Investigation into criticisms of the Wraith III rear damper suspension.
| Identifier | ExFiles\Box 9\5\ 05-page075 | |
| Date | 26th May 1937 | |
| SECRET. 646 Rm. {William Robotham - Chief Engineer} Copy to E. {Mr Elliott - Chief Engineer} Da. {Bernard Day - Chassis Design} 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. LES. {Ivan A. Leslie} (Is this a victory or a defeat?) Rm {William Robotham - Chief Engineer} E {Mr Elliott - Chief Engineer} /Ev. {Ivan Evernden - coachwork} 3/M.26.5.37. Re: WRAITH III. REAR DAMPER SUSPENSION. --------------------------------- We have investigated the criticisms of the Wraith III. Rear Damper Suspension given in Rm {William Robotham - Chief Engineer} /Les.1/JH. 6.5.37. The attachment of the damper to the brackets is carried out by a method shown on R.R. Scheme 323 which is common to the rear dampers on all of our cars. It has the virtue that it is tightened up once and for all time on the bench. If we were to adopt the suggestion for the deletion of the shouldered ferrules, the bolt diameter would have to be .5" (not .437") if the damper casing were to remain standard. We then have to face the fact that to remove a damper by attaching the damper from its brackets would entail extracting the 3/8" diameter fitting bolt from the aluminium casing. We are afraid that the fit would be lost. It would appear, therefore, beneficial to retain the design as originally drawn on LeC.5133, and to remove the damper brackets from the frame when the damper has to be taken down. All of the fixing nuts appear to be reasonably accessable and not obscured by coachwork. They are, however, covered by pipes and by wiring. Since, however, we have to make a fresh layout of the pipes and wiring at this point, we will at the same time make provision for easier access to these damper bracket fixing bolts. Should it be desired to try the .5" diameter fitting bolts in the place of the ferrules to ascertain whether the wear due to extraction on the bore is a serious matter, a thickness of washer will be required under the nut to ensure that the thread does not go into the plate bracket. One ought to use a castle nut, but this is (Cont'd) | ||
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).