Sydney’s oldest suburban passenger trains have been temporarily removed from service following a series of cabin break-ins and vandalism incidents.

The K-set trains, which have operated across Sydney’s rail network for nearly 45 years, were withdrawn this week as authorities work to address security concerns.

Sydney Trains Chief Executive Matt Longland said several recent incidents, allegedly involving young people entering restricted train cabins and interfering with controls, prompted the decision.

NSW Police said one incident occurred last week on a train travelling towards Summer Hill, where two teenagers allegedly accessed a restricted driver’s cabin, used the train horn and attempted to operate other features.

Police said the pair allegedly assaulted a Transport for NSW staff member at Summer Hill Station after being asked to leave the train. A 13-year-old and a 15-year-old boy were later arrested and released pending further investigations.

Authorities said the temporary suspension aims to prevent further incidents while security measures are reviewed.

Unlike newer trains, K-sets are not equipped with onboard security cameras, making them more vulnerable to vandalism and unauthorised access.

Transport for NSW is now considering short-term security upgrades, including possible camera installations and additional security measures, before the trains return to service.

Introduced in 1981, the K-set fleet was the first suburban train series in New South Wales to feature air conditioning. Although retirement plans are already underway, officials said the temporary suspension does not mark the end of the fleet’s service.