Employees of the Leningrad Mining Institute together with workers of the mine № 1/2 of the trust “Uglegorskugol” in 1967-1968 conducted at the mine observations of the manifestations of rock pressure at different methods of excavation and roof management. The purpose of the observations was to improve the technology of excavation of semi-decaying layer VI and to choose the most rational method of roof management. Formation VI is relatively sustained, the excavated thickness is 0.95-1.10 l, the dip angle is 8-15° The roof of the formation is represented by layered mudstones (0.4-0.6 m) and dense fine-grained sandstones (15-20 m). The stratum is underlain by argillites (0.1 m) and siltstones of medium strength, up to 8-10 m thick.

Joint efforts of the staff of the Leningrad Mining Institute and the Sakhalinugol combine in 1967-1968 conducted numerous mine and laboratory studies aimed at improving the development systems, mechanization of cleaning works and roof management of thick layers of hollow dip.