Workers inspect the damage near Richmond station on Wednesday. Credit:Wayne Taylor There have also been significant delays on the Williamstown and Werribee lines, as knock-on effects on Metro's badly delayed trains hit commuters in Melbourne's west too. Metro repair staff worked through a rainy Tuesday night in a bid to replace the burnt-out cables, which supplied power to the network’s signalling system in that area. But the extensive job of replacing cabling will take until Thursday morning - meaning train commuters could endure a second morning of delays on those lines. Metro Trains' most current advisory states that “damaged signalling cables has meant that we have to run a reduced service’’ on all four lines.

Metro spokeswoman Larisa Tait said delays were expected to extend into the evening on the four lines as Metro crews repaired the fire damage. ‘‘All services on the Pakenham, Cranbourne, Frankston and Sandringham services will run direct from Flinders Street to Richmond and will not run through the City Loop," she said. "We are advising our customers who normally travel from a City Loop station (Parliament, Melbourne Central, Flagstaff) to travel to Flinders Street instead to catch their service." She said Metro was trying to have repair works at Richmond completed before the first train ran on Thursday morning, but this could not be confirmed until later on Wednesday night. She said cancellations had caused delays of up to 20 minutes on the four affected lines on Wednesday afternoon’s peak-hour services, which she said were "busy".

Few commuters were still at Flinders Street station just before 7pm, with a number of people running to make it onto their trains home. Michael Forbes, who works for the state government, said his morning commute took longer than usual on Wednesday, with fewer, more crowded trains running in the morning peak. Commuters "had to squeeze on...and that of course slows the train down as well," Mr Forbes said. "When we got closer to Richmond we were advised the train couldn't go too fast between Richmond and Flinders Street (due to the repairs) which took several extra minutes." Denise said it took her about two and a half hours to get from the city to Brighton on Tuesday, compared to her usual 20-minute journey. Many connecting trams to other train stations were packed with people, she said.

Commuters faced more pain on Wednesday evening when a train broke down in the City Loop around 6pm. The faulty train caused delays to the Craigieburn, Sunbury and Craigieburn lines. About 50 replacement buses have also been operating across the network during the day and will continue into the evening peak. A Yarra Trams spokesperson confirmed extra trams were running on routes 3, 6, 8, 70 and 72 to supplement the trains at Caulfield, Armadale, Hawksburn, South Yarra, Glenhuntly, Richmond, Flinders Street and Toorak stations. But there were signs Melbourne’s tram system was also being affected by the train problems, with Yarra Trams suggesting passengers on St Kilda Road should walk to the Junction to increase their chances of catching a tram.

Workers trying to finish repairs at the Richmond site have said the most likely cause of the fire was rats chewing through PVC covering on a high-voltage power line near Richmond station and multi-core cabling that ran with it, exposing bare wires. The fire that had subsequently started had been fanned by an air hose in the cable boxes. Electrical Trades Union organiser Gerry Glover, who has worked for the past decade on Melbourne’s train system, said signal technicians at the site had done a ‘‘great job’’. ‘‘All last night it was pissing down rain and there are blokes who worked right through it.’’ He said the cause of the fire was not neglect of the system, because the cabling in question that had sparked the fire was relatively new.

About 30 repair staff were on site near Richmond station opposite AAMI Park soccer stadium when The Age was on site on Wednesday afternoon. One worker, who asked not to be named, said it appeared rats were a likely cause of the fire. An MFB spokeswoman said that between 50 and 100 people had been evacuated from a train at Richmond station at about 8pm on Tuesday. A police spokeswoman said the fire was not being treated as suspicious and no injuries were reported. Ms Tait said commuters should check Metro's Twitter feed and the Metro and PTV websites for further updates.

"We are very sorry and ask customers on the affected lines to allow extra time and be patient while we do our best to run as many trains and supplementary buses and work to resume services as quickly and safely as we can," she said. Daniel Bowen, a spokesman for the Public Transport Users Association, said the network was badly disrupted on Wednesday evening. "We are certainly seeing a lot of disruptions again tonight, with large numbers of cancellations, as well as a lot of trains diverted out of the City Loop. It is going to be a hard slog home for passengers tonight. "The bigger question here is how the equipment is in such a condition that this has happened. "The fact that a relatively small fire resulted in the closure of four rail lines last night and continued disruption 24 hours later - it’s clearly not good enough for a city of our size.

"It causes a lot of disruption and lot of economic cost, it’s like shutting down three freeways at once," he said. With Jane Lee