A battery powered mobile vacuum sweeper to remove loose coal and coal dust from underground coal mine workings was designed, built, tested, and evaluated. Pick up and conveying rates vs. air volumes, velocities, and nozzle shapes were determined for coal rubble in a laboratory pneumatic handling system. A 375 cfm gas/solids wet separation system consisting of a drop-out box and a venturi scrubber was developed and tested in the laboratory to clean effluent air to the very high degree required to preclude degradation of the ambient (mine) air. Two designs were made, one for belt conveyor and one for general district cleanup. The belt cleanup machine was chosen for test and demonstrated in an underground coal mine performing cleanup work in belt haulageways and on ribs. Although the dust separation system performed adequately, various mechanical problems caused the machine clean-up rate to be too slow for practical use. (GRA)