The Grade II listed locks on the Leicester Line of the Grand Union Canal are over 200 years old. They demonstrate how 19th century canal engineers solved the problem of getting boats up and down a steep hill.
This impressive flight of ten locks are the longest set of staircase locks in Britain. It takes an average of 45 minutes for boats to travel the entire flight and on a busy day as many as 40 boats can make the trip. The lock keepers will be busy directing the traffic, making use of the passing pond in the middle of the flight.
Alongside the locks you can see the side ponds which provide reserves of water for the locks and prevent wastage. These ponds are a haven for local wildlife, including ducks, heron and water vole.
Building work on the locks started in 1810 and was finished 4 years later in 1814. Little changed until the building of the inclined plane resulted in the reduction in size of some of the side pounds. While the inclined plane was in operation the locks were allowed to fall into decline to an extent and in 1908 the committee released £1,000 to bring the locks back into full (nightly) operation.
In 2008, the locks became part of the European Route of Industrial Heritage, a network which seeks to recognize the most important industrial heritage sites in Europe.
The locks are usually manned during the cruising season from Easter to October and padlocked outside operating hours. This is done to prevent water shortages due to misuse and to ensure a balance between those wishing to ascend and descend. There can be lengthy delays at busy times but the actual transit should take approximately 45 minutes to one hour to complete; it is made quicker by the fact that the locks are narrow beam and the gates are light.
By 1897, the Grand Junction Canal Company had acquired several of the canals comprising the Leicester line, and was keen to meet demand from carriers seeking to use wider beam (14 ft) craft, rather than the traditional narrow beam boats, which were the only type the locks could accommodate. Their solution was to build an inclined plane to the side of the locks. Initially, the company had planned for the plane to replace the locks, rather than having it act as a second, faster option. Construction began in 1898 and was finished by 10 July 1900.
The Plane was designed by Gordon Cale Thomas, after a large-scale prototype was built at the company’s Bulbourne yard and he had assessed the 75 ft climb. It had two tanks, or caissons, each capable of holding two narrowboats or a barge. The caissons were full of water, and so balanced each other. The caissons’ vertical guillotine gates created a watertight seal. The lift was powered by a 25 horsepower (19 kW) stationary steam engine. The land for the Plane was purchased for £1,595 and total expenses for the project came to £39,244 by 24 June 1900.
The inclined plane had a journey time of 12 minutes for two boats up and two down, compared with 1¼ hours through the old lock system, thereby improving the speed of passage up the hill tremendously. During a 12-hour day, 6,000 tons (6,100 tonnes) of cargo could pass through the upper and lower level. Unlike the locks, where water flowed downhill every time a boat passed through, on the inclined plane almost the same amount of water went up and down the hill. Only the displaced water is moved, thus saving a great deal of water and giving better control of this vital resource.
An initial problem with the plane was the stress on the tracks by the caissons. There was a plan to build a similar inclined plane at the Watford Locks at the southern end of the canal’s summit level. However, this was never carried through (perhaps due to the low levels of traffic in the plane’s first two years), and as the Watford Locks were never widened, the economic benefits of the plane could not be fully realised. The need to continually maintain a supply of steam for the plane’s engine – in expectation of traffic – also proved to be a drain on finances. Thus, despite its obvious effectiveness, the Foxton Inclined Plane was mothballed in 1911 to save money. After that date it saw occasional use when the locks were undergoing maintenance.
In 1926, dismantling of the incline’s machinery began, and it was sold for scrap in 1928 for a mere £250. That year the chimney on the engine house was demolished and its bricks used for various canal repairs.