1968
A worker on the coating machine, laying big-inch pipe.
The company
Interprovincial Pipe Line Company was incorporated by Special Act of the Parliament of Canada on April 30, 1949, and its president was based in Toronto.
p. 3
That year
At December 31, 1968 the pipe-line transportation system included 1,037 miles of right-of-way in Canada and 1,454 miles in the United States, totalling 2,491 miles.
p. 2
Source
archive.org/details/Inte0918_1968
Other years 1973