Rail infrastructure fire safety – building for the future, learning from the past

This article by Sulaiman AlMohammadi (Saudi Arabia Railways) and Peter Stephenson (Warringtonfire), gives an overview of the development of the rail infrastructure in the UK and in the Kingdom of Saudi Arabia and compares current fire and life-safety guidance in both countries.

Providing a safe and secure rail network is a major concern across the globe and if something goes wrong, safety can literally ‘go off the rails’ in any number of ways. However, improving awareness with designers, contractors, rail operators, employees and all associated with infrastructure, can make a significant difference to the overall safety and efficiency of the railway system for passengers, rolling stock, stations and built assets.

Railway safety is a very complicated subject, and many aspects come into consideration. Globally, many qualitative and quantitative railway safety and risk analysis techniques and methods are used within the industry to reduce risk to as low as is reasonably practicable (ALARP). A key consideration, often overlooked, is the emergency response requirements for the first responders to a variety of potential incidents, often in remote and harsh locations. For example, the Saudi Building Code identifies that the Authority Having Jurisdiction (AHJ) can require additional fire-protection provisions for buildings and assets with remote or challenging locations.

Railways are generally one of the safest means of ground transportation, especially for passengers, employees and the movement of goods. However, there are serious issues involved in both maintaining this position and sustaining the public perception of railway safety excellence. The railway industry now finds itself in a situation where actual and perceived safety concerns are real issues, to be dealt with in a new public culture of rapid change, short-term pressures and instant communications.

Railways are a traditional industry with histories extending over at least two centuries. There are many possible causes of risk through operation, design of vehicles, and rail infrastructure, and from external factors such as vandalism and road incidents. Risk management is being used increasingly to support decision making in the railway industry and in influencing design decisions. While risk management is used to justify and prioritize investment, any safety and risk information produced must be processed for decision-making purposes. If risks are high, risk-reduction measures must be applied or the design, operation and maintenance must be reconsidered to reduce these risks or to control the possible consequences. If risks are negligible, no actions are required but the information produced needs to be recorded for certification purpose. 

Kingdom of Saudi Arabia

The Kingdom’s rail network plays a key role in meeting the objectives of the Saudi Vision 2030, which includes a strategic framework to reduce Saudi Arabia’s dependence on oil; diversify its economy; and develop public service sectors such as health, education, infrastructure, recreation and tourism. Key goals include reinforcing economic and investment activities, increasing non-oil international trade, and promoting a softer and more secular image of the Kingdom.

In 1947, King Abdulaziz Al Saud, ‘The Founder of KSA’ agreed upon the idea to build a commercial port to harbor the huge ships that brought in oil drilling equipment, and later the oil tankers and approved the start of the railway project to connect the new port. Thus the railway sector was born. A few years later in 1951, the first railway line between Riyadh and Dammam started with the goals of building an integrated transportation system. In 2021, Saudi Railways Company (SAR) assigned to take over the operations and management of the network from the Saudi Railway Organization, starting 1 April, 2021.

Established in 2006, SAR is the owner and operator of the North Train Railway Network, and now, the new enabler of the Railway industry, and carries on the vision to build a sustainable passenger and cargo transport. SAR trains currently run through three main networks (North – East – Haramain) with lengths of more than 5,500km, and 15 passenger stations, through which more than 33 million passengers have been transported.

SAR also operates freight trains, as more than 2,000 freight wagons and 157 locomotives are all geared to transport more than (10) million tons annually. As SAR operates one of the ten longest freight trains in the world, SAR managed to transport more than 58 million tons of minerals from 2011 until the end of 2020, which contributed to displacing more than 4.5 million trucks from the roads.

