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).
Rocker shaft failure after 25 hours, proposing a change in material to a higher carbon, heat-treated steel tube.
| Identifier | ExFiles\Box 43\3\ Scan087 | |
| Date | 2nd December 1926 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to HJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to BY.{R.W. Bailey - Chief Engineer} X4003 Hs{Lord Ernest Hives - Chair}1/LG2.12.26. RR. F.10 - ROCKER SHAFT. We have had a rocker shaft break on an engine after 25 hrs. running. On previous engines we have run approximately 200 hrs. without failure. We are sending a piece of the broken shaft to WW. It will be seen that there is a fatigue failure through one of the oil holes. The material used for this shaft is the standard drawn steel tube. EY. is instructing that in future these rocker shafts shall be made from drawn tube with a higher carbon content and heat treated. It might be thought advisable, that as the inlet rocker is to be modified, it is arranged so that the load on this shaft is reduced. Hs.{Lord Ernest Hives - Chair} | ||