Crofton Pumping Station, near the village of Great Bedwyn in Wiltshire, England, supplies the summit pound of the Kennet and Avon Canal with water.
The steam-powered pumping station is preserved and operates on selected weekends. It contains an operational Boulton & Watt steam engine dating from 1812, making it the oldest working beam engine in the world in its original engine house and capable of doing the job for which it was installed.
Description
thumb|left|[[Wilton Water, the canal and railway from the pumping station]]
When the canal was built, no reliable water sources were available to fill the summit by normal gravitational means. However, a set of usable springs were found adjacent to the canal route about east of the summit pound, and about below it. Arrangements were made for these springs to feed the pound below lock 60 at Crofton Locks. Some years later a reservoir (Wilton Water) was created to improve the supply to this pound, and this can now be seen across the canal from the pumping station.
Water from below lock 60 was taken by a culvert to the foot of a well sunk from the pumping station, which is built on the hillside more than above the canal. The pumps take the water from this well and discharge it into a feeder channel next to the pumping station. The water flows along this channel under the force of gravity until it reaches the summit pound about to the west.
thumb|Inside the boilerhouse
For day-to-day operation, the pumping station now uses electric pumps, automatically controlled by the water level in the summit pound. However, the original steam driven pumping equipment has been preserved and is still operational. A single operable Lancashire boiler provides steam to the engines.
Number 1 engine, built by Boulton and Watt in 1812 and rebuilt as a Cornish engine in the 1840s, is a single-acting, condensing engine with a bore of , a stroke of and indicated power of . It drives a lift pump capable of lifting , or approximately one ton of water, per stroke, at a rate of 11 strokes a minute.
Number 2 engine, built by Harvey and Co. of Hayle in 1846 as a double-acting Sims patent combined cylinder engine and rebuilt in 1903 to a Cornish Engine, is a single-acting, condensing engine with a bore of , a stroke of and indicated power of . It drives a force pump capable of lifting , or approximately one ton of water, per stroke, at a rate of 10.2 strokes a minute.
Initially the problem of the shortened chimney was overcome by the use of an electric fan to improve draught, but between 1996 and 1997 the chimney was repaired and restored to its full original height of .
In July 2009, the modern electric pumps at Crofton failed. While awaiting repair, British Waterways contacted the Kennet and Avon Canal Trust who put Crofton into steam.
In 2012 the Boulton and Watt engine celebrated its 200th birthday. Several special steamings were held, including a visit from the Duke of Gloucester.
Visiting
The pumping station opens to visitors and the engines are in steam on designated days.
See also
- Claverton Pumping Station, another restored pumping station on the Kennet and Avon canal
References
Bibliography
- Booklet 'Crofton Pumping Station' edition 2, printed by ESP Color Ltd in 2001, no explicit publisher or copyright details but believed to be published by the Kennet and Avon Canal Trust. Obtained from Crofton Pumping Station in 2004.