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).
Investigation into brake fade on a Phantom III (35-EX), detailing pedal movement measurements and their causes.
| Identifier | ExFiles\Box 92\4\ scan0113 | |
| Date | 21th November 1935 | |
| To E.{Mr Elliott - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} c. to GWH.{George W. Hancock - Head Chateauroux} c. to By.{R.W. Bailey - Chief Engineer} c. to Mx.{John H Maddocks - Chief Proving Officer} X30Z Hs{Lord Ernest Hives - Chair}/AFM.{Anthony F. Martindale}17/KW.21.11.35. Phantom III Brake Fade - 35-EX. We have made a thorough investigation into the above trouble. The following sponge measurements have been made using, where necessary, a pedal load of 200 lbs. without servo, or 52 lbs. with servo, (which is the same thing) as occasion demanded. | Reason for Pedal Movement | Movement of Pedal Inches | |---|---| | Minimum clearance between shoes and drum. | .91 | | Sponge in rear drums, chiefly due to a drum expansion of .035" on dia. | 1.20 | | Due to temperature difference of 80°C. between shoes and drum. | 0.75 | | Total loss in drums - | 2.86 + | 2.86 | | Slack in cables | .21 | | Opening of servo | .82 | | TOTAL LOSSES | 3.89 | + Total loss in Ph.II drums is only .98". | ||