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).
Table detailing the failures of road springs, including their running time, fracture positions, and material properties.
| Identifier | WestWitteringFiles\M\2Jan1925-March1925\ Scan2 | |
| Date | 1st January 1925 guessed | |
| -3- ROAD SPRING FAILURES. Ref. No. | Piece No. | Time run. hrs.mins. | Position of spring. | Position of leaf. | Position of fracture. | Thick-ness. | Brinell. | Comp-ression. | Rebound --- | --- | --- | --- | --- | --- | --- | --- | --- | --- 038 | F.70880 | 18 17 | Near | Top. | 14" to front. | .305" | 401 | 1.8 | 2.3 | | 17 34 | | Next to bottom. | 4.5" to front. | .261" | 415 | --- | --- | | 15 9 | | Bottom | 2" to rear. | .263" | 401 | --- | --- 039 | F.70881 | 23 58 | Off | Top | 2.5" to front. | .307" | 375 | 1.6 | 2.1 | | | | 5th. from top. | 11" to rear. | .272" | 401 | --- | --- 040 | F.70880 | 16 5 | Near | Top | 16" to rear. | .308" | 401 | --- | --- 042 | F.70881 | 17 16 | Near | Top | Under rear 'D' clip. | .307" | 388 | --- | --- Average life of these springs - 18 hrs. 54 mins. He/R B. | ||