2013) (Fig. Thus, different locations within the compartment may be receiving different temperatures at different times throughout the fire. Obviously, the damage to the walls remaining after the fire is the cumulative result of all items that burned and the investigator would not be able to tell if the damage witnessed was the first item or a later item burning (e.g. Developing a process for the objective identification of areas requiring further attention during fire investigation that is universally accepted by the community is recommended to increase the reliability and accuracy of fire origin determinations. United States Department of Justice, Washington, D.C. (USA), Brannigan F, Bright R, Jason N (1980) Fire Investigation Handbook. Plenary Paper presented at the International Symposium on Fire Investigations. When the flame plume has not intersected the ceiling, heat fluxes along the ceiling surface near the centerline of a plume have been recorded to range between 80 and 100kW/m2 within 01m radial distance, while heat fluxes between 1.0 and 1.6m radial distances ranges between 10 and 70kW/m2 (Dillon 1998; Lattimer and Sorathia 2003). Annotated by Robert A. Corry. Arson investigators were surveyed about how they investigate fires and cited interpretation of burn indicators as the most common method of establishing arson. He reports. As the combustion zone is not attached to a fuel item or fuel package any longer, it becomes more difficult for the fire investigator to evaluate whether the damage was caused by a flame plume burning attached to a fuel item or if it is the UHCs burning detached from a fuel item due to ventilation-controlled conditions. This type of damage was noted in the USFA study with specificity (Shanley et al. An optical measurement method was developed to arrive at optical properties of smoke deposited out of a smoke layer onto glass filters. Cue 3-elevation of the line of demarcation is consistent with the height of the fuel item. 1997). Learn. clean burn) and with wash from the hoseline for suppression. Paper presented at the Fire and Materials Conference. All of the fire pattern studies have been summarized in Additional file 1. https://doi.org/10.1186/s40038-015-0008-4, DOI: https://doi.org/10.1186/s40038-015-0008-4. Section 5, Ch. Charles C. Thomas Publisher, Illinois (USA), Francis J, Chen A (2012) Observable characteristics of flashover. Ngu (2004) performed similar experimental work as Schroeder (1999). Areas of demarcation are locations along a surface that exhibit similar damage characteristics (e.g. The majority of this review is of North American work. The compartments were 12ft by 12ft with 8ft ceiling heights (3.6m3.6m2.4m) with a single door opening 3ft by 6ft-10in. walls, ceiling, contents) within a compartment. Several recent studies have provided processes to assist in the objective identification of the varying degrees of damage, including a degree of fire damage scale for visible damage (Gorbett et al. Ideally, the investigator would be able to look at a materials surface and distinguish the varying DOFD across its surface and this examination would be consistent with the findings of other qualified investigators. This includes the spring housing and rear slider block. Upper layer gases inside the compartment are driven by density differences due to their higher temperature and lower density. Fire investigation texts describe the characteristics of the lines of demarcation associated with a plume-generated pattern as a progression through triangular, columnar and conical patterns. Once these parameters are identified and organized, various techniques can be applied to facilitate the collection of critical information, analysis of the data and facilitation of a decision. 1997). The original definition of fire patterns and how it was used in NFPA 921 was all inclusive of the varying degree of damage to materials, clusters of damage, geometric shapes and the process of using damage to arrive at an area of origin (NFPA 2004). For example, the location of fire department entry, the use of positive pressure ventilation and the change of ventilation upon arrival should result in fire patterns that are similar to ventilation-generated fire patterns. A series of nine full-scale studies, funded by the National Institute of Justice, were conducted with ignitable liquid fuel spilled on carpeted and vinyl flooring with varying ventilation scenarios (Mealy et al. Shanley et al. The scene investigators most important hypothesis is the correct identification of the origin of the fire (NFPA 2014). Several myths have been associated with geometric shapes that cause investigators pause before using the shapes as descriptors. Journal of Testing and Evaluation 40. doi:10.1520/JTE104261, Madrzykowski