Longitudinal train dynamics of electric multiple units under rescue

Abstract

Once operating trains are disabled on the railway lines, an efficient manner is to utilize the train for train rescue. Owning to the different train and coupler types, it is difficult to formulate uniform regulations for train to train rescue. In this paper, the longitudinal train dynamics of electric multiple units under rescue were analyzed by field and laboratory tests. The angling behavior of the braking-induced coupler under compressed in-train forces was analyzed. A dynamic model for the train and draft gear system was developed considering accurate boundary limitations and braking characteristics. The safety indices and its limits for the coupled rescue train were defined. The dynamic evaluations of different train to train rescue scenarios were analyzed. It is indicated that the coupler vertical rotation occurs during the emergency braking applied by the assisting train. The vertical force components of in-train forces lead to the carbody pitch behavior and even cause local destructions to the coupler system. The carbody pitch motion can arise the inference of in-train devices. Based on the safety evaluation of train and coupler system, the regulations for typical train to train rescue scenarios were formulated.