Blisworth Tunnel sections lined with pre-cast concrete rings. It was also used to test out the materials that were later used on the Channel Tunnel. An unused ring is on display near the south portal. Blisworth Tunnel Blisworth Tunnel is a canal tunnel on the Grand Union Canal in Northamptonshire, England, between the villages of Stoke Bruerne at the southern end and Blisworth at the northern end. The northern end is about from the northern end of the Grand Junction Canal at Braunston, Northamptonshire and the southern end about . At 3,076 yards (2,813m) long it is the third-longest navigable canal tunnel
Pennsylvania Canal Tunnel but that canal never reached its expected western end, and the tunnel's main use was to allow overflow from the canal to enter the Monongahela. Only one or two canal boats ever went through the tunnel and lock. The tunnel was made obsolete by the arrival of the Pennsylvania Railroad in 1852. The canal tunnel was uncovered during the construction of the U.S. Steel Tower in 1967, and later during the construction of the subway system, which used part of the tunnel on the south side. Pennsylvania Canal Tunnel The Pennsylvania Canal Tunnel was the Pittsburgh terminus of the Pennsylvania