New Orleans-based Bisso Towboat Inc., has awarded a contract to boatbuilder Main Iron Works, Houma, La., to build a new 100', 6,008-hp Tier 4-compliant ASD tractor tug. Construction is scheduled to begin later this summer, with a delivery in the fall of 2019.

“It will be very similar structurally and from a profile to our last newbuild, Liz Healy, as the vast majority of the changes will be in the engine room for the SCR system and larger Z-drives and a larger bow winch and bow staple to accommodate the increased horsepower/bollard pull,” Scott Slatten, Bisso’s president, said in an email. “Beyond that, we were able to pretty much use our existing design with some minor changes in tankage and hull and the above.”

Main propulsion will come from twin Caterpillar 3516E, Tier 4 diesels, producing 3,004 hp at 1,800 rpm each. The Cats will drive Rolls-Royce US 255FP azimuthing thrusters with 98.4"x94.3" 4-bladed stainless steel props in stainless steel nozzles, giving the new tug a bollard pull of 80 tons.

Auxillary equipment will include a JonRie 240 escort winch, John Deere 99-kw gensets and a full complement of safety, monitoring and electric equipment.

Slatten said the new tug will be the most powerful ship-assist tug on the Mississippi River and further enhance Bisso’s position as having the largest fleet of ASD tractor tugs serving the Mississippi River ship-assist trade.

Capacities will include 30,162 gals. of diesel fuel; 1,442 gals. lube oil; 1,442 gals. hydraulic oil; 3,000 gals urea; and 9,538 gals. potable water.

Ken Hocke has been the senior editor of WorkBoat since 1999. He was the associate editor of WorkBoat from 1997 to 1999. Prior to that, he was the editor of the Daily Shipping Guide, a transportation daily in New Orleans. He has written for other publications including The Times-Picayune. He graduated from Louisiana State University with an arts and sciences degree, with a concentration in English, in 1978.