A BLOWN fuse was the culprit for yesterday's rail chaos.
A suspected power surge shortly after 7am blew the fuse at Cardiff, where the power supply from the grid enters Network Rail's own power network, knocked out back-up supplies, and caused signaling failure on the railway line around the capital.
It left around 30 trains unable to move, for safety reasons.
Commuters were hit with a rash of "delay" signs when they arrived at stations in South Wales yesterday morning as engineers from Network Rail and Western Power Distribution worked on the problem.
The power also went down on the railway line in Bridgend, Barry and in the valleys up to Caerphilly.
The failure also affected points and level crossings. British Transport Police ruled out any foul play.
An estimated 20,000 passengers were caught up in the chaos, with a knock-on effect reported on the roads.
Train operators urged customers to use alternative methods of transport and desperately sought to arrange coaches.
A statement from Network Rail at 2.30pm yesterday said: "With the assistance from colleagues of Western Power, we managed to restore full power supply to operate our signalling at around 10am.
"Trains are now on the move, however there are still some slight delays as we ease into normal timetable by this evening's rush hour."
It continued: "We are very sorry for the inconvenience caused and we advise passengers to check before they travel into and out of Cardiff today."
Tom Goskar, of Swansea, caught the 6.28am from Swansea to Salisbury, in Wiltshire.
"I will be four hours late, and will have spent seven hours travelling," he said. "I can't understand how they hadn't been testing backup power for the signalling equipment."
Natalie, of Swansea, caught the 7.16am train from Llansamlet, with her dog.
"We slowed to a halt thinking wild horses were on the tracks again but no information was given for about 10 minutes, after which they announced the problem, leaving me 30 minutes late for work," she said.
"My dog was panting and shaking leaving me stressed out. I was sitting on the train five minutes away from Bridgend for and hour and a half.
"It's terrible. Always drama." Another passenger heading into Cardiff from Mountain Ash praised the guard for letting passengers use his mobile phone and for giving out information regularly.
