Powerful Tug For The Mississippi
By Jack Burke26 November 2019

Bisso Towboat Co. in Luling, Louisiana, USA, announced the delivery of its first EPA Tier 4 Final and Subchapter M azimuth stern drive (ASD) tractor tug. At 6008 bhp, the Andrew S. is the most powerful Tier 4 tug on the Mississippi River, according Caterpillar Marine, which supplied two Cat 3516E main engines, each generating 3004 bhp at 1800 rpm and incorporating a selective catalyst reduction (SCR) system.
To become both EPA Tier 4 Final and Subchapter M compliant, and meet their increased power requirements, Bisso’s team worked with several companies. Caterpillar Marine Territory Sales Manager, Charlson Smith, collaborated with Bisso to select the engine package for the Andrew S.
“Our 3500 series engine is compact and reliable. Five of Bisso’s tractor tugs have 3516s in them already,” said Smith.
The Andrew S. measures 100 x 38 x 13.5 ft. and has an estimated bollard pull of 84 tons. Additional features of the tug include U.S. Coast Guard-approved engine room monitoring and fire/alarm systems, a fixed CO2 fire extinguishing system, and both the engine room and crew quarters have soundproof insulation.
Main Iron Works Inc., located in Houma, Louisiana, constructed the tug. With the Andrew S., Bisso now has a total of 13 tugs a part of their fleet, eight of which are ASD tractor tugs, making the company the largest fleet owner of ASD tractor tugs on the Mississippi River.
Bisso plans to christen the Andrew S. on the Mississippi River during the International WorkBoat Show in New Orleans, Louisiana, USA, on Dec. 5. Additionally, that day, the tug will be available for attendees to visit. To learn more about Caterpillar’s Tier 4 Final solutions and SCR system, stop by the Caterpillar exhibit at WorkBoat, booth #2801.