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).
Unreliability of Phantom III brakes and proposing a design revision.
| Identifier | ExFiles\Box 92\4\ scan0206 | |
| Date | 28th September 1936 | |
| Hs{Lord Ernest Hives - Chair}/AFM.{Anthony F. Martindale}4/KW.28.9.36. Phantom III Brakes. Our experiences of the past two years with Phantom III brakes lead us to think that a design revision of the system would be advisable. In spite of a standard heavy construction, the stigma of unreliability is still attached to it; in an emergency the front braking which is of paramount importance is often conspicuously absent. The design of the front brakes is at fault: they are so spongy that it is possible to pull the bell-crank levers on the front pivots practically to the limit of their travel with the naked hand, the brakes being fully adjusted. The rear brakes were originally also exceedingly spongy and a cure has been effected by the addition of 14 lbs. unsprung weight. This is a particularly unfortunate addition to have had to make to a soft-riding car on which the shock dampers do not act on rapid reversals, as the rear wheel continually patter and the brake control is much reduced. Also the rear brakes run far too hot, they frequently smoke, causing damage to the Ferodo and severe distortion of the carrier plates. If we were using aluminium shoes, seizures might be quite common. It is very obvious that a change to 14" dia. aluminium drums both front and rear would be an enormous advantage. We have hitherto refrained from asking for a design of this sort for Ph.III till the construction had proved itself reliable; but we are now producing a set of rear 14" dia. alum. brakes for our Continental Ph.III. We are therefore only short of a design for the front brakes. Now that Wraith is finished we hope that you will be able to produce this design for us, as we are sure it will be worth while. Hs{Lord Ernest Hives - Chair}/A.F.Martindale. | ||