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).
The life of Dumb Irons during bumping tests.
| Identifier | ExFiles\Box 119\2\ scan0044 | |
| Date | 4th May 1914 | |
| Wor{Arthur Wormald - General Works Manager}/Merl8/L4514. May 4th. 1914. LIFE OF PARTS ON BUMPING TESTS. DUMB IRONS. Piece No. | Description. | Time Hrs. Mins. | Results. | Reference. F.1046 | Dumb Iron, near side. | 7 - 48 | Cracked. | Wor{Arthur Wormald - General Works Manager}/Hy{Tom Haldenby - Plant Engineer}19/L221013. " | " | 8 - 18 | Broke. | " | " | 6 - 11 | Broke behind first horizontal bolt. | Wor{Arthur Wormald - General Works Manager}/Hy{Tom Haldenby - Plant Engineer}19/L101113 " | " | 20 - 25 | Broke. | Wor{Arthur Wormald - General Works Manager}/Hy{Tom Haldenby - Plant Engineer}14/L17214 " | " | 4 - 6 | " | Wor{Arthur Wormald - General Works Manager}/Hy{Tom Haldenby - Plant Engineer}3/L26913. Average life before breakage. F.1046 Dumb Iron, near side 9 hrs 21 mins. Average over 5 | ||