Abstract: A vacuum box in fluid communication with a tractor that removes coatings from surfaces. The vacuum box includes a vacuum inlet in fluid communication with a source of negative pressure and a debris inlet in fluid communication with the tractor so that debris is drawn into and collected within a hollow interior of the vacuum box. A water outlet provides a drain for water that collects within the vacuum box. A sloped false bottom wall is disposed within the hollow interior so that debris collects atop it. The vacuum box is emptied by draining water from it, followed by opening a door formed in the vacuum box at the lower end of the sloped false bottom wall so that the collected debris slides down the false bottom wall and out the door into a debris receptacle.

Abstract: An apparatus for cleaning the interior sidewall of a large diameter tube includes a centrally-apertured circular brush plate adapted to fit within a lumen of the tube. A fluid conduit is mounted in the aperture so that an upper part of the fluid conduit is positioned above a plane of the circular brush plate and a lower part is positioned below the plane. A nozzle assembly is disposed in radial relation to the lower part of the fluid conduit. A hose provides fluid communication between a remote source of water under pressure and the fluid conduit. The circular brush plate is inserted into the lumen of the tube and is gradually advanced through the tube. The nozzle assembly is rotated about an axis defined by the fluid conduit as the circular brush plate is advanced through the tube so that water under pressure cleans the interior sidewall of the tube.

Abstract: Concrete on a vertical wall is removed for resurfacing in the substantial absence of microfracturing by a crawler apparatus that is lowered from the top of the wall to the bottom by remote control. The crawler is raised and lowered by cables that are reeled in or out depending upon the direction of rotation of the output shaft of a motor. A rotating nozzle blasts a focused stream of very high-pressure water against the concrete to be removed. The nozzle is carried back and forth along the breadth of the crawler as the crawler descends the face of the concrete wall so that a vertical strip of concrete substantially equal in width to the width of the crawler is removed. The crawler is then returned to the top of the wall and moved laterally to begin removal of the next vertical strip of concrete.