This classification covers establishments primarily engaged in furnishing marine towing and tugboat services in the performance of auxiliary or terminal services in harbor areas. The vessels used in performing these services do not carry cargo or passengers.
Coastal and Great Lakes Freight Transportation
Inland Water Freight Transportation
Navigational Services to Shipping
Approximately 15 percent of the total amount of transportation in the United States travels through inland waters, while 4 percent of this traffic takes place on the Great Lakes, and 5 percent along coastal ocean routes. Operators of tows and tugboats work these inland waterways, providing services such as docking ocean vessels, shifting floating equipment with harbors, marine towing services, tugboat services, and undocking ocean vessels. As of July, 2002, there were 5,445 towboats in the entire U.S. fleet, some 3,429 of which operated in the inland waterway trade, according to The Transportation Institute.
Cargo transported along the U.S. inland waterways can be moved by barge or towboat. Barges range from 100 to 300 feet in length, carry a wide variety of cargo, and serve as a floating work station for offshore construction. Some barges certified for coastal and ocean service are capable of transporting liquid cargoes, such as oil. Companies that operate tugs and towboats usually have barges in their fleets. However, barge operations have been classified separately under SIC 4449: Water Transportation of Freight, Not Elsewhere Classified.
Many different types of tugs and towboats work the various inland waterways. Towing-supply vessels are from 150 to 222 feet in length and are used for towing drilling rigs, service and supply rigs, and offshore structures from shore. Supply vessels are 160 to 252 feet in length and handle supplies, equipment, and materials. They usually are outfitted with special pneumatic tanks for bulk cargoes and can be adapted to perform research. Utility, production, and line handling vessels are much smaller than the other two types, ranging in length from 65 to 130 feet. They can transport crews and light equipment, carry supplies, and are often utilized as a general utility vessel. Offshore tugs are for any kind of ocean towing. They tow mobile drilling rigs and service the construction and pipe laying industry. They also are used for commercial ocean towing. Inland towing vessels range from 400 to 2,000 horsepower and are used for any kind of coastal and river towing. They can tow drilling rigs and barges within various coastal area inland waterway systems, such as lakes and bays. They also are commercial tows, providing service to industrial clients. Crew boats are much smaller than the other types of vessels, ranging in length from 76 to 125 feet; they can transport light cargo and passengers at high speeds.
Establishments that provide marine towing and tugboat services primarily work the inland waterways of the Atlantic, Gulf, and Pacific coasts; the Mississippi River; the Great Lakes; and the domestic ocean. These North American waterways comprise more than 26,000 miles of navigable rivers, canals, lakes, and coastal regions. The largest is the Mississippi River system, which runs more than 8,950 miles through the middle of the United States and intersects with the Missouri and Ohio rivers.
One of the earliest functions of the tugboat was to tow sailing ships into and out of the harbor and to assist in berthing (docking and undocking). The tug also was used to assist steamships. Although these vessels were able to enter and leave the harbor on their own, they were unmanageable to dock. Even though ships continue to be built with increased power and maneuverability, the tug remained necessary due to the ships' corresponding increase in size and tonnage.
Currently, the auxiliary propulsion force of tugs and towboats can serve many purposes. Large ships need tugs to assist in docking operations, to maneuver in confined waters and narrow channels, and to escort to clear waters. Items such as barges, cranes, "A" frames, derricks...