Train Fire Research Articles

Understanding fire combustion characteristics and available safe egress time in underground metro trains: A simulation approach

Due to insufficient oxygen supply in the tunnel, incomplete combustion of the underground metro train fire easily produces toxic gases and smoke dust, causing difficulty in breathing for passengers and rescue. The experimental study of the fire combustion characteristics of metro trains in the tunnel is of great significance for designing metro fire extinguishing and fire prevention systems and providing reliable guidance for emergency evacuation in fire scenarios. A train fire model is established to study the effects of various factors on fire combustion characteristics and calculate the available safe egress time (ASET). The smoke spread characteristics under different conditions such as fire source power, fire source location, carriage layout, and train location are simulated. The simulation results show that the fire source power, location, and seat arrangement have a significant impact on the smoke spread characteristics of carriage fires and ASET.

Simulation on passenger evacuation of metro train fire in the tunnel

The metro tunnel space is relatively closed, it is difficult to rescue after the metro train fire accident, which causes heavy casualties and property losses. Studying the safe evacuation of passengers under fire smoke spread has important significance. The numerical simulation methods are used to analyze the reliability of passenger evacuation in metro train fire scenarios. Firstly, the required safety evacuation time (RSET) calculation methods in short-distance and long-distance tunnels are developed combining the pre-action time and train response time. Then, a passenger evacuation model in metro trains is established in Pathfinder software to simulate the evacuation process under different passenger loads, carriage layouts, evacuation strategies, and train locations. The simulation results show that the RSET is affected by passenger load, seat arrangement, evacuation strategies and train locaitons. The critical point calculation method effectively finds out the critical point of the train location, which guides emergency evacuation strategies in fire scenarios.

Backward heating behavior and emergency operating speed of moving subway train fires on open lines

Backward heating behavior and emergency operating speed of moving subway train fires on open lines

Comprehensive risk assessment of Pakistan railway network: A semi-quantitative risk matrix approach

Pakistan Railway (PR) is vital to the country's transportation infrastructure, facilitating passenger and freight transportation. However, the growing number of accidents associated with PR has raised concerns about its overall safety. In addition, there have been limited research efforts to investigate PR accidents and their underlying causes The present study conducts a comprehensive risk assessment and safety management of PR using a semi-quantitative risk matrix approach. The study combines historical accident data and expert evaluations to assess the likelihood and consequences of different railway accident types and potential contributing factors. The descriptive statistics analysis has revealed varying degrees of severity for different types of railway accidents in Pakistan. For instance, accidents like passenger and goods train derailments and collisions at unmanned level crossings were identified as extreme and intolerable, whereas train fire accidents were categorized as high and undesirable. Moreover, accidents attributed to human error are classified as extreme and intolerable, while those caused by negligence of road users and track defects are classified as high and undesirable. The study utilized the risk matrix approach and identified critical risk areas that can help the decision-makers prioritize effective risk mitigation strategies. In light of the present study's findings, policy implications, such as investment in infrastructure to mitigate risks associated with aging or deteriorating tracks, bridges, and tunnels, and human resource development for railway personnel to improve their skills, decision-making abilities, and awareness of safety protocols, are recommended.

Effect of Door Openings on Train Fire Scenarios within a Subway Depot

It is challenging to control smoke in the case of a train fire occurred in the subway depot with a complex internal structure. In this paper, the effect of door opening state on smoke behavior characteristics induced by subway depot fire scenario was investigated. A series of numerical simulation were conducted by Fire Dynamics Simulator (FDS) software. Three key parameters were analyzed corresponding to the temperature, visibility and CO concentration for evaluating smoke propagation respectively. Results show that temperature distribution and CO concentration at 2 m height inside the train with train door opening state are lower than those with the train door closed. However, visibility at 2 m height inside the train shows the opposite trend. The results can provide reference in the ventilation system design and emergency evacuation scheme for the subway depot.

