apparatus and methods are disclosed for accessing a drill pipe bore through a drill pipe top drive unit . the top drive is carried by a traveling block so it may be used for simultaneous application of rotational and longitudinal force on the drill string . a pack - off body has a shortened effective length due to mounting a flange thereabouts for securing to the top drive unit once a gooseneck circulation flow line has been removed in accordance with the method of the invention . a sheave support arm is mounted in cantilever fashion to the pack - off body and carries thereon two sheave wheels provided at desired locations to direct a wireline cable radially outwardly without frictionally engaging either the traveling block and hook or the top drive unit . the angles of bending of the wireline by placement within the support arm are chosen to prevent damage to the wireline containing an electrical connector .