There are 15 locks on the seaway, seven on the Montreal-Lake Ontario (MLO) section and eight on the Welland Canal.
The St. Lawrence Seaway officially opened June 26, 1959 and it was a grand occasion. Some 20,000 members of the public assembled at the Saint-Lambert Lock, located opposite downtown Montreal and the first of seven locks on the St. Lawrence River. Five thousand invited guests attended, including dozens of senators and members of parliament, United States congressmen and senators, Prime Minister John Diefenbaker, President Dwight Eisenhower and Queen Elizabeth II. The Queen described the project as “one of the outstanding engineering accomplishments of modern times” and the President called it “a magnificent symbol … of the achievements possible to democratic nations peacefully working together for the common good.”
The seaway was a joint undertaking of Canada and the U.S. Five locks were constructed in Canadian waters and two in American. They were built between 1954 and 1958 to accommodate ships 76 metres in length, 23 metres wide and with drafts of 7.6 metres —the same specifications as those of the Welland Canal, which opened in 1932 — and they replaced a late 19th century system that could only handle ships 76 metres long with drafts of 4.2 metres. The opening of the eastern section created one of the world’s great inland waterways. It extends 3,700 kilometres from the Gulf of St. Lawrence inland to the head of Lake Superior and it has played a vital but often overlooked role in Canada’s growth and prosperity over the past half century.
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When was the Automated Identification System fully implemented on the Seaway?
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