Abstract: A boom is mounted within a sleeve for longitudinal translation and the sleeve is hinged to a base plate that is securable by a C-clamp to a superstructure beam in front of a manway cover. An hydraulic actuator bears against the sleeve to adjust its elevation. A powered cable winch is joined to one end of the boom and its cable passes through the boom which is hollow to the opposite end and about a pulley to a fastener for attachment to an eye secured in the upper edge of the manway cover. A presser foot is hydraulically actuated to bear against the manway cover with the cable attached to the cover so that the bolts holding the cover in place can be removed. The cable can be payed out to lower the cover to a suitable location below. Guide pins are provided for installation in the mounting flange to pilot the cover into registration with the bolt holes when the cover is to be mounted rather than demounted.