Unsupervised learning of derivational morphology from inflectional lexicons

A railroad car dumper, suitable for dumping cars of a unit train, is disclosed. The dumper has a frame and a carriage, with tracks on the carriage to receive a car from adjacent tracks. The frame has a sidewall to support a car on the tracks during dumping with the car couplers on the axis of rotation of the dumper. The dumper frame is shiftable laterally, while the carriage remains fixed to maintain alignment of the carriage tracks with the adjacent tracks. Lateral shifting of the dumper frame while the carriage and tracks remain fixed permits a locomotive, larger than the cars to be dumped, to pass through the shifted frame.