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).
Brake testing where sustained use caused overheating and the burning of wooden wheel spokes.
| Identifier | ExFiles\Box 26\4\ Scan072 | |
| Date | 9th May 1919 | |
| Contd. -2- EH/LG9.5.19. the brake was still effective and there was still ample range left on the lever. We ran another test by using the foot brake and hand brake alternately, keeping each brake on for 3 minutes and then changing over to the other. The HP. absorbed was the same as on previous tests - 12 HP. and 1000 engine revs. We ran the brakes under these conditions for 24 minutes - 12 minutes on the foot brake and 12 minutes on the side brake. The brake drums were red hot for the last 16 minutes of the run. The brakes were quite effective the whole time. The reason we stopped the test was because the wooden spokes in the rear wheels commenced to burn. The results we have obtained with these brakes are rather suprising because from the appearance one would say that they are the very worst type for getting rid of the heat. When we were running these tests there was no question of the brake drum expanding when using the internal brake and bringing the external brake into action. There was always ample clearance on the brake even when the brake drum was at a bright-red heat. The brake drums are made of mild steel. EH. | ||