The City rail K set class EMU (Electric Multiple Unit) passenger train is a type of train that is used to haul passengers on commuter and suburban rail lines.

The hardware structure, work rules, software design and anti_interference est. questions of BFP2-127/K type rail catcher of inclined roadway are discussed.

There is a transition station in orbit, a rail derailment and k-buffer, the buffer between the rail in the orbit and the derailment.