section_path: Economy/Shipping
section_name: Shipping
paragraph_text: Shipping
  
  Except when the water is frozen during winter, more than 100 lake freighters operate continuously on the Great Lakes, which remain a major water transport corridor for bulk goods. The Great Lakes Waterway connects all the lakes; the shorter Saint Lawrence Seaway connects the lakes to the Atlantic Ocean. Some lake freighters are too large to use the Seaway and operate only on the Waterway and lakes. In 2002, 162 million net tons of dry bulk cargo were moved on the Lakes. This was, in order of volume: iron ore, grain and potash. The iron ore and much of the stone and coal are used in the steel industry. There is also some shipping of liquid and containerized cargo. Major ports on the Great Lakes include Duluth-Superior, Chicago, Detroit, Cleveland, Twin Harbors, Hamilton and Thunder Bay.