• Jacking Systems

    With the acquisition of BLM and our continued commitment for service of the National Series Jacking Systems, NOV is well positioned to meet all your jacking system requirements.

     

    Description

    With the acquisition of BLM and our continued commitment for service of the National Series Jacking Systems, NOV is well positioned to meet all your jacking system requirements.

    NOV's BLM Jacking System utilizes the rack and pinion principle and consists of a set of simultaneously operated units, allowing lifting and lowering of jack-up type platforms.

    NOV's BLM jacking units are fitted pairs on each side of a double rack or two single racks welded to the leg chord of the rig. The jacking unit can also be mounted in a single rack. The units can be used on square, triangular lattice, or tubular legs.

    Our jacking units are typically self-contained. The unit consists of a gear box that is driven by an electric motor designed and built at NOV's BLM facility. The gear box drives the main jacking pinion that meshes with the rack.

    GENERAL DESCRIPTION:

    Mechanical
    Each unit incorporates one reduction gear with a fully watertight fabricated steel casing.

    All gears, including the final reduction gear, are totally enclosed and splash-lubricated.

    Each unit can be easily removed from the jack frame as a single component with the motor and climbing pinion.

    NOV provides a full range of jacking units that can be arranged on the rig at various heights, in order to meet the exact lifting requirement for the rig. The jacking units are fitted into jacking frames, which are either welded to the hull (fixed system) or installed in a jack house with shock pads (floating system). The jacking frames can also be mounted through jack links.

    Electrical
    Motors
    The jacking units are supplied with NOV's line of totally enclosed BLM AC motors. Windings are encapsulated in epoxy resin to ensure ultimate protection against humidity and mechanical resistance.

    The motors are fitted with a self-cooled electro-brake incorporating fail safe design. The brake is spring-activated when the controller is in the off position, or in the event of power failure.

    Three thermal switches included in the wiring protect the motor against overheating. A heating resistor prevents condensation inside the motor when it is not in use.

    Jacking console
    All necessary push buttons and signals are displayed on the jacking console, which is placed in the jacking control room. Local control is available near each leg.

    Switchgear
    All motors of one leg are fed through a cabinet placed in a sheltered control room. Inside the cabinet, control gears and relays operate the motors.