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 Phantom 4-wheel braking distribution and performance.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan279 | |
| Date | 17th September 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.D. EXPERIMENTAL REPORT. ORIGINAL Expl. No. REF: Hs{Lord Ernest Hives - Chair}2/LG17.9.25. 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. +8420/K5420 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 W.W. 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 W.W. The weights of the cars are 48 cwts. and 31 cwts. respectively. Hs.{Lord Ernest Hives - Chair} | ||