Tunnel Safety - Articles and news items
Issue 1 2015 • 12 March 2015 • Dr Fathi Tarada, Managing Director Mosen Ltd
For the past few decades, the risk of fire within underground metro systems has meant the need for tunnel ventilation to control the spread of smoke. However, significant improvements in fire resistance and running capability for rolling stock have reduced the risk of fire within metro tunnels. Instead, the need to evacuate passengers from stranded trains without the risk of heat exhaustion has become the key criterion for tunnel ventilation in a number of international metro tunnels. Dr Fathi Tarada, Managing Director of Mosen Ltd and Eurotransport Editorial Board Members, describes here the emergence of a new paradigm in metro tunnel ventilation, which has significant consequences for metro system owners, operators, contractors, designers and the general public…
Issue 4 2012 • 31 August 2012 • Fathi Tarada, Tunnel Safety Expert, Managing Director of Mosen Ltd and Eurotransport Editorial Board Member
Major infrastructure projects in Europe are increasingly integrating the requirements of persons with reduced mobility into the early stages of their design. For example, significant investment is earmarked for step-free access for a number of major surface stations within the Crossrail West scheme on the outskirts of London. New lifts and overbridges are being planned by Network Rail, in order to facilitate access to all platforms in stations such as West Drayton and Maidenhead. Such infrastructure works will benefit a wide range of people including mothers with prams as well as a wide range of people with disabilities.
The definition of disability is wide and encomp – asses persons of limited mobility, hearing and vision. It includes the elderly, infirm and wheelchair users. The infrastructure and facilities provided by transport networks should therefore go further than just providing wheelchair access, and should include aural and visual information systems, including induction loops; appropriate warning surfaces at the top and bottom of stairs and at platform edges; and alternative access arrangements where physical barriers make it impossible or difficult to use the service.
Considering the aging nature of European societies, the proportion of people with disabilities is significant and rising. For example, it is currently estimated that 4,600,000 people have walking difficulties in the UK, and 800,000 of these people use a wheelchair.
Issue 6 2011 • 3 January 2012 • Haukur Ingason, Professor of Fire Protection Engineering at the Department of Fire Technology at SP Technical Research Institute of Sweden and Anders Lönnermark, Senior Research Scientist at the Department of Fire Technology at SP Technical Research Institute of Sweden
In September 2011, the Swedish METRO project finalised a large scale test programme in an abandoned railway tunnel. The objective of the METRO project is to improve safety in underground metro systems and to explore differences in the fire behaviour of the carriage using different types of interior materials. Further, the role of passenger luggage in the fire development was investigated. The test programme included both fire and explosion tests. The results are still undergoing analysis, but the test programme has already generated lots of new interesting information to report on. One thing that has become clear is the importance of the choice of lining material and the effects of passenger luggage on the fire spread.
About the large scale tests
A total of four tests were carried out in the 276m-long Brunsberg tunnel outside Arvika, Sweden. The abandoned tunnel was taken out of service when a new tunnel was constructed to reduce the sharpness of a bend in the route. Three fire tests using liquefied fuel as the ignition source were carried out first. The first test was a small pan with diesel oil mounted under the carriage while tests two and three were simulated arson attacks inside the carriage using petrol poured on a seat. A total of two carriages were used for the three fire tests.
Issue 2 2011 • 6 May 2011 • Professor Haukur Ingason, Senior Research Scientist, SP Technical Research Institute
In the fire safety design process for underground metro systems, the design fire is usually an issue that requires long discussions and consensus among designers. The main reason is the complexity of fires in metro cars and lack of large scale test results which confirm the design assumptions. This article gives an overview of fire development in underground metro cars and gives an insight into a large scale test series that is planned for autumn 2011 in Sweden.
Increased demand for mass transport
Rapid advances in underground construction technology and increased demand for mass transportation of people force us to build more-and-more complex underground mass transport systems. The fire risks and conse – quences of fires usually become key issues in the design process.
Issue 2 2011 • 6 May 2011 • Prof. Dr.-Ing. Alfred Haack, former Executive Board Member at STUVA (Research Association for Underground Transportation Facilities) and Past President of ITA (International Tunnelling and Underground Space Association)
A functioning mass transit system is most important to back up mobility in large cities and conglomerations. This has been recognised for nearly 150 years: the first metro worldwide was inaugurated in London in January 1863. It was a steam driven system. The first electrified trains started in November 1890, again in London. The first metro on the continent followed in 1896 and was installed in Budapest. Paris started its metro in 1900, Berlin in 1902 and Hamburg in 1912.
The size of the route network depends on the population of the city or the area served by the subway system. London operates its underground network with a length of 410km and 270 stations – by far the largest network in Europe (and worldwide), followed by Madrid with 325km, Moscow with 300km and Paris with 215km.
Issue 5 2009, Past issues • 28 October 2009 • Dr. Fathi Tarada, Director of Fire Safety Engineering, Halcrow Group Ltd, Co-Chairman of the PIARC Working Group on Air Quality, Fire and Ventilation, and member of the Technical Advisory Committee for the International Symposium on Aerodynamics and Ventilation of Vehicle Tunnels
Fire suppression is emerging as a key risk reduction measure for consideration in tunnels under construction or undergoing refurbishment. However, understanding the possible benefits, limitations and costs of fire suppression, and reflecting that understanding in the project decision-making process, is still a nascent science. This article describes some of the latest technical guidance available, and how it was applied to two tunnels in order to reduce societal costs related to fires, and to minimise construction costs and programmes.
