Abstract: A tension control device for an anchor line rope of large diameter, which winds off or onto a winch drum at a marine vessel includes an arm with a first inner link arm with a first sheave arranged near the first link arm's outer end, a second, intermediate link arm arranged rotatable adjustable on the first arm and arranged with a second intermediate sheave near the second link arm's outer end, and a third, outer link arm arranged rotatable adjustable on the second, intermediate link arm and arranged with a third sheave near the third, outer link arm's outer end. The second, intermediate link arm's angle is regulated by use of a first actuator arranged between the first, inner link arm and the second link arm. The third, outer link arm's relative angle to the second, intermediate link arm is regulated by a second actuator. Each sheave includes a brake.