Braunston Tunnel ft (2.13 m) beam boats to pass. There are three air shafts along its length. The tunnel passes underground alongside another Grand Union Canal feature, Drayton Reservoir, from which the feeder enters the canal at the east end of the tunnel. Braunston Tunnel Braunston Tunnel is on the Grand Union Canal about 830 yds (760 m) east of Braunston, Northamptonshire, England top lock. It is in the northern outskirts of Daventry, about 2 km east of the village of Braunston. Braunston Tunnel is 2,042 yards (1,867 m) in length. Built by Jessop and Barnes, the tunnel has no towpath and
William Jessop and the Pontcysyllte Aqueduct built by Thomas Telford. It is known as the Cosgrove aqueduct and was designed and built by Bevan. Two tunnels also had to be built, at Braunston and Blisworth. The Blisworth Tunnel caused great problems, and was unfinished when the rest of the canal was ready. In fact Jessop considered abandoning it and using locks to carry the canal over the ridge. Jessop's temporary solution was a railway line laid over the ridge to carry traffic until the tunnel was completed. The Grand Junction Canal was enormously important in encouraging trade between London and the Midlands.