Fremantle Railway Bridge Early Warning System

The Fremantle Rail Bridge in Perth Western Australia carries both passenger and freight services over the Swan River between the Fremantle port and North Fremantle. The rail bridge generally aligns North and South, with Perth City to the North. On the 3rd May 2011, a refuelling ship called the Parmelia 1, crashed into the rail bridge at Fremantle, damaging the overhead traction wiring system and cutting rail access in and out of the West Australian port city.

The fully-loaded ship collided with the bridge about 6.30am, badly damaging a reinforced concrete mast which supports the overhead power supply and brought trains to a standstill. The damaged sustained can be seen in the pictures on the cover of this brief. Nobody was injured and there was no fuel spill into the harbour. This incident highlighted the need be able to be detect collision impacts of any seafaring vessel with the rail bridge, and automatically stop trains from traversing over the bridge.

The Public Transport Authority of WA (PTA) would like to install a warning system on Fremantle Rail Bridge which will trigger an immediate, real-time alarm when a measured impact or force, over a predetermined threshold, is exceeded. The system needs to provide a mechanism which will interface with the current signalling system and place signals reading over the alarmed area of the rail bridge back to ‘STOP’. In the event of an actual collision, the structural integrity of the bridge will be assessed and certified by an appropriately qualified third party consultant as nominated by PTA, prior to the alarm being reset and the signalling system restored to normal operation. The Public Transport Authority also requires details of the level of critical spare equipment items it should carry for this system. Please also note that both passenger and freight trains travel across Fremantle Rail Bridge and the proposed early warning system must be able to discern between forces from vessel impacts and forces from regular passenger and train movements.