The service failed spectacularly on Thursday, with Ballarat commuters forced to endure multiple cancellations and delays as V/Line announced a mysterious wheel fault which is causing serious safety concerns for its VLocity trains.

Thursday’s failure followed a week of unexplained train cancellations which have brought the service to its knees.

This latest problem follows months of under performing and overcrowded services which have driven commuters to the point of despair. 

V/Line released a statement on Thursday that said trains will require additional maintenance due to “higher than normal wheel wear”.

“This means fewer carriages are available to operate the timetable and in some cases, train services will need to be replaced with coaches,” the statement read. 

The V/Line Ballarat Line Twitter page outlined around 10 Thursday services on the Ballarat line that were either cancelled, changed to buses or reduced in carriage number. 

V/Line did not indicate how long the maintenance process would last, but confirmed that six Ballarat services have experienced carriage reductions since Monday.

“V/Line is working closely with Bombardier to schedule the required maintenance so that carriages can be returned to service as soon as possible,” V/Line spokeswoman Ebony Jordan said. 

“V/Line, Bombardier and an independent expert from the Institute of Rail Technology are investigating the cause of the issue.”

Wheel wear was first identified in December, but V/Line does not yet know why it is happening.

It can’t rule out the possibility that damage is being done on the Regional Rail Link between Southern Cross Station and Geelong.

Opposition spokesman for public transport David Hodgett said he attended a briefing organised by the government about V/Line with the Department of Economic Development, Jobs, Transport and Resources on December 21 in which questions were asked about maintenance of VLocity carriages. 

"My staff member specifically asked a question about V/Line's Bombardier maintenance contract," he said. 

"The reply I received was that quote 'the Bombardier maintenance contract offers very good value for V/Line' and that 'Bombardier was meeting 97-98 per cent of its performance requirements under the contract'.

"With December 21 less than the 30 days ago, that V/Line says it was aware of the major safety problem, it is disappointing that at this briefing, the Andrews Labor government chose to deliberately mislead the Liberal Party."

Public Transport Users Association spokesperson Paul Westcott said the service was in “crisis”.

“I think for Ballarat people in particular, there's been real problems with the RRL,” Mr Westcott said.

“There's obviously the single track (issue), but then you've also had timetabling problems, clashes with Geelong and while one can forgive the teething problems, we're hoping by now that things are back on track. This really adds another big problem.”