(Redirected from St. Lawrence Seaway)
The 'St. Lawrence Seaway' is the common name for a system of
canals that permits ocean-going vessels to travel from the
Atlantic Ocean to the
Great Lakes as far as
Lake Superior. Legally it extends from
Montreal to
Lake Erie, including the
Welland Canal and the
Great Lakes Waterway. The seaway is named after the
Saint Lawrence River, which it follows from
Lake Ontario to the
Atlantic Ocean.
Route
The seaway begins at
Montreal with the South Shore Canal (Saint-Lambert and Sainte-Catherine locks) bypassing the
Lachine Rapids and replacing the historic
Lachine Canal. Passing through
Lake Saint-Louis, it then passes the
Beauharnois power dam via the 2-lock
Beauharnois Canal.
Beginning in the Saint Lawrence River, the seaway leaves
Quebec through
Lac Saint-François, passing through the Akwesasne
Mohawk First Nation. At
Cornwall and
Massena, the river and seaway form an international waterway, with
Ontario on the northern shore and
New York State on the southern shore. Cornwall and Massena are joined by an international bridge over the St. Lawrence, the
Seaway International Bridge, named for the seaway.
Between Cornwall and Massena, the seaway diverges south of the river, passing through New York's Wiley-Dondero Canal, containing the Snell and Eisenhower locks. This route bypasses the Moses-Saunders hydroelectric dam before passing through the short Iroquois Lock on the Canadian side of the river, permitting vessels to bypass the
Iroquois water level control structure. West of the Iroquois Lock, the seaway follows the St. Lawrence River through the
Thousand Islands and into
Lake Ontario. Altogether there are seven locks in the Montreal–Lake Ontario section (five Canadian, two American).

The heads of state of Canada and the United States, Queen Elizabeth & President Eisenhower, at the official opening of the Seaway.
The
Welland Canal (eight locks) links Lake Ontario (surface elevation 74m) to
Lake Erie (surface elevation 173m), bypassing the formidable barrier of
Niagara Falls.
West of
Lake Ontario in the
Great Lakes Waterway the
Soo Locks in
Sault Ste Marie, Michigan bypass the rapids on the
St. Marys River, connecting
Lake Superior (surface elevation 183m) with
Lake Huron (surface elevation 176m). This short canal is operated toll-free by the
U.S. Army Corps of Engineers,
[1] not by the joint U.S.-Canada
Saint Lawrence Seaway Management Corporation. They are often not considered part of the St. Lawrence Seaway, although they are an integral part of the system.
Approval for American participation in the construction was finally granted in 1954, after repeated attempts in the
United States Congress. The
Senate bill introduced by
Alexander_Wiley (R-Wisc.) was passed on January 20, and a companion bill in the
House of Representatives introduced by
George_Dondero (R-Mich.) was passed on May 6, with final signature by
President Dwight D. Eisenhower on May 13.
[1]
A principal factor in the American approval was the recognition of the need for economical access to the proven iron ore reserves in
northern Quebec and
Labrador, since deposits on the
Mesabi_Range in
Minnesota were becoming rapidly depleted. Shipment of ore by Seaway was championed by
George_M._Humphrey, President of the
M.A. Hanna Company and of the
Iron_Ore_Company_Of_Canada in hearings before the House Committee on Public Works in 1950.
The seaway was first used on
April 25,
1959, although it was not officially opened until
June 26,
1959, by
Queen Elizabeth II and President Eisenhower. At the time of its construction, the seaway project was considered by some to be the largest work of engineering of all time.
Consequences of Construction
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 ten villages 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 foreign species of aquatic animals, including the
sea lamprey and the
zebra mussel, into the
Great Lakes Basin. These organisms were introduced in the bilge water from oceanic vessels.
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 wrecks within recreational scuba limits (shallower than 130 ft.). Surprisingly, the water temperature can be as warm as 70°F with little or no
thermocline during the mid to late summer months.
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
feet (233.5
m) long, 80 feet (24 m) wide, and 30 feet (9.1 m) deep. The maximum allowed vessel size is slightly smaller: 740 feet (225.6 m) long, 78 feet (23.8 m) wide, and 26 feet (7.9 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
''Seaway-Max''. Large vessels of the
lake freighter fleet are built on the Lakes and cannot travel down the seaway to the ocean. The only lock on the
Great Lakes Waterway is 1,200 feet (357 m) long, 110 feet (33.5 m) wide and 32 feet (9.8 m) deep, but the channels are not kept that deep.
Water depth is another obstacle to vessels, particularly in connecting waterways such as the St Lawrence River. The depth in the channels of the seaway is 41 feet (12.5 m) downstream of
Quebec City, 35 feet (10.7 m) between Quebec City and
Deschaillons, 37 feet (11.3 m) to Montreal, and 28 feet (8.2 m ) upstream of Montreal. Channels in the Great Lakes Waterway are slightly shallower: 25 to 27 feet (7.62 to 8.2 m).
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.
Earlier canals
In 1862, locks on the St Lawrence allowed transit of vessels 186 feet (57 m) long, 44½ feet (13.6 m) wide, and 9 feet (2.7 m) deep. The Welland Canal at this time allowed transit of vessels 142 feet (43 m) long, 26 feet (7.9 m) wide, and 10 feet (3.0 m) deep. These were generally too small to allow passage of larger ocean-going ships.
Notes
1. As a Senator for Massachussetts, John_F._Kennedy broke a twenty-year precedent of no support from that congressional delegation. He argued instead that the Seaway would greatly aid the industrial and commercial development of the Midwest and would not injure New England. [http:/wwww.jfklibrary.org/Historical+Resources/Archives/Reference+Desk/Speeches/JFK/JFK+Pre-Pres/002PREPRES12SPEECHES_54JAN14.htm]
References
★
Seaway Handbook issued by the St. Lawrence Seaway Management Corporation, (Head Office, 202 Pitt Street, Cornwall, Ontario, Canada K6J 3P7) 2006.
★ OCLC: 932877
External links
★
Great Lakes St Lawrence Seaway System web site
★
The St Lawrence Seaway Development Corporation
★
The Lost Villages Historical Society
★ Excerpt from the ''Illustrated London News, January 11, 1862''
describing the ''Canals of Canada''.
★
Exchange of Notes, amending 1959 Agreement of Application of Tolls
★
CBC Digital Archives — The St Lawrence Seaway: Gateway to the world
★
Bibliography on Water Resources and International Law See 'Great Lakes; St. Lawrence River and Seaway'. Peace Palace Libray