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 failure of side spare wheel carrier brackets for the Wraith III, with proposed design modifications.
| Identifier | ExFiles\Box 114\3\ scan0217 | |
| Date | 26th May 1937 | |
| SECRET. 1013 Rm.{William Robotham - Chief Engineer} Copy to Ds. By.{R.W. Bailey - Chief Engineer} RHC.{R. H. Coverley - Production Engineer} HPS.{Horace Percy Smith - Experimental Factory Mgr} Rm{William Robotham - Chief Engineer}/Les.{Ivan A. Leslie} E/Ev.{Ivan Evernden - coachwork}2/M.26.5.37. WRAITH III. SIDE SPARE WHEEL CARRIER. With respect to Rm{William Robotham - Chief Engineer}/Les.1/AP.3.4.37, and the failure of the side spare wheel brackets DW.128 at the end of 24 hours, we understand that these brackets were made in sheet steel .092" thick. We also understand that the gauge has now been increased to .104" in order to obtain an even gauge. We suggest that these thicker brackets be tested on the bump chassis when next it is being run. We feel that the top corner of the bracket near the upper fixing bolt is where the tear occurs due to sudden change in the relative rigidity and suggest that it may fail with the thicker bracket. We might modify the shape experimentally in accordance with either of the sketches below in order to ease off the change of rigidity, and suggest that this should be tried if the thicker gauge bracket is not a success. E/Ev.{Ivan Evernden - coachwork} CUT DOWN THUS. SCHEME 1 SCHEME 2. | ||