Pinchbeck Engine

The Pinchbeck Engine is a drainage engine, a rotative beam engine built in 1833 to drain Pinchbeck Marsh, to the north of Spalding, Lincolnshire, in England. Until it was shut down in 1952, the engine discharged into the Blue Gowt which joins the River Glen at Surfleet Seas End.

Museum
In 1952 the engine was rendered obsolete by modern electric pumps and stood forgotten until being opened to the public as a museum in 1979. The coal store was cleared and now houses the associated Museum of Land Drainage. The museum complex includes the blacksmith's shop, still in its original condition. The museum is operated by the Welland and Deepings Internal Drainage Board, successors to the commissioners who erected the engine. The buildings are Grade II listed and also a Scheduled Ancient Monument.

The chimney was demolished in 1952, and no actions were taken to preserve the boiler, which is no longer in a fit state to be used. The engine is a static exhibit, which can be rotated by an electric motor for demonstration purposes.

Beam engine
The engine is a 20 hp condensing steam engine with an overhead beam supported by an 'A'-frame. It was built by the Butterley Company of Ripley, Derbyshire. It has a single cylinder of 35 in bore and 56 in stroke. The flywheel is 18 ft in diameter. The engine ran at up to 30 rpm.

The engine is gear-coupled to a single scoop wheel in an adjacent compartment. There are 40 paddles around the circumference of the 22 ft wheel, which could lift a maximum of 7500 impgal of water per minute through an 8 ft lift. The annual effort varied between 1093000 LT tons of water lifted, and 3690000 LT. Typically the engine was operated for around 180 days a year and an engine man was permanently retained, living on the site.

The boiler dates from 1895 and is a twin furnace Lancashire boiler, delivering 12 psi. It consumed around 1 -Lcwt of coal per hour. Coal supplies were originally brought by barge, but after the land was successfully drained a railway line was laid from Spalding to Boston, and coals were delivered to a nearby goods facility. They were then transported on a very short narrow gauge railway line in colliery-style tubs. The motive power for this appears to have been human. One of the tubs and a metre or so of line is displayed at the museum.

The engine is said to be the earliest 'A'-frame engine still in situ, the longest-working beam engine in the Fens, and the last in use.