D, Kerber S (2009) Fire Fighting Tactics under Wind Driven Conditions: Laboratory Experiments. However, if the fire were to remain in fuel-controlled conditions, it is not expected that this slight change in the damage from the plume would be sufficient to cause an erroneous conclusion as to the cause of the damage. Historically, fire investigators have been individuals without any formal education or training in scientific methodology. Therefore, determining if and when the fire transitions from a fuel-controlled to a ventilation-controlled condition is an important distinction. The fuels were burned against a gypsum wallboard lining material within a compartment lined with gypsum wallboard. National Research Council, Washington, D.C. (USA), Oullette J (2008) ATF FRL Fire Test Report 3589, 3593, 3595. He encouraged investigators to focus on low burns, because as he says any low point in a burn should be investigated as a possible origin (Kirk 1969). It was not until 2008 that NFPA 921 changed the definition of the term with the introduction of the term fire effects. (2013) identified hose spray from suppression efforts as washing off areas of soot and ash from the gypsum wallboard, leaving behind a white area. Fire and Arson Investigator Journal of the International Association of Arson Investigators 11:1518, Crofton, MD, Kirk P (1969) Fire Investigation. [4], The U-shaped development in physical skill comes from the development and recession of muscular strength, on the graph the Y-axis is muscular strength and the X-axis is time. The lack of damage has often times been overlooked in most discussions related to fire patterns. It was once thought that narrow V-patterns were produced by a fast developing fire and wide V-patterns were produced by a slow developing fire (Kennedy and Kennedy 1985). Fire effects are the bases for the varying DOFD that was discussed in the previous section. The section on char suggested that the investigator go backward from the areas of little char to deeper char establishing the path of fire clearly (Straeter and Crawford 1955). The present paper establishes a review of the work done over the past 80years, which addresses the current situation of the profession in light of this recommendation by the National Academy of Sciences. This combination of using damage in the context of the fire behavior variables was new to the profession in 1955, but then apparently lost for the next 40years. The presence of a ventilation opening is necessary. Mealy et al. The principle behind fire patterns was first linked to the need to trace the fire spread (Rethoret 1945). Therefore, no systematic scale for the degree of damage had been proposed or adopted. Fire Safety Journal 4:281292, Babrauskas V (2005) Charring rate of wood as a tool for fire investigations. Much of the earlier published research was focused on examining cross-sections of the wallboard, visibly determining the depth of calcination based on different bands of color within the cross-section (Posey and Posey 1983). Consequently, Kirk can be credited as the first person to describe the damage by a fire as a geometric shape. These photographs and annotations are provided to illustrate the burn pattern . Given these findings, damage cues 1, 2 and 3 are used as the most accurate damage cues for classifying a fire pattern generated by upper layer. Custer was the first to discuss a concept of shadowing by content items and how these areas of lesser damage assisted the investigator in identifying direction of heat exposure (Custer and Wright 1984). Proximity requires that the varying fire effects be within the same vicinity to each other. In fuel-controlled fires, the greatest damage within the compartment is typically found near fuel item(s) or fuel package(s) that have undergone combustion. FIRE PATTERNS. V-pattern, U-pattern, hourglass-pattern). Fire investigators describe this consistent damage to tops of contents as radiant heat damage being caused by the upper layer. Consumption is a function of heat transfer and the material properties. NFPA, Quincy, MA, Drysdale D (2011) An Introduction to Fire Dynamics, 3rd edn. Department of Justice, USA, Mealy C, Gottuk D (2012) A Study of Calcination of Gypsum Wallboard. 