It is likely a Kiama-bound passenger train struck a hatch on a freight train because of a failure to properly secure the hatch after maintenance, an investigation has found.
The Office of Transport Safety Investigations was tasked on behalf of the Australian Transport Safety Bureau to look into the incident that occurred on the evening of July 21 last year.
The passenger train hit an open air hatch on a stationary Pacific National NR locomotive near Loftus station, damaging the guard's windscreen and passenger doors on passenger train's lead carriage.
No one was injured and the incident resulted in minor delays on the South Coast line during peak hour.
OTSI found it was likely that the hatch was not properly secured during maintenance and this was missed in roll-by inspections, because the hatch's design meant it could look like it was locked, without being secured correctly.
The hatch also exceeded the outline of the freight train, or the space it would occupy in motion, meaning that when it swung out it encroached on the train on the adjacent track.
Australian standards state that external hatches should be designed so they cannot swing beyond the outline of the train.
"If this cannot be achieved, the Australian Standard suggests a range of secondary measures that can prevent an incident like this one occurring," OTSI chief investigator and chief executive officer Dr Natalie Pelham said.
After last year's incident, Pacific National and its maintenance provider United Group Limited carried out an assessment of the NR fleet and added a second latch to hatches.
They also issued a bulletin to maintenance staff on the correct procedure for securing hatches.