A sheet steel manufacturer, in need of a means to simultaneously raise and lower two access doors on an annealing furnace, turned to Thern for a solution. Using wire rope and directional sheaves, Thern’s single winch system allowed for installation away from the intense heat of the furnace, providing convenient access for maintenance crews and extended equipment life. Because the two doors were located at different distances from the winch, Thern engineered this unit using two drum compartments with different diameters to accommodate the different line speeds needed to control both doors in unison. This winch configuration allows for both doors to be fully opened and closed in the same amount of time, eliminating the need for multiple winches or larger, more complex and expensive control systems.