The safety record of timber railway bridges in the UK: 1840–1870

The nineteenth century saw numerous bridge failures across the UK, Europe and North America as engineers struggled to master the difficulties of constructing in iron, particularly cast iron. Following the collapse of Robert Stephenson's (1803–1859) Dee Bridge in 1848, engineers have focused on these disasters in order to improve both safety and the overall performance of bridges. In comparison, little attention has been paid to the safety record of the thousands of timber railway bridges built across the UK. This paper seeks to readdress this imbalance. Drawing upon primary sources, it provides the first comprehensive review of the safety record of timber railway bridges constructed between 1840 and 1870. It discusses the perceptions of contemporary engineers and the general public, focusing on issues regarding material selection and their ongoing assessment and maintenance. It also highlights the safety advantages of certain bridge types, particularly where engineers faced geotechnical problems, such as slips and subsidence of embankments. By documenting the accidents associated with timber bridges, it is shown that despite problems with decay, the threat of fire and problems under dynamic loading, timber bridges were considerably safer than cast-iron bridges. Of the thousands constructed in the UK, none failed under service.