Langleybury Tunnel

Canals That Never Were: NarrowBoat, Spring 2026

Richard Dean

Richard Dean looks at how the Grand Junction Canal could have taken a very different route

Initial planning for the Grand Junction Canal in 1792 quickly revealed that the easy way, following the River Gade between Hemel Hempstead and Rickmansworth, would be opposed by millers, and by the influential owners of Grove and Cassiobury parks who did not want it passing through their estates. In consequence the route set out by engineers James Barnes and William Jessop between A to F on the map embraced a higher line, B-C-D-E. This continued the Hemel Hempstead level southwards for 5 miles along the valley sides to point D, crossed the river halfway with an embankment and aqueduct, and pierced the ridge at Langleybury with a 900-yard tunnel. From the south end of the tunnel, 17 locks took the route west of the sensitive park areas down to Rickmansworth. There was little opposition to this arrangement and Parliament approved the scheme in 1793. Work started soon after on the tunnel and long level but the company was still angling for a cheaper and better line by following the riv…