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).
Load specifications for the Wraith steering rollers.
| Identifier | ExFiles\Box 153\4\ scan0004 | |
| Date | 28th July 1939 | |
| 1300 & 650 To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}9/MH.{M. Huckerby}28.7.39. WRAITH STEERING ROLLER LOADS. The loads normal to the surface of the U groove as required by Mr. Smith of Hoffmann's are as follows:- (a) Maximum load in normal service 4,400 lbs. (b) Load at which faulty balls failed (2 times normal max.) 8,800 lbs. (c) Load at which correctly heat treated roller normally fails, but which balls have withstood satisfactorily. (3½-4 times normal max) 15,000- 17,500 lbs. Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} | ||