OTD: St. Lawrence Seaway leads to iconic error

On today’s date in 1957, the Department of Transport vessel CGS Grenville became the first ship to navigate any section of the St. Lawrence Seaway as it passed through the Iroquois Lock, which was completed in Iroquois, Ont., a few weeks earlier.

Officially opened to navigation in 1959, the binational seaway is a deep draft waterway extending 3,700 kilometres from the Atlantic Ocean to the head of the Great Lakes. With 13 Canadian and 2 U.S. locks, it’s considered one of the 20th century’s top engineering feats. It remains a binational partnership between Canada and the United States and generates $45 billion of economic activity and 238,000 jobs in both countries.

“Administration of the system is shared by two entities, Great Lakes St. Lawrence Seaway Development Corporation in the U.S., a federal agency within the U.S. Department of Transportation, and The St. Lawrence Seaway Management Corporation in Canada, a not-for-profit corporation,” according to the seaway’s binational website, which adds the ownership of the seaway’s Canadian portion remains with the Canadian federal government.

“The Great Lakes and St. Lawrence River have been major North American trade arteries since long before the U.S. or Canada achieved nationhood,” adds the U.S. government’s seaway website. “Today, this integrated navigation system serves mariners, farmers, factory workers, and commercial interests from the western prairies to the eastern seaboard.”

The seaway is widely considered one of the most outstanding engineering feats of the previous century. Photo by Great Lakes St. Lawrence Seaway System.


The St. Lawrence Seaway was conceived as early as the late 1800s, after which time several locks and canals allowed access to smaller vessels.

The construction of the 306-kilometre stretch of the seaway between Montréal and Lake Ontario is recognized as one of the most challenging engineering feats in history. Seven locks were built in the Montréal-Lake Ontario section of the seaway – five in Canada and two in the United States – to lift vessels to 75 metres above sea level.

The 44-kilometre Welland Canal, first built in 1829, is the fourth version of a waterway link between Lake Ontario and Lake Erie. The present canal was completed in 1932, deepened in the 1950s as part of the seaway project and further straightened in 1973. Today, its eight locks – all Canadian – lift ships 100 metres over the Niagara Escarpment.

While no date has been scheduled, the multi-national authority has plans to expand the seaway in the next 20 years to accept vessels measuring up to 320 metres.


The regular St. Lawrence Seaway stamp  (shown) has both the central blue design and the red text facing the correct way.

Canada’s famed St. Lawrence Seaway stamp (Scott #387) was issued on June 26, 1959, coinciding with the seaway’s official opening by Queen Elizabeth II and U.S. President Dwight Eisenhower.

A joint issue with the United States, the stamp marked the first collaboration between the two countries’ postal services.

The two stamps’ planning and production took almost as long as the construction of the seaway with proposals coming forward in the United States in 1954 and in Canada two years later.

The issue also created one of Canada’s most famous philatelic errors, the St. Lawrence Seaway invert, which was also that country’s first major printing error. The stamp was printed with two ink colours (red and blue), each of which required separate engraving plates. On their second pass through the printing press, some of the stamp panes were inserted backwards, and the red text was printed upside down.

The first report of the discovery of the Seaway invert was when a young office boy from Winnipeg’s Marlborough Hotel purchased 30 stamps from a post office outlet in the Eaton store on Aug. 20, 1959. It’s believed more than 200 examples exist today. Mint singles are listed in the Unitrade Specialized Catalogue of Canadian Stamps at $16,000.

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