A BIM-FDS Based Evacuation Assessment of Complex Rail Transit Stations under Post-Earthquake Fires for Sustainable Buildings

Post-earthquake fire is considered as a catastrophic secondary disaster to personal and property safety, especially in complex rail transit station. This is primarily attributed to intricate infrastructure, densely populated floors, and the unrestricted layout of these areas. The aim of this study is to evaluate the evacuation capacity of complex railway stations under post-earthquake fires, and provide sustainable recommendations for building design. In this article, an evacuation assessment of a complex rail transit station under the post-earthquake fire for sustainable buildings was conducted from the internal environment and external rescue based on Building Information Modeling (BIM) and Fire Dynamic Simulation (FDS). The internal environment evacuation assessment simulation experiments were conducted in six hypothetical high-risk scenarios. In addition, the external rescue assessment was based on investigation of the route and the required rescue time during different periods of holidays and workdays. The results show that (1) The influence caused by different sizes of fire area in the power distribution room is smaller than those in the train at the platform floor. (2) In fire scenarios with the same fire area but different fire locations, the temperature is more affected than the CO concentration in the power distribution room. (3) It shows slight differences between single-floor fire and double-floor fire on evacuation of small area fire in power distribution room. Meanwhile, optimized design recommendations are proposed to reduce the risk of emergency evacuation in both internal and external environments of rail transit stations for sustainable future buildings, which include strategically locating the power distribution room away from public areas, installing fire-resistant doors around the room, increasing the quantity of smoke detectors and alarms with regular maintenance, minimizing the size of the power distribution room, developing specific emergency plans for train fires, and incorporating small fire stations in urban planning near complex public buildings to mitigate post-earthquake road obstruction challenges.

Heat transfer mechanism and emergency operating speed of moving train fires in a metro tunnel

The primary strategy for a burning train in metro tunnels is to drive it out of the tunnel, or to the station or safe area ahead. However, the heat transfer mechanism and the emergency operating speed of moving train fires in tunnels have not been addressed. In this study, a 1:10 train-tunnel model was designed to conduct a series of moving model experiments. The results show that with the increasing train speed in tunnels, the flame height decreases, the flame width and length first increase and then decrease, and the flame tilt angle increases. The maximum temperature at the train top increases by 81.7 % when the train speed increases from 2 to 6 m/s. A piecewise model is proposed to predict the maximum temperature at the train top. The maximum temperature rise at the tunnel ceiling is 17.4 K and exponentially decreases with the train speed, posing a limited threat to the tunnel structure. The convective heat flux received by the train accounts for 82.1 %–94.4 %. The heat transfer between the train, tunnel and flame is codetermined by the train-tunnel aerodynamic effect and fuel-rich zone. The emergency operating speed of the train is suggested to be 22.8 km/h when the heat release rate is 7.5 MW. This study innovatively reveals the combustion behavior of moving train fires in a metro tunnel and proposes guidelines for determining the emergency operating speed of burning trains. The results can provide references for the fire safety design and running capacity improvement of metro trains.

A Calculation Method of Heat Release Rate Based on Flame Spread Rate: Applied in a High-Speed Train Carriage Fire

ABSTRACT Heat release rate (HRR) is an important parameter for the fire safety assessment of high-speed trains and the design of tunnel ventilation systems. However, the existing theoretical calculation methods of the HRR do not consider the fire development process and can not accurately obtain the HRR of high-speed trains. This paper uses a combination of theoretical analysis and numerical simulation to study the HRR of high-speed train fires. Firstly, based on the flame spread rate, a calculation method of the HRR is established, called the spatial time-series superimposed method. The accuracy of the calculation method is verified through a small-scale combustion experiment. Then, the calculation model of the HRR of the high-speed train fire is obtained according to the heat release rate per unit area (HRRPUA) of the carriage material, the flame spread rate in the carriage, and the spatial time-series superimposed method. Afterward, the calculation model is modified according to the change in combustion intensity during the flame spread in the high-speed train carriage. Finally, the calculation method of the HRR established in this paper is compared with several existing calculation methods. The results show that the HRR curve obtained by the calculation model is consistent with that obtained by the FDS simulation. The maximum relative error is less than 25%, and the relative error of the peak heat release rate (PHRR) is 7.4%. Therefore, this study can provide a reference for the fast and accurate calculation of the HRR of the high-speed train carriage fire.

Investigating the influence of outdoor temperature variations on fire-induced smoke behavior in an atrium-type underground metro station using hybrid ventilation systems

