Transportation Fire Safety

Indrek Wichman’s (2003) article, “Material flammability, combustion, toxicity, and fire hazard in transportation,” focuses on providing a technical overview of transportation fire safety. To achieve this objective, the author conducts combustion literature. Through the literature review, the author looks into the technical as well as scientific engineering issues that focus on addressing different components related to fire initiation and its spread, including different products of combustion as well as their toxicity. The review also accounts for the practicality of fire prevention in vehicles, among other modes of transport. In this light, the author’s primary focus is the examination of features that include toxicity, flammability, as well as the combustion of materials related to transportation, including transportation fires. In this light, this paper identifies the main points addressed in the article.

One of the main points that the author identified in the article relates to considerations of fire safety. The three means of addressing the issue of fire safety in vehicles, as provided for by the author, include “fire prevention, fire minimization, and fire suppression” (Wichman, 2003, p. 250). The fundamental element considered in preventing fires, which is a fire safety measure, relates to the selection of materials that have the potential of inhibiting ignition sources. The fundamental concern for the aspect of fire minimization involves the use of fire resistance materials in different locations in the vehicle from which fire might be propagated. In relation to the aspect of fire suppression, the author emphasizes on the importance of having suppressant stream in the in the vehicle. In addressing the different components considered in ensuring fire safety in vehicles, the author takes note of the scientific and technical concerns that might arise.

In relation to the idea of ensuring fire safety in vehicles used for transportation, the researcher identifies different components that include fire growth, its chemistry, and the relevance of the same in the different transportation stages. He indicates that it cannot be possible to address the three components in isolation without the growth of fire (Wichman, 2003). In this regard, without the initiation, it is not possible for fire to grow, individuals cannot prevent it, and the examination of the different fire processes cannot be examined. If the initiation of the fire occurs, it means that the growth and the chemical processes involved in its growth can be studied, which is a provision that calls for an assessment of the products of combustion that might sustain the growth. The other main point that the author addresses relates to the initiation process. At this stage, the author looks into different initiation aspects that include provisions related to the ignition process, flammability, and the rate of heat release. In relation to the ignition of fires in vehicles used for transportation, the author addresses the chemical components in gases, liquids, and solids, which can facilitate the ignition process. For gaseous elements, ignition occurs through the chemical reaction between the heat generated through a chemical reaction and the rate with which the gas loses heat through conduction and radiation (Wichman, 2003). However, the gas volume that should be ignited should be large and the temperature required for the ignition to occur should be high. For liquids, the author emphasizes on the idea that liquid fuels are ignited through the introduction of sufficient heat that can ensure the formation of flammable air at the surface of the liquid. The flammability of this component is determined by the flash point, which can be understood as the liquid surface temperature at which the vapor formed on the surface of the liquid ignites into a flame. However, the liquid can only be ignited in the presence of a pilot flame. The in-depth temperature of the liquid also influences the ignition process. Contrary to the ignition process that characterizes the ignition process in liquids, the author identifies the flammability of solid elements as dependent on the combustibility of the materials. Combustible materials can be understood as the form of burning configuration that can ensure the ignition of a fire. For solids, the author provides four explanations for the flammability, which are based on the attainment of suitable surface temperatures that can facilitate the ignition and explanations based on the oxygen concentration required to ensure the ignition occurs (Wichman, 2003). These explanations emphasize on the thermal responses of the flammable solid materials.

In addressing the aspect of the flammability and ignition processes, the author focuses on describing the fundamental features of the materials by using experimental methods, particularly in liquids and solids. From the literature review on the flammability and ignition processes, the author uses reviewed information to conclude that the spectral radiant properties available in solids can assist in determining the behavior of the ignition process. The example he provides to emphasize on this development is based on the provision that the radiation emanating from a hot layer that exists in a compartment fire can ignite at a faster rate compared to a diffusion flame (Wichman, 2003). Regardless of the differences in the characteristic components that can facilitate the ignition process, the author emphasizes on the idea that the measure of the flammability of a given material primarily depends on the critical mass flux at the point of ignition. Another main point that can be identified in the article relates to the concept of fire spread. The author emphasizes on the fact that fire spread studies focus on addressing the question related to the speed with which a fire can spread over a given surface. This question confirms the notion that explaining how fire can spread over a liquid surface is fairly simple compared to the spread over solid fuels. The complexity of the explanation when considering the spread of fires over solid surfaces is dependent on the notion of liquid motion. The author also takes note of the theory of fire spread over liquid as well as solid fuels, which is an important inclusion in the article that can ensure the audience understand how fire spreads on different surfaces. The theory is based on the distinction created in terms of the thermal thickness or thinness of the spread of flames (Wichman, 2003). The other feature of the spread of flames in a particular surface depend on provisions such as the velocity of the fire, the temperature, and the concentration fields in place, which can affect the theoretical models used in explaining the tip structure of flames. This information provides the audience with insights that could assist in explaining the spread of flames through an assessment of the flow structure of the fire.

Considering the primary focus on the article, the author covers discussions about the characteristics of fire in different types of vehicles. In buses, the author claims that ignitions originate on seats, the growth and spread of the fires that might occur emanate from paper trash, newspapers, and lighter fluids on the bus seats. In addition to the identified components that can facilitate the spread of the fire, the cushion contains chemical components that can influence the burning of the interior of a bus. Subway cars also contain almost the same interior as buses, which means that the fires in the interior of the trains or subway cars can spread in the same way as the interior of buses. For aircraft cabins, the author identifies thermoforming as responsible for the ignition and spread of fires. The author indicates that the primary source of fires in other motor vehicles is related to vehicle crashes. The severity, impact type and the availability of ignition sources can facilitate the ignition and spread of the fire.

The author conducts a review of the technical aspects that characterize the ignition, growth, and spread of fires. Through the technical applications and analysis of arguments presented by other researches, the author indicates that the full-scale assessment of fires, in relation to transportation provisions, is an expensive venture. On the other hand, he admits that the assessment is challenging. However, he takes note of the notion that the facilities constructed from the literature review can be used to enhance the capability of implementing technical provisions needed for preventing or managing fires in vehicles used for transportation. For this reason, he advocates for the need to carry out tests that can be used to improve the safety of vehicles, even though complete safety is difficult, if not impossible, to achieve.

Reference

Wichman, I. (2003). Material flammability, combustion, toxicity and fire hazard in transportation.  Progress in Energy and Combustion Science ,  29 (3), 247-299. Doi: 10.1016/s0360-1285(03)00027-3