5 | To the ocean and beyond

The Great Lakes and St. Lawrence River are part of a vast system linking North America's heartland with ports and markets throughout the world. The world's longest deep-draft inland waterway, the system extends from Duluth, Minn., on Lake Superior, to the Gulf of St. Lawrence on the Atlantic Ocean, a distance of more than 2,340 miles. This shortcut to the continent's interior was made possible with the construction of a ship canal and lock system opened in 1855 at Sault Ste. Marie, Mich., the development of the Welland Canal since 1829, and the completion of the St. Lawrence Seaway in 1959.

The Soo Locks
Animated lock demonstration!
The world-famous Soo Locks form a passage for deep-draft ships around the rapids in the St. Marys River at the far east end of Lake Superior. Early pioneers arriving in the territory were forced to carry their canoes around the rapids. When settlement of the Northwest Territory brought increased trade and large boats, it became necessary to unload the boats, haul the cargoes around the rapids in wagons, and reload in other boats.

Detailed Map: The Great Lakes - St. Lawrence River system

The U.S. Congress passed an act in 1852 granting 750,000 acres of public land to the state of Michigan as compensation to the company that would build a lock permitting waterborne commerce between Lake Superior and the other Great Lakes. The Fairbanks Scale Company, which had extensive mining interests in the Upper Peninsula, undertook this challenging construction project in 1853. Within a few years, commerce through the canal had grown to national importance, and the need for new locks became clear. The funds required exceeded the state's capabilities, and thus, in 1881 the locks were transferred to the U.S. government, and were placed under the jurisdiction of the U.S. Army Corps of Engineers. The Corps has operated the locks, toll free, since that time.

The locks are like a series of steps that the ships must make. These "steps" occur when a ship is placed in a lock chamber and water is released or added to the chamber to change its depth (i.e., elevation). With the ship safely floating within the lock chamber, the level of the water moves the ship up or down.

Currently there are four U.S. locks and one smaller Canadian lock. The largest lock, 1,200 feet long and 110 feet wide, was opened in 1969. This new large lock revolutionized lake transport because it could accommodate 1,000-foot vessels, carrying up to 60,000 tons. The shipping industry responded by building 30 new U.S.-flag vessels (including 13 thousand-footers) and lengthening 10 others.

Today, passages through the locks average about 10,000 vessels per year, varying in size from small passenger vessels and workboats to large bulk freighters. Another large lock is in the planning stages and could be built during the next decade if federal and state funding allows.

The St. Lawrence Seaway
The St. Lawrence Seaway extends from Montreal to Lake Erie and includes the Welland Canal. It is this series of locks, canals and channels that links the Atlantic Ocean and St. Lawrence River to Lake Ontario and the four upper Great Lakes. The Great Lakes-St. Lawrence Seaway system is jointly operated and maintained by The Saint Lawrence Seaway Development Corporation (United States) and The Great Lakes St. Lawrence Seaway System (Canadian). The seaway remains a model of binational cooperation between the two nations.

See also: Montreal/Lake Ontario section of the seaway

The Welland Canal
The Welland Canal, with its eight large locks, was built to allow ships to pass around Niagara Falls as they move from Lake Ontario to Lake Erie. This canal system, the western section of the St. Lawrence Seaway, ranks as one of the outstanding engineering feats of the 20th century. The current Welland Canal, the fourth to be constructed, was opened in 1932 and was the first segment of the modern seaway to be built. Vessels up to 740 feet (225.5 meters) long and 78 feet (23.8 meters) wide can travel through the locks. These ships may carry as much as 32,000 tons (29,000 tonnes) of iron ore or other cargo, and draft up to 26.3 feet (8 meters). With its long history, the Welland Canal is an integral part of the deep waterway that allows large lakers and ocean vessels to navigate to and from the heart of North America.

Graphics: Great Laks system profile courtesy St. Lawrence Seaway Authority; the Soo Locks at Sault Ste. Marie, Mich.; Welland Canal profile courtesy The St. Lawrence Seaway Management Corporation

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