Reduced services on the Cranbourne and Pakenham lines until further notice due to software problem

The Andrews government is asking commuters to be patient as specialists work to fix bugs in the system that are causing a peak-hour squeeze.

Commuters on the Cranbourne and Pakenham lines will have less frequent train services.

Peak-hour commuters on two of Melbourne’s busiest railway lines are being jammed into overcrowded trains because of a software issue forcing less frequent services.

The government has conceded it does not yet know when the issue will be resolved, asking for patience as specialists work to fix bugs in the system.

From January 30, passengers on the Cranbourne and Pakenham lines have been told to expect a “reduced service” during the morning and afternoon peaks until further notice.

The problem is linked to the installation of high-capacity signalling along the railway line that will allow for “turn up and go” services through the Metro Tunnel.

The Andrews government says it does not know when the issue will be resolved. Picture: Andrew Henshaw

But problems have emerged getting the modern technology to work together with the 20th-century system currently used across Melbourne’s railway network.

In the final days of testing the signalling, software issues were still present and experts in Australia and abroad have been called in to deal with the problem.

Transport officials have asked passengers to plan ahead and have made buses available to step in where required.

Peak hour services along these lines, often running as often as every four minutes, are now being advertised as running an average of six to seven minutes.

But Public Transport Users Association spokesman Daniel Bowen said passengers were waiting even longer and the change was sparking severe overcrowding on trains.

Cancellations and alterations to the schedule were also forcing some commuters to wait 30 to 40 minutes for a train.

“Upgrades are very welcome but this has clearly not gone to plan, and Public Transport Victoria and Metro need to be clearer about the causes of these disruptions, and ensure that accurate timely information is provided to passengers,” Mr Bowen said.

“Every effort should be made to fix the problem as soon as possible, and to minimise delays and crowding, including outside peak hours.”

Cancellations and schedule changes mean some passengers face a wait of up to 40 minutes for a train. Picture: Nicole Garmston

Rail Projects Victoria, who oversee the upgrades and the Metro Tunnel project, are leading the repair efforts but cannot say when trains will return to normal.

“We’ve got a team of experts working hard to resolve a technical software issue on the Cranbourne and Pakenham lines that is affecting the number of services that can run,” a spokeswoman said.

Trains on the nearby Frankston and Stony Point lines are not affected and the disruptions largely do not affect off-peak services.

High-capacity signalling allows trains to wirelessly speak to each other so that services can run closer together.

When up and running alongside the Metro Tunnel, it is expected to allow for 30 trains an hour on Sunbury, Cranbourne and Pakenham lines.

Experts have warned of teething issues as the technology is rolled out into Melbourne’s older network.

A software meltdown created massive delays and blowouts on London’s Crossrail project because of problems getting the new signalling program to talk to parts of the network built during the Victorian era.