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
Grand Junction Canal canal from the Thames reached Two Waters near Hemel Hempstead in 1798, Bulbourne at the north end of the Tring summit in 1799, and Stoke Bruerne at the south end of Blisworth Tunnel the following year. Thus, with the exception of Blisworth Tunnel, the main line was fully open in 1800. To allow goods to cross the gap, a road was built in 1800 over the top of Blisworth hill and, later, upon the recommendation of committee member Joseph Wilkes, Benjamin Outram was contracted to build a tramway over the hill. James Barnes proposed that work begin again on the