Rail safety investigations & reports

Uncontained battery failure involving Sydney Light Rail Vehicle 053, Randwick LRV Depot, New South Wales, on 3 April 2020

Investigation number:
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final Report

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What happened

On 3 April 2020, light rail vehicles (LRV) 053/054 were stabled at the light rail depot in Randwick, New South Wales. At approximately 0249, workers heard a loud noise and on investigating found a battery enclosure cover on the ground between two other LRVs. The cover was identified as originating from LRV 053.

Closed-circuit television cameras within the light rail depot captured the ejection of the cover from LRV 053. The cover was ejected with a flash visible followed by a plume of smoke or vapour and the cover landed approximately 6 m away.

There was significant damage to the battery compartment and batteries on LRV 053 and also minor damage to two other vehicles. There were no reported injuries.

What the ATSB found

The software controlling the battery charging likely corrupted during the uploading process which went undetected. The fault with the software resulted in overcharging the batteries on multiple LRVs, including LRV 053. The overcharging of batteries was not detected prior to the occurrence through Alstom’s validation or fault monitoring processes.

The overcharging of LRV 053 batteries generated excessive hydrogen within the batteries. The battery enclosure on LRV 053 ruptured when flammable gases were released into the enclosure in the presence of an ignition source. The risk of explosion had been identified although relied on risk controls that were ineffective at preventing the escalation in this instance.

What has been done as a result

Alstom made changes to the management of train fault data to generate automatic alerts for battery over temperature faults. A new fault code was created within the train control monitoring system to monitor the battery charging temperature and alert the driver if any of the defined thresholds were exceeded.

Additionally, further software validation and testing will be conducted by the battery charger software supplier, as well as during software acceptance testing and following uploading of revised software by the maintainer.

Safety message

The introduction and commissioning of new assets must ensure that design requirements and risk controls are tested and validated as functional. Additionally, fault monitoring and maintenance regimes must monitor asset condition, so as to avoid conditions that might escalate and contribute to accidents.

Download final report
[Download  PDF: 2.72MB]

The occurrence


Safety analysis


Safety issues and actions

Train details

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Safety Issue

Go to RO-2020-005-SI-01 -

Alstom's validation and fault monitoring processes

Neither Alstom’s validation processes nor fault monitoring processes were sufficient to detect the overcharging of batteries prior to the event.

Safety issue details
Issue number: RO-2020-005-SI-01
Status: Closed – Adequately addressed
General details
Date: 03 April 2020   Investigation status: Completed  
Time: 0249 AEDT   Investigation level: Defined - click for an explanation of investigation levels  
Location   (show map): Randwick Depot   Investigation phase: Final report: Dissemination  
State: New South Wales    
Release date: 03 December 2020   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Train details

Train details
Line operator Altrac Light Rail Partnership  
Train operator Sydney Light Rail  
Train registration LRV053/054  
Type of operation Light Rail Vehicle  
Sector Passenger - metropolitan  
Damage to train Substantial  
Last update 03 December 2020