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).
Phantom 4-wheel braking distribution, detailing modifications and performance on chassis 46-PK.
| Identifier | ExFiles\Box 66\5\ scan0024 | |
| Date | 12th June 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.D. 48420 EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}/T/317.9.25. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. BJ. c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} PHANTOM - 4-WHEEL BRAKING. x8420 x5420 The present 'V' series braking distribution - Direct - servo to rear - servo to front is 1 - 2 - 2. The braking on chassis 46-PK which we left at WW. has been reduced to 1 - 1 - 1 by increasing the mean radius of the servo operating face cams from .544" to 1.088". This has reduced the total number of braking units available from 2120 to 1275. Although the braking on 46-PK car appears to be quite satisfactory at moderate low speeds, the braking at high speeds we should not consider satisfactory. It is a fact on any car that considerably more pedal pressure is required at high speeds than low speeds. The ratio of braking on 46-PK at WW. is now the same as on 8-G-111 which is also at WW. The weights of the cars are 48 cwts. and 31 cwts. respectively. Hs.{Lord Ernest Hives - Chair} | ||