Tay Bridge Disaster: The Theories

The mystery of the tay bridge disaster hasn’t been solved yet but experts are still trying to find out the cause of this mysterious event. It happened during a fierce storm on ‘Sabbath Day’. Many theories were made but the main ones were made by: Bill Dow, Tom Martin and Peter Lewis.

Bill Dow’s theory is that the front carriages derailed and and ran into one of the cover plates, the force of which would be strong enough to shatter the iron lugs. The iron lugs were the bridge’s structural support, but because they were shattered the bridge was left defenceless against the fierce winds of the storm. One of the girders fell during the construction of the built and was bent. This same girder was restraightened and put on the bridge. Over time the girder bent again and the bridge became vunerable to the force of the winds on that terrible night. Bill Dow thinks this is the reason the Tay bridge collapsed.

Tom Martin’s theory is mainly to do with the speed of the winds. As the train drove up to the higher girders a strong gush of wind increased the overturning force of the storm and as a result the base of the windward column started to lift. This was causing problems to the bridge because this column was holding up the bridge. This caused the diagonal ties to to start breaking and developing up from the second level. Because of this, the weak bolting connections broke as well as causing the leeward side of the bridge to collapse. As that side fell there was a kickback on the other side of the bridge thus causing the whole bridge to collapse. This is what Tom Martin thinks caused the collapsing of the Tay bridge.

Peter Lewis’ theory is mainly to do with the train that passed earlier on the bridge. It was said to have been crossing the bridge during strong winds and heavy rainfall. It was also said that sparks had been seen coming from the wheels. This could have been because the train was being pushed over by the wind; the bridge was moving back and forth or both. Either way the train did get back to the other side safely but the combined forces or the strong winds and the oscillation of the bridge caused alot of damage to the tie bars which stabilise the the bridge. When the mail train from Edinburgh came, the wind was equally strong as last time. It moved through the low girders pleasingly although sparks were seen flying by the signalmen as it disappeared into the darkness. At that point the bridge started collapsing. It was left in a critical state by the other train and this train was much heavier than it carrying a 35 tonne loco rather than a small tank engine. This is how Peter Lewis explains the Tay Bridge disaster.

 All the theories make sense but which one is right or if any of them are right are the questions which may never be answered.