Hazard Complexity of rail infrastructure
Knowledge and understanding
|Complexity of rail infrastructure||
Understand all associated hazard knowledge
The railway's built environment has developed over many decades, with varying facilities to assist fire and rescue service intervention. The construction and topography of the rail system varies widely and will have an effect on fire and rescue service operations and safe systems of work.
Some areas of the rail network present additional risk due to the complexity of the location. These locations can include large rail terminals, junctions, regional stations or places where rail lines are used by more than one rail system. At complex layouts or junctions, rail vehicles may move from one track to another in a short space of time, and may approach from either direction.
At level crossings the railway will interface with road or pedestrian users, which can present an additional complexity.
For complex infrastructure or depots and sidings, pre-planning and tested communication arrangements should be put in place.
To effectively manage a rail incident, it is essential that fire and rescue service responders have a suitable awareness of the nature and complexity of the rail infrastructure they are attending. For the purposes of fire and rescue service intervention, railway infrastructure can be broadly categorised as managed and unmanaged.
Managed infrastructure is typically within an urban rail system, such as a metro system or rail infrastructure that has holistic emergency response protocols, often managed by a train operating company.
Unmanaged infrastructure is typically remote from urban areas and is likely to be managed by Network Rail. Both types will prompt a certain response from the infrastructure operators, but this will differ according to infrastructure operator capability and the geographical constraints that may affect response and attendance times.
The main infrastructure will include stations, track, depots, sidings, railway arches and overhead line equipment (OLE). All will have their own inherent hazards.
Larger train stations are likely to be complex environments. There may be adjoining properties that may become involved in an emerging incident and neighbouring properties that may need to be considered for evacuation purposes. Larger train stations may have phased evacuation, depending on the nature of the incident or the means of alarm initiation. It is vitally important for responding crews to fully understand the infrastructure risks and the principles of evacuation. See National Operational Guidance: Operations.
A station usually consists of one or more buildings for passengers, and possibly goods, and may be constructed over a number of levels. A 'terminal' or 'terminus' is a station at the end of a railway line.
Large train stations may have a number of rail companies operating in different areas, with varying emergency procedures. Railway stations will have public and non-public areas; the areas for providing public access will generally present limited hazards. Some facilities provided to keep the public safe can present a potential obstruction to a fire and rescue service, for example, platform edge doors or barriers. Methods of opening these facilities should be readily available to station staff.
Non-public areas can present additional hazards to those generally encountered in public areas, such as:
- Fast-moving rail traffic
- High voltage electrical equipment for train stations and infrastructure
- Power supply equipment
- Unusual direct access to the track
In addition to the hazards encountered on other parts of the railway, firefighters and station staff should also be aware of other factors that may have a bearing on incidents located on, or near, a railway station. Many railway premises are historic buildings and are likely to have heritage value.
Railway lines that run though major towns or cities are frequently elevated. To achieve this, arches are constructed and can be adapted for a variety of uses, such as garages, storage, entertainment venues, offices and workshops.
In an incident within the arch, a number of additional hazards can be present. These include:
- Difficult access - the arch may only have one point of entry and the main entrance can span a large opening and be strongly secured
- Lack of openings - making ventilation difficult to achieve.
- Arduous working conditions - caused by the lack of ventilation and heat retention by the structure of the arch, which is generally constructed of thick masonry
- Complicated layout - due to internal modification of the arch
- Contents of the arch - may include highly flammable goods, hazardous materials or gas cylinders
- If involved in a fire, the effects on the rail infrastructure above, including the effect of any smoke on the movement of rail traffic and overhead line equipment (OLE)
See National Operational Guidance: Fires in the built environment
Depots or sidings
Depots or sidings can be described as a short stretch of track, or tracks, that are connected to the main infrastructure. They may be provided for a number of purposes, such as:
- Parking rolling stock
- Storing rail vehicles, including those carrying hazardous materials
- Loading and unloading
- Maintenance facilities particular to the type of vehicle such as fuel, chemicals, gas cylinders and waste
- Allowing rail vehicles to pass
- Parking rail vehicles for servicing, cleaning or maintenance
- Loading or unloading goods
- Storing of track welding powder
- Storing of detonators (used as warnings signals)
Depots or sidings may differ from the main infrastructure in that:
- Sidings are often designed to allow several trains to be spaced closer than usual
- No signal may be provided
- Their control and ownership may be shared between several parties
The shunting of wagons around a depot may take place without warning and personnel should not stand immediately behind, in front of, or adjacent to, rolling stock on a siding or depot. Until a clear assurance has been provided that all train movements have been controlled, fire and rescue service personnel must not:
- Attempt to move between two stationary rail vehicles, or a stationary rail vehicle and a set of stop blocks, unless there is at least a gap of 30 metres between them
- Crawl under, or over, any rolling stock
These locations can present a challenge to the fire and rescue service as various areas presumed to be under their control may be under separate ownership and management control.
