The Dogdyke Engine is a drainage engine near Tattershall, Lincolnshire, in England. The drainage of of land around Tattershall was authorised in 1796, and came under the control of the Witham Third District commissioners in 1844 The building dates to 1856 when a rotative beam engine was built to replace windmill style engines possibly dating to 1540 and draining land between the rivers Bain and Witham. The engine discharged into the River Witham, but has a long fetch from a drain parallel to the river called The Dogdyke engine drain originating just south of Kirkstead at a place called Parkbeck. 1856 is relatively late and Wheeler does say that the 1856 engine replaces one installed in 1841, but the location of that is unknown. The building is a grade II listed ancient monument. Engines Bradley and Craven Beam engine and scoop wheel, built 1856 Ruston & Hornsby Diesel engine and centrifugal pump, built 1940 Ruston & Hornsby auxiliary engine. Steam engine The steam engine is maintained by a preservation trust, and steamed on weekends throughout the summer. Although the Pinchbeck Engine is older, it can no longer be steamed. The preservation trust claim this is the oldest working steam drainage engine. The engine built by Bradley & Craven Ltd of Wakefield has a flywheel, and a cylinder of diameter and stroke. The construction is similar to an 'A' frame, but the decorative form of the cast iron upright obscures that basic shape and might be considered unique. The scoop wheel is in diameter and runs at up to 7rpm through a 4:1 gearbox from the engine. The first boiler, which lasted until 1909, was a twin tube Cornish type, working at 12psi. The replacement was a Lancashire boiler made by Fosters of Lincoln, delivering 15psi. Although the structure of this boiler survives, its rear end has been removed to make room for a modern vertical boiler which is used for the demonstration steamings. The original Chimney was struck by lightning in 1922 and reduced somewhat. It was felled in 1941 after the conversion to diesel operation. Diesel engines The two diesel engines are maintained by The Witham Third District Internal Drainage Board as a standby for the nearby electric pumping station. They are usually operated when the museum is open. The steam engine was replaced in 1940 by a Ruston & Hornsby 7XHR diesel engine, serial number 194833, driving a