In the development of thin and medium-thickness steeply dipping seams using systems with long stopes along the dip, the most labor-intensive and arduous is supporting the face area, which takes up to 55-60% of working time.

To reduce coal losses during hydraulic mining of thick steeply dipping seams by the sublevel hydraulic extraction system, flexible metal floors are used, separating coal from the caved rock and, along with completeness of extraction, allowing coal extraction to be carried out without support in the stope.