Seamless railway| Where did the “bang” sound of the railway go?

Seamless railway

Seamless railway

It always could be heard the sound of “dang, bang, bang” when we traveled by train. But now it can’t be heard, why?

In the past, the railway lines were composed of 12.5m or 25m steel rails, which were connected by rail joint splints in the middle, so that the gap between the rails was maintained at 6mm. The main purpose of this is to reduce the internal stress of the rails due to thermal expansion and contraction. The sound of “bang bang” is produced by the wheels colliding with the rail when the train passes through the rail joint.

In order to improve the smoothness of the track and improve the comfort of passengers, the current railway lines generally use seamless railways. The rails are joined together by welding, which eliminates rail joints and train noise.

However, in northeast China, especially in areas with large temperature differences between winter and summer, there is a problem of the thermal expansion and contraction of steel rails, and there is a lot of pressure inside the seamless railway, so regular release operations are required.

So there is a question: Do you know how rail stress relief operates?

The whole process of rail steel relief


01 Cutting Rail

After the construction blockade order was issued, the operators used gas welding to cut a gap in the rail according to the position measured in advance and then cut the rail with a cutting machine.

02 Loosen Bolts and Fasteners

Using a hydraulic bolt wrench, loosen the bolts and fasteners that bind the rail.

03 Put in the Drum

Use a hydraulic press and a crowbar to raise the rail, and put a roller under the rail so that the rail can expand and contract smoothly.

04 Relieve Stress

Use a tensioner and rail collider to strengthen the rails to help the rails release pressure as soon as possible.

05 Grinding Joints

Tighten the bolts and weld the rails by thermite welding.

06 Grinding Joints

A grinding machine is used to find the weld of the rail after welding.

07 Complex Fasteners

Using the hydraulic bolt blackboard ti fully re-tighten the line bots to ensure the safety and stability of the line.

08 Equipment Re-inspection

Operators use the track ruler to conduct a comprehensive inspection and acceptance of the construction line, and the release operation is over.