Dynamometer testing results for the B.V. and Wraith gearboxes.
| Identifier | ExFiles\Box 99\4\ scan0274 | |
| Date | 8th June 1939 | |
| To Sg. {Arthur F. Sidgreaves - MD} from Rm {William Robotham - Chief Engineer} /Gry. {Shadwell Grylls} HS. {Lord Ernest Hives - Chair} c. By. {R.W. Bailey - Chief Engineer} c. C. c. OX. c. RHC. {R. H. Coverley - Production Engineer} c. EX. Rm {William Robotham - Chief Engineer} /Gry. {Shadwell Grylls} S/AH.8.6.39. TESTING OF B.V. GEARBOX. Up till 3 years ago we used to consider that a dynamometer run of 2 hours on each gear was an adequate test for new gearboxes. During the development of the P.III overdrive box we discovered that our gearbox would stand a very much severer test. In America the dynamometer test for standardisation of gearboxes is 10 hours on second gear and 1 hour on first gear. This has been found to be adequate for a normal driver. The testing we now consider necessary for a new type of gearbox should allow for the abnormal driver as well. The following is a resumé of the testing done on the B.V. and the Wraith gearbox. DYNAMOMETER. B.V. (2000 r.p.m.) 1 hour on top gear. 100 hours " overdrive. 30 " " 2nd. 9½ " " 1st. This was a non-stop test. The strip examination showed the only failure to be the 1st. motion shaft bearing. This has now been greatly increased in capacity. Wraith (1500 r.p.m.) Early Testing 10.2.37. 2 hours on top. 10 " " 3rd. 2 " " 1st. ½ " " 2nd. after which the side shaft failed and was subsequently stiffened as on P.III. Second test carried out 18.11.38 because of failure of 1st. motion shaft. Continued. | ||
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).