By comparison the railway system in Great Britain is the oldest railway system in the world. The first locomotive-hauled public railway opened in 1825, which was followed by an era of rapid expansion. Most of the track is managed by Network Rail, which in 2017 had a network of 15,811km (9,824 miles) of standard-gauge lines, of which 5,374km (3,339 miles) were electrified. These lines range from single to quadruple track or more. In addition, some cities have separate metro, light rail and tram systems (including the extensive and historic London Underground). There are also many private railways (some of them narrow-gauge), which are primarily short lines for tourists. The main rail network is connected with that of continental Europe by the Channel Tunnel and High Speed 1 (originally the Channel Tunnel Rail Link), which fully opened in 1994 and 2007, respectively. Much of the development of fire-safety guidance embraced major stations that terminated in city centres, resulting in long platforms with single direction travel distances and the move from steam to diesel and now, more commonly, the electrification of the infrastructure.

The UK Government has recently published its long-awaited plans for an overhaul of the rail network, placing control of infrastructure and services under a new public body. Under the UK Government’s plans, the rail industry will be rebranded as Great British Railways (GBR). 

GBR will run and plan the network, as well as providing online tickets, information and compensation for passengers nationwide.

Design challenges

Local and international building codes for typical buildings do not readily address the unique fire-safety challenges associated with modern train station design.

NFPA 130, ‘Standard for Fixed Guideway Transit & Passenger Rail Systems’, represents best practice for the fire-safety design of train stations and is used extensively internationally, forming part of the NFPA suite of documents that are understood to be acceptable to Civil Defence, for example in Saudi Arabia. This standard also provides flexibility in the fire-safety design to allow the designers to use normal entry/egress routes and components (escalators, etc.) in an emergency, something that codes for the design of a typical building would not allow. Consequently, this NFPA standard forms part of the design basis for the metro stations. There are, however, elements of a station design that are beyond the scope of NFPA 130, so additional codes need to be referenced. 

Whilst NFPA 130 focuses on the fire-safety design of platforms and concourse areas, the standard must be supported by a Building Code for the detailed design of areas that are ancillary to the platform and concourses. NFPA 101 ‘Life Safety Code’ has been adopted to support NFPA 130 for the fire-safety design. 

References to, and the use of, local codes such as the Saudi Building Code, are in response to requests from the relevant AHJ.

London Underground standards have been referenced for evacuation calculations on numerous rail projects and are in line with international best practice, and Network Rail provides guidance on 12 key principles for station design.

Demonstrating compliance

Fire engineering employs performance-based design solutions, where necessary, to achieve the life-safety goals and objectives of prescriptive requirements within documents such as NFPA 130 and provide an equivalent or greater level of fire safety. The life-safety goals and objectives of NFPA 130 should be given due consideration for the areas covered by that standard:

• Life safety goals: NFPA 130, Chapter 4.2 (Goals)
• Life safety objectives: NFPA 130, Chapter 4.3 (Objectives)

When deviating away from code guidance, a performance-based design should achieve both the goals and objectives. This provides a performance-based alternative to the prescriptive provisions of the Code. The performance-based option is a process that can be used to determine whether the building design satisfies the fire-safety goals and objectives specified in the Code. It is not the intention of the performance-based approach to replace the prescriptive Code but to demonstrate an equivalent, or better than, level of safety as the prescriptive guidance (NFPA), and as such provide design flexibility.

The key areas of performance-based design revolve around the use of evacuation and CFD modelling to determine the performance of the egress system and the tenability for this period. 

The provision of sprinklers in a railway station requires careful consideration. NFPA 130: Clause 5.7.3.1 recommends that automatic sprinkler protection be provided in areas of stations used for the following: 

• Concessions
• General storage
• Refuse rooms
• Other similar areas with combustible loading, except train ways

Where there are high ceiling levels and sprinklers are unlikely to be effective, their removal from the design should be robustly demonstrated to the AHJ with particular consideration given to the fire loading where it is not similar to areas listed in NFPA 130.

