Tensioning device for contact wire

A weight (1) links to a rail track overhead contact wire or catenary wire (8) to be stretched via turn-round devices (16). The weight is guided through two square-on guide devices (12). Guide elements (11) linked to the weight lock into the guide devices. To prevent the weight from falling if the catenary wire breaks, the weight uses a lever (6) for each guide device to grip onto the rail track overhead contact wire or catenary wire and the guide elements.