Marine Log


May 17, 2006

Bisso Towboat takes deliver of Alma S

Bisso Towboat Co., Inc., New Orleans, the oldest continuously operating tugboat company on the Mississippi River, has taken delivery of its new 4,300 HP reverse z-drive ship-assist tug Alma S from Main Iron Works, Houma, La.

The company has also announced an agreement with Main Iron Works to begin construction of a 4,000 HP reverse z-drive ship-assist tug.


The 100 ft x 38 ft x 13.5 ft Alma S is powered by two EMD 16-645E6 main engines, producing 2,150 HP each at 900 RPM, which drive ywo) Ulstein-Aquamaster US 2001 Z-drives.

The Z-drives feature 90.6 inch diameter x 82.4 inch pitch stainless steel propellers set in stainless steel Kort nozzles.

The tug's estimated bollard pull is 60 tons.

Electrical service is provided by a pair of 100 kW generators powered by John Deere 6068TMGK engines. Deck equipment includes a Markey DYSF-42 hydraulic bow winch, with render/recovery feature and equipped with 500 ft of 8 inch circumference Plasma line and a 100-ton Washington Chain and Supply quick-release tow hook.


Auxiliary equipment includes EMI engine and fire/smoke alarm systems, complete electronics package including Simrad autopilot/heading sensor, Furuno radar, GPS, fathometer and AIS, Heli-Sep Oily/Water separator, Owens Kleen Tank sewage treatment plant and 750 GPM fire monitor.

Other features include sound proof insulation throughout the crew quarters and engine room and stainless steel h-bitts, quarter bitts and bow staple. For crew comfort, the galley and all bunk rooms are equipped with flat screen TV's and DVD players.


Tankage includes capacity for 43,000 gallons of diesel, 1,800 gallons of lube and hydraulic oil, 11,000 gallons of potable water and 1,900 gallons of dirty/waste oil.

The Alma S described as "an almost exact carbon copy" of Bisso Towing's 1999-built Cecilia B. Slatten which was the first reverse Z-drive ship-assist tug built for use on the Mississippi River.

The Alma S features only a few minor modifications to the design of the 1999 vessel, primarily in the areas of increased crew comfort and improved operational capabilities.

The Alma S joins Bisso Towing's fleet of 12 tugs on the Mississippi River and will be positioned in the St. James/Convent area to service the large tankers and bulk carriers that call in that area.

The addition of the Alma S allows Bisso Towing to lay claim to being the only Mississippi River ship-assist company to have multiple Z-drive tugs in addition to being the only Mississippi River ship-assist company to have a fleet comprised solely of multiple-screw vessels as follows: 2 twin Z-drives, 2 triple-screw and 9 twin-screw tugs.

The as yet unnamed newbuild will have the same hull and quarters design as the Alma S but will feature two Caterpillar 3516B main engines, producing 2000 HP each at 1600 RPM, driving two Ulstein Aquamaster US 2005 Z-drives.

Construction is scheduled to begin in late 2006 with delivery expected in late 2007.