Until relatively recently, the issue of tunnel fire suppression was considered very differently in various parts of the world. In Japan, fixed fire suppression systems are installed in tunnels with a length of 3,000m or longer, and which have a traffic volume of 4,000 vehicles per day or greater. The Australasian Fire Authorities Council’s fire safety guidelines for road tunnels require installation of fire suppression systems in long road tunnels in Australia. However, European tunnel designs generally followed World Road Association (PIARC) guidelines, which did not support the principle of tunnel fire suppression prior to 2008. The same reticence with respect to tunnel fire suppression was evident prior to 2008 in the National Fire Protection Association (NFPA)’s standard 502, which is widely used in North America and elsewhere.
Four years have passed since the European Directive 2004/54/EC on minimum safety requirements for tunnels in the Trans-European road network became effective in 2004. In almost all EU member states, the EU Directive considerably changed the legislative background of road tunnel safety as well as the relevant national technical guidelines.
The EU Directive thus initiated an impetus towards harmonisation of regulations in Europe. At the same time, it animated the communication between countries with many years of experience of routine road tunnel operations and those countries, which do not have many tunnels in their existing network, but which are going to build many kilometres of new road infrastructure in near future. The 4th International Conference on Tunnel Safety and Tunnel Ventilation offered a perfect stage to continue and enhance that communication.
Fire incidents in trains can be divided into two main groups: those we can manage and those we cannot. For example, if a burning train comes to a stop inside a tunnel, the situation may become very difficult to manage, both for the tunnel operators and fire services. Such scenarios are fortunately rare. Statistics show that the risk of a large fire incident in a train is low. The risk is even lower of such an incident in a tunnel. This is a fact that many involved in the safety issues of trains and underground subway systems are very well aware of.
Despite the risk of fire incidents in tunnels being very low, there have been occasions when fires have developed into catastrophic events and these few disastrous fires have placed a focus on fire safety in rail and subway tunnels. When such incidents occur, the media focus becomes extremely high and the work of safety authorities and tunnel operators comes under close scrutiny. The agenda is set by these incidents but it does not necessarily mean that the safety standards are ruled by them.
In the past decade, over four hundred people worldwide have died as a result of fires in road, rail and metro tunnels. Fires in tunnels have destroyed over a hundred vehicles, brought vital parts of the European road network to a standstill – in some instances for years – and have cost the European economy billions of Euros. Tunnels are being upgraded, research is being carried out and new technologies are being developed, but are our tunnels becoming safer?
The recent fire in the Burnley Tunnel in Melbourne, Australia (23 March 2007) involved a collision of two heavy goods vehicles (HGV) and two cars. The fuel tank on one of the HGVs ruptured in the crash, resulting in a small explosion and a fairly large fire was produced instantly. This fire was probably more severe than the fire which resulted from the collision of two HGVs in the St Gotthard Tunnel, Switzerland, in October 2001. That spread to involve a long line of vehicles, claimed 11 lives (nobody died in the actual crash) and destroyed a significant length of the tunnel interior. Yet the fire in the Burnley Tunnel did not spread much and no lives, beyond the three who died in the collision, were lost.
Tunnels are no more dangerous than the rest of the road network; in fact, they are generally safer. However, in case of an incident in a tunnel, the possible consequences in terms of life safety, damage to infrastructure assets and disruption to traffic flow are significantly magnified.
A recent example is the fire on the double-decker bus in the Limehouse Link Tunnel in London, which occurred on 30 October 2005. Mercifully, the fire happened on a quiet Sunday morning with little traffic and there weren’t any injuries or fatalities. But traffic through the East End of London was severely disrupted during the immediate aftermath of the fire, as well as during the subsequent tunnel refurbishment; which required the full closure of the tunnel until 15 November 2005.
Since 1999, road tunnel safety has become a subject of growing interest in the public as well as among tunnel specialists. This is largely because of different incidents that have led to an increased risk awareness.
The recent catastrophes in the Mont Blanc tunnel, the Tauern tunnel, and Gotthard tunnel have demonstrated the urgent need for improving the prevention and mitigation of tunnel accidents, including adequate detection systems and being prepared operation staff and emergency services.
Both ADR and RID regulations enable the competent authorities responsible to restrict the transport of dangerous goods through tunnels. However, account should be taken of the tunnel characteristics, and a risk assessment including the availability and suitability of alternative routes and modes and traffic management should be conducted.
ARCADIS has studied the transport of dangerous goods for a 53 kilometre railway tunnel through the Alps between Italy and France. Transport of dangerous goods in both train and trucks on trains is foreseen in the future. Analysis, modelling and studies about the possible effects of an accident involving dangerous substances in the tunnel were carried out.
Having just entered the third and ultimate year of the L-surF project, it is recognised that research on safety and security is more than welcome to the European Community. At least, this was one of the conclusions of the 2nd Security Research Conference held in Berlin under the German presidency of the European Community at the end of March 2007.
Large Scale Underground Research Facility on Safety and Security’ is the full title of the design study L-surF which is implemented as a ‘Specific Support Action’ in the 6th European Framework Programme for Research and Technological Development. This design study on research infrastructure (RIDS) is being carried out by five European partners who are leading the field in safety and security research focussing on enclosed spaces. VSH (Switzerland), SP (Sweden), STUVA (Germany), TNO (The Netherlands) and INERIS (France) are concentrating their knowledge and efforts in terms of conducting a feasibility study, with the end aim of constructing a ‘Large Scale Underground Research Facility on Safety and Security’. The closer the project comes to its end, the picture of what L-surF will become in the future – after the termination of the project – becomes more apparent.