Described are the main technical parameters of 3 types of tight-lock draft gears for multiple units in Europe and Japan,which are going to be imported by the Railway in our country.

Design of Tight-lock Coupler and Draft Gear of Metro Based on CAD/CAE Integration;

Through the research carried out in such aspects as the design calculation, fatigue test, production technology, dynamics testing on track, the causes to insufficient margin of coupler yoke strength appeared in the initial stage of operation of the tightlock coupler draft gears are found out, and effective measures for solution are put forward.

In this paper, the structure, function principles and the relevant development process of the national retractable tightlock coupler draft gears are described.

Described are the research and development of the new type of coupler draft gears on passen-ger cars of Russtan Railway, as well as the structure features and main parameters of the four types of tight-lock couplers.

The essay concludes the causes resulting in separation of freight train,such as separation due to the uncoupling device,rupture of coupler yoke as well as the natural separation of train couplers.