1982; Mealy et al. Lines of demarcation are the borders defining the differences in certain heat and smoke effects of the fire on various materials. Processes that identify thresholds needed for fire patterns to be identified can be better defined through experimental work or pattern recognition studies. These researchers proffered that the closer the fuel item burning was to the wall surface, the sharper the contrast and angle to the lines of demarcation and the more likely the damage would resemble a V in shape. Fire effects are the physical or chemical changes that occur to different materials when exposed to the byproducts of combustion (e.g. This rule of thumb of burning duration had been the source for some misconceptions related to determining if a fire was incendiary and fell into disrepute around the mid-1990s. Accessed January 1, 2015, Morgan M, Henrion M (1990) Uncertainty: A Guide to Dealing with Uncertainty in Quantitative Risk and Policy Analysis. In fact, a recent sentinel event analysis of wrongful convictions found that this one misconception is the most common factor in wrongful arson convictions (Bieber 2014). Combustion and Flame 132:157159, Pennsylvania (USA), Sugawa O, Kawagoe K, Oka K, Ogahara I (1989) Burning behavior in a poorly ventilated compartment fire ghosting fire. Mass loss of the furniture items was measured at the end of each test and was showed to relate well to the area of origin. The rooms were instrumented with heat flux gauges, thermocouples and gas sampling probes. 2012). Combustion that fire investigators will most commonly encounter is predominantly diffusion flames. Madrzykowski and Fleischmann (2012) performed a study of the response of gypsum wallboard and the reproducibility of the damage pattern created when exposed to known heat release rate (HRR) fires with varying types of fuel sources and wall construction. NFPA 921 is recognized as establishing the standard of care for the fire investigation profession and is the only consensus document that exists for fire investigators. U-shaped development, also known as U-shaped learning, is the typical pattern by which select physical, artistic, and cognitive skills are developed. The correct word is nadir, but to remain consistent with these texts apex will be used. Proper fire investigation should determine the fire cause, the cause of the resulting property damage and most importantly, the cause of bodily injury or loss of life to civilians and firefighters. SFPE Handbook of Fire Protection Engineering. The level of damage was varied based on the visible appearance of the number of cracks within set distances and the widths of those cracks. Safety, Security And Emergency Management | Safety, Security . 1997; NFPA 2014; Carman 2008). The characteristics of damage that have been reported in the literature to assist investigators in determining the cause of the fire pattern will be evaluated here. Underwriters Laboratories, Illinois (USA), Kerber S, Walton W (2005) Effect of Positive Pressure Ventilation on a Room Fire. Finally, type of damage indicates the physical or chemical changes to the material, such as penetration, flaking, deposition, consumption and other material decomposition fire effects. 1997). Kirk continues the discussion by cautioning the investigator that this pattern will be altered by the presence of obstructions, or of readily burned fuel in localized areas, and he warns that a very common complication arises when areas of excellent ventilation are present where intense burns will be noted in such areas that may well distract the investigator from following the fire pattern back to its point of origin (Kirk 1969). 1997). Investigations Institute, Florida (USA), Claflin P (2014) Effects of Multiple Ventilation Openings on a Post-Flashover Compartment Fire. The damage data used by fire investigators in origin determination starts with the ability of the investigator to observe varying damage along surfaces of contents, walls, ceiling, floor and structural members. However, most of these documents also cautioned against relying solely on the use of visible observations and encouraged the investigator to take samples of fire debris for analysis. Babrauskas (1981) reports on ignition of secondary items based on burning a series of common residential fuels and evaluating the heat flux to transducers at varying lateral distances. (3.48m3.58m) with a ceiling height of 8ft (2.4m). Dillon (1998) went on to illustrate that some of the corner flame height approximations resulted in 40% uncertainty, but others were as close as 2%. 