FIELD: geological examination; applicable in surface and underwater work in laying of cables of fiber-optic systems. SUBSTANCE: method includes giving feed and rotation to tool. After attaining of required depth of cutting-in, feed for cutting-in is discontinued, and tool is given longitudinal feed. Tools installed in spindle heads of hydraulic pumps are arranged stepwise to overlap one another and have similar diameter and angle of inclination for all cutting plates of tool. They are rotated in pairs in opposite directions. Diametrical parts of hydraulic pumps and turning stage support whose width equals diameter of hydraulic pump are smaller in size than minimal width of trench. Tools unit is removed from ground by its reverse feed with breakage of formed profile due to crushing and cutting off by its edges of hollows with cutting profile formed on periphery of tool bodies. Number of tools are selected so that zone of overlapping by working edges of ground is varying from 80 to 68%. Said interaction field by maximum is left for extreme, and by minimum for all intermediate tools installed according to stepwise system of cutting. EFFECT: higher productivity and technological potentialities. 2 dwg
