Coupled single-axle running gears—a new radial steering design

Abstract

New railway vehicle concepts with broader and shorter carbodies necessitate new running gear concepts. One of the possibilities, the single-axle running gear, offers several advantages. The disadvantage of the conventional single-axle running gear during curving can be counteracted with a simple coupling between the single-axle running gears of the neighbouring carbodies. This paper presents parameter analysis and design principle of the coupled single-axle running gears. They can be constructed for an almost ideal curve negotiation in a great range of curve radii. The coupling of the running gears not only improves the running characteristics in a curve but also increases the stability limit. Bombardier Transportation Winterthur has developed the coupled single-axle running gears called FEBA. The test runs with prototype as well as with serial running gears in the Norwegian commuter train Class 72 have fully confirmed the anticipated running characteristics.