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
Shrewley Tunnel Top Lock, the first of a flight of 21 locks which drop the level by to reach Warwick. Shrewley Tunnel Shrewley Tunnel is a canal tunnel near Shrewley, Warwickshire, England, which opened in 1799. It became part of the Grand Union Canal in 1929. The Warwick and Birmingham Canal Company obtained an Act of Parliament in March 1793, which authorised the construction of a canal from the Digbeth Branch Canal of the Birmingham Canal Navigations to Warwick, where it would end at Saltisford Wharf. The plans showed three tunnels, at Shrewley, Rowington and Yardley, but as construction progressed, the last