Abstract: A self-movable mine refuge chamber powered by a drive assembly, preferably in the form of a set of crawler or tractor mechanisms, mounted on the chamber, so that the chamber can be moved through the mine without use of any other motive force. The drive assembly further includes a tilt assembly so that one end of the other of the chamber can also be tilted to establish a modified height profile to permit obstacles along the path to be negotiated. The drive assembly is powered by an on-board, detachable power supply module and, using controls from outside the chamber, the chamber can be maneuvered through working tunnels or roadways, crosscuts, or other passageways within the mine, and be positioned and repositioned at will.

Abstract: A self-movable mine refuge chamber powered by a drive assembly, preferably in the form of a set of crawler or tractor mechanisms, mounted on the chamber, so that the chamber can be moved through the mine without use of any other motive force. The drive assembly further includes a tilt assembly so that one end of the other of the chamber can also be tilted to establish a modified height profile to permit obstacles along the path to be negotiated. The drive assembly is powered by an on-board, detachable power supply module and, using controls from outside the chamber, the chamber can be maneuvered through working tunnels or roadways, crosscuts, or other passageways within the mine, and be positioned and repositioned at will.

Abstract: An apparatus and method is provided for demolishing concrete chimneys. The apparatus for demolishing concrete chimneys from the top downward comprises: (a) a first support, (b) a second support, (c) means for forcibly vertically moving the supports relative to each other, (d) a crane carried by said first support, and rotatably attached through an upright axis, and (e) means for power actuated rotation of the crane about the upright axis.