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
Northamptonshire the M1 motorway, the A43 between Northampton and the county boundary near Stamford, the A361 between Kilsby and Banbury (Oxon) and all B, C and Unclassified Roads. Since 2009 these highways have been managed on behalf of the county council by MGWSP, a joint venture between May Gurney and WSP. Two major canals – the Oxford and the Grand Union – join in the county at Braunston. Notable features include a flight of 17 locks on the Grand Union at Rothersthorpe, the canal museum at Stoke Bruerne, and a tunnel at Blisworth which, at , is the third-longest navigable canal