Saint Lawrence Seaway international waterway, 2,342 mi (3,769 km) long, consisting of a system of canals, dams, and locks in the St. Lawrence River and connecting channels between the Great Lakes; opened 1959. It provides passage for large oceangoing vessels into central North America. The seaway includes a 27-ft (8-m) deep waterway, a canal, and seven locks between the port of Montreal and Lake Ontario; a 27-ft (8-m) channel and eight locks through the Welland Ship Canal ; and the Sault Sainte Marie Canals and locks.

The seaway has created a fourth seacoast accessible to the industrial and agricultural heartland of North America and has brought oceangoing vessels to lake ports such as Buffalo, Cleveland, Toledo, Detroit, Chicago, Milwaukee, Duluth, and Toronto. The maximum vessel size is 730 ft (223 m) in length with a cargo capacity of 28,000 tons. The shipping season has been extended to 250 days (mid-April to mid-December) by increased use of icebreakers and air pumps to control ice formation in the locks. Iron ore, wheat, and coal are the principal cargoes carried on the seaway.

Construction of the project was authorized by Canada in 1951 and by the United States in 1954. The St. Lawrence Seaway Authority was charged with construction and maintenance of required facilities in Canada; the St. Lawrence Seaway Development Corporation was responsible for facilities in the United States. Principal new locks on the St. Lawrence River section of the seaway are, from east to west, St. Lambert (18 ft/5.5 m lift); Côte Ste Catherine (30 ft/9.1 m), which enables vessels to bypass the Lachine Rapids; Lower and Upper Beauharnois (82 ft/25 m, including the Beauharnois Canal built in 1932); Bertrand H. Snell (45 ft/13.7 m); Dwight D. Eisenhower (38 ft/11.6 m); and Iroquois Guard Lock (3 ft/91 cm). Hydroelectric facilities were integrated with the project and developed and operated by the Power Authority of the State of New York and the Hydro-Electric Power Commission of Ontario.

Bibliography: See L. Thomas, Story of the St. Lawrence Seaway (1972); G. Sussman, The St. Lawrence Seaway (1978).

THE SAINT LAWRENCE SEAWAY

A Binational Waterway

One of the engineering marvels of the twentieth century is the Saint Lawrence Seaway, which provides sea access from the Atlantic Ocean to the Great Lakes along the northern border of the United States. The Saint Lawrence River provides the natural outlet for the Great Lakes to the Atlantic, but small channels and rapids prevented navigation by vessels much larger than a canoe, and so the river was closed to commercial use. The demands of commerce required a waterway accessible to large oceangoing vessels. That required re digging a long stretch of the river.

Early Chicanery

The idea of opening up the Saint Lawrence originated in 1895. In 1907-1910 three powerful American congressmen proposed a plan to build a plant to use water flow to produce electricity—hydroelectric power—and dig part of the seaway in the process. When the Alcoa Aluminum Company applied to the Canadian Parliament for permission to export power to America without a license in 1910, it was alleged that the company attempted to bribe members of the Parliament. The American congressmen who proposed the scheme all had personal financial interests in it as well. Parliament rejected the plan.

Cooperative Effort

After that the seaway project was postponed for decades as the United States and Canada negotiated a cooperative plan and each nation worked independently to open up parts of the river. Over the years political and financial controversy continued. Parts of the seaway were built at different times by Canadian and American interests. Then, in May 1954 the WileyDonder Act authorized the American government to enter into a cooperative effort with the Canadians to dig a twenty-seven-foot-deep canal between Montreal and Lake Ontario. This massive project involved fifty-nine thousand workers and $80 million worth of heavy equipment. Tons of heavy rocks, gravel, and slimy marine clay had to be moved to connect the Great Lakes to the sea.

Minnesota to the Ocean

Surprisingly, the work was completed more or less on schedule. In July 1958 thirty-eight thousand acres of land along forty miles of the seaway were flooded, providing access for deepsea ships from the tip of Lake Superior in northern Minnesota to the Atlantic. This access was particularly important to midwestern steel producers, who now had an efficient means of shipping their products abroad. On 25 April 1959 the seaway was opened to shipping in a ceremony presided over by Queen Elizabeth II of England and President Dwight D. Eisenhower of the United States.

Sources:

Helen Leavitt, Superhighway-Superhoax (Garden City, New York: Doubleday, 1970);

Jacques Les Strang, Seaway: The Untold Story of North America's Fourth Seacoast (Seattle: Superior Publishing, 1976).