Innovative Ways

Mitchell's Screw-Pile Lighthouse

<P> Alexander Mitchell invented the screw-pile, a major improvement over the standard straight pile. With his son, he patented his cast iron screwpile design in the 1830s. By 1840 Mitchell combined his cast iron screwpile moorings with another pile construction technique and built the first screwpile lighthouse type at the mouth of the Wyre, an important harbor in Lancashire, England. Mitchell used 36-inch-diameter wooden timbers on whose bottoms were attached his cast iron screwpile devise. Completed in 1841, his structure was the first lighthouse to be built upon a screwpile foundation made entirely of iron. </P> <P> A protected, screw-pile lighthouse was typically a light-weight, wooden tower on iron stilts, the legs of which are tipped with cork-screw like flanges. These legs are turned into the soft ground of protected waters, such as bays and sounds. This new type of lighthouse was dependent upon the development of wrought-iron columns for the legs and cast-iron for the screw-like flanges. This technology permitted the construction of lighthouses on sites too soft to support the weight of a heavy tower. </P> <P> <EM> Text & Right Image: Courtesy of <A HREF="http://www.uscg.mil">USCG</A>. Left Image: 'Screw-Pile Lighthouse' from ''Sea Stories'', publ. 1910 by Century Co. N.Y. </EM> </P>

Mitchell's Screw-Pile Lighthouse

Mitchell's Screw-Pile Lighthouse

<P> Alexander Mitchell invented the screw-pile, a major improvement over the standard straight pile. With his son, he patented his cast iron screwpile design in the 1830s. By 1840 Mitchell combined his cast iron screwpile moorings with another pile construction technique and built the first screwpile lighthouse type at the mouth of the Wyre, an important harbor in Lancashire, England. Mitchell used 36-inch-diameter wooden timbers on whose bottoms were attached his cast iron screwpile devise. Completed in 1841, his structure was the first lighthouse to be built upon a screwpile foundation made entirely of iron. </P> <P> A protected, screw-pile lighthouse was typically a light-weight, wooden tower on iron stilts, the legs of which are tipped with cork-screw like flanges. These legs are turned into the soft ground of protected waters, such as bays and sounds. This new type of lighthouse was dependent upon the development of wrought-iron columns for the legs and cast-iron for the screw-like flanges. This technology permitted the construction of lighthouses on sites too soft to support the weight of a heavy tower. </P> <P> <EM> Text & Right Image: Courtesy of <A HREF="http://www.uscg.mil">USCG</A>. Left Image: 'Screw-Pile Lighthouse' from ''Sea Stories'', publ. 1910 by Century Co. N.Y. </EM> </P>

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New techniques pioneered in Ireland included a novel way of using concrete to build new dock walls under water at Dublin port in the 1860s. Developed by Bindon Blood Stoney, it attracted international interest. The metal diving bell used for the work is still at Sir John Rogerson's Quay.

The tram between Portrush and Bushmills in Co Antrim that opened in 1882 was the world's first water-powered tram. Designed by local engineer William Traill, it was powered by a hydro-electricity station on the Bush River. It was popular with Belfast daytrippers until it closed in 1949. The line reopened in 2001 with a steam train.

In 1833 a blind engineer, Alexander Mitchell, found a way to anchor lighthouses in soft sand, using 'screw piles'. His idea was so successful, it was used around the world to build lighthouses, piers and even railways.

The viaduct built to carry the Dublin-Belfast railway across the River Boyne at Drogheda in the 1850s was an innovative iron lattice construction. It was the longest of its kind in the world then, at 155 metres, and a major engineering triumph.

Richard Turner was a 19th-century Dublin iron-master who found new ways to make metal bars slender yet strong. In the 1840s, these were used to build tall and airy glasshouses that let in as much light as possible. Turner built major glasshouses for Kew Gardens in London, and for the Botanic Gardens at Belfast and Dublin.

Another noted engineer in the metal foundry business then was Robert Mallet. He had a scientific approach to problems and came up with many inventions, but he is remembered for his research into earthquakes and as the father of seismology.