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).
Article from an automotive journal describing a new type of underframe for rail cars that allows them to negotiate sharp curves.
| Identifier | ExFiles\Box 54\3\ Scan211 | |
| Date | 1st July 1926 | |
| Automotive Industries July 1, 1926 5 Driving axle unit and cushioned drive gear of new Swiss railcar Driving axle with cover removed, showing double-gear drive Underframe of eight-wheeled railcar of Swiss Locomotive Works New Type of Underframe Allows Rail Cars to Negotiate Sharp Curves Has shaft drive to front and rear axles. No differential gear used. Developed by Swiss firm. A NEW truck or underframe for street cars and rail cars has been developed by the Swiss Locomotive and Machine Works of Winterthur, Switzerland. The chief objects aimed at in the design are the overcoming of difficulties in negotiating curves of short radius. It is pointed out that in cities it is impractical to use curves of long radius, and curves with radii of 33 to 40 ft. are standard. This, in turn, makes it necessary to use a short wheelbase of 80 to 120 in., and with such a short wheelbase the ends of the car necessarily overhang a great deal. This overhanging of the car body causes unpleasant pitching in regular operation. The characteristic feature of the new underframe is a shaft drive to the front and rear axles. As may be seen from the illustrations herewith, the car has four axles, the two inner axles supporting a truck upon which the power plant is carried. The front and rear axles are very similar to motor truck axles with so-called double gear reduction. Each of these axles has its propellor shaft encased in a trumpet-shaped housing which connects with the transmission gear on the central truck by means of a ball and socket joint. The whole structure therefore is flexible and can readily follow curves of comparatively short radius. The drive to each axle is through a first reduction by bevel gears and a final reduction by spur gears. The rear axle is split and driven by two sets of spur gears. No differential gear is used, but a certain amount of differential action is obtained by providing the driven gears with cushion springs. The chief object in using this differential device is to do away with the shrill noises produced by the slipping of the wheels on the rails at sharp curves. Automotive Type Brakes Brakes of the automotive expanding type are provided on the axles and are entirely enclosed, hence they are protected from dust and dirt. The body of the car is supported on the front and rear axles through half-elliptic springs. It is admitted that the change from four to eight wheels involves a certain complication, but the manufacturers state this disadvantage is far overbalanced by the advantages of reduced upkeep of both car and track, an in- | ||