Express unveils unique tug for handling coal barges: Duty

Express Marine, a traditional family-owned East Coast tug and barge company, has taken a giant leap into the future with the introduction of a modern-looking z-drive tug for use in towing barges loaded with coal.

The company’s first such tug, a 102-footer named Duty, was delivered from Patti Shipyard in Florida in early 2007. A sister ship, slightly smaller in length but with more of a raised forecastle deck, is due out from the same yard by the end of this year.

Duty is a 3,000-hp tug with full towing gear, Caterpillar power, carbon-fiber propeller shafts and SteerProp azimuthing thrusters for propulsion power. It is one of just a handful of U.S. tugs with z-drive propulsion used for barge towing. The company’s six other tugs are twin-screw, conventionally powered vessels ranging from 1,600 to 3,600 hp. Duty underwent bollard pull tests on the Gulf Coast after its delivery and turned in a forward-pull rating of 40 tons, according to the company.

“There’s new technology out there and we want to be at the crux of new developments,” said Croft Register, operations manager for the New Jersey-based company. He added that the z-drives would give the new tug a maneuvering advantage and facilitate maintenance and replacement of propulsion gear when the need arises.

Riley Johnson and Bill Hudnell, alternating captains of the new tug, received their z-drive training at the Paul Hall Center for Maritime Training in Piney Point, Md., and at Holland College Maritime Training Center on Canada’s Prince Edward Island. The captains and crewmembers took delivery of the new tug in early 2007 and began working with a 365-foot hopper barge running between New Jersey and Baltimore through the Chesapeake & Delaware Canal. In early summer the tug is expected to be matched with one of the company’s coastwise coal barges, the largest of which is 470 feet in length.

Express operates a fleet of 30 barges in general towing service, with emphasis on coal and dry-bulk cargo. The company has been delivering coal to utility plants on the East Coast for 70 years and, more recently, to utility plants on the Gulf Coast as well. Duty is the eighth tug in the Express fleet.

For offshore towing, Duty is set up with a single-drum hydraulic towing winch built by JonRie InterTech of Manahawkin, N.J. The winch, with 82,000 pounds of line pull, is set up with 2,200 feet of two-inch towing wire. The winch gets hydraulic power from one of the tug’s three auxiliary power generators. Providing underway control over the tow wire is a tow-pin package from Smith Berger Marine of Seattle that includes two hydraulic pins, a hold-down clamp and transom roller. JonRie InterTech also provided capstans for use next to the tow winch and on the bow.

The tug is also set up with port and starboard custom-designed deck winches for wire push gear, thus keeping the towing winch free from involvement with push gear. A large 10-ton hydraulic North Pacific deck crane is mounted on the port side, aft of the boat deck. And the profile of each side of the tug is highlighted by fixed pads projecting out from the sides to keep the tug stabilized while pushing in a barge notch.

A number of Express tugs have this pad arrangement, which was originally designed by the company for use by its 1150 class of barges for service to the Hudson Generating Station in Jersey City, according to Register.

“These are deep notch barges, and the pads on the tugs press up against the flat spot at the aft end of the notch on each side. Since the pads are fixed in place, the tugs typically force their way into the notch (and back out again) usually with a generous application of grease on the pads,” said Register.

“When loading or unloading, the tug gets out of the notch and stands by on the side. Then when the barge is ready, the tug re-enters the notch with its own draft matching the draft of the barge,” he added.

Because Express Marine tugs are often operating in areas where there is a lot of coal dust in the air, some of them, including Duty, are set up with expanded air filtration capacity — both for use by air-breathing engines and for interior ventilation.

Duncan MacLane, the company’s in-house naval architect, said much of the extra filtration equipment is located in the stack assembly. “Any air that is coming into the boat, whether it be for ventilation or for internal combustion, goes into a filter bank, and any air that is going down to the engines gets filtered twice,” he said.

“Whenever you are loading coal there can be a fair amount of coal dust flying around, so we take steps to keep it outside the tug as best we can. Of course exposure to dust also depends on how the coal is loaded into the barge and on where the tug is stationed while this is going on.”

MacLane, who helped design the tug with Seattle naval architecture firm Jensen Maritime Associates, said there are some refinements, but no major changes, being planned for the company’s next new tug, currently under construction at Patti Shipyard in Pensacola. That tug will be slightly smaller at 94 feet, and with a raised forecastle, but with basically the same machinery package, he said.

Duty is one of the first tugs built in North America with Steerprop azimuthing stern drives. Steerprop is part of a private company based in Finland. Steerprop drives are regularly used on European tugboats. In the United States, Steerprop is represented by Karl Senner Inc., Kenner, La.

By Professional Mariner Staff