| Tay Bridge disaster | |
|---|---|
| Details | |
| Date | 28 December 1879 |
| Time | 19:13 |
| Location | Dundee |
| Country | Scotland |
| Rail line | Edinburgh to Aberdeen Line |
| Cause | Structural failure |
| Statistics | |
| Trains | 1 |
| Passengers | 70 |
| Deaths | 75 (estimate-60 known dead) |
| Injuries | 0 |
| List of UK rail accidents by year | |
The Tay Bridge disaster occurred on 28 December 1879, when the first Tay Rail Bridge, which crossed the Firth of Tay between Dundee and Wormit in Scotland, collapsed during a violent storm while a train was passing over it. The bridge had been designed by noted railway engineer Sir Thomas Bouch, using a lattice grid that combined wrought and cast iron. Major engineering flaws were the cause of the collapse, and the disaster ruined Bouch's reputation as an engineer.
Like all rail lines intended to carry passenger trains, the Tay Bridge had been subject to a Board of Trade inspection before it opened. The inspection was conducted over a three-day period in February 1878 during what were described as 'favourable' weather conditions. The bridge was passed for opening subject to conditions such as a speed limit and minor remedial work. The inspection report noted '... When again visiting the spot I should wish, if possible, to have an opportunity of observing the effects of high wind when a train of carriages is running over the bridge ...'.[1]
Contents |
During a violent storm on the evening of 28 December 1879, the centre section of the bridge, known as the "High Girders", collapsed, taking with it a train that was running on its single track. 75 people were believed to have been on the train, a figure established by a meticulous examination of ticket sales, some from as far away as King's Cross, and including 5 staff; all were killed.[2][3] There were 60 known victims, but only 46 bodies were found, two of which were not recovered until February 1880.[4]
Investigators quickly determined many faults in design, materials, and processes that had contributed to the failure. Bouch claimed to have received faulty information regarding wind loading, but his later statements indicated that he may have made no allowance for wind load at all.[5] Bouch had been advised for earlier designs that calculating wind loads was unnecessary for girders shorter than 200 feet (61 m), and had not implemented wind loading calculation for his new design although it used longer girders.
The section in the middle of the bridge, where the rail ran inside high girders (through trusses), rather than on top of lower ones (deck trusses), to allow a sea lane below high enough for the masts of ships, was potentially top-heavy and very vulnerable to high winds. Neither Bouch nor the contractor appeared to have regularly visited the on-site foundry where iron from the previous half-built bridge was recycled. The cylindrical cast iron columns supporting the 13 longest spans of the bridge, each 245 ft (75 m) long, were of poor quality. Many had been cast horizontally, with the result that the walls were not of even thickness, and there was some evidence that imperfect castings were disguised from the (very inadequate) quality control inspections.
In particular, some of the lugs used as attachment points for the wrought iron bracing bars had been "burnt on" rather than cast with the columns. However, no evidence of the burnt-on lugs has survived, and the normal lugs were very weak. They were tested for the Inquiry by David Kirkaldy and proved to break at only about 20 long tons (20 t) rather than the expected load of 60 long tons (61 t). These lugs failed and destabilised the entire centre of the bridge during the storm.
The official enquiry was chaired by Henry Cadogan Rothery, Commissioner of Wrecks, supported by Colonel Yolland (Inspector of Railways) and William Henry Barlow, President of the Institution of Civil Engineers. They concluded that the bridge was "badly designed, badly built and badly maintained, and that its downfall was due to inherent defects in the structure, which must sooner or later have brought it down. For these defects both in the design, the construction, and the maintenance, Sir Thomas Bouch is, in our opinion, mainly to blame."[6]
There was clear evidence that the central structure had been deteriorating for months before the final accident. The maintenance inspector, Henry Noble, had heard the joints of the wrought-iron tie-bars "chattering" a few months after the bridge opened in June 1878, a sound indicating that the joints had loosened. This made many of the tie-bars useless for bracing the cast-iron piers. Noble did not attempt to re-tighten the joints, but hammered shims of iron between them in an attempt to stop the rattling.[2]
The enquiry destroyed Bouch's professional reputation: "The chief blame for this casualty rests with Sir Thomas Bouch" wrote the chairman, albeit noting that it was his decision alone to lay the blame publicly.[7] The enquiry recommended the Board of Trade to impose a rule catering for wind loading of 50 or 55 lb per square foot in future structures.[7]
The locomotive, NBR no. 224, a 4-4-0 designed by Thomas Wheatley and built at Cowlairs Works in 1871, survived the disaster, being salvaged from the river and repaired. It remained in service until 1919, acquiring the nickname of "The Diver"; many superstitious drivers were reluctant to take it over the new bridge.[8][9][10][11]
The Victorian poet William Topaz McGonagall commemorated this event in his poem The Tay Bridge Disaster, widely regarded as so bad as to be comical. Likewise, German poet Theodor Fontane, shocked by the news, wrote his poem Die Brück' am Tay (with allusions to William Shakespeare and Friedrich von Schiller). It was published only ten days after the tragedy happened. Hatter's Castle, the 1931 novel of Scottish author A. J. Cronin, includes a scene involving the Tay Bridge Disaster, and the 1942 filmed version of the book dramatically recreates the bridge's catastrophic collapse. The bridge collapse figures prominently in Barbara Vine's 2002 novel The Blood Doctor. Scottish author Sorche nic Leodhas wrote a story The Tay Bridge Train, about a man who survives because he is warned not to take the Tay Bridge train.
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