The Efficient Tugboat: Efficienty of a Different Type: Laney Chouest

When it comes to large tugs, none is larger than the Laney Chouest, the world's largest anchor handling tug supply (AHTS) vessel. At 348- x 72- x 31-ft., the Laney Chouest is the king of all tugs in the Gulf of Mexico, or anywhere else for that matter. It was built by the North American Shipbuilding, Larose, La. a part of Edison Chouest Offshore, Galliano, La. who also owns and operates the vessel.

The vessel is super efficient since it is designed to do several jobs that formerly needed separate vessels For example, the vessel will set suction piles that anchor floating oil production facilities to the seabed using the largest tow winch every built. That is a huge job for any anchor handler.

The vessel is also a supply boat with below main deck tanks to hold 337,791 gallons of fuel oil, 663,169 gallons of rig/ballast water, 7,367 barrels of liquid mud, 42,332 gallons of potable water and 12,583 cubic feet of dry bulk material delivered at 80 PSI. The Laney Chouest also is a major cargo carrier. The rear deck measures 183.5 ft. by 56 ft. and can hold 3,000 long tons of cargo. In addition, the vessel has an ROV to support suction pile placement and other sub sea construction work. A 42-in. diameter moon pool is included for keelhauling objects.

Two 20-ton cranes and a 2.5-ton crane assist in the suction pile placement and other subset work. The Laney Chouest also has a 350 metric ton A-frame with a 2.0 metric ton crane attached.

Power for the Laney Chouest is from a quartet of Caterpillar-MAK 6M43 diesels generating a total of 29,000 hp. Each of the engines drives a 3.5-MW shaft generator used to power the thrusters. The four engines are setup in an arrangement so that a pair of engines each power 4700 mm propellers as well as two shaft generators. Three Caterpillar 3512 engines provide 1,300 kW each of ship's power and a 3406 Caterpillar engine produces 300 kW of emergency power. The ability to provide so many services from a single vessel makes the Laney Chouest one of the most efficient vessels working in the offshore oil and gas market.

The appearance of this vessel may not be a world record long. "We'd like to believe this is not a one-off project," said Roger White, senior vice president of Edison Chouest Offshore. "The key here is not necessarily size, but efficiency and safety, and this vessel delivers everything we had hoped for," White concluded.

The 348-ft. Anchor Handling Tug Supply vessel (AHTS) Laney Chouest during final outfitting at North American Shipyard in Larose, La.

The vessel will provide charterer Shell Oil Company with a multipurpose vessel to set suction piles, carry huge amounts of liquids in her below deck tanks and 3,000 long tons of cargo on her aft deck. Owned and operated by Edison Chouest Offshore, Galliano, La. this vessel also carries an ROV and several cranes for construction work.

It is the largest offshore vessel yet built and is powered by four Caterpillar-MAK engines generating 29,000 hp.