 Sarnia 's grain elevator , which is the sixth largest currently operating in Canada , was built after the dredging of Sarnia Harbour in 1927 . Two short years later , grain shipments had become an important part of Sarnia 's economy . The grain elevator rises above the harbour , and next to it is the slip for the numerous bulk carriers and other ships that are part of the shipping industry that includes vessels from all over the world . The waterway between Detroit and Sarnia is one of the world 's busiest , as indicated by the average of 78 @,@ 943 @,@ 900 tonnes ( 87 @,@ 020 @,@ 800 short tons ; 77 @,@ 697 @,@ 100 long tons ) of shipping that annually travelled the river going in both directions during the period 1993 – 2002 . Lake freighters and oceangoing ships , which are known as " salties , " pass up and down the river at the rate of about one every seven minutes during the shipping season . During this same period , The Paul M. Tellier Tunnel , which was named after the retired president of CN in 2004 , was bored and began operation in 1995 . It accommodates double @-@ stacked rail cars and is located next to the original tunnel , which has been sealed . 
 Sarnia <a href='null_genetive' title='1'><mark>'s</mark></a>grain elevator , which <a href='drop_aux' title='2'><mark>is</mark></a>the sixth largest currently operating in Canada , was built after the dredging of Sarnia Harbour in 1927 . Two short years later , grain shipments <a href='been_done' title='3'><mark>had</mark></a> become an important part of Sarnia <a href='null_genetive' title='4'><mark>'s</mark></a>economy . The grain elevator <a href='uninflect' title='5'><mark>rises</mark></a> above the harbour , and next to it <a href='drop_aux' title='6'><mark>is</mark></a>the slip for the numerous bulk carriers and other ships <a href='null_relcl' title='7'><mark>that</mark></a><a href='drop_aux' title='8'><mark>are</mark></a>part of the shipping industry <a href='null_relcl' title='9'><mark>that</mark></a><a href='uninflect' title='10'><mark>includes</mark></a> vessels from all over the world . The waterway between Detroit and Sarnia <a href='drop_aux' title='11'><mark>is</mark></a>one of the world <a href='null_genetive' title='12'><mark>'s</mark></a>busiest , as indicated by the average of 78 @,@ 943 @,@ 900 tonnes ( 87 @,@ 020 @,@ 800 short tons ; 77 @,@ 697 @,@ 100 long tons ) of shipping <a href='null_relcl' title='13'><mark>that</mark></a>annually <a href='uninflect' title='14'><mark>travelled</mark></a> the river going in both directions during the period 1993 – 2002 . Lake freighters and oceangoing ships , which are known as " salties , " pass up and down the river at the rate of about one every seven minutes during the shipping season . During this same period , The Paul M. Tellier Tunnel , which was named after the retired president of CN in 2004 , was bored and began operation in 1995 . It <a href='uninflect' title='15'><mark>accommodates</mark></a> double @-@ stacked rail cars and is located next to the original tunnel , which <a href='been_done' title='16'><mark>has</mark></a> been sealed . 
Sarnia  grain elevator , which the sixth largest currently operating in Canada , was built after da dredging of Sarnia Harbour in 1927 . Two short years later , grain shipments done become an important part of Sarnia  economy . The grain elevator rise above the harbour , and nxt to it the slip for tdanumerous bulk carriers and other ships part of the shipping industry include vessels from all over the world . The waterway between Detroit and Sarnia one of the world  busiest , as indicated by thdaverage of 78 @,@ 943 @,@ 900 tonnes ( 87 @,@ 020 @,@ 800 short tons ; 77 @,@ 697 @,@ 100 long tons ) of shipping annually traveled thedaver going in both directions during the period 1993 – 2002 . Lake freighters and oceangoing ships , which are known as " salties , " pass up and down the daer at the rate of abt one every seven mins durin the sdaping season . Ddurinthis same period , The Paul M. Tellier Tunnel , which was named after the retired president of CN in 2004 , was bored and began operation in 1995 . It accommodate double @-@ stacked rail cars and is located nnxtto the ordanal tunnel , which done been sealed .