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).
Secret memo discussing the decision to implement a slow speed servo for the 4-wheel brake system and outlining a conversion plan.
| Identifier | ExFiles\Box 73\2\ scan0224 | |
| Date | 29th January 1924 | |
| X9940 To Hs.{Lord Ernest Hives - Chair} Rg.{Mr Rowledge} ) FROM R.{Sir Henry Royce} E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} ) S E C R E T. R1/M29.1.24. c. to CJ. BJ. WOR.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} RE. 4 WHEEL BRAKES. X.9940 I have come to the conclusion that it is nearly hopeless to try to get the high speed servo thoroughly reliable and wired Derby and London my decision. Now that we know and realise how desirable for so many reasons, and how almost indispensable, the slower speed servo is, it will be best to go for it all out. I have therefore recommended that we push on with all force possible our EAC.4. as advised in a recent memo. Directly this is finished and with all speed, we get out a scheme of conversion for present cars, somewhat as follows :- (1) Alter exhaust pipes to put dynamo on engine. (2) In space cleared by (1) arrange a slow speed servo motor as near as possible like EAC.4. (3) Couple all brakes together and equalise by vertical or horizontal floating lever as in EAC.4. Naturally item (2) is the difficult one, and may result in a new box to take the present gearbox parts. It must be thoroughly well done, oil retaining, and all gears enclosed, and to the best of my memory there may be room for the worm drive on the third motion shaft in the usual place, but Mr. Stent and I had many schemes for getting a drive in by worm and spur reduction. I think the servo must be on a cross shaft in the usual way and I also think the dynamo must be moved as suggested above. I should have one good bite at it and leave the chassis somewhat cleaned up and improved rather than try to crowd in more parts as I feared we should have to do. Perhaps someone can suggest a less drastic scheme than this, which I fear must mean a new gearbox casting or some very difficult patching, or burning, and welding on new features. Every effort should be made not to scrap anymore of the internal parts of the present box than is necessary, because generally they will be found in excellent condition and should run silently in the new or modified box. contd:- | ||