Method of operation of positive guidance system for a tank-cleaning device

摘要

A guidance system and method for positively guiding a tank sludge-removal unit or the like around the inside of a tank, including a plurality of winch assemblies mounted at radially spaced locations on the top perimeter of the tank each having a control line which extends into the tank for connecting either directly to the unit or indirectly to a lifting line via a pulley device used for raising and lowering the unit within the tank, thereby enabling the position and/or the direction of movement of the unit to be positively controlled by selective operation of the winch assemblies and/or lifting line. A line-forwarding device is also provided for use in forwarding control lines of the winch assemblies to an access opening in the tank.