Train 5BS7 was 15 minutes into its Brisbane to Sydney journey when it collided with a stationary track vehicle at Greenbank staff station. Train 5BS7 and the track vehicle were both given authority to enter the Greenbank staff station yard limits.

A misunderstanding between the train controller and signaller in regard to the anticipated departure time of the south bound train in combination with workload and train graph endorsement issues contributed to the erroneous granting of this authority. Long standing safeworking practices then contributed to the lack of an effective block between these opposing movements.