Beam engine

A Watt engine: showing entry of steam and water

A beam engine is a type of steam engine where a pivoted overhead beam is used to apply the force from a vertical piston to a vertical connecting rod. This configuration, with the engine directly driving a pump, was first used by Thomas Newcomen around 1705 to remove water from mines in Cornwall. The efficiency of the engines was improved by engineers including James Watt, who added a separate condenser; Jonathan Hornblower and Arthur Woolf, who compounded the cylinders; and William McNaught, who devised a method of compounding an existing engine. Beam engines were first used to pump water out of mines or into canals but could be used to pump water to supplement the flow for a waterwheel powering a mill.

The cast-iron beam of the 1812 Boulton & Watt engine at Crofton Pumping Station – the oldest working, in situ example in the world

Back of Museum De Cruquius near Amsterdam, an old pumping station used to pump dry the Haarlemmermeer. It shows the beams of the pumping engine and the 9 meter drop in water level from the Spaarne river. The beam engine is the largest ever constructed, and was in use till 1933.

The rotative beam engine is a later design of beam engine where the connecting rod drives a flywheel by means of a crank (or, historically, by means of a sun and planet gear). These beam engines could be used to directly power the line-shafting in a mill. They also could be used to power steam ships.