A mine air crossing includes opposite side walls and a deck extending from side wall to side wall. Each side wall includes a plurality of sections assembled side-by-side and interconnected by quick-connections. Similarly, each deck may include deck sections assembled side-by-side and interconnected by quick-connections.

A jack includes a base, a guide extending from the base, and an extensible member having an extensible fit with the guide and extending from the guide to have a free end. A support is located at the free end of the extensible member. An actuator is capable of extending the extensible member. The guide and extensible member have portions which are laterally offset with respect to the base and the support such that when the support is in pressure engagement with a panel, the laterally offset portions are disposed adjacent one side of the panel to leave an area between opposite sides of the panel substantially unobstructed.

A mine stopping installed in a mine passageway includes a plurality of elongate panels extending generally vertically in side-by-side relation from a floor to a roof of the passageway to at least partially close the passageway. A generally horizontal elongate brace extends generally between the walls of the passageway adjacent to the panels. A generally vertical column extends from the floor to the roof and is adapted for reinforcing the brace. Braces and anchor beams for stoppings are also disclosed.

A mine door system for closing a mine doorway comprises a door hinged adjacent the doorway for swinging relative to the stopping between a closed position and an open position swung outwardly away from the stopping. A keeper is mounted in fixed position relative to the doorway. The system further comprises a trigger-actuated latch mechanism including a detent engageable with the keeper for latching the door in its closed position and a trigger operably connected to the detent in a latched position. The mechanism is constructed and configured so that actuation of the trigger causes the detent to move from a latched position in which the detent engages the keeper for latching the door closed to an unlatched position in which the detent is disengaged from the keeper for allowing the door to be opened.

A panel system for making mine ventilation structures. The panel system comprises a plurality of elongate metal panels having flanges along sides thereof configured for overlapping one another when the panels are placed in side-by-side relation. When the panels are secured together they form a unitary load-bearing structure. Related methods and equipment for installing the panels are also disclosed.