Abstract: There is shown a barge-type ocean going vessel which on each corner has four hydraulically operated rams having foot portions on their downward ends. These rams are adapted to push downwardly to engage the bottom of the bay or harbor in which the barge is located. As they become seated on the harbor floor, the rams are advanced sufficiently to lift the barge above a bouyancy level. Within this barge is secured a crane which is liftable by a plurality of hydraulically operated jack screws. These screws lift the crane above the deck of the barge sufficiently for the crane to swing in any direction to do any lifting job normal to a crane. The platform upon which this crane is carried has arms extending therefrom, which arms are adapted to be swung to the side of the barge and secured thereto in such a manner that a load on the crane is transferred from the platform upon which the crane is mounted to the side of the barge. When the crane is stored, it is swung lengthwise of the barge and is lowered below deck.