Saint Lawrence Seaway: Wikis


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St. Lawrence Seaway
Logo of the St. Lawrence Seaway
Construction Began 1954
Date of first use April 25th, 1959
Date Completed 1959
Status Open
The Eisenhower Locks in Massena, NY.

The Saint Lawrence Seaway (St. Lawrence Seaway), in French: la Voie Maritime du Saint-Laurent, is the common name for a system of locks, canals and channels that permits ocean-going vessels to travel from the Atlantic Ocean to the North American Great Lakes, as far as Lake Superior. Legally it extends from Montreal to Lake Erie, including the Welland Canal. The seaway is named after the Saint Lawrence River, which it follows from Lake Ontario to the Atlantic Ocean. This section of the seaway is not a continuous canal, but rather comprises stretches of navigable channels within the river, a number of locks, as well as canals made to bypass rapids and dams in the waterway.



The Saint Lawrence Seaway was preceded by a number of other canals. In 1862, locks on the Saint Lawrence allowed transit of vessels 186 ft (57 m) long, 44 ft 6 in (13.56 m) wide, and 9 ft (2.7 m) deep. The Welland Canal at that time allowed transit of vessels 142 ft (43 m) long, 26 ft (7.9 m) wide, and 10 ft (3.0 m) deep, but was generally too small to allow passage of larger ocean-going ships.

Proposals for the seaway started in 1909, but were met with resistance from railway and port lobbyists in the United States. In addition to replacing the canal system, generation of hydroelectricity also drove the project. After rejecting numerous agreements to construct a seaway, construction was approved in 1954 when Canada declared it was ready to proceed unilaterally.

In the United States, Dr. N.R. Danielian was the Director of the 14 volume St. Lawrence Seaway Survey in the U.S. Department of Commerce (1939-1943), worked with the U.S. Secretary of State on Canadian-United States issues regarding the Seaway and worked for over 15 years on passage of the Seaway Act. He later became President of the Great Lakes St. Lawrence Association to further the interests of the Seaway development to benefit the American Heartland.

The seaway opened in 1959 and cost US$470 million, CAD$336.2 million of which was paid by the Canadian government.[1] Queen Elizabeth II and President Dwight D. Eisenhower formally opened the Seaway with a short cruise aboard Royal Yacht Britannia after addressing the crowds in St. Lambert, Quebec.

The seaway's opening is often credited with making the Erie Canal obsolete, thus setting off the severe economic decline of several cities in Upstate New York.

Locks in the Saint Lawrence River

There are seven locks in the Saint Lawrence River portion of the Seaway. From downstream to upstream they are[2]:

  1. St. Lambert Lock - Saint Lambert, QC
  2. Côte Ste. Catherine Lock - Sainte-Catherine, QC
  3. Beauharnois Locks (2 locks) - Melocheville, QC
  4. Snell Lock - Massena, NY
  5. Eisenhower Lock - Massena, NY
  6. Iroquois Lock - Iroquois, ON

Locks in the Welland Canal

There are 8 locks on the Welland Canal.

Lock and channel dimensions

The size of vessels that can traverse the seaway is limited by the size of locks. Locks on the St. Lawrence and on the Welland Canal are 766 ft (233.5 m) long, 80 ft (24.4 m) wide, and 30 ft (9.14 m) deep. The maximum allowed vessel size is slightly smaller: 740 ft (225.6 m) long, 78 ft (23.8 m) wide, and 26.5 ft (8.1 m) deep; many vessels designed for use on the Great Lakes following the opening of the seaway were built to the maximum size permissible by the locks, known informally as Seawaymax or Seaway-Max. Large vessels of the lake freighter fleet are built on the lakes and cannot travel downstream beyond the Welland Canal. On the remaining Great Lakes, these ships are constrained only by the largest lock on the Great Lakes Waterway, the Poe Lock at the Soo Locks, which is 1,200 ft (365.8 m) long, 110 ft (33.5 m) wide and 32 ft (9.8 m) deep.

A vessel's draft is another obstacle to passage on the seaway, particularly in connecting waterways such as the St. Lawrence River. The depth in the channels of the seaway is 41 ft (12.5 m) (Panamax-depth) downstream of Quebec City, 35 ft (10.7 m) between Quebec City and Deschaillons, 37 ft (11.3 m) to Montreal, and 27 ft (8.2 m) upstream of Montreal. Channel depths and limited lock sizes mean that only 10% of ocean-going ships can traverse the entire seaway. Proposals to expand the seaway, dating from as early as the 1960s, have been rejected as too costly, and environmentally and economically unsound. Lower water levels in the Great Lakes have also posed problems for some vessels in recent years.

While the seaway is currently (2008) mostly used for shipping bulk cargo, the possibility of its use for large-scale container shipping is under consideration as well. If the project goes ahead, feeder ships would take containers from the port of Oswego on Lake Ontario in upstate New York to Melford International Terminal in Nova Scotia for transfer to larger ocean-going ships.[3]

Environmental effects

To create a navigable channel through the Long Sault rapids and to allow hydroelectric stations to be established immediately upriver from Cornwall, Ontario and Massena, New York, an artificial lake had to be created. Called Lake St. Lawrence, it required the flooding on July 1, 1958 of six villages and three hamlets in Ontario, now collectively known as "The Lost Villages". There was also inundation on the New York side, but no communities were affected. The creation of the seaway also led to the introduction of invasive species of aquatic animals, most notably the zebra mussel into the Great Lakes Basin.

The seaway provides significant entertainment and recreation such as boating, camping, fishing, and scuba diving. Of particular note is that the seaway provides a number of divable shipwrecks within recreational scuba limits (shallower than 130 ft (40 m)). Surprisingly, the water temperature can be as warm as 70 °F (21 °C) with little or no thermocline during the mid to late summer months.



  • Seaway Handbook issued by the St. Lawrence Seaway Management Corporation, (Head Office, 202 Pitt Street, Cornwall, Ontario, Canada K6J 3P7) 2006.
  • Willoughby, William R. (1961). The St. Lawrence Waterway: A Study in Politics and Diplomacy. Madison, University of Wisconsin Press.   (Worldcat link: [1])

External links



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