Normal bogies of trunk locomotives are not fitted to the switching services on
the curve line with small radii. With the increasing of the axle load, this case is getting
worse. The technical characteristics and the test results on the bogies of the diesel
locomotives used on mountainous areas and heavy mineral fields are introduced in this
paper. A dynamics analysis for a heavy switching locomotive is provided, with
improving measures for the locomotive are investigated. The theoretical calculation and
the field tests show that it is profitable for the curving behavior to adopt roller friction
side bearers, meanwhile, some succeeded experiences of bogies should be used to
develop the heavy switching locomotive.