The beam engine was used to draw out water from mines, as well as to pump water into canals. The engine consisted of a large wooden frame into which a pivoted overhead beam was used to apply force generated by a vertical piston and transfer that movement to a pump rod.
The piston’s movement was driven by a coal-heated boiler, which generated steam and fed it into the piston’s cylinder.
When the piston was at its apex – moving the beam and dropping the pump rod – the cylinder was injected with cold water, creating condensation and eventually a vacuum, thereby drawing the piston down and raising the pump rod again in a cycle.
Early beam engines (eg Newcomen’s) were quite inefficient due to their lack of a separate condenser, but this was improved upon by later models like the Watt steam engine.