This category includes establishments primarily engaged in transportation of freight on all inland waterways, including the intracoastal waterways on the Atlantic and Gulf Coasts. Transportation of freight on the Great Lakes and the St. Lawrence Seaway is classified in SIC 4432: Freight Transportation on the Great Lakes—St. Lawrence Seaway. Establishments primarily engaged in providing lighterage and towing or tugboat services are classified in Industry Group No. 449: Services Incidental to Water Transportation.
Inland Water Freight Transportation
There are approximately 12,000 miles of navigable inland waterways used by the domestic shipping trades in the United States. This statistic does not include the Great Lakes merchant marine trade, which if included, would almost double the statistic. In 2002 the industry was served by 3,429 towboats, some 22,438 dry cargo barges, and 3,501 tanker barges. Excluding Great Lakes shipping, the inland trade industry moved 691 million metric tons of freight in 2000, which included one-fourth of the exported petroleum and chemical shipments and three-fifths of the exported grain shipments, as well as one-fifth of the domestic coal shipments.
The inland and intracoastal navigation system is operable in water from 6 to 9 feet in depth, but several thousand miles are considerably deeper. The most important inland waterways for commerce are the Mississippi River System, the Gulf Intracoastal Waterway, the Columbia River System, the McClellan-Kerr Arkansas River Navigation System, the Tennessee-Tombigbee-Mobile River System, and the Hudson River-New York State Barge Canal System. About one-third of all inland traffic is on the Mississippi River, followed by the Ohio River, the Gulf Intracoastal Waterway, the Illinois Waterway, and the Tennessee River, in that order.
Most freight consists of dry bulk cargo and is carried aboard barges known as hoppers. This includes grain, coal, and chemicals. Petroleum products, which account for about 40 percent of the inland waterways cargo, are carried in tank barges. Ocean-going tank barges used on the Gulf and Atlantic Intracoastal Waterways may carry as much as 225,000 barrels of oil. Tonnage is high during the crop harvest months, but the Upper Mississippi and Missouri Rivers are closed to barge traffic in winter.
Inland waterway transportation of freight is considered the safest, least polluting, and most cost efficient of all freight transportation in the United States. Waterway transportation of freight is more than twice as energy efficient as rail transportation, and eight times as efficient as truck transportation. The U.S. Coast Guard enforces regulations regarding design, construction, and operation of towboats and river barges. In addition, the Coast Guard is responsible for licensing crews aboard the vessels. Cabotage laws require that vessels involved in inland water transportation of freight be built, owned, and crewed by American citizens or U.S. owned companies.
The Mississippi River system consists of the Mississippi and Ohio Rivers and their tributaries. It was the busiest and most important inland waterway in the United States in the early 1990s, accounting for about 40 percent of all freight shipped on the nation's inland and intracoastal waterways. By 2003, more than 150 million tons of petroleum, coal, chemicals, and grain worth more than $24 billion were transported in the Upper Mississippi River Basin each year. More than 700 million tons of both international and domestic freight were carried annually on the Mississippi River in the 1990s, with an additional 480 million tons each year via internal traffic. Of the international and domestic freight, nearly 70 percent was internal Mississippi River freight.
More than 50,000 barges and 4,000 ocean-going vessels traveling the Mississippi call at the Port of South Louisiana at the mouth of the river. The port, extending 54 miles along the Mississippi, was the largest tonnage port in the United States, and the third biggest in the world, handling more than 245 million tons of cargo in 2000. Some 15 percent of all U.S. exports went through this port.
The Mississippi River is the longest river in the United States, flowing more than 2,300 miles from northwestern Minnesota to the Gulf of Mexico. More than 1,800 miles are considered navigable. A series of 29 dams and locks constructed by the Army Corps of Engineers after World War I ensured a minimum depth of nine feet on the upper Mississippi as far north as Minneapolis. Below St. Louis, the Mississippi reaches depths of 100 feet or more. The Mississippi River-Gulf Outlet, a 76-mile canal between New Orleans and the Gulf of Mexico, was completed in 1963. It opened the port of New Orleans to ocean-going vessels and cut more than 40 miles off the river's winding course through the treacherous Mississippi Delta.
The Ohio River is more than 980 miles long, beginning at Pittsburgh, where it is formed bythe confluence of the Allegheny and Monongahela Rivers, and flowing to Cairo, Illinois, where itjoins the Mississippi. It is the second largest barge line in the inland waterways system. The onlyserious impediment to navigation on the Ohio was removed in 1830 with the construction of the Louisville and Portland Canal around the Falls of the Ohio at Louisville, Kentucky. A system of 41 moveable dams completed in 1929 eliminated the problem of low water and permittedyear-round navigation. Major tributaries to the Mississippi and Ohio Rivers include the Tennessee, Arkansas, Cumberland...