A signal failure halted all services in and out of the Glasgow Central leaving travellers stuck in the station - as temperatures soared to 28C.
Scores of trains in and out of Glasgow Central were delayed or scrapped because of the signalling fault, which began affecting services before 4pm yesterday.
Transport chiefs urged travellers to avoid using Glasgow Central as engineers worked to fix the fault.
The travel misery affected thousands of passengers on the eve of the Commonwealth Games.
One commuter said a half-hour journey home took almost two and a half hours.
She added: "I was in an overcrowded train with no room to move. It was not pleasant."
She said buses were put on to take some stranded passengers home.
Visitors have already begun flocking to the city for the biggest sporting event ever held in Scotland.
But today Network Rail bosses pledged they were ready to tackle any railway problems during the Games.
A spokesman said: "Over the last three months, we have upgraded equipment to ensure the infrastructure is in as good a condition as possible.
"We have increased our staffing levels over the next two weeks and have dedicated teams across the city who will be ready to quickly attend any problems."
Passengers said there were long queues and overcrowding in the station as delays continued until around 6pm until the backlog was cleared.
A Network Rail spokesman added: "We lost power to the points on the bridge outside Central station.
"It was a mechanical fault."