Fire Assessment of a Subway Train Fire: A Study Based on Full-Scale Experiments and Numerical Simulations
Abstract
1. Introduction
2. Experimental Setup
2.1. Experimental Platform
2.2. Fire Source and Materials
3. Experimental Results and Discussions
3.1. Heat Release Rate and Burning Processes
3.2. Gas Temperature
3.3. Status of Electrical Circuit
4. Numerical Simulations of the Fire Development in the Entire Train
4.1. Simulation Model and Scenarios
4.2. Validation of the Simulation Method
4.3. Discussions on the Simulation Results of Entire-Subway-Train Fires
5. Discussions and Improvement of the Duggan Method
6. Conclusions
- (1)
- Through the full-scale experiment, the seat that the fire source was placed on was barely ignited, and the power supply and control cables, as well as the network communication lines, worked normally during the standard luggage fire. The HRR curves of the standard luggage fire in the subway train were measured, and the maximum HRR was consistent with the standard HRR curve provided in EN 45545-1, but the fire duration was obviously shorter.
- (2)
- Two typical entire-train fire scenarios, namely luggage and gasoline pool fires, were investigated through numerical simulations. Under the luggage fire condition, only a small area of the combustible that directly contacted the tilted flame was ignited (without flame spread) when the subway train doors opened. Under the extreme fire scenario with a gasoline pool fire and exposed winterproof material, the side wall and the roof were ignited at about 20 s and continually spread to the adjacent compartment. The HRR reached 12 to 18 MW at about 80 s in these scenarios.
- (3)
- The Duggan method, which assumes that all combustibles inside the train compartment burn at the same time, did not conform to the current subway train fires based on the experimental and numerical simulation results. A simple revised frame is proposed herein.
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
References
- Meng, N.; Wang, Q.; Liu, Z.; Li, X.; Yang, H. Smoke flow temperature beneath tunnel ceiling for train fire at subway station: Reduced-scale experiments and correlations. Appl. Therm. Eng. 2017, 115, 995–1003. [Google Scholar] [CrossRef]
- Wang, J.; Yan, W.; Xu, H.; Zhi, Y.; Wang, Z.; Jiang, J. Investigation of the probability of a safe evacuation to succeed in subway fire emergencies based on Bayesian theory. KSCE J. Civ. Eng. 2018, 22, 877–886. [Google Scholar] [CrossRef]
- Liu, C.; Zhong, M.; Tian, X.; Zhang, P.; Xiao, Y.; Mei, Q. Experimental and numerical study on fire-induced smoke temperature in connected area of metro tunnel under natural ventilation. Int. J. Therm. Sci. 2019, 138, 84–97. [Google Scholar] [CrossRef]
- Chen, J.; Long, Z.; Wang, L.; Xu, B.; Bai, Q.; Zhang, Y.; Liu, C.; Zhong, M. Fire evacuation strategy analysis in long metro tunnels. Saf. Sci. 2022, 147, 105603. [Google Scholar] [CrossRef]
- Pan, L.W.; Lo, S.M.; Liao, G.X. Experimental study of smoke control in subway station for tunnel area fire by water mist system. Procedia Eng. 2011, 11, 335–342. [Google Scholar]
- Zhang, S.; Cheng, X.; Yao, Y.; Zhu, K.; Li, K.; Lu, S.; Zhang, R.; Zhang, H. An experimental investigation on blockage effect of metro train on the smoke back-layering in subway tunnel fires. Appl. Therm. Eng. 2016, 99, 214–223. [Google Scholar] [CrossRef]
- Cong, W.; Cheng, X.; Shi, L.; He, K. Study on smoke propagation characteristics of a carriage fire in longitudinally ventilated tunnel. Fire Technol. 2024, 60, 2231–2247. [Google Scholar] [CrossRef]
- Song, H.; Chen, Q.; Wu, Z.; Yao, H.; Lou, Z.; Bai, Z.; Li, J.; Yu, Y. Sensitivity Analysis of Influencing Factors of Fire SmokeTransport on Subway Station Platforms. Fire 2023, 6, 448. [Google Scholar] [CrossRef]
- Dong, S.; Wang, K.; Jia, C. A study on the influence of rail top smoke exhaust and tunnel smoke exhaust on subway fire smoke control. Sustainability 2022, 14, 4049. [Google Scholar] [CrossRef]
- Sajid, Z.; Yang, Y.; You, P.; Deng, H.; Cheng, X.; Danial, S.N. An Explorative Methodology to Assess the Risk of Fire and Human Fatalities in a Subway Station Using Fire Dynamics Simulator (FDS). Fire 2022, 5, 69. [Google Scholar] [CrossRef]
- Xu, W.W.; Zheng, J.H.; Yu, D.L. Review on Study of Personnel Evacuation in Subway Station Fires. Ind. Saf. Environ. Prot. 2015, 41, 65–69. (In Chinese) [Google Scholar]
