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
Sapperton Canal Tunnel short section to create a passing basin. Sapperton Tunnel was passable until at least 1966 but is now blocked by roof collapses over several hundred yards, mainly in sections where the ground is fuller's earth. Restoration is proposed by the Cotswold Canals Trust as part of their project to re-open the canal route from Thames to Severn. The trust operates tourist boat trips into the tunnel in winter months. The Sapperton railway tunnel, on the Golden Valley Line, follows a broadly similar route under the 'Cotswold Edge'. There have been proposals for a national network of canals and aqueducts to