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).
Issues with Bentley front brakes, including overheating, component failures, and necessary modifications.
| Identifier | ExFiles\Box 83\2\ scan0202 | |
| Date | 29th January 1938 | |
| 200a CHATEAUROUX. I/29.1.38. To. Rm.{William Robotham - Chief Engineer} from Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} c.c. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} (text struck through) GRX 6.B.IV. - BENTLEY. Front Brakes. Thank you for your memo Rm.{William Robotham - Chief Engineer}6/R.27.1.38 the contents of which have been noted. Regarding the aluminium brake drum which gave trouble, we attribute the failure to general overloading and over-heating of the drum as a result of too much front braking. We found that the near side brake rope was fouling the front expansion box, which had warped over during the running. We have re-set this. It may have been the reason we were getting more braking on the offside, but it is not very conclusive. The links to the anti-judder bob-weights are fitted with anti-rattle clevis pins. The Thackeray washers which are used to maintain a side load on the clevis pins are much too strong for the purpose, the friction in the joints being sufficient to overcome the brake pull-off the springs. We have substituted a weaker type of spring washer which does not go choc-a-bloc, for the Thackeray washers; this seems to have overcome the trouble. This requires design modification. The offside front linings were down to the rivets so we have been obliged to re-line the front brakes ourselves with B.Z.obtained from Paris. We noted a lot of superficial cracks on the friction surface of the offside cast iron brake drum, which we attribute to the heat and judders before we reduced the front leverage. We do not think they will have any adverse effect, but will examine the drum at intervals. ---------- Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} Ivan M.{Mr Moon / Mr Moore} Waller. | ||