The Tay Bridge disaster
The first Tay Bridge, opened in 1878, carried the railway over the estuary of the Tay at Dundee. At over three kilometres it was then one of the longest bridges in the world, and its designer, Thomas Bouch, was knighted for it. It was built of cast and wrought iron on slender piers.
On the evening of 28 December 1879 a gale was blowing from the west. A passenger train from Edinburgh began to cross the high central section, and witnesses on the shore saw a shower of sparks, and then the lights disappeared. The middle of the bridge, with the train, had fallen into the water. Everyone on board died; the exact number is not known, and the most reliable estimate is about seventy-five.
The inquiry
A court of inquiry found that the bridge had been badly designed, badly built and badly maintained. The wind loading had not been properly considered, the cast-iron columns had been poorly cast and were weakly joined to the piers, and no one had looked after the structure after it opened. The inquiry put most of the blame on Bouch. His reputation was destroyed and he died the following year.
The disaster changed British practice. Engineers began to take wind pressure seriously, and bridges were afterwards designed with much greater margins. A new Tay Bridge, built beside the stumps of the old one, opened in 1887, and is still in use.