The Frozen Rail Joint(JointBar, FishPlates) refers to the RailJoint that makes the rail-rail end of the connecting rail always in a tight state. Special crescent washers can be used to squeeze the bolt holes of ordinary rail joints. It is adopted that the rail joints should not be installed within the full length of the small bridge on the exposed bridge and within the temperature span of the steel beam with the rail expansion adjuster. The conditions for rail welding are not available. In the South of China, it is used to connect standard length rails of ordinary lines into frozen long rail lines, which has received good results similar to welding long rail seamless lines.
The opposing rail joint is a way in which the two rail joints of the track are arranged opposite to each other. When the train passes through the joint, the left and right wheels of each axle impact the rail seam at the same time. Since the elasticity of the two trajectories is roughly equal, the driving is relatively stable, so it is the main way of setting the rail joints of the main rail.The staggered rail joint is a setting method in which the left and right rail joints of the track are staggered by half the length of the rail before and after. When the train passes through the joint, the two wheels of each axle alternately impact the rail seam left and right. The apparent difference in elasticity of the two trajectories caused the train to shake. It is only used on secondary routes with lower driving speeds.Welding of frozen joints is one of the important construction procedures of subway(metro) construction. To ensure that the construction tasks can be completed with high quality and efficiency, before welding the rails, a drop weight test should be carried out in advance to determine the welding process parameters to make sufficient preparations for the welding construction. When welding, the smoothness and running surface of rails are controlled within 0-0.3 mm and the guide surface within 0-0.2 mm through instrument measurement, etc., so that the connection between the long rails can be integrated and effectively reduce the shaking feeling while train passing through the end, also improves the safety and comfort during in the train.
