Bus Safety Investigation Report - Bus Fire MO9994 - Green Valley 8 August 2022

View the Bus Safety Investigation Report 

What happened

On 8 August 2022, the driver of bus MO9994 noticed smoke while conducting a passenger service on route 805 from Liverpool and Cabramatta. The driver stopped at The Valley Plaza shopping centre bus stand and safely evacuated the three passengers on board, only after instruction from their company operations control centre. 

There were no injuries but the vehicle was destroyed. 

What we found

The investigation identified:

• An electrical fault within the accessory panel located above the driver’s position likely generated heat which ignited surrounding combustible material, resulting in an intense fire.
• Inadequate protection of the accessory panel’s electrical circuit from faults.  
• Deficiencies in asset management processes.  
• A lack of suitable and recent practical driver training for emergency response.  
• The bus accessory panel circuit could not be isolated, so the system was not protected from the ongoing provision of energy to escalate a fire from a short circuit. 

Actions taken by directly involved parties during the investigation

Transport for NSW (TfNSW)

• Issued TS 03961:1.013 Bus Mounting and Installation of Electrical Equipment Standard. This document was a first issue with the designation TS 03961 and superseded T BU FL 01701 ST Mounting and Installation of Electrical Equipment, version 1.0.
• Advised that it could undertake a targeted inspection program, including a sample of Volvo B7RLE/Custom CB80 configuration, and a parallel inspection of sample model configurations. Following the findings from that process, TfNSW could then determine the requirement for a more widespread inspection of buses.

Recommendations

OTSI made the following recommendations:

Bus and coach operators 

• Review maintenance regimes to ensure inspections adequately address and remedy any issues with wiring integrity and security, including protection of live terminal posts and proximity to other conductive components.
  
  Ensure that a practical, competency-based driver refresher training program for emergency procedures, with training documented and records maintained, is in place to provide drivers with an effective level of skills and knowledge to safely manage an emergency.

TfNSW

• Review current asset management requirements to apply a more comprehensive safety risk management and regulatory framework for long-term asset management, and ensure required specifications are delivered by bus and coach manufacturers and installers for assets operating public passenger services.
• Ensure provisions for the supply of documentation to bus operators and maintainers, including wiring schematics, for asset build and all pre- and post-delivery installations.
• Ensure provisions for continued Original Equipment Manufacturer (OEM) support for the life cycle of assets procured under the Transport for NSW Bus Procurement Panel program.
• Develop and implement an inspection and rectification program to ensure electrical circuits on the current fleet of buses operating accredited Transport for NSW passenger services are adequately protected and can be effectively isolated as required.

Transit Systems NSW

• Review emergency procedures and documentation, and driver training to ensure emergency procedures are relevant and reflect the configuration of individual buses, including isolation switch activations.
• Develop and implement a practical, competency-based driver refresher training program for emergency procedures, with training documented and records maintained, to ensure that drivers are provided with an effective level of skills and knowledge to safely manage an emergency.
• Develop and implement an inspection and rectification program to ensure electrical circuits on the Transit Systems NSW current fleet of buses are adequately protected and can be effectively isolated as required.

Volvo Bus Australia

• Review technical assurance processes to ensure that assets built and delivered in accordance with Transport for NSW Bus Procurement Panel specifications comply with documented requirements.