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).
Specification for brake drums on new axles, addressing casting distortion issues and required modifications.
| Identifier | ExFiles\Box 114\1\ scan0298 | |
| Date | 19th March 1940 | |
| 1015 & 1028 To Ev.{Ivan Evernden - coachwork} from Rm{William Robotham - Chief Engineer}/PJH. c.c. Ev{Ivan Evernden - coachwork}/HH. c.c. Rm{William Robotham - Chief Engineer}/MHR.{M. H. Rigby} Rm{William Robotham - Chief Engineer}/PJH.8/MH.{M. Huckerby}19.3.40. BRAKE DRUMS FOR NEW AXLES. We give below a specification of the brake drums we require on the new axles specified in our Rm{William Robotham - Chief Engineer}/PJH.2/BA.E.2.40. 4.B.50. 31.G.VII. Drums similar to existing standard B.V. except for reduced thickness of end plates 0.104 before machining and 0.010 machining allowance each side at bolting flange. (Finished thickness of flange 0.084.) 9.B.V. 1.R.1. 1.RT.II. Two rib drums similar to Exs.1755 cast to size externally with limits of + 0.050 on the dia. Backplates 0.104 thick as above. We are informed by Vs.{J. Vickers}, who has cast all our drums with "cast in" backplates, that during the casting process the backplate distorts axially 0.050 ± 10 away from the G of the car. He suggests that the backplate should have an initial dish of 0.050 towards the G of the car so that it will be approx. correct after casting. Will you please detail the drums mentioned above and incorporate the dish on the detail of the backplate. Rm{William Robotham - Chief Engineer}/PJH. | ||