Thursday, March 24, 2022
ONRSR is reminding rail transport operators (RTOs) about a range of risks, causes and controls associated with fires and explosions on passenger rolling stock.
Fires on rolling stock can be deliberately lit, caused by rolling stock faults or started accidentally; RTOs should identify all possible causes.
Fires on rolling stock can result in catastrophic loss of life although this is not the case for the vast majority of fires on rolling stock due to the effectiveness of fire safety controls.
RTOs should continue to identify new potential safety controls and make an assessment as to whether they are reasonably practical to implement as well as reviewing their current operations to ensure that existing fire safety controls are in place and effective.
ONRSR’s investigations into fires on rolling stock have identified causes and contributing factors across the four areas listed below. While not exhaustive and given the range of operational environments within the Australian rail industry, the following causes, contributing factors and controls should be noted.
The causes of fires can be classified into organisational, technological, individual, and environmental factors.
1. Organisational factors e.g.
2. Technological or equipment factors e.g.
3. Environmental factors e.g.
4. Individual factors e.g.
While not exhaustive and given the range of operational environments within the Australian rail industry, the following controls should be noted. Operators must consider a range of factors, including the likelihood of the hazard and the degree of harm to determine what controls are reasonably practicable to implement (see the ONRSR Guideline – Meaning of duty to ensure safety so far as is reasonably practicable SFAIRP for more information).
The example controls listed here have been taken from AS7529.3:2014 “Australian Railway Rolling Stock- Fire Safety - Passenger”. RTOs should engage fire safety experts to determine which controls are appropriate for specific rolling stock as well as determining appropriate methods for demonstrating compliance to AS7529.3 or other fire safety standards. Fire safety experts should also be engaged to assess the impact of any proposed modification to rolling stock that may have an impact on fire safety.
While there appears to be few ways to eliminate fires on trains, there are several substitution and engineering controls that can minimise the risk.
Some of the substitution controls operators have employed to prevent or reduce the consequences of fires on rolling stock:
1. Fire load controls aim to reduce, remove, or prevent the accumulation of combustible material that can fuel fires on rolling stock. Combustible materials include fuel, oils, litter, luggage, dust, or debris that can contribute to large fires on rolling stock. Examples of controls to remove fire loads include:
2. Ignition source controls are controls that remove or contain items that are potential sources of ignition. Many ignition sources exist on rolling stock: resistors, exhaust from combustion engines, and heating elements in HVAC systems. Examples of ignition source controls include:
Some of the engineering controls operators have employed to prevent or reduce the consequences of fires on rolling stock:
1. Compartmentation controls are designed to inhibit the spread of fire on passenger rolling stock. By dividing rolling stock into a series of compartments limits the spread of fire and helps people evacuate, and emergency services with their rescue operations. Each compartment aims to form a barrier to combustion, smoke, heat and toxic gases. Examples of compartmentation controls include:
2. Fire suppression system controls include both fixed fire suppression systems and portable extinguishers carried on rolling stock:
3. Ventilation controls: Under normal operating conditions, ventilation systems ensure fresh air is provided to passengers during fires, limiting oxygen to the fire and providing clean air to passengers. In the event of a fire, it should be possible for the driver or train crew to shut down air conditioning or ventilation systems to prevent the recirculation of smoke within passenger or crew compartments.
Some of the administrative controls operators have employed to prevent or reduce the consequences of fires on rolling stock:
1. Fire detection and alarm systems detect the presence of smoke, heat or fire. These controls should be located in passenger areas, where ignition sources are located - and, when alarms are activated, they:
2. Escape, evacuation and refuge system controls include:
3. Procedures and training controls include:
This information is provided as guidance only and may not be applicable to all rail transport operators.