Certain locations will require the fire and rescue services to carry out pre-planning to establish the managing party (and its location) and identify the uses and processes that are undertaken at the location. This information should be used to develop appropriate Site-Specific Risk Information (SSRI). These plans should identify areas of ownership and management responsibility such as:
- Who operates in which area?
- Whose responsibility is it to provide safe access for the fire and rescue service?
- Who controls power supplies to which areas?
- Who are vehicles controlled by, and to what extent?
- Who the fire and rescue service should contact to obtain information relating to hazards and risks, including what is stored on rail vehicles?
- What are the arrangements for attendance of the responsible person at tactical command?
- What are the means of identifying the responsible person at tactical command, and what authority they will have over the wider premises?
Railway wagons loaded with hazardous materials are occasionally parked in railway sidings or depots. Military explosives should not be transported with other goods and may be undeclared.
Incident commanders must be aware of the potential for a wide variety of hazardous loads at such locations, and of the importance of liaising with rail staff, where available, to identify loads.
The permanent way
The track on a railway or railroad, also known as the permanent way, is the structure consisting of the rails, fasteners, sleepers, and ballast (or slab track), plus the underlying subgrade. It enables rail vehicles to move by providing a dependable surface on which their wheels can roll.
The term permanent way also refers to line-side structures, such as fences. This can also be referred to as the operational railway and it is normal that the area between the two boundary fences is called the operational railway. The track bed and surrounding infrastructure can cause a potential for slips, trips and falls for personnel entering, or working in, this environment.
The track side has traditionally been used as a temporary store of redundant railway material, as well as undergrowth or waste from fly tipping. This again provides further slip, trip and fall hazards. If a decision is taken to evacuate passengers along the track, then consideration should be given to the speed at which they can safely move, and in dealing with those of limited mobility.
Incident commanders should consider the effect that unusually large volumes of water may have on the rail infrastructure. Such volumes of water, for example, from flooding or high volume pumping, can weaken embankments and misalign running rails. This can have disastrous outcomes even some time after the event. Because of the potential for such damage, the permanent way should not be used as a conduit for removing large volumes of water from nearby flooding incidents.
A set of railway points is a mechanical installation enabling rail vehicles to be guided from one track to another. Points can be either mechanically or electrically moved from within a signal box or a control room and may be remotely operated. Remote operation can result in foot entrapment, severe injuries and increased risk of exposure to rail vehicles impact.
Points represent a significant trap hazard to firefighters as they can move rapidly without warning. The points are set automatically when a signaller selects a route for a rail vehicle
A single signalling centre can control many miles of track, so a signaller should not be expected to have an awareness of personnel in the vicinity of points. If entry onto the tracks is required, proportionate control over the railway must be applied and this will usually prevent point movements but the risks from points movements should always be considered.
To avoid railway points becoming frozen and inoperable during cold weather, point heaters that are predominantly powered electrically are used. Traditionally, LPG was used to fuel point heaters. The gas cylinders were normally housed in small wooden cabinets next to the track and the main heating assembly would be supplied with gas via a length of low pressure tubing. Examples of these may still be found on heritage or industrial railways.
Even after traction power has been isolated, points can still move and trap feet as they are powered by a separate electrical system and may still be operated from non-electric or diesel traction rolling stock.
Heritage railways retain the line-side hazards from that era (some of these can still be found across Network Rail infrastructure). Hazards connected with heritage railways may be:
- Point operating rods - running adjacent to the tracks in the cess and crossing the tracks underneath the running rails, creating entrapment, slips trips and fall hazards
- Semaphore signal operating wires, pulleys and rods - running adjacent to the track in the cess on raised supports, and crossing the tracks underneath the running rails, creating entanglement, trips and falls hazards
- No response from a railway incident officer (RIO) as these networks are not part of the normal National Rail infrastructure
- No immediate engineering support for incidents, derailments, etc.
Bridges and viaducts
A bridge is a structure built to span a gorge, valley, road, railway track, river or any other physical obstacle. The design of a bridge will vary depending on the function of the bridge and the nature of the terrain on which the bridge is constructed. There are a number of additional hazards to consider when dealing with incidents in the vicinity of bridges, such as working at height, restricted safety areas and difficult access. Before any entry into tunnels or viaducts, rail traffic must be stopped.
Bridges that have been struck by moving road or rail traffic should be examined by the infrastructure manager. See network rail bridge strike protocol.
Viaducts are used to overcome steep gradients that are caused by geographical features such as gorges and valleys. They are raised sections of track, supported on pillars or on a series of arches.
All bridges and viaducts have unique identifying numbers marked by a metal plaque. These numbers should be relayed to the infrastructure manager, and can be used to establish the exact location of incidents.