Researchers of the Branch Academy of Coal Science went to coal mines of the Sunchon Area Youth Coal Mining Complex and the Pukchang Area Coal Mining Complex to develop technologies suitable for their actual conditions and introduce them in production.

The Research Institute of Coal Mining has developed chain props to increase their supporting capacity more than ten times and raise the mining rate.

Some coal mines, including the February 8 Jikdong Youth Coal Mine, have boosted coal output by 20 percent with chain props.

Scientists who went to the Kangdong Area Coal Mining Complex remodeled the tractor of 10-ton-capacity electric car to raise the traction rate 1.3 times.

The Coal-dressing Research Institute has built a new air coal-dressing process in the Sunchon Area Youth Coal Mining Complex and solved all the scientific and technological problems arising in its operation.

Scientists of other research institutes have invented a mass mining method and a new coal hewing method and developed such equipment as large-sized hydraulic crusher and a new model of hydraulic rock-drill.