Abstract: A hydraulic device is provided capable of moving heavy loads along a slotted track. The hydraulic device has a cylinder and piston unit, a jack that is connected to one or more ratcheting claws, and a sliding member having slots for placement of one or more ratcheting claws. To prevent brittle fracture of the hydraulic device during the movement of heavy loads under extreme cold conditions, the hydraulic device has a chamber for placement of heatable members that heat various elements of the hydraulic device, thereby reducing the likelihood of brittle fracture of the hydraulic device during operation. The hydraulic device may have one or more pairs of tandem ratchet claws that evenly distribute load forces along the slotted track. The device may also have detachable side weldments that hold the jack and claws for easy placement and removal of the device on a beam.

Abstract: A gripper system for moving drilling rigs on offshore drilling platforms supported on flanged skid bases having a pair of side plates with flanges for engaging the underside of the skid base flange. The side plates are supported on a pair of rotatable shafts, having eccentric cam surfaces for engaging the upper surface of the skid base flanges. Each shaft is independently rotated and clamped by an hydraulically operated cam locking actuator adapted to rotate the respective shaft and eccentric cam surfaces. The side plates are bolted to a main frame, also supported on the rotatable shafts with the bolts acting as pivot pins for attaching a hydraulic jack means between the gripper assembly and the drilling rig to be moved. The drilling rig is moved by successive clamping and releasing of the cam locking gripper assembly and operation of the hydraulic skid jack means.