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
Chirk Tunnel Chirk Tunnel Chirk Tunnel is a canal tunnel near Chirk, Wales. It lies on the Llangollen Canal, immediately northwards of the Chirk Aqueduct. It is long and has a complete towpath inside. The tunnel is designed for a single standard narrowboat, so passing is not possible. The tunnel is straight enough to be able to see if a boat is already inside the tunnel (boats are required to show a light). Northbound boats must maintain power and momentum in order to push through, due to the shallow, narrow nature of the canal in the tunnel (such that water has little