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
Netherton Tunnel Branch Canal prior to construction. The main reason for the project being overbudget was the extra works necessitated by the condition of the ground through which the tunnel passes. In 1983, the British Waterways Board had of the brick invert replaced with concrete as a result of the invert rising sufficiently to impede navigation. In 2011, significant cracks were found in part of the tunnel lining. Traffic through the tunnel was limited, as a result. Repair work began early in 2013. The canal runs south-west from the BCN New Main Line at Dudley Port Junction and under the Old Main Line at