A train smashed into an object on the Tay Bridge on Wednesday night, causing considerable delays for passengers.
The East Coast service between Aberdeen and Leeds screeched to a halt after hitting the piece of piping near the Fife end of the crossing.
Travellers were left stranded for over an hour as emergency engineers checked the train for damage.
Several trains were diverted as a result of the collision.
People near the Fife side of the bridge reported hearing a loud crashing noise before seeing the train come to a halt.
One eyewitness, Calum Gillies, said: “I heard a really loud bang just before the football started and looked out of my window.
“The train was stopped and men in high-visibility vests were walking by the train, looking between the carriages as if something might have been caught under a wheel.
“It was just before the World Cup match started, around 8pm and it was still there well into the second half.”
A spokesman for East Coast Rail said: “Our 6.18pm service from Aberdeen to Leeds is thought to have struck a piece of metal grating in an area known as Tay Rail Bridge South.
“Where that came from is not clear at the moment, but it is something that we, with Network Rail, will be investigating.
“The safety of the train was not affected, but it had to be checked before moving off to Edinburgh and was delayed by about an hour.
“At Edinburgh we switched trains and passengers continued their journey to Leeds.”
Passengers took to Twitter to say the train had been stationary for an hour as work continued to get services back to normal.
Andrew Lowson said: “So the train hit something crossing the Tay shook a lot followed by loud screeching noise as it came to an emergency stop.”
Another praised East Coast services saying “Staff are doing it right, we are well informed and being kept comfy.”