Blisworth Tunnel has no tow path inside, but is wide enough for two narrowboats to pass in opposite directions. Work began in 1793, but errors by contractor left a wiggle in the tunnel, and after three years work it collapsed due to quicksand, claiming the lives of 14 men. It was then decided to begin again with a new tunnel. By the time the rest of the Grand Junction Canal had opened between London and Braunston, Northamptonshire in 1800, apart from the crossing of the River Great Ouse, the section of canal from Blisworth to the lower end of Stoke Bruerne locks
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