Underground metro systems are expanding rapidly worldwide, necessitating research on energy-efficient ventilation systems, fire safety, and smoke control. This study investigates the optimisation of hybrid mechanical-natural ventilation for smoke control in complex metro stations. Full-scale winter/summer experiments and numerical simulations examined a double-deck atrium-type station. Results demonstrate the atrium fires are more significantly impacted by outdoor temperature variations versus concourse/platform fires, with a 70 K versus 30 K temperature rise above the fire respectively. The heat of the gathered high-temperature smoke inside the atrium can reach up to 900 K under a 5 MW train fire energy release. The dimensionless Archimedes number (Ar) defines the ratio of thermal buoyancy to gravitational forces. Cold exterior winter air (Ar<1) entering via the atrium ceiling openings restricted vertical smoke diffusion, enabling enhanced lateral propagation. With rising outdoor temperatures from −20 °C to 10 °C (Ar<1), the natural smoke extraction efficiency increased from 0 to 18 %, coupled with vertical airflow velocities accelerating from −3.5 m/s to 1.5 m/s. When outdoor temperatures were between 10 °C and 40 °C (Ar>1), airflow velocity only changed slightly. Empirical models predict internal temperature profiles as a function of external meteorology. The findings provide crucial engineering insights into integrating weather data and adaptable ventilation protocols for scenario-based smoke prevention/mitigation. Further work should examine seasonal variations beyond the tested -20‒40 °C range. Overall, considering outdoor climate effects allows 30 % optimisation of hybrid ventilation systems for fire safety in underground metro stations. This study promotes technological advances in energy-efficient transport infrastructure resilience.

Prediction of back-layering length in subway tunnel with on-fire train running

The exploitation and utilization of urban underground space effectively contribute to the sustainable development of society. Tunnel fire safety is necessary to ensure normal operation. Motion train fire is more serious and complex than stationary fire in tunnels due to the influence of unsteady piston wind. This study investigates the smoke back-layering characteristics of a burning subway train during emergency braking. A three-dimensional unsteady numerical model adopting the dynamic mesh technique is built to investigate the smoke diffusion characteristics of motion train fire. Experimental tests are conducted based on a 60 m-long scaled-down experimental setup to verify the accuracy of the numerical model. On this basis, the dynamic characteristics of smoke back-layering length as the longitudinal wind pressure is less than the critical value are studied, considering the influence of heat release rate (HRR), train speed, and train deceleration. The results indicate that the maximum back-layering length follows the logarithmic law with the variation of longitudinal wind pressure. An empirical model is proposed to predict the maximum back-layering length at various longitudinal wind pressure, and it is helpful to the optimization design of ventilation systems for tunnel motion fire.

Study on moving fire smoke characteristics and mechanical ventilation system of tunnel

Limited by the narrow space of the tunnel, fire has become one of the important factors threatening the safe operation of subway especially the fire on a moving vehicle. Researches on moving fire through the large length-width ratio of tunnels are extremely lacking at present. This study investigates the characteristics of moving fire and the influence of mechanical ventilation under different conditions. First, a three-dimensional model of the tunnel with the moving train is established, and the dynamic mesh simulation is conducted and validated by the experiments. Then, the variation of smoke temperature distribution under different fire source intensities, train speeds, and blocking ratios are studied. Based on the smoke flow characteristics, the mechanical ventilation with different layouts of draught fans is investigated. It is found that the maximum growth rate of smoke spread is 70.90% with an increase of two fans. Finally, the influence of the tunnel shaft on the smoke characteristics under different fire source locations is discussed. When the fire source is under the shaft, the smoke discharge efficiency reaches the highest, almost 5.89% and 21.91% higher than other conditions. This study provides the basis and reference for the research and control of the tunnel moving fire.

Preparedness for Fire Emergency in the Nutrition Laboratory at University X in Semarang: as a Safety Education for University Students

The Occupational Safety and Health Administration (OSHA) indicates that academic laboratories are 11 times more dangerous than the industrial sectors. The nutrition laboratory is a place that has a high potential to cause fire because there are cooking activities, where these activities are very risky because they deal directly with fire and gas cylinders there. If the gas cylinder has a leak, it can cause a fire risk. This study aims to look at the preparedness of fire disaster management in the Nutrition Laboratory at University X in Semarang city. The research design used in this research was a descriptive qualitative. There were 3 informants, namely the person in charge of the nutrition laboratory and 2 students of the Nutrition Study Program. Data collection techniques used in this research was in-depth interviews. The results showed that the nutrition laboratory at University X in Semarang city already had management related to fire prevention such as the availability of fire extinguishers, evacuation routes, and assembly points. It is recommended that related parties complete active and passive protection systems, improve fire prevention teams, train and socialize, and conduct regular testing of active protection facilities in the Nutrition Laboratory.

