, printed from the Looking at Buildings website on Saturday 15th March 2025
Although almost all iron had to be wrought by hand, it was also possible to cast the smelted ore into shapes by using moulds. This method offered the possibility of mass production for decorative and other components and eventually entirely superseded small-scale wrought ironGlossary Term [3] production. Cast ironGlossary Term [4] revolutionised building technology from the end of the 18th century, when it was first used in a structural capacity. Its strength made it suitable for load-bearing but its brittle nature meant it was liable to fracture under tension.
Large scale production of wrought ironGlossary Term [5] for structural use was aided by Henry Cort's development of the puddling process in 1784 and the subsequent invention of mills for rolling the iron into bars and other standard components suitable for building. Its flexibility and strength under tension made it suitable for trusses and beams and in particular for wide-span structures such as bridges.
The major innovation in the structural use of metals was the discovery of steel. After c.1880 rolled steel, similar but stronger than wrought ironGlossary Term [6] was used in creating self-supporting framed structures which could be built to great heights.
Since the mid-20th century numerous other metals, such as aluminium, have also played an increasing role in different types of structure.
Last updated: Saturday, 13th November 2010