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).
Tabulating the life and failure characteristics of vehicle leaf springs.
| Identifier | ExFiles\Box 106\1\ scan0024 | |
| Date | 22th May 1925 | |
| R.R. 493A (50H) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF:Hs{Lord Ernest Hives - Chair}/LS/LG22.5.25. SPRING FAILURES. Life of springs. hrs. mins. | Piece No. | Position on chassis. | Position of frac: to centre. | Position of leaf. | Thickness of leaf. | Brinnel test. 17 40 | F.53172 | N.S. rear. | 11" rear. | Top | .284" | 388 24 45 | F.53172 | O.S. rear | 21" forward. | Top | .283" | 363 17 35 | " | N.S. rear. | 20 1/8" forward. | Top | .285" | 401 8 10 | " | " | 20" forward. | Top | .285" | 415 27 5 | " | O.S. rear | 19 7/8" forward. | Top | .286" | 388 29 10 | " | " | 18 1/2" rear. | Top | .285" | 401 27 10 | " | N.S. rear. | 15 1/4" forward. | Top | .285" | 401 67 50 | F.51906 | O.S. front. | 7 1/2" rear. | Top | .237" | 401 Average life of 4 N.S. rear springs. 22 hrs. 20 mins. " " " 3 O.S. " Hs{Lord Ernest Hives - Chair}/L.Swindall. | ||