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).
Testing E.A.C. servo brake shoes lined with cast iron.
| Identifier | ExFiles\Box 26\4\ Scan239 | |
| Date | 1st January 1924 | |
| R.R. 493A (40 H) (SL 42 12-7-23). J.H. D.{John DeLooze - Company Secretary} EXPERIMENTAL REPORT Expl. No. 9910 9840 REF: Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}/1,024.1.24. E.A.C. SERVO. We have tested servo brake shoes lined with cast iron on our testing rig. The effective co-efficient of friction of this material appears to be much the same as unburnt Ferodo. The wearing qualities are slightly better. In addition, after being heated to a bright-red heat and allowed to cool down, neither its wearing qualities or its co-efficient of friction show much alteration. If anything, it wears better after this treatment. The worst feature of cast iron seems to be that its co-efficient of friction decreases as the slipping speed is increased. The servo does not heat up so quickly when run uncooled with this type of lining. We should say that after 5 minutes running uncooled, the drum is at a temperature of 300°C judging from its colour, as opposed to red heat when Ferodo is used. We are making further comparative tests with the Ferodo. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||