Collieries in the western part of the country applied a new method of blasting to raise the tunneling speed 1.5 times, while those in the Pukchang area introduced the inertial load-haul equipment to increase the coal output 1.5 times with less supply materials and manpower.

Besides, the Coal Science Branch developed a new type of chain coal-cutter which helps considerably raise the mining speed and put the mechanization of pit work on a higher level.