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).
Steering failures on Wraith and Bentley series chassis, proposing solutions and future design improvements.
| Identifier | ExFiles\Box 153\1\ scan0259 | |
| Date | 14th April 1939 | |
| 1300 To BY.{R.W. Bailey - Chief Engineer} & Rm.{William Robotham - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} Hs.{Lord Ernest Hives - Chair} C. & LA.{L. A. Archer} From RHC.{R. H. Coverley - Production Engineer} RHC.{R. H. Coverley - Production Engineer}1/FH.14.4.39. WRAITH AND BENTLEY STEERING. With reference to the Steering failures we should be pleased if you would issue definite instructions as to what action is to be taken regarding such failures and whether it is intended that all Steering Followers on Wraith A.{Mr Adams} and B. Series and Bentley M.{Mr Moon / Mr Moore} Series, making a total of 500 Chassis, are to be changed. This would appear to be the correct course since Steering failures have been produced on both types of Chassis when subjected to test. The estimated Factory Cost of fitting new Followers will be £3. 5. 6d. per Chassis at W. giving the following totals :- Wraith A.{Mr Adams} and B. Series - 300 Chassis ... £982. 10. 0d. Bentley M.{Mr Moon / Mr Moore} Series. - 200 Chassis ... £655. 0. 0d. Total ... £1637. 10. 0d. Since examination of the failures in service indicates faulty Heat-treatment of Material, a decision is also required as to what action is to be taken with Suppliers of Steering Followers, whether they are to be called upon to make some contribution to the Cost of Changeovers, and if so, to what extent Before a decision is made in this direction it would be well to bear in mind that the Material specified needs very expert handling during Heat-treatment if a reliable standard is to be maintained. This is proved by the fact that some 100 pieces were produced in these Works up to the Hardening stage which, when examined after Heat-treatment, were found to be faulty. The fact of difficulty being encountered even when treatment is under Works control indicates the grave risk involved when manufacture is undertaken by outside Suppliers. It is therefore recommended that investigation should be pursued with the object of introducing an alternative Material, and at the same time Steering design for future Chassis reviewed as it is apparent that the factor of safety is much too low and that subsequent designs should embody more robust Rollers capable of withstanding the heavy impact loads liable to be imposed in service. RHC.{R. H. Coverley - Production Engineer} | ||