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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}
  
  
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).


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