Policy model for development of tourism villages based on local wisdom towards self-reliant village in Pangandaran Regency, Indonesia

The purposes of study are (1) analyze strengths, weaknesses, opportunities and threats of tourism village destination in Regency Pangandaran and (2) to formulate policy model for development of tourism villages based on local wisdom towards self-reliant village in Pangandaran Regency. This study uses a qualitative descriptive research method with approach studies case. Primary data collection techniques in the form of interviews, focus group discussion, observation and document study. Results of analysis of SWOT (strength, weakness, opportunity, threat) of tourism village destination in Pangandaran Regency, especially (a) Strength: (1) airport Nusawiru as access for tourist international and inter bus city or between province that has destination to Regency Pangandaran; (2) culture famous Sundanese friendly. (b) Weakness: (1) standardization policy opening and development destination tour new to district Pangandaran not yet available; (2) access good way not yet evenly on each destination existing tours; (3) readiness resource man for accept tourists and awareness will industry tourist not yet maximum. (c) Opportunity: (1) have many potency destination unexplored tourism; (2) existence track train fire and airport Nusawiru as well as Harbor Bojong Salawe; (3) training about tourism through extracurricular for learner and language foreign for society. (d) Threat: (1) stability nature and impact environment in implementation exploitation destination travel; (2) degradation score culture and potential leave inheritance existing culture. Policy model for development of tourism villages based on local wisdom towards independent villages include tradition, community empowerment and participation society.

Simulation of fire emergency evacuation in a large-passenger-flow subway station based on the on-site measured data of Shenzhen Metro

Abstract Because of its large capacity, high efficiency and energy savings, the subway has gradually become the primary mode of transportation for citizens. A high density of passengers exists within a large-passenger-flow subway station, and the number of casualties and injuries during a fire emergency is substantial. In this paper, Pathfinder software and on-site measured data of Pingzhou station in Shenzhen (China) were utilized to simulate a fire emergency evacuation in a large-passenger-flow subway station. The Required Safe Egress Time (RSET), number of passengers and flow rates of stairs and escalators were analysed for three fire evacuation scenarios: train fire, platform fire and hall fire. The evacuation time of the train fire, which was 1173 s, was the longest, and 3621 occupants needed to evacuate when the train was fully loaded. Occupants could not complete the evacuation within 6 mins in all three fire evacuation scenarios, which does not meet the current standard requirements and codes. By changing the number of passengers and the number of stairs for evacuation, the flow rate capacity and evacuation time were explored, which have reference values for safety management and emergency evacuation plan optimization during peak hours of subway operation.

Influence of subway train fire locations on the characteristics of smoke movement in a curved tunnel.

Scenario models of a moving subway train can help investigate the influence of different fire locations on smoke propagation characteristics in curved tunnels. To this end, this study adopts the three-dimensional Unsteady Reynolds Average Navier-Stokes equations method and the renormalization group k-ε two-equation turbulence model with buoyancy correction for numerical analysis. The motion of the train is replicated using the slip grid technique. The results indicate that when a fire breaks out on a moving train in tunnels, the piston wind leads the longitudinal movement of the smoke. If a fire erupts in the head or middle car of a moving train, the time of smoke backflow is delayed by 30 s or 17 s, respectively, compared to that for the tail car. The obtained results provide a theoretical basis for reasonably controlling the smoke flow in subway tunnels and reducing casualties in fire accidents.

Numerical Simulation on Train Length Effect on Smoke Propagation in a Stopped Train Fire

It is important to keep fire safety for subway system especially for subway tunnel. This paper selects a 2.2 km tunnel of Beijing subway as the research object, and studies fire scenario for a stopped train with natural ventilation. The multi-scale method where a three-dimensional field model and a one-dimensional network model are combined is used to simulate smoke propagation in a tunnel fire. The effects of train length on the smoke propagation, temperature and visibility distribution are analyzed. The results show that during the initial period of 120s, the influence of train length on temperature distribution, visibility distribution and smoke distribution is not obvious. However, after 120s period, smoke distribution becomes more concentrated with the increase of train length, and the impact of stack effect is more obvious. For a shorter train, the concentration of smoke is higher. The temperature distribution inside the 60 m train is higher than those of 120m and 160m trains.

A study of the critical velocity and the confinement velocity of fire accident in a longitudinally ventilated underground train with different door opening scenarios

The critical velocity, confinement velocity and smoke back-layering length are significant factors for smoke control in a tunnel fire. This research aims to analysis the correlation of these 3 key smoke control parameters in the different door opening scenarios during a fire in the metro train carriage that stopped in the tunnel. Scaled model experiment measurement and numerical simulations were carried out for the propagation and control of smoke. Five fire locations in the train and two side doors opening scenarios of the train were considered. Results show that smoke back-layering length in the train can be barely influenced by the activation time of the longitudinal ventilation system. However, the opening of side doors could result in a shorter smoke back-layering length in the train. Furthermore, we present a dimensionless correlation for the critical velocity and confinement velocity of underground train fires caused by fires in the double-length narrow space of an underground tunnel. This study provides a predictive model for the design of smoke control systems for fire of train stopped in underground tunnels.

