Tay Bridge Disaster

[kudu]

The main reason that the bridge collapsed was that it was unable to withstand the terrific wind pressure that it was exposed to, partly because it was a science that was largely unknown at the time but mainly because the castings failed due to the poor workmanship.

I read somewhere of the theory that the bridge was intact until the train started crossing and that the wind dislodged the train which crashed against the high girders and brought the bridge down. This is based partly on eye witness descriptions.

[third-rail]

The main reason that the bridge collapsed was that it was unable to withstand the terrific wind pressure that it was exposed to, partly because it was a science that was largely unknown at the time but mainly because the castings failed due to the poor workmanship.

I read somewhere of the theory that the bridge was intact until the train started crossing and that the wind dislodged the train which crashed against the high girders and brought the bridge down. This is based partly on eye witness descriptions.

i suspect that as you say the carriages came of the rails in the gale and bounced around inside the stucture which would explain all the coaching stock axles being bent and distorted,and that impact of the coaces hitting the sides of the high girders coupled with the wind pressure would find the weakness that would bring the structure down. it was also noticed that no damage had been done in the gale to the signal box.

[Mickey]

On a VIDEO 125 video/dvd called TRAINS FROM THE ARCH there is some early film footage taken from a train passing over the TAY BRIDGE (after doubling) and coming the other way is a train either hauled by THE locomotive involved in the TAY BRIDGE DISASTER in 1879 or a class mate (i can't remember?) i believe the commentary goes onto say that this film was filmed exactly 20 years to the day after the disaster in 1899.

[60041]

I read somewhere of the theory that the bridge was intact until the train started crossing and that the wind dislodged the train which crashed against the high girders and brought the bridge down. This is based partly on eye witness descriptions.

i suspect that as you say the carriages came of the rails in the gale and bounced around inside the stucture which would explain all the coaching stock axles being bent and distorted,and that impact of the coaces hitting the sides of the high girders coupled with the wind pressure would find the weakness that would bring the structure down. it was also noticed that no damage had been done in the gale to the signal box.

You could well be right, there had been frequent complaints about the speed of trains across the bridge before the disaster, and it was also said that the bridge felt as if it was moving when a train crossed the High Girders resulting in a very uncomfortable ride.
Many regular travellers were so concerned about this that they had gone back to using the ferry.
A combination of excess speed coupled with the wind pressure and the movement of the bridge could well have caused a derailment with the results noted above.
Some observers had noted a series of flashes on the bridge at the time of the disaster and these could have been the train striking the sides of the bridge.

[richard]

From memory I think I read in "Red for Danger" that the previous train had also produced the flashes. These were noticed by one of the guys in the signal box. This is why both of the signal box crew explicitly watched the Diver's train head out on to the bridge - they were looking for the flashes.


Richard

[gresleybear]

Hello all. An interesting discussion, as usual. It was stated earlier in this thread that the bridge was intact when it collapsed. While that is partially true because no span had yet fallen into the river, the bridge had deteriorated since completion. Many of the diagonal braces had worked loose, the result of the poor foundry work at Wormit. They had been ineffectively repaired, if at all, so they could no longer perform their function of distributing stresses.
John Thomas in his excellent book on the subject, recounts the findings of the inquiry, which found that the bridge collapsed because of poor design, workmanship, and maintenance. It would have come down eventually, but the raging storm that night certainly hastened its demise.
Sir Thomas Bouch asserted in his defense that the gale blew a carriage into the girders, bringing the bridge down. These assertions were rejected by the inquiry. After all this time, the debate continues and we may never know for certain what toppled the bridge. There's my two cents worth.

Forward!

John

[60041]

More on the Tay Bridge disaster from the BBC:
http://www.bbc.co.uk/news/uk-scotland-t ... um=twitter