Dn 640 is the fixed crossing of gauge of 1520 mm, type P50, with the crane line of type KP80, grade 1/9. This is a special design for port tracks laid in the area of gantry cranes to allow the car supply to the loading area. In order to increase the service life of the crossing and reduce the cost of its maintenance, the filled section rail crossing was replaced by solid cast one made of high-manganese steel.
The fixed crossing project was developed for the ports of the Baltic republics.