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 results of road spring failure tests.
| Identifier | ExFiles\Box 106\1\ scan0048 | |
| Date | 3rd July 1925 | |
| R.R. 493A (50n) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. -5- Expl. No. REF: Hs{Lord Ernest Hives - Chair}/LS/LG3.7.25 ROAD SPRING FAILURES. | Life of spring, hrs,mins. | Piece No. | Position on chassis. | Diagram. | Position of fracture to centr: | Position of leaf. | Thickness of leaf. | Brinell test | |---|---|---|---|---|---|---|---| | 20 35 | F.53336 650 lbs. | N.S. front. | | 1½" rear. | Top | .250" | 401 | | 24 30 | F.53336 600 lbs. | O.S. front. | | 1¼" rear | Top | .252" | 415 | | 18 5 | F.53337 700 lbs. | N.S. front. | | 1¾" rear. | Top | .248" | 401 | | 35 38 | F.53337 700 lbs. | O.S. front. | | 1¾" rear. | Top | .246" | 401 | | 21 50 | F.53337 700 lbs. | N.S. front. | | 2" rear. | Top | .252" | 400 | | 7 58 | F.53336 650 lbs. | O.S. front. | | Centre bolt. | Top | .246" | 375 | | 25 28 | F.53336 650 lbs. | N.S. front. | | 2" rear | 4th. from bot-tom. | .202" | 401 | | 26 38 | F.53336 650 lbs. | N.S. front. | | 1¼" rear | Top | .249" | 388 | | 27 10 | F.53336 650 lbs. | O.S. front. | | 1¼" rear | Top | .246" | 401 | | 18 2 | F.53337 700 lbs. | N.S. front. | | 1¼" rear. | Top | .252" | 415 | With 600 lbs. spring, clips bang up against frame member about every 20 or 30 revs. With 650 lbs. spring there is clearance, but would come hard on buffer rubber. 700 lbs. (12½%) springs there is 1½" to 2" clearance. Average life of 5 N.S. springs = 21 hrs. 2 mins. " " " 4 O.S. " = 23 hrs. 49 mins. Hs{Lord Ernest Hives - Chair}/L. Swindall. | ||