A new era, or a return to an old era, starts this week on Sydney’s public transport system as police begin taking responsibility for security on the city’s trains, buses and ferries.

The transport minister, Gladys Berejiklian, and the police minister, Mike Gallagher, joined senior officers this morning in announcing a new NSW Police Transport Command had started operation.

It is not the first time police have been put in charge of Sydney’s transport security. They were responsible for transport security before 1998, when the then minister, Carl Scully, hired Chubb security guards to patrol trains.

The Chubb guards were in turn replaced by RailCorp’s transit officer division in 2002. That division will now be shrunk from 600 staff to 150 over the next two years, and officers spread across buses and ferries, as well as trains.

On the numbers, the O’Farrell government’s changes mean a thinning in the ranks of “revenue protection” officers to check passenger’s tickets.

Ms Berejiklian said the Police Command, which will have an eventual strength of 600, “had a specific role in relation to safety and security”.

“They are there to take charge and make the system as safe as possible,” Ms Berejiklian said.

“The police presence will not only deter criminals but make sure any anti-social behaviour is clamped down upon,” she said.

The creation of the Police Command was announced in February, but is this week taking effect.

At the moment it is staffed by 300 officers transferred from the Commuter Crime unit. Over the next two years they will be joined by another 300 officers as more recruits make their way through the police academy.

The Police Commissioner, Andrew Scipione, said transport command officers would be based in three main hubs in central, south-west and north-west Sydney and seven satellite hubs, including the Hunter, Central Coast and Illawarra regions.

They will work across the train system as well as buses and ferries.

Ms Berejiklian said the restructure would be “cost-neutral” by about 2014.

She said current transit officers would have four options over the next two years: they could try to become police officers; remain as part of the 150-strong transit officer division; take up voluntary redundancy; or apply for other transport jobs.

Jacob Saulwick is the Herald’s Transport Reporter.