The Kaechon Area Coal Mining Complex established a base for production of concrete props, necessary for the research and introduction of effective tunnel supporting technology, and a process for producing iron plate suited to the field conditions.

The Tukjang Area Coal Mining Complex manufactured and introduced a contact AC car with high traction power and an efficient muck loader and invented a device for raising the utilization rate of compressed air.

Similar achievements were made by other coal mining complexes across the country.