3D Simulation of Battery Fire on a Large Steel Frame Structure due to Depleted Battery Piles

Lithium ion batteries (LIB) can rupture and result in thermal runaway and battery fires. In the process of transporting lithium ion batteries using trains, the massive collection of batteries can cause train fire and pose significant danger to the public. This is especially critical when the fire occurs amid a heavily populated metropolitan environment. This paper reports the 3D analysis of a warehouse with possible train fire due to LIB rupture and the fire propagation at a rail yard. Six critical fire cases with the battery train in close vicinity to the warehouse were considered. The six fire cases are the worst-case scenarios of a Monte Carlo simulation of different fire cases that may occur to an actual steel storage facility at the Capital Railyard, Raleigh, North Carolina. A 3D finite element (FE) frame model was constructed for the steel warehouse and the most critical fire cases were simulated. The results indicated that several structural components of the warehouse would experience large stresses and deflections during the simulated battery fires and resulting in instability to the structure. Specifically, members of the roof frame represent the most critical elements and that the members can result in large deformations as early as 4 minutes after the fire starts. Furthermore, effective utilization of fire protection can delay somewhat the fire effects and extend time to failure to 45 minutes and in one of the simulated cases, prevent structural instability. Thus, fire from LIB waste transport using train is a very realistic problem due to the thermal runaway, and the analysis performed in current study can be used as a preventive investigation technique for buildings that may be exposed to the train fire risk.

Application of the high-pressure water mist system in a railway tunnel rescue station

• Full-scale fire suppression experiments and numerical simulations in a rescue station were performed. • Suppression effect inside and outside train increased with increasing droplet size. • Convective cooling was the main controlling mechanism on suppressing a train fire. • Radiation heat flux received by the floor exponentially decayed with the distance from fire. • Longitudinal ventilation could effectively improve the suppression effect of water mist system. The fire safety of the rescue station as an important issue has not been well concerned. This study investigated the suppression performance of the high-pressure water mist system in a railway tunnel rescue station through CFD (Computational Fluid Dynamics) simulation and full-scale experiments. Eleven groups of numerical simulations and full-scale experiments were designed with various working pressures (5 and 8 MPa), mist droplet diameters (173.2, 178, and 192.9 μm), and longitudinal ventilation velocities (0, 1.5, and 2.5 m/s), in which the simulations were carried out by employing SIMTEC (Simulation of Thermal Engineering Complex) software. Results show that the temperature control effect both in the carriage and above the platform increases along with a bigger mist droplet diameter, in which convective cooling is found to be the main controlling mechanism. However, with increasing mist droplet diameter, smoke concentration increases, and oxygen concentration decreases. Moreover, the radiant heat flux received by the floor presents an increasing first and then decreasing tendency with the increase of distance away from the fire source (denoted by l ). Furthermore, in the region of l ≥ 2.5 m, radiant heat flux has an exponential attenuation with l . In addition, it is also found that the longitudinal ventilation system can effectively improve the suppression performance of the water mist system on a shielded fire. With increasing ventilation velocity, smoke temperature and radiant heat flux in the region of l ≥ 2.5 m decrease. In all cases, numerical results match well with experimental results, which validates the effectiveness of the CFD simulation. This study provides a significant reference for the fire safety design of the railway tunnel rescue station.

Effectiveness of cluster-based inductive ventilation system in railway tunnels: Case study using full-scale experiment and fire dynamic simulation

A calculation method considering ventilation resistance was proposed for designing a cluster-based inductive ventilation system for a real passenger-dedicated railway tunnel. In the system, jet fans were installed only at the two portals, instead of being arranged along the tunnel. A 20 MW train fire was simulated in Fire Dynamics Simulator (FDS) 6.6 to reproduce the designed fire, and the tunnel ventilation was validated using full-scale ventilation experiments. The simulation results showed that the growth of the ventilation velocities was periodically fluctuating. At a height of 2 m above the rail surface, the temperatures always remained below 60 °C, and the visibilities upstream of the fire were not affected by the smoke. It can be concluded that the designed ventilation scheme can effectively inhibit smoke backflow, and both the cluster-based inductive ventilation system and calculation method are feasible.