Fire simulation in a full-scale bilevel rail car: Experimental analysis to assess passenger safety

Abstract

The increasingly occurrence of fires risk within public transport facilities prompted many countries to improve public vehicle security implementing specific researches. The provision of a useful reference point for the compatibility of passengers and goods rail transport, with final attention to the preservation of the environment and the human health, represent the general target of such investigations. As a result, this manuscript presents the outcomes of a full-scale experimentation of fire in a bilevel rail car for passengers' transport, useful to evaluate human exposure to toxic loads during a fire. The research consisted in the temperature measurement in various positions and its comparison with a simulation model based on the theoretical approach. Furthermore, visibility and air quality (O2, CO2, CO, TOC, particulate matter) were analyzed inside the rail car. The comparison between numerical methods and data obtained allow understanding that the numerical model is an effective simulation tool of fire dynamics, especially within the lower deck, although it underestimates the trend of air temperature in the upper deck. Overall, the fire causes a rapid and considerable reduction of oxygen, down to a minimum value of 9.6% by volume, and an increase of particulate matter concentration and total organic carbon, up to maximum values of respectively 2200 mg/Nm3 and 800 mg/Nm3. Evaluations about the toxicological risk for human health and the environment are reported within the study, highlighting difficulties and threats in fire risk prediction and human exposure to toxic load as function of numerous factors, such as construction materials of railcars and passenger health state.