- He, S.-J.; Li, J.; Chen, W.-W.; Ding, T.-C.; Zhi, J.-Y. The impact of subway car interior design on passenger evacuation and boarding/alighting efficiency. Sci. Rep. 2023, 13, 19682. [Google Scholar] [CrossRef] [PubMed]
- Jiang, H.; Yang, X.; Yang, Y.; Li, Y.; Pan, F.; Kang, Y.; Ding, J. Simulation-based heterogeneous pedestrian evacuation in subway stations. Int. J. Mod. Phys. C 2022, 34, 2350066. [Google Scholar] [CrossRef]
- Chen, S.; Tao, T.; Zhou, X.Y. Evacuation Study of Metro Compartment FireTypical Scenarios Based on Numerical Simulation. Urban Mass Tranist 2023, 26, 147–154. (In Chinese) [Google Scholar]
- Li, Z.Y.; Ingason, H. A new methodology of design fires for train carriages based on exponential curve method. Fire Technol. 2016, 52, 1449–1464. [Google Scholar] [CrossRef]
- Shi, C.; Zhong, M.; Chen, C.; Jiao, W.; Li, J.; Zhang, Y.; Zhang, L.; Li, Y.; He, L. Metro train carriage combustion behaviors—Full-scale experiment study. Tunn. Undergr. Space Technol. 2020, 104, 103544. [Google Scholar] [CrossRef]
- Xi, Y.J.; Lin, J.H.; Su, Y.C.; Tian, X.; Li, D. Subway car fire spreading rules and evacuation safety studies. J. Railw. Sci. Eng. 2017, 14, 619–625. (In Chinese) [Google Scholar]
- Zhang, L.; Wu, X.; Liu, M.; Liu, W.; Ashuri, B. Discovering worst fire scenarios in subway stations: A simulation approach. Autom. Constr. 2019, 99, 183–196. [Google Scholar] [CrossRef]
- Ju, W.; Wu, J.; Kang, Q.; Jiang, J.; Xing, Z. Fire Risk Assessment of Subway Stations Based on Combination Weighting of Game Theory and TOPSIS Method. Sustainability 2022, 14, 7275. [Google Scholar] [CrossRef]
- Peng, M.; Cheng, X.; Cong, W.; Yang, H.; Shi, L.; Yuen, R.; Zhang, H. Experimental investigation on the characteristics and propagation of fire inside subway train. Tunn. Undergr. Space Technol. 2021, 107, 103632. [Google Scholar] [CrossRef]
- Zhang, B.S.; Lu, S.X. Numerical Simulation and Analysis of Compartment Fire in Subway Train. Appl. Mech. Mater. 2012, 166–169, 2726–2730. [Google Scholar] [CrossRef]
- ISO 9705-1:2016; Reaction to Fire Tests–Room Corner Test for Wall and Ceiling Lining Products—Part 1: Test Method for a Small Room Configuration. ISO: Geneva, Switzerland, 2016.
- IEC 60331-1; (Edition 2.0), Tests for Electric Cables Under Fire Conditions–Circuit Integrity-Part 1: Test Method for Fire with Shock at a Temperature of at Least 830 °C for Cables of Rated Voltage up to and Including 0.6/1.0 kV and with an Overall Diameter Exceeding 20 mm. International Electrotechnical Commission: Geneva, Switzerland, 2018.
- IEC 60331-2; (Edition 2.0), Tests for Electric Cables Under Fire Conditions–Circuit Integrity-Part 1: Test Method for Fire with Shock at a Temperature of at Least 830 °C for Cables of Rated Voltage up to and Including 0.6/1.0 kV and with an Overall Diameter Not Exceeding 20 mm. International Electrotechnical Commission: Geneva, Switzerland, 2018.
- EN 45545-1:2013; Railway Applications-Fire Protection on Railway Vehicles-Part 1: General. BSI: London, UK, 2013.
- UIC 564-2:1991; Regulations Relating to Fire Protection and Firefighting Measures in Passenger Carrying Railway Vehicles or Assimilated Vehicles Used on International Services. BSI: London, UK, 1991.
- ARGE. ARGE Guideline–Part 2 “Firefighting in Railway Vehicles” Functional Assessment for the Efficiency of Fire Suppression and Extinguishing Systems in Passenger and Staff Areas, Electric Cabinets and in Areas with Combustion Engines; ARGE: Istanbul, Turkey, 2013. [Google Scholar]
- PyroSim User Manual. Available online: https://support.thunderheadeng.com/docs/pyrosim/2024-2/user-manual (accessed on 15 May 2025).
- McGrattan, K.; Hostikka, S.; McDermott, R.; Floyd, J.; Weinschenk, C.; Overholt, K. Fire Dynamics Simulator User’s Guide; NIST Special Publication 1019: Gaithersburg, MD, USA, 2013. [Google Scholar]
- Yang, Y.; Zhang, Q. Numerical Study on the Effect of Tunnel Slope on Smoke Exhaust Performance in Metro Tunnels. Fire 2025, 8, 28. [Google Scholar] [CrossRef]
- Jiang, H.L.; Teng, J.; Wang, D.; Zhou, L.; Chen, Y.R. Numerical Investigation of the Wan’an Bridge Fire and the Protection Effect of Intumescent Flame-Retardant Coatings. Fire 2025, 8, 184. [Google Scholar] [CrossRef]
- GB 51298-2018; Standard for Fire Protection Design of Metro. China Construction Industry Press: Beijing, China, 2013.
