Newcomen Memorial Engine

Steam cylinder end

Pump end of beam. Top of weight visible

The blanking plate at the bottom of the steam cylinder presumably covers the hole where injection water was originally admitted

The steam admission valve is housed within the square chest. The valve is opened by raising the valve spindle by means of a pinion acting on a rack on the spindle. The pinion is rotated by the long horizontal lever - manually to start the engine, and then automatically by a pair of tappets attached to the wooden rod, which rises and falls with the rocking beam. The pinion also acts on another rack to open the water injection valve when the steam valve is closing

The bent rod suspends a weight. The bell crank is weighted to overbalance so as to ensure positive opening and closing of the valve

Water injection tank with injection valve and overflow. Water form here enters the cylinder to condense the steam to allow atmospheric pressure to force the piston down

'Pickle Pot' condenser below cylinder

The black 'pipe' is a section of the original pump barrel

The Newcomen Memorial Engine can be seen in Dartmouth, home of Thomas Newcomen, at The Engine House, Mayors Avenue, Dartmouth, Devon, TQ6 9YY.

For more information and a map, see the 'Discover Dartmouth' Newcomen Engine webpage, which describes the engine as the oldest preserved steam engine in the world.

It was originally built c.1725 to pump water out the Griff Colliery in Staffordshire. It was moved to a coal mine at Measham, and in 1821 it was bought for use at Hawkesbury Colliery, Warwickshire and worked there until 1913. In 1964 it was reassembled in Dartmouth, the home town of its inventor, by the Newcomen Society.

The Dartmouth engine shows most of the features of the earliest Newcomen engines. It has a simple, untrussed, wooden beam with arch heads, chain connections and wooden spring beams. The current steam valve and water injection mechanisms apparently date from 1821, and are activated automatically by a plug-rod, as in the early engines. Another change was the provision of a separate ‘pickle-pot’ condenser, fitted directly beneath the cylinder. The engine can be operated by a hydraulic mechanism to demonstrate the motion of the engine and the operation of the valves.

The main cast iron components, including the steam cylinder, piston and pump barrel are original 1725 items, made by the Coalbrookdale Co. The cylinder bore was measured in 1963 and found to be no more than 1/16" (1.6mm) out of truth. Many of the wooden components, including the beam, are thought to be original.

The above information was taken mainly from a display board adjacent to the engine and from 'The Beam Engine' by T E Crowley

See Also

Loading...