The paper reports on three epochs of bridge building in Wales. The first period, from Roman times to the start of the Industrial Revolution, was dominated by the use of local materials (stone and timber) by local craftsmen. The second period was an integral part of the Industrial Revolution when new bridge building materials (cast iron, wrought iron and steel) were developed and used in the construction of canal and railway bridges. The third period was associated with the growth of traffic following World War II when concrete and steel became the dominant bridge building materials during the development of the trunk roads and motorways.
The paper shows, in simple terms, the fundamental structural engineering developments underpinning these developments as new materials became available for bridge building. In particular, the evolvement of various beam cross-sections, tubes and trusses is discussed. Attention is also given to the significant contribution of four world-renowned bridge builders: William Edwards who built the famous arch bridge at Pontypridd; Thomas Telford who built the Pontcysyllte Aqueduct and the Menai Suspension Bridge; Robert Stephenson who built tubular bridges at Conway and over the Menai Straits and I. K. Brunel who built the unique Chepstow Railway Bridge and the railway timber viaduct at Landore, Swansea. Finally, the paper draws attention to some of the unique bridges of Wales.