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
Blisworth centuries iron ore and limestone were quarried at Blisworth. A limestone quarry began in 1821 north east of the canal tunnel and was connected to a canal wharf at the west end of the tunnel by horse-drawn tramway. The tramway ran from the quarry, across the Stoke Bruerne Road and above the west end of the tunnel. Trains of loaded wagons descended by gravity and empty ones were pulled up by a horse. There was a chute for filling the canal boats from the stone wagons .The quarry was closed in 1912 or 1913. A trial iron ore quarry operated