A look back in History: the early use of Wrought Iron as building material

(On the right: drawing of Abraham Darby cast iron bridge. For history informations click on image)

Otherwise iron continued to be employed on a grand scale only for major structures such as bridges. But the limitations of cast iron meant that it was essential to use wrought iron in such instances.

The use of wrought iron trusses in combination with cast iron columns led to the creation of the first large scale iron buildings without supporting masonry. This began in the second quarter of the 19th century with the use of standardised cast iron beams with wrought iron trusses in the construction of the Crystal Palace in London in 1851. The trusses made it possible to replace masonry arches and vaulting between the vertical supports and create buildings with wider spans and large internal spaces. This technology was widely applied to a variety of buildings from conservatories to exhibition halls and railway stations.

Steel can be rolled into shapes, such as railway tracks, but it is far less brittle than iron and could improve upon its predecessors. Independent steel-frame buildings were pioneered in the United States in the 1880s but the technology did not appear in Britain until 1906 at the Ritz Hotel.Even then the possibilities were not fully explored. The steel frame had a profound impact on the exterior appearance of buildings, which no longer relied on load-bearing masonry. The steel “skeleton” could simply be clad in a variety of other materials, principally glass. Steel trusses also allowed the construction of buildings with mighty internal spans.