The first design of the Kennet & Avon canal by the distinguished Scottish civil engineer, John Rennie, called for a 4.5 km (2.5 mile) tunnel between the Wiltshire villages of Crofton and Burbage but, in those days, tunnelling was a very expensive and uncertain process and a cheaper alternative was sought. This involved raising the summit level of the canal and constructing a much shorter tunnel. However, this new summit was 12 m (40 ft) higher than any reliable local, natural water source and so a pumping station was needed at Crofton to keep it topped-up. It was estimated that this scheme saved £41,000 (equivalent these days to about to about £8,000,000) in the cost of canal construction, a very substantial saving.
Crofton Pumping Station was built in 1807 and started work soon after. The first engine installed in the building was a 0.9 m (36 inch) bore Boulton and Watt which had a wooden beam and began working in 1809. In 1812, a 1.06 m (42 inch) bore Boulton and Watt engine was installed beside it. In 1846, the 0.9 m bore Boulton and Watt was replaced by a Sims Combined Cylinders Engine constructed by Harvey of Hayle.
The pumping station is located 1¼ km (¾ mile) to the east of the summit. It raises the water to a level slightly above that of the summit, delivering it via a specially constructed feeder channel, called, from Cornish tin mine practice, a leat.
Both the 1812 Boulton and Watt, and the 1846 Harvey engine (in its final form) are in working condition, and are steamed publicly on several weekends through the summer months from a coal fired Lancashire boiler. When the Pumping Station is in steam, it actually carries out the job for which it was built as the electrically powered pumps, that now normally do the job, are switched off.
|The Original Installation
The first engine installed in the Engine House at Crofton was a second hand Boulton and Watt, purchased in 1802 from the West India Dock Company. This engine had a 90 cm (36 inch) diameter steam piston and a 2.5 m (8 foot) stroke. It had a wooden beam and worked a 66 cm (26 inch) diameter lift pump. It arrived at Crofton in 1807, and was at work by 1809……..
|1896 – 1905 The Final Changes
In 1896 the No.1 engine (Boulton and Watt) suffered a major failure. With the No.2 engine now derelict, this caused a problem in keeping the canal open, and GWR were forced to do something about it as they had legal obligations to maintain the waterway……..
|1905 – 1968
Both engines were in regular service until 1952, and the 1812 Boulton and Watt continued to be used spasmodically until 1959, when, due to deterioration, the top 11 m (36 feet) of the chimney were removed making it impossible to fire the boilers as there was not enough draught……..
On 14th April 1968, Crofton Pumping Station was purchased by the Kennet and Avon Canal Trust from British Waterways for £75 with the objective of restoring it to full working order. An appeal for funds was launched and a team of volunteers, including several qualified engineers began planning the work to restore the building, boilers and engines………