The fire strategy for the station under consideration should address credible fire scenarios and may include the following:

• Train-way fire – a fire occurring within the train way can happen in one of two ways: either a stationary train within the station, or the arrival of a train that’s already on fire and necessitating evacuation of passengers. A fire that occurs on-board a moving train presents a greater risk to on-board passengers and passengers on the platform compared to a stationary vehicle fire, as the fire will have had time to develop prior to arriving at the station.
• Platform (baggage) fire – fire load on platforms will consist of transient fire loads, mainly luggage. A fire involving such a hazard may not present a significant risk to passengers where the open nature of the platform and the smoke control systems are designed to keep tenable conditions during evacuation. 
• Public area fire – a fire within the public areas of the station can occur from two primary types: fixed or transient fire hazards.

• Transient fire hazards include luggage or rubbish containers. These will present a relatively low fire load; however, they are unenclosed and open to the concourse. 
• Fixed fire hazards can consist of retail concessions, ticket offices, etc. These hazards may be enclosed in fire-resistant construction with active protection including smoke control, fire shutters and automatic sprinklers. 

Fires occurring within such locations will initially only present a risk to occupants within the compartment of fire origin. Those within the main concourse will not be placed at immediate risk. 

• Retail area fire – retail areas may often be split into a number of smaller units, rather than a single destination retail unit (department store). As such, phased evacuation of the retail areas and main station could be considered, focused on the level of management available within the large retail unit. 
• Car park – a fire in the multi-storey underground car park would be separated from the main station by fire-rated compartmentation and would present a risk to the people within the car park and the adjacent accommodation only, and could be considered as a separate evacuation zone to that of the main station.
• Ancillary accommodation fire – all non-public areas, ancillary to the public concourse and platform areas, will be separated from public areas with fire-resistant construction. A fire occurring in such areas will not immediately affect the greater concourse or platform population.

What’s new?

In the UK, the British Standards Institute recently released updated guidance contained in BS 9992 ‘Fire safety in the design, management and use of rail infrastructure’ code of practice. This is a comprehensive new British Standard on the fire safety aspects of railway station and tunnel design. Until now, no single British Standard existed in this area and those who design, manage and procure works on railway infrastructure have had to use a range of existing codes that provide partial and sometimes outdated guidance. This new standard seeks to consolidate and update design guidance and is aimed at a wide range of stakeholders including but not limited to:

• Railway operators and infrastructure managers
• Train Operating Companies (TOCs) – safety managers, station and tunnel managers and engineers
• Design houses (single and multi-disciplinary) – project managers, project engineers and fire safety engineers
• Architects of railway infrastructure
• Building contractors (project managers, project engineers)
• System design contractors (engineers)
• Suppliers and installers of fire protection systems in railway infrastructure (fire detection and alarms, fire suppression systems, smoke control ventilation, pressurisation and extract systems, fire resisting structures and separating elements, materials with fire performance requirements)
• Regulators and maintainers

The standard provides recommendations and guidance on the design, management and use of railway buildings, and the permanent way to achieve reasonable standards of fire safety for all people in and around rail infrastructure, and covers:

• Stations (surface, sub-surface and enclosed)
• Platforms
• Tunnels
• Viaducts
• Elevated rail
• Train care deports and maintenance facilities
• Training facilities
• Sidings
• Signalling/control facilities
• Ancillary buildings

The main aim is to achieve an adequate standard of life safety in the event of fire. A secondary objective is protecting property and the operation of the railway and businesses against the impact of fire. These objectives can also assist responding fire and rescue services and Civil Defence, and provide environmental protection.

The recommendations given apply to the design of new premises, and to material alternations, extensions and material change of use of existing premises. 

The standard does not cover fire safety of rolling stock, or fire-safety design strategies for extreme events such as terrorist or similar actions. It complements BS 9999 and varies from it only where appropriate to support the particular ways in which railway infrastructure is constructed or operated. 

The future

The international rail industry will continue to share best practices and lessons learned from past incidents to develop guidance that caters to the diverse requirements for the safe design, construction and operation of a cost-effective and efficient network. It is important to work with all relevant stakeholders, including fire responders, to ensure that in the event of an incident, appropriate resources can be mobilized to minimize the impact to the infrastructure. 

For more information, go to www.sar.com.sa www.warringtonfire.com