Before welding, fine tune the interface of the two rails.
The steel rails have just been welded.
Heat treatment to increase the hardness of the rail joint.
The staff uses the electronic ruler to detect the flatness of the steel rail welding.
Steel rail "B super" - inspection detection.
The length of this steel rail is 500 meters long and welded from 5 100 meters of steel rail. The welding joint has to be derusted, hot, fine grinding and testing, etc., which is to make the steel rail joint tenacious. The 100-metre rail is so hard that it can be as tough as noodles after 500 metres.