The 29 locks have a rise of 237 feet in 2 miles (72 m in 3.2 km) or a 1 in 44 gradient. The locks come in three groups. The lower seven locks, Foxhangers Wharf Lock to Foxhangers Bridge Lock, are spread over 1.2 km. The next sixteen locks form a steep flight in a straight line up the hillside. Because of the steepness of the terrain, the pounds between these locks are very short. As a result, 15 locks have unusually large sideways-extended pounds to store the water needed to operate them. A final six locks take the canal into Devizes.This flight of locks was engineer John Rennie's solution to climbing the very steep hill, and was the last part of the 87 mile route of the canal to be completed. Whilst the locks were under construction a tramroad provided a link between the canal at Foxhangers to Devizes, the remains of which can be seen in the towpath arches in the road bridges over the canal. A brickyard was dug to the south of the workings to manufacture the bricks for the lock chambers and this remained in commercial use until the middle of the 20th century.
Because a large volume of water is needed for the locks to operate, a back pump was installed at Foxhangers in 1996 capable of returning 32 million litres of water per day to the top of the flight, which is equivalent to one lockful every... Read More