Big Power for Z-drive Barge
Seaspan Coastal Intermodal of the Washington Marine Group put a new trailer-carrying push-barge into operation in late summer. It is the second that they have built to this design and they have made a few upgrades. The original barge was connected in as an articulated-tug-barge (ATB) unit with a friction pad system. On arrival at Seaspan's associated company Vancouver Shipyards, from the builders in China, the new barge had sets of solid steel pads welded into place in the stern notch. Each of the port and starboard pads includes three vertically distributed 400 mm diameter receptor holes for the air-over-hydraulic pins that had been retrofitted to the tug, Seaspan Challenger. This JAK-400 ATB system provides a powerful positive lock for the ATB.
The new barge, at 456 x 82 ft. was also wider than the original to increase its carrying capacity to 54 of the 45-ft. truck trailers. These are parked on what looks like a big seagoing parking lot for the 24-mile crossing from the mainland to Vancouver Island. Like the original, the new barge had a big (1,800-hp @ 1,900 rpm Heavy Duty rating) V-16 Cummins KTA50 powered Rolls-Royce Z-drive bow thruster installed at Vancouver Shipyards. A wire harness connection allows the start-up and operation of the Cummins engine from the wheelhouse of the tug. In docking the 360 degree rotation of the thruster facilitates precise alignment with the loading ramp. Turned to push astern at 1,000 rpm it will also balance the idled push of the single screw 3600 hp tug. In addition to the wired controls, the new engine and Z-drive are equipped with a radio controlled remote that will allow the Z-drive to be turned 90 degrees to port or starboard as well as straight aft. In an emergency, should the barge be separated from the tug, his remote will allow the bow thruster to be utilized to hold the barge off the shore. The new barge, named Coastal Spirit, joined five other Seaspan vessels in the Vancouver Island to mainland rail and truck service.