Originally, it was one of two steam engines used to pump water back up to the
summit level of the
BCN Old Main Line (Birmingham Canal) canal at
Smethwick, not far from the
Soho Foundry where it was made. The other engine, also built by
Boulton and Watt, was at the other end of the summit level at Spon Lane. In 1804 a second Boulton and Watt engine was added alongside the 1779 engine. The engines were needed because local water sources were insufficient to supply water to operate the six
locks either side of the canal's original summit. The locks could have been avoided if a tunnel had been built, but the ground was too unstable for
James Brindley to build a tunnel using the techniques available at the time. In the 1780s, a
cutting was constructed by
John Smeaton, enabling three of the six locks on each side to be removed. In the 1820s,
Thomas Telford constructed a new canal parallel to the old in a deeper cutting, at the
Birmingham Level, creating the largest man-made earthworks in the world at the time. It was spanned by the
Galton Bridge. The engine was still needed, despite both these developments, and Thomas Telford constructed the
Engine Arm Aqueduct carrying the
Engine Arm branch canal over his New Main Line so that coal could still be transported along the arm to feed the Smethwick Engine. Pumping Station In 1892, a replacement engine was built in a new pumping house, now
Grade II listed, next to Brasshouse Lane, as the original Smethwick Engine was considered uneconomic to repair; the latter was removed for preservation in 1897–98 to the BCN, later
British Waterways,
Ocker Hill depot where it remained until acquired by
Birmingham City Council. It is now part of the collection of Birmingham Museums and is on display at
Thinktank, Birmingham Science Museum at
Millennium Point. It is the oldest working engine in the world. at the site of the Smethwick Engine The engine house was demolished in 1897. Its original site and foundations can still be seen on Bridge Street North in Smethwick, just north of the junction with Rolfe Street. Tours of the site can be arranged through the
Galton Valley Canal Heritage Centre which is based in the New Smethwick Pumping Station and regularly opened by Sandwell Museum Service and The Friends of Galton Valley. The pumping station was featured in an episode of
The Water Boatman presented by
Alan Herd on the
Discovery Shed TV channel in November 2011. ==Points of interest==