Before revision: History William Fairbairn documented the development of the Britannia and Conwy tubular bridges for the Chester and Holyhead Railway in 1849; in it, Fairbairn describes how Robert Stephenson enlisted his aid to revise Stephenson's original concepts, which would route rail traffic inside riveted steel tubes, supported by chains, with a circular- or egg-shaped cross-section.
After revision: upSection from the original Britannia Bridge, showing top and bottom stressed-skin constructionHistory William Fairbairn documented the development of the Britannia and Conwy tubular bridges for the Chester and Holyhead Railway in 1849; in it, Fairbairn describes how Robert Stephenson enlisted his aid to revise Stephenson's original concepts, which would route rail traffic inside riveted steel tubes, supported by chains, with a circular- or egg-shaped cross-section.