water power in Ireland can be traced back to the early Christian era. Then it was employed in grinding grain for family use. Primitive mills, powered by waterwheels, were usually sited along a small mountain water course. Many monastic settlements had water‐powered grain mills. The waterwheels had their paddles set horizontally to catch the flow of water. They were attached to millstones which were turned to grind the grain. Some have been dated between ad 630 and ad 926. Water power technology remained at this level until the early 17th century
plantations. Settlers brought with them new developments in water power from Great Britain and the Continent. These were introduced or adapted to tasks previously performed by humans or animals. Among these improvements was the now familiar vertical waterwheel.
Water power was vital for industrialization, in a country largely devoid of coal and iron. In 1870 it provided one‐quarter of Ireland's recorded horsepower, compared to one‐twentieth of Great Britain's. The drawback of water power is that its user can be at the mercy of floods and frost in winter or droughts in summer. Its use was greatest in Ulster, particularly in the development of the
linen industry, from the first quarter of the 18th century. Then water was used in flax scutching mills, and in beetling mills, wash mills, and for rubbing boards in the bleaching process. In the 19th century, mechanized spinning and powerloom weaving were driven by water as well as
steam. Many model mill villages were specifically built on sites suitable for the exploitation of their water power resource. The
Ordnance Survey maps of the 19th century show an extensive network of rural mills, of every kind, powered by water. The main types were
flour mills, threshing mills, spade mills, saw mills, and
paper mills.
The turbine, pioneered by an Ulsterman, James Thomson, brother of Lord Kelvin and professor of engineering at
Queen's University 1854–73, was a significant development, making water power much more effective and removing the need for large waterwheels. Turbines in turn made possible the generation of
electricity by hydroelectric power. This was used from the end of the 19th century to run trams from Bessbrook to Newry in Co. Down and from Portrush, Co. Antrim, to the nearby tourist attraction of the Giant's Causeway. Later the same technology became the major source of electricity in southern Ireland, through the Shannon Hydroelectric Scheme at
Ardnacrusha.
Bibliography
Coe, W. E. , The Engineering Industry of the North of Ireland (1969)
Peter Collins