Abstract: A vertically and laterally adjustable frame for a mine ventilation structure having two or more pairs of adjustable height support columns, and a plurality of adjustable length support beams, each support beam mounted to and spanning between a pair of the support columns. A mine overcast and a method of assembling an overcast in an intersection within a mine are also provided, with the overcast including a vertically and laterally adjustable frame, and a plurality of side and ceiling panels mounted to the frame.

Abstract: A mine ventilation structure including a support structure, a plurality of side panels and ceiling panels mounted on the support structure, and a cementitious sealing composition applied over at least one surface of the side or ceiling panels. A method of assembling an overcast in an intersection within a mine is also provided.

Abstract: A remotely-operable vehicle for cleaning material from beneath a structure. The vehicle includes a body having a front portion and a rear portion, a pair of support arms pivotally supported within the body, a drive system for moving the vehicle, a hydraulic system, a receiver for receiving control signals from a remote control device, a processor which generates signals for operating the drive system and the hydraulic system in response to received control signals, and at least one cleaning attachment removably attached to the vehicle at a proximal end of each support arm. A vehicle system as well as a method of cleaning coal from beneath a conveyor belt in a coal mine are also provided.