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 testing and specification of Phantom III clutch plates.
| Identifier | ExFiles\Box 129\3\ scan0116 | |
| Date | 18th February 1936 | |
| X 1110 To E.{Mr Elliott - Chief Engineer} & By.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} c. to Da.{Bernard Day - Chassis Design} c. to Hdy.{William Hardy} c. to Mx.{John H Maddocks - Chief Proving Officer} c. to Roy.{Sir Henry Royce} Hs{Lord Ernest Hives - Chair}/Smth.14/KW.18.2.36. Phantom III Clutch. There is very little further to report on this subject since the issue of Hs{Lord Ernest Hives - Chair}/Smth.2/KW.5.1.36. We have had 33-EX running about with the same type Borg & Beck centre plate as has been specified for the first 12 chassis, but without the U-slots, and using 10% weaker thrust springs to Rm.{William Robotham - Chief Engineer}31. This clutch has been quite smooth and free from jaggers, but slipped when attempting a 2nd gear start on Green Bank (1 in 3½) with four people up. We think that this test was possibly too severe and we are waiting for an opportunity for confirmatory tests before we pass an opinion on the weaker springs. We are now fitting 32-EX, 34-EX, and 36-EX with Borg & Beck plates to specification EX.44, as instructed for the 12 chassis. These plates will at least be no worse than that on 33-EX, since they incorporate U-slots which give better cushioning and flatter facings. We are also about to try a compound cushion plate of the Long type manufactured by Borg & Beck, and hope to have this on the road in the course of a week or so. In view of the fact that a specification for the 50 chassis is urgently required, we recommend that we use the same plates as on the 12 cars. The Long type of plate is the only one we know of which is likely to be better, and no-one in this country has any experience of the manufacture of it. The one we have got from Borg & Beck is the first they have built and has been very much of an experiment from their point of view. If we decide to order 50 more plates to EX44 we should consider the question of arranging with Borg & Beck to make tools for the work. The plates we have ordered for the 12 chassis are being hand made and will cost about £4 each. If we order the plates in quantity the tools would cost about £155 and the plates 19/- each. Hs{Lord Ernest Hives - Chair}/P.Ll.Smith. | ||