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).
Technical memorandum comparing the self-locking coefficients of Rippletto, Girling, and Lockheed brake systems.
| Identifier | ExFiles\Box 121\1\ scan0302 | |
| Date | 1st July 1940 | |
| 1029 To Rm.{William Robotham - Chief Engineer} from Ev{Ivan Evernden - coachwork}/DB.{Donald Bastow - Suspensions} Ev{Ivan Evernden - coachwork}/DB.{Donald Bastow - Suspensions}15/JH.1.7.40. Rippletto Brakes. In Rm.{William Robotham - Chief Engineer}3/JMS.24.6.40. the self locking coefficient of the Girling brake system is given as /u = .6 to.7 and the remarks made that self-locking does not seem likely. Further on referring to the Lockheed 2 leading shoe brakes the remarks occur:- "The self-wrapping coefficient of 2.66 is very high and somewhere near the limit. Care would have to be taken with the linings". I think it is worth placing on record that the self-locking coefficient of the Lockheed 2 leading shoe brakes is .7, in other words no less than that quoted for the Girling System. The difference in the self wrapping coefficients in the two brake systems is purely due to the fact that in the Lockheed system both shoes are contributing to this while in the Girling one shoe only is doing so. Ev{Ivan Evernden - coachwork}/DB.{Donald Bastow - Suspensions} DB.{Donald Bastow - Suspensions} | ||