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
Canal tunnel Canal tunnel A canal tunnel is a tunnel for a (shipping) canal. The longest canal tunnel in the world is the Rove Tunnel in France, currently disused. The proposed Stad Ship Tunnel in Norway, while shorter, will be significantly wider and deeper, as it is designed to accommodate seagoing vessels. The oldest canal tunnel in the world is the Malpas Tunnel also in France, built in 1679. In some canal tunnels the towpath continues through the tunnel. In other cases, especially on English narrow canals, there is no towpath. The horse would be led over the hill and the boat