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).
Testing of a Leyland gearbox on a bus chassis and requesting a comparison with in-house designs.
| Identifier | ExFiles\Box 136\2\ scan0302 | |
| Date | 23th October 1940 | |
| To Ev.{Ivan Evernden - coachwork} from Rm.{William Robotham - Chief Engineer} Handwritten: Gearboxes copy in Leylands 1153 Rm.{William Robotham - Chief Engineer} 4/ET.23.10.40. Herewith detail drawings of the various parts of the Leyland gearbox. I tried this box on a bus chassis and, although Leyland themselves seem delighted with it, the operation was heavy according to our standards, in spite of the very long gear lever with extended travel. One interesting feature is the very small cone angle they use on the second speed; I believe this is 5°. They say it has only been made possible owing to forced lubrication of the cones, particulars of which I am obtaining. It is noticeable that it was not possible to engage second speed from rest, owing to this small angle. They do not mind this as they say that bus drivers should start from first. I should be interested to have a comparison between this box and a box which we ourselves should design for a passenger vehicle of the same displacement, i.e. what factor of safety do they work to on the lower gears for bus work, compared with our own practice? Rm.{William Robotham - Chief Engineer} | ||