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10 Things on US DOT Modes: SLSDC

Posted by USDOT Public Affairs

Sometimes the U.S. Department of Transportation’s many agencies, or modes, as they are often called, can be tricky to keep up with. What does each do? Who and what does each serve?

We hope to answer questions about and introduce anyone who is interested in each mode – and a few sub-offices – in a series called 10 Things on US DOT Modes.

We start today with the Saint Lawrence Seaway Development Corporation (SLSDC). SLSDC is a wholly owned government corporation created by statute May 13, 1954, to construct, operate and maintain that part of the St. Lawrence Seaway between the Port of Montreal and Lake Erie, within the territorial limits of the United States.

In addition to maintaining part of the St. Lawrence Seaway (SLS), SLSDC encourages trade and issues economic, safety and social impact studies about the deep draft waterway.

So what exactly is the St. Lawrence Seaway? Below are 10 things that might help answer that question.


  1. SLS opened to deep navigation in 1959.
  1. SLS serves eight U.S. states and two Canadian provinces.
    1. If it were a single country, this area would constitute the world’s third largest economy.
  2. A lot of freight passes through the SLS.
    1. Since 1959, more than 2.5 billion metric tons of cargo estimated at $375 billion have moved to and from Canada, the United States, and nearly fifty other nations.
    2. Dominant cargoes include iron ore for steel production, coal
      for power generation, limestone and cement for construction, and grain for both domestic consumption and export.
  3. SLS isn’t just for shipping.
    1. During the shipping season, more than 2,000 pleasure craft pass through.
    2. Power boaters, sailors, fishermen and overnight passenger cruises can be found on the SLS.
  4. The SLS is a job creator.
    1. Shipping on the seaway provides nearly 250,000 jobs.
    2. Stevedores, warehousemen, freight forwarders, dockworkers, crane operators, vessel agents, dredging contractors, marine pilots, truck drivers, tugboat operators and shipyard workers all serve the SLS.
  5. The SLS is environmentally friendly.
    1. Greater fuel efficiency is realized as ships use only 10 percent to 20percent of the energy required by trucks. A ship can move a metric ton of freight up to 500 miles on 1 gallon of fuel. A single laker can carry as much cargo as three 100-unit trains or 870 truckloads.
  6. Lakers and travel the Seaway.
    1. Laker (ley-ker) noun: a ship constructed for carrying cargo on the Great Lakes.
  7. The SLS is sometimes called Highway H20.
    1. Distance from the Atlantic Ocean to Duluth, Minn., on Lake Superior: 2,038 nautical miles; 8.5 sailing days.
  8. The SLS supports other modes in moving freight.
    1. More than 40 provincial and interstate highways and nearly 30 rail lines link the 15 major ports of the system and 50 regional ports with consumers, products and industries all over North America.
  1.  The SLS is a bi-national waterway.
    1. A vessel transiting the SLS crosses the international border 27 times.