Standing beside the canal adjacent to Jessop’s magnificent aqueduct across the Derwent is the impressive structure that houses Leawood Pump.
The canal was originally fed by water from Bonsall Brook and Leawood Sough at Cromford as their combined water left Arkwright’s original cotton mills after turning their waterwheels. Leawood Sough was a long adit built into the hills towards Wirksworth to drain lead mines. As the lead miners dug deeper, a lower sough was needed – the Meerbrook Sough – which comes out at Homesford Cottage about a mile to the south.
Once this came into use in 1841, there was no longer sufficient water to maintain the canal’s level; canals lose water by evaporation, leakage and by the use of the locks down the Erewash Valley.
A temporary pump was installed by the canal company close by to what is now called the Railway Narrows. This sufficed until the coming of the main line railway necessitated the removal of the pump so a new pump was ordered in 1844 from Graham & Co’s Milton Ironworks at Elsecar. This was not finally completed until 1850 but is largely what you see today.
Because of restrictions of the hours when the mill owners allowed water to be pumped into the canal (8pm Saturday to 8pm Sunday), the pump was built seven times larger than would normally be needed, so as to pump a week’s worth of water into the canal in 24 hours. As the canal had originally been built a foot deeper than normal, it could act as a reservoir to make the water last for the week.
The pump worked until after the Second World War and has more recently been restored by volunteers. It is fired by two locomotive-type boilers supplying steam at 40psi to a massive beam engine. The 33ft beam weighs 27 tons and pumps 4 tons of water per stroke from the Derwent into the canal.
The complicated details of its operation are best appreciated on a visit to the engine on one of its steaming days, which take place monthly through the summer.