Abstract: The invention comprises a mechanism for playing out and taking up a loop of an elongated, flexible line, such as an electrical power cable or a hydraulic hose line to maintain tension in the loop. More specifically, a housing is provided within which at least one loop of line is positioned. A traveling member within the housing engages the loop and slides in one direction to play out portions of the loop from the housing and in a second direction to take up portions of the loop within the housing. This traveling member is biased in the second direction so that the apparatus automatically takes up slack in the lines.