Field Visit
Cornish Beam Pumping Engine, Prestongrange, East Lothian
Now preserved as a major industrial monument, this giant beam engine at the former Prestongrange Colliery is also a worthy tribute in Scotland to its makers, the famous engineering firm of Harvey and Co. of Hayle, Cornwall. Built in 1874 to pump water from a depth of 800 ft., it is a single-acting non-rotative beam -engine of a type once extensively used in draining mines in Britain, but notably in Cornwall, where the majority of these types of engines were manufactured.
In common with other 'Cornish' engines, its distinctive feature is the design of the stroke which in essence utilises high pressure steam, aided by a system of 'cut -off' levers and valves, in such a way as to give the piston a much smoother action.
The engine forms an integral part of the engine-house and the massive cast-iron beam, which weighs approximately 30 tons, must coneceivably have been raised to its height of 27 ft. by means of jacks as the building work proceeded or winched into position subsequently on timber shores (this latter method was employed at the Ryhope Pumping Station, Co. Durham). (1) The beam is 33ft. in length and 6ft. 4 in. in depth at the centre, with the fulcrum located eccentrically at a point 18ft. from the steam end, giving the latter a stroke of 12ft. and the pump rams one of 10ft. (2)
Equipped with a steam cylinder of 70 in. in diameter, the engine developed a normal working speed of 3 1/2 strokes per minute, and a water pumping capacity of 650 gallons per minute.
The engine was modified in 1895 to work larger shaft pumps with rods of 23 in. square Oregon pine, for which purpose an ingenious overhead strengthening truss had to be contrived on the beam. The engine continued to be fully operational until 1954 and is planned to become the centre-piece of a historical site devoted to the Scottish coal industry.
Notes
(1) See Hudson, K World Industrial Archaeology (1979), illustration 195.
(2) Technical Information Sheet, Prestongrange Museum.
References
Cossons, N, BP Book of Industrial Archaeology (1978), 3rd imp., 102-3
Buchanan, R A , Industrial Archaeology in Britain (1980), new ed. 253-4
Butt, J, and Donnachie, I, Industrial Archaeology in the British Isles (1979), 42-3
NOTE: In the Journal of the Trevithick Society (1982), however, researches of K. Brown attribute the make of the engine itself to JE Mare of Plymouth in 1853 and only the beam itself to Harvey of Hayle. The panel above the door, inscribed 'M 1874 L' stands for Matthew Loam of Liskeard who sold the engine in partnership with Harvey of Hayle and who erected it at Prestongrange that year. (See detailed account and correspondence in the manuscript file).
Information from NRHE, MS 232/LO/EA/3 record sheet.
