Caen Hill Locks
The Caen Hill Locks are a stretch of 29 locks on the Kennet and Avon Canal (see Kennet and Avon Canal) west of Devizes. At this point the Mid Wilts Way runs along the towpath beside the locks. Alternatively, the locks can be reached by car: follow the A361 west out of Devizes, take the turning to the right signed Rowde, and the car park (£3 all day) is then signed from the road to Rowde.
These 29 locks, out of a total of 104 locks, were the last stretch of the canal to be built. Their purpose was to overcome a rise of 237 feet over two miles. To climb this gradient, a barge enters the lock chamber through the open lower level gates; the gates are closed and water is allowed to fill the lock chamber until the water level is equal with the upper level; and then the upper level gates are opened to allow the barge to move out of the lock. This procedure has to be repeated for each of the locks.
Completed in 1810 under the supervision of John Rennie the Elder, the Caen Hill Locks represent another remarkable feat of engineering in the building of the canal. A brick-making factory was built to provide the large number of bricks required to line the chambers of the locks. During the construction phase a horse-drawn tramway ran parallel to the canal route to convey goods across this stretch. Rennie had originally planned that the canal should be routed through Marlborough which would have avoided any major changes in height, but then abandoned the plan because of the uncertainty of water supply.
The central section of the Caen Hill Locks is a series of 16 locks in very close proximity to each other and is now a scheduled monument. To enable the water supply in these locks to remain topped up, each of the locks has a side pond of one million gallons. Under this arrangement a fall of eight feet of water in a lock alters the level of water in a corresponding side pond by only one inch. In 1996 a back pump was installed at Foxhangers capable of pumping seven million gallons of water a day up to the top flight.
It takes about 3 to 5 hours for a boat to get through all the locks, depending on whether they can share the work with another boat or not.
