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).
Examination of squeaking locomotive front brakes and a proposed solution involving spring loading.
| Identifier | ExFiles\Box 12\5\ 05-page255 | |
| Date | 21th January 1931 | |
| Copy for files. x74-0. 21.1.31. x79301 19-EX. Locomotives Front brakes to N. sch. 3140. Shoes Spring Loaded from the top 50 lbs. Both brakes gave a high pitch squeak, but no groans. The bedding was examined and found that rear shoes had bedded themselves with the springs compressed. The front shoes bedding themselves on the stops. This means the rear shoes owing to the forward motion of the car had been rapping on, where as the front shoes had been rapping against the stops. The suggested method is to increase the load of the spring. At low pressure braking the shoe is on its stops, and at high pressure braking it would compress the spring. The spring should be high rating and the stops adjusted so that only about .015" of spring movement at the maximum. This should not be sufficient to lose any effective movement of the brake ropes. The disturbance should be enough to prevent squeaking. From examination of the bedding of above shoes, I should suggest the front shoe being spring loaded from bottom of the shoe. I.A. Leslie. | ||