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).
Table of dimensions for servo-operated brakes across various models.
| Identifier | Morton\M19\ img091 | |
| Date | 4th December 1930 guessed | |
| TITLE: DIMENSIONS OF SERVO OPERATED BRAKES TABLE HEADERS: TYPE | FRONT BRAKES - ARC OF CONTACT OF EACH BRAKE STRAP LENGTH | FRONT BRAKES - WIDTH OF SHOE | FRONT BRAKES - DIA. OF DRUM | REAR BRAKES - ARC OF CONTACT OF EACH BRAKE STRAP ANGLE | REAR BRAKES - WIDTH OF SHOE | REAR BRAKES - DIA. OF DRUM TABLE DATA: Silver Ghost & Phantom I | 13.0" | 1.70"* | 15.0" | 99°* | 2.00" | 17.0" Phantom I (Later Series) | 11.3" | 1.75"* | 15.0" | 86°* | 2.00" | 17.0" Phantom II | 14.0" | 1.75" | 15.0" | 107° | 1.75" | 16.0" Phantom II (Lorry Chassis) | 13.9" | 1.75" | 15.2" | 106° | 2.25" | 16.0" Phantom II (Locomotive Type) | 14.1" | 1.75" | 15.2" | 108° | 2.25" | 16.0" 20 H.P. | 11.7" | 1.30" | 14.4 | 118° | 2.00" | 14.0" 20 H.P. (Later Series) & 25 H.P. | 11.7" | 1.30" | 15.3 | 125° | 2.00" | 14.0" FOOTNOTE: * INCREASES TO AN ADDITIONAL 3.0" & 23° RESPECTIVELY WITH WEAR. | ||