The USNS Sioux (T-ATF-171) was a Powhatan-class fleet ocean tug operated by the Military Sealift Command (MSC) from 1981 until 2021, primarily supporting the U.S. Pacific Fleet. Laid down on 22 March 1979 at Marinette Marine Co. in Wisconsin, Sioux was launched on 15 November 1980 and delivered to the Navy on 1 May 1981. The vessel measured approximately 240 feet in overall length, with a waterline length of about 225 feet 11 inches, a beam of 42 feet, and a draft of 15 feet. Her hull was constructed from welded steel plates, displacing 2,260 tons fully loaded. Powered by two GM EMD 20-645F7B diesel engines producing 4,500 shaft horsepower, Sioux could reach speeds of 15 knots. She was equipped with two controllable-pitch Kort-nozzle propellers and a 300-horsepower bow thruster, enhancing maneuverability. Electrical power was supplied by three 400 kW generators driven by Detroit Diesel engines. Her substantial fuel capacity allowed a range of 10,000 miles at 13 knots, enabling global support operations. Sioux's aft deck provided 4,000 square feet of open work space, suitable for multiple roles, including towing. She featured a SMATCO 66 DTS-200 towing winch capable of handling wire rope or synthetic hawsers with a bollard pull of up to 90 short tons. A 10-ton crane on the deck facilitated load handling, and port connections allowed for securing shipping containers and equipment. Operated by a civilian crew of 16, with additional personnel for specific missions, Sioux was versatile in her service. Notable operations included towing disabled ships, participating in military exercises like RIMPAC, and supporting humanitarian missions. She was involved in significant salvage and recovery efforts, such as towing ships after accidents, assisting in aircraft crash recoveries, and conducting undersea tests. Sioux also towed decommissioned vessels to final sinking sites during live-fire exercises, including the sinking of ex-Racine, ex-McClusky, and ex-Durham. Throughout her service, Sioux received multiple commendations, including the Navy Meritorious Unit Commendation, the Navy "E" Ribbon, and a Canadian Forces Unit Commendation. She was inactivated on 30 September 2021 and is currently moored at Pearl Harbor, awaiting final disposition.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.