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 the average life before breakage for front springs made from different types of steel.
| Identifier | ExFiles\Box 119\2\ scan0016 | |
| Date | 26th May 1914 guessed | |
| Wor{Arthur Wormald - General Works Manager}/Mcr5/L27514. FRONT SPRINGS. Sheet. 3 Average life before breakage. P.4145. Front Spring. 12 hrs 18 mins. Average over 3 " " Vickers steel 5 " 4 " " 4 " Front Spring Woodhead's steel 8 " 34 " c" 14 | ||