPRINGS. <94-10 Rogers We give below comparisons of one of the latest 1150 lbs. Firths springs (which have given excellent results) compared with one of the previous springs which gave only fair results. SATISFACTORY. Initial camber. | Thickness of leaf. Top leaf. | 1.350 | .293 2nd. leaf. | 1.850 | .258 3rd. leaf. | 1.750 | .250 4th. leaf. | 1.650 | .240 5th. leaf. | 1.800 | .237 6th. leaf. | 1.400 | .230 7th. leaf. | 1.125 | .225 8th. leaf. | .900 | .225 9th. leaf. | .670 | .212 10th. leaf.| .400 | .212 11th. leaf.| .200 | .200 UNSATISFACTORY. Initial camber. | Thickness of leaf. .625 | .310 2.00 | .250 1.950| .250 1.800| .250 1.550| .235 1.375| .230 1.125| .220 .900 | .220 .750 | .215 .425 | .210 .200 | .210 Hs. {Lord Ernest Hives - Chair} | ||