The lifting tongs are the right assistant to lay the rails. The lifting rings of the lifting tongs are generally installed on the gantry cranes, cranes and other large lifting equipment. The lower integral claw will clamp the rails, and the middle clip will play a fixed role. Then the large lifting equipment will drive the lifting tongs to achieve the lifting of steel rails. However, in recent years, China has vigorously developed the construction of urban subways and intercity express ways. During the construction process, it is necessary to carry out the underground track laying work. The space is quite narrow, which is not conducive to the smooth implementation of the laying work. Therefore, workers will first use lifting tongs to connect the rail and rail sleepers on the ground.

The rail sleepers and rails bear the weight of a huge subway and many people. Therefore, there are strict requirements on the bearing capacity, stability and other aspects. According to the principle of thermal expansion and contraction, there must be a certain gap between the rail and the rail to prevent the rail bulge phenomenon caused by excessive heat, which affects the normal operation of the train. The use of lifting tongs can quickly connect the rails and sleepers together, and at the same time, adjust the distance between the rails in fine places, and then fix them with fasteners. After the completion of the rail layout work, it is also necessary to move the rail into the subway tunnel with the lifting tongs and large gantry crane. After the placement is stable, the rail flat car responsible for transportation will slowly transport the rail to the designated location, and then release the lifting tongs to place the rail and sleeper stably. Then the workers will adjust the height of the rail slightly until the laying work is completed successfully.

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