The automatic train protection (ATP) and electronically controlled pneumatic braking (ECPB) systems on BHP’s trains could not interface to dump brake pipe pressure if an ECPB emergency or penalty brake application became ineffective in arresting an uncommanded train movement.
The ATSB is satisfied that the action being taken by BHP has reduced the risk of this safety issue.
Following the runaway and derailment accident involving M02712, and after collection of physical site evidence, BHP formed an independent team to investigate and analyse the accident. The following summarises the improvement actions identified relevant to this safety issue, and the intent and the status of implementation, as advised by BHP on 20 January 2020 and updated 31 January 2022:
Action
Investigate a solution for the effective intervention by the WAIO Railway Network’s braking system for rollaway events, and either implement that solution, or demonstrate that controls are in place to address the relevant risks so far as is reasonably practicable.
Intent
To examine engineering/system solutions that ensure train braking system is effective in all rollaway situations, otherwise put in appropriate controls to manage the risk.
Progress (ongoing)
BHP along with our supplier partners have developed a software engineering solution that ensures that the Automatic Train Protection system has access to all modes of braking on the train, ensuring effective braking in a rollaway situation. This software has been successfully trialled on a number of BHP locomotives [following notification of change to ONRSR on 30 August 2019] …and is being rolled out to the BHP locomotive fleet. While this failsafe engineering control is being implemented across the fleet, a procedural control is in place as agreed with the ONRSR [see Driver response – Brake pipe emergencies and penalties]. This control is regularly audited according to action below.
Action
Create and implement a tailored system for the BHP Rail Network, to analyse locomotive data logs to aid in verifying safety related procedural compliance and system performance.
Intent
To provide a single source of information for Rail personnel to verify that critical procedural steps are being completed.
Progress (Complete)
BHP Rail Operations Analysis and Improvement team have developed and implemented a software system that analyses and generates reports on locomotive data logs. The reports are then manually interpreted and actioned accordingly.
The BHP proactive action update also advised that:
BHP is continuing to invest in technologies to improve systems and safety and a commitment to deliver against the SFAIRP (so far as is reasonably practicable) principles. BHP’s Rail Technology Program will improve the safety integrity level of the Railway signalling and control system to a SIL4 level. This significant investment is due for completion in the medium term.
