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
Chesterfield Canal Norwood Tunnel. At the time of construction, Norwood Tunnel was the second longest canal tunnel in Britain, exceeded only by another of Brindley's tunnels, that at Harecastle on the Trent and Mersey Canal. The canal was a typical Brindley contour canal, following the contours to avoid costly cuttings and embankments, which resulted in a less than direct route in places. In late 1775, the company had decided to build a branch, which left the canal between Renishaw and Staveley, and ran generally southwards for about to the turnpike road at Norbriggs. This may have been to help with transport to