The fire that is causing delays.
Commuters will face further delays on major train lines in the morning peak as Metro crews work to repair damage caused by a fire next to railway tracks at Richmond station.
A fire broke out in an electrical substation near Richmond station about 6.30pm on Tuesday night, affecting signalling equipment.
Trains were suspended on a number of major lines for about five hours. Twelve firefighters attended the scene and brought the fire under control within an hour.
Some outbound trains resumed on the Cranbourne, Frankston, Pakenham and Sandringham lines about 11pm. Buses were still replacing city-bound trains between Elsternwick and Richmond.
But Metro spokeswoman Leah Waymark said fewer trains would be running on these lines until Wednesday afternoon at the earliest, as the fire had burned the "trunking where the signalling cables are housed".
"Our crews are on site assessing the damage and teams will work through the night to repair as much of the affected infrastructure as we can," she said.
No injuries were reported. A police spokeswoman said the fire was not being treated as suspicious.
Ms Waymark 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.
An MFB spokeswoman said that between 50 and 100 people were evacuated from a train at Richmond station about 8pm. Ms Waymark was unable to comment on this.
The Alamein, Belgrave, Glen Waverley and Lilydale lines were also temporarily delayed on Tuesday night when power was turned off to enable MFB to extinguish the fire.
Shadow Minister for Public Transport Jill Hennessy said trying to get home on the train on Tuesday night had been a complete disaster for commuters..
"Incidents like this show just how important it is to have a train system that actually works and can cope with disruptions but Denis Napthine's government is too dysfunctional to fix our trains,'' Ms Hennessy said.
"It is vitally important to ensure problems on one line don't cascade across the network, only Labor will build Melbourne Metro Rail and double the city loop."
with Richard Willingham