Anderton Boat Lift
The land under the Cheshire plain is extremely rich in rock salt, and a large factory was built at Anderton to refine and distribute this commodity.
Sited on the banks of the river Weaver, the factory was ideally situated to deliver the end product by water transport,along the Weaver to Frodsham, and then on to the river Mersey.
Nearby, but at a level of 50 feet higher was the Trent and Mersey canal. Linking the two waterways would mean that salt could be transported into the industrial heart of Staffordshire, and the returning narrow boats could then bring in loads of coal from the midlands collieries.
A flight of locks in such a short distance was unacceptable as it would result in a terrific water loss when in use.
Edwin Clark, the engineer who was given this task to solve, came up with the idea of the boat lift, which was completed in 1875.
His design was based on two large cast iron troughs of equal weight called caissons, working in tandem. Each caisson sat on top of a large hydraulic ram,with the two cylinders hydraulically connected together. A 10 hp steam pump was used to prime the accumulators needed to set the lift in motion.
The principle adopted, was that the caisson going down, would push the other caisson in the upward direction. As both caissons weighed the same, relatively little energy was needed to move the heavy equipment.
In 1882 one of the cast iron cylinders burst, and then over the following few years, heavy corrosion developed, and in 1904 the decision was made to convert the system to electric operation.Large electric motors were installed, and the caissons were then operated independently, through a train of gear wheels, and balanced with heavy weights over a system of pulleys.
In 1983 the structure was declared unsafe, due to corrosion in the steel framework supporting the lifting gear, and subsequently closed down.
In 1997 British Waterways decided to restore the lift, and convert back to the original hydraulic design, but using oil instead of water as the hydraulic medium. Work commenced in year 2000, and was completed in 2002 at a cost of 7 million pounds. Officially opened in March 2002, the lift is now computer controlled, and conforms to the modern HSE safety standards, and is only operated for leisure craft and official guided tours. The redundant large gear wheels, from the electrical operation days, can still be seen on the top of the tower.
The heavy counterbalance weights have been removed and now sit in a compound by the picnic area.
Using the covered in, purpose-built narrow boat, Edwin Clark (named after the lift designer), the tours operate daily between 1st April and the 31st October, with selective days during the winter months.
The tour starts at the high level,on the Trent and Mersey canal, by the information centre, and souvenir shop. After an initial safety talk by the tour guide, the craft moves into the caisson. Two large lock gates are then lowered, one to seal the water in the caisson and the other to cut off the supply from the canal.
After all the safety interlocks are in place, the caisson begins its descent to the river Weaver, and the other caisson rises to the river level. During the lowering down to the river, an informative talk is given by the tour guide, covering the history of the equipment.
As the two caisson pass each other, a clear view is seen of the hydraulic lifting ram.
At the bottom, the two lower lock gates are then raised, and mechanically locked in the upper position, to allow the Edwin Clark to leave the boat lift.
An optional short cruise of 30 minutes with a descriptive commentary, then takes place along the river Weaver, before returning to the lower mooring.