Tay Bridge disaster Tay Bridge disaster During a violent storm on Sunday 28 December 1879, the first Tay Rail Bridge collapsed as a train from Wormit to Dundee passed over it, killing all aboard. The bridge—designed by Sir Thomas Bouch—used lattice girders supported by iron piers, with cast iron columns and wrought iron cross-bracing. The piers were narrower and their cross-bracing was less extensive and robust than on previous similar designs by Bouch. Bouch had sought expert advice on wind loading when designing a proposed rail bridge over the Firth of Forth; as a result of that advice he had made no explicit
Tay Rail Bridge Bouch had used the technique for viaducts including the Belah Viaduct (1860)) on the South Durham & Lancashire Union Railway line over Stainmore, but for the Tay Bridge, even with the largest practicable caissons the pier dimensions were constrained by their size. Bouch’s pier design set six columns in a hexagon maximising the pier width but not the number of diagonal braces directly resisting sideways forces. The engineering details on the Tay Bridge were considerably simpler, lighter, and cheaper than on the earlier viaducts. On these the machined base of each column section docked securely into a machined enlarged section