An apparatus for wrapping fiber optic cable around an overhead line (A), has a carriage (1) which sits on the overhead line (A) and is movable along the overhead line (A). A supply of fiber optic cable (B) is located on one side of the carriage (1) and a counterbalance (3) for the cable supply is located on the other side of the carriage (1). A gear set (4) is arranged to the fiber optic cable (B) around the overhead line (1). A substantially constant tension is applied to the fiber optic cable (B) during all modes of operation of the apparatus.