- Duggan, G.J. Usage of ISO 5660 data in UK railway standards and fire safety cases. In Fire Hazards, Testing, Materials and Products, Proceedings of A One Day Conference, Shropshire, UK, 13 March 1997; Rapra Technology Ltd.: Shrewsbury, UK, 1997; p. 3. [Google Scholar]
Basic Information | Validation Simulation | Simulations of Entire Subway Train |
---|---|---|
Turbulence solver | Smagorinsky large eddy model | |
Ambient temperature | 16 °C | 20 °C |
Ambient pressure | 1.01325 × 105 Pa | 1.01325 × 105 Pa |
Mesh size | 0.05 × 0.05 × 0.05 m | 0.10 × 0.10 × 0.10 m |
Structure | Material and Thickness | Density/kg·m−3 | Specific Heat/kJ·kg−1·K−1 | Heat Conductivity/W·m−1·K−1 | Emissivity | Ignition Temperature/°C | |
---|---|---|---|---|---|---|---|
Driver’s cage | Countertop | Fiberglass (4 mm) + paint (240 μm) | 3243 | 0.78 | 0.18 | 0.74 | 294 |
Wall and roof | Prepreg (4 mm) + paint (240 μm) | 1024 | 1.45 | 0.17 | 0.89 | 599 | |
Window | Glass (6 mm) + PVB (5.32 mm) + glass (4 mm) | 2480 | 0.70 | 0.87 | 0.90 | 400 | |
Passengers’ compartment | Floor cloth | Rubber (3 mm) | 3503 | 1.47 | 0.08 | 0.46 | 216 |
Seat | Fiberglass | 1950 | 1.18 | 0.51 | 0.74 | 508 | |
Lampshade | Polycarbonate sheet (4 mm) | 5561 | 0.97 | 0.20 | 0.59 | 237 | |
Window | Glass (6 mm) + hollow layer (21 mm) + glass (5 mm) | 2480 | 0.70 | 0.87 | 0.90 | 400 | |
Wall and roof | Aluminum plate (3 mm) + paint (240 μm) | 2700 | 0.90 | 235.00 | 0.80 | 400 |
Experiment No. | Simulation Area | Type of the Fire Source | Location of the Fire Source |
---|---|---|---|
S-0 | Experimental area | Luggage fire | On the seat |
S-1 | Entire train | Luggage fire | On the seat |
S-2 | Entire train | Luggage fire | On the floor |
S-3 | Entire train | Gasoline pool fire | On the seat |
S-4 | Entire train | Gasoline pool fire | On the floor |
Measure Point | 1-1 | 1-2 | 1-3 | 1-4 | 1-5 | 2-1 | 2-2 | 2-3 | 2-4 | 2-5 | |
---|---|---|---|---|---|---|---|---|---|---|---|
Tp (°C) | E 1 | 34.50 | 32.20 | 70.80 | 49.40 | 37.60 | 51.20 | 20.90 | 26.90 | 19.90 | 19.00 |
S 2 | 27.30 | 41.85 | 86.54 | 50.66 | 44.72 | 49.54 | 18.66 | 24.00 | 16.03 | 16.07 | |
Relative error (%) | 20.9 | 30.0 | 22.2 | 2.6 | 18.9 | 3.2 | 10.7 | 10.8 | 19.4 | 15.4 |
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. |
© 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Share and Cite
Wang, X.; Zhang, K.; Shi, Q.; Zeng, B.; Li, Q.; Li, D. Fire Assessment of a Subway Train Fire: A Study Based on Full-Scale Experiments and Numerical Simulations. Fire 2025, 8, 259. https://doi.org/10.3390/fire8070259
Wang X, Zhang K, Shi Q, Zeng B, Li Q, Li D. Fire Assessment of a Subway Train Fire: A Study Based on Full-Scale Experiments and Numerical Simulations. Fire. 2025; 8(7):259. https://doi.org/10.3390/fire8070259
Chicago/Turabian StyleWang, Xingji, Keshu Zhang, Qilong Shi, Bin Zeng, Qiang Li, and Dong Li. 2025. "Fire Assessment of a Subway Train Fire: A Study Based on Full-Scale Experiments and Numerical Simulations" Fire 8, no. 7: 259. https://doi.org/10.3390/fire8070259
APA StyleWang, X., Zhang, K., Shi, Q., Zeng, B., Li, Q., & Li, D. (2025). Fire Assessment of a Subway Train Fire: A Study Based on Full-Scale Experiments and Numerical Simulations. Fire, 8(7), 259. https://doi.org/10.3390/fire8070259