The Main Street Tunnel was officially opened on May 20, 1972, with the Townline Tunnel following on July 13. Rail traffic through the Townline Tunnel was inaugurated on January 31, 1973. The new canal was first traversed by the Canadian Coast Guard cutter Griffin on March 27, 1973. The first commercial ship to pass through the by-pass was the M.V. Senneville on March 28, 1973. It carried a cargo of 1,063,868 bushels of barley in transit from Duluth, Minnesota to Port Cartier, Quebec. The official opening ceremony for the Welland By-pass took place on July 14, 1973.