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).
Graph plotting the wear of different driving face materials against the number of slips.
| Identifier | ExFiles\Box 85\2\ scan0346 | |
| Date | 9th December 1937 | |
| WEAR OF EACH DRIVING FACE. RADII SPRINGS 141 LBS. u = .18 TAKE UP NORMAL BRONZE SPRINGS 161 LBS. u = .157 TAKE UP QUICK WEAR RATIO 5.4 TO 1 WEAR RATIO 5.5 TO 1 WEAR RATIO 7 TO 1 WEAR RATIO 8 TO 1 WEAR RATIO 5.1 TO 1 WEAR RATIO 4.75 TO 1 WEAR RATIO 4 TO 1 SPRINGS 132 LBS u = .192 EXCESSIVE SLIP SPRINGS 117 LBS u = .215 SLIPPING BADLY FERODO RADII GRAPHITE BRONZE NO SLIP SOME SLIPPING OCCASIONAL SLIPPING SLIP GRADUALLY INCREASING AS SPRINGS LOOSE POUNDAGE NUMBER OF SLIPS AT 30 SECOND INTERVALS RM.{William Robotham - Chief Engineer}476 WMC C 9/12/37 | ||