Intensive mining in the Kuzbass region (Russia) and high environmental impact imply the development of both energy saving and environmental saving technologies. One of the directions is the decrease in the use of heavy vehicles via the non-transport flat seams mining. At the same time to increase the efficiency of the draglines operation, it is necessary to have information about the internal structure of the breakdown rock mass formed by the explosion of high (H ≥ 30 m) ledges. The drilling and blasting parameters used (especially the slope of the boreholes) give a fundamentally different structure of breakdown rock mass: with vertical boreholes, a more homogeneous structure of breakdown is observed than with the use of inclined ones. At the same time, when using inclined boreholes, a more suitable breakdown profile is formed to accommodate the draglines.