Nearly 70 trains have been cancelled this week after Metro banned V/Line's VLocity carriages from suburban tracks because a boom gate failed to close properly when a VLocity train approached the Progress Street level crossing at Dandenong last Friday.

It has caused chaos for regional commuters and prompted a series of crisis meetings with the state government.

However, rail authorities became aware of the issue when similar level crossing failures occurred in 2011 and 2012.

And, according to one source, issues with the train involved in Friday night's incident have been long known.

"These cars have had recurrent issues with failing to activate track circuits for some time," the source said.

"[Train] unit 1147 is a repeat offender."

After the 2011 and 2012 level crossing failures, Metro introduced short-term fixes, including a monthly track cleaning program, which is referred to as track scrubbing, as well as installing Track Circuit Assisters – and upgrading existing ones – across the network to help boom gates recognise VLocity trains.

However, authorities failed to implement a permanent solution recommended in a report by Metro's top engineer in 2013, which would have involved putting axle counters on tracks shared by Metro and V/Line services.

The axle counters have been installed on the Stony Point line, but not yet across the rest of the network.

"They will be progressively rolled out to tracks shared by Metro and V/Line services," a Public Transport Victoria spokesman said.

The boom gate issue is the second problem to beset the regional operator in the past fortnight. 

V/Line was forced to pull many of its newest trains out of service because of a sudden and mysterious spate of wheel faults over fears they could cause a train to derail.

The problem was confined to the operator's VLocity carriages, the newest in the fleet, which continue to roll out of the Bombardier factory in Dandenong at a cost of hundreds of millions of dollars.

However, according to Rail, Tram and Bus union secretary Luba Grigorovitch, the wheel issue was separate to the boom gate problem.

"It's a coincidence that these issues have occurred at the same time," she said.

Ms Grigorovitch said the boom gate issue arose from poor maintenance of the tracks – specifically the lack of track scrubbing – which was Metro's responsibility.

"V/Line pays $20 million per year to use the Metro track and in return they don't even receive the basic maintenance to allow basic services to run," she said.

"Metro have not hesitated here to point the finger at everyone but themselves. It is shocking to learn that they are so deeply complicit in the travel chaos they have forced onto regional commuters.

"It's just not fair that regional passengers are made suffer while Metro fails to invest their millions in basic safety maintenance."

There has been a significant amount of testing of the VLocity fleet undertaken over the past few days, and engineers and safety experts are currently analysing the data gathered.

Testing is ongoing and Public Transport Victoria anticipates that by the middle of the week Metro will have a clearer picture as to the actions required for VLocity trains to safely resume running.

 – The Age