Bisso Towboat Co. Inc., Luling, La., has signed a contract with Main Iron Works, Houma, La., to build a 4,480-hp ASD ship-assist tug.

The new tug will be a carbon copy of the recently delivered Z-drive tug Becky S. The 100'x38'x13'6" Becky S. has the same design as the previous four azimuthing stern-drive tugs Main Iron has constructed for Bisso in the last 17 years. The Becky S. has a little more horsepower than its sister tugs — 4,000 hp versus 4,480 hp. The tug has a pair of Caterpillar 3515T3MPL Tier 3 main engines (compared with the other tugs' Cat Tier 2 engines) that each produce 2,240 hp at 1,600 rpm. The new tug will be powered by two Cat 3516C Tier 3 main engines also producing 2,240-hp each at 1,600 rpm. Propulsion will be provided by a pair of Rolls­ Royce US 205 FP Z-drives featuring 90.4"x 82.4" 4-bladed stainless steel propellers set in stainless steel nozzles.

Electrical service will be provided by two 99-kW Marathon generators powered by John Deere  4045AFM85 Tier 3 Engines. The new Bisso tug will be equipped with a JonRie lntertech Series 230 hydraulic bow winch equipped with 500' of 8" circumference synthetic hawser. Bollard pull will be an estimated 60 tons.

Tankage will include 30,163 gals. of diesel fuel, 1,826 gals. each of lube and hydraulic oil, and 10,938 gals. of potable water.

Construction is expected to begin immediately with delivery in early 2016.

This will be the sixth ASD tractor tug constructed for Bisso by Main Iron and the 10th new tug constructed in the past 25 years for Bisso by Main Iron Works. The new tug will bring the total number of tugs in the Bisso fleet to 13.

Founded in 1890, Bisso is the oldest continuously operating tugboat company on the Mississippi River and operates the largest fleet of ASD tractor tugs on the Mississippi.