2009-DN-BX-K232. The fire pattern studies revealed that specific damage cues identified during fuel-controlled conditions were not as prevalent during ventilation-controlled conditions. The origin determination is necessary to make an accurate cause assessment. Thus, the total percentage of participants choosing the correct area increased 3.9% with the inclusion of measurable data as part of the given. The only method that appears to be systematized and examples provided was the truncated cone method in conjunction with the heat and flame vector analysis (Kennedy and Kennedy 1985). Conversely, as the smoke moves away from the room of origin the temperatures will decrease, which causes the smoke to descend within the compartment causing lighter soot to deposit across the entire elevation of wall surfaces. Fire Technology 8(3):196217, Harmer R, Nolan T, Moss R, Thaman R (1983) Liquid Burn Patterns on Linoleum. This pattern has been associated with a fuel package that has the potential HRR to overcome the thermal inertia and start a pyrolysis reaction in the surface material, thereby creating the pattern, but insufficient energy to produce a plume which reaches any horizontal restriction above the fuel package (Hicks et al. Test 1 had the window and door open for the entire duration of the fire, test 2 had the window hinged closed until flashover and then the window was left opened for the duration of post-flashover and test 3 had no window. Fire and Arson Investigator Journal of the International Association of Arson Investigators 64(1):3747, Custer R, Wright C (1984) Open Windows and Thermal Inversions may Complicate a Fire Investigation. aromatic and unsaturated hydrocarbons). However, some data exists that indicates if a compartment fire does not transition to a fully involved state, then the floor patterns may persist (Putorti 2001; Mealy et al. 2010; Mealy et al. Putorti reported, comparisons of the conditions of the rooms and furnishings after the experiments resulted in the determination of several similarities, as well as many differences, between experiments with the same method of ignition (Putorti 1997). Because the varying DOFD serves as the foundation for all later interpretations, ultimately leading to an origin determination, more research is needed to either demonstrate that investigators reliably identify varying DOFD or the industry needs processes that are shown to be reliable and valid (Gorbett and Chapdelaine 2014). 2012; Mealy et al. Determining which effect or effects reflect varying degrees of damage is the key to successfully assessing damage. Paper presented at the 8th International Conference, Fire and Materials 2003. The researchers used ImageJ software and a Kodak gray scale and found good agreement between the optical measurement methods and smoke pattern images developed along wall surfaces. Fire investigation (origin and cause determination) is an integral part of the total fire safety model, including fire prevention and protection for a community. The ULG patterns are characterized by level lines of demarcation (or lines with similar elevation) with a generally uniform degree of damage (NFPA 2014). [1], Last edited on 10 November 2021, at 10:13, https://en.wikipedia.org/w/index.php?title=U-shaped_development&oldid=1054493463, This page was last edited on 10 November 2021, at 10:13. In this study, a DOFD scale was developed as a ranking system to reflect the varying degrees of visible fire damage to gypsum wallboard based on its response to heat exposure and visible damage indicators. Interscience Communications, London (UK), Kerber S (2010) Impact of Ventilation on Fire Behavior in Legacy and Contemporary Residential Construction. Suppression factors may also impact the visible and measurable damage that investigators use. The term related also is included to permit the linkage of the lines of demarcation with progressively increasing or decreasing degrees of damage, such as flow of a hot gas into/out of a compartment. Correspondingly, this heat source is often attributed to igniting contents throughout the compartment, especially those items located relatively high in elevation around the compartment (e.g. Alternative explanations are now commonly given when discussing penetrations through floors, including: radiant heat, furniture items, melting plastics and pre-existing openings in the floor during fully involved compartment fire (NFPA 2014) (Fig. J of Forensic Sci. There have been many references to penetrations through floors within the early texts on fire investigations, but few provided any guidance on how to interpret from the damage if the fire was moving up through the hole or down. Encyclopedia Britannica Company, Chicago, www.Merriam-webster.com/dictionary/pattern, Pitts W (1994) The Global Equivalence Ratio Concept and the Prediction of Carbon Monoxide Formation in Enclosure Fires. The prescribed process by Mealy (2013) was time consuming due to the requirement on the user to be extremely careful in watching the gauge and then marking the probe with a piece of tape to document the depth, thus introducing potential error. The fourth part of the review focuses on the practice of using damage in fire investigation to assist in determining the area of fire origin. From this work, the researchers used gravimetric measurements of these filters to demonstrate and validate an analytical model for smoke deposition based on thermophoresis. In this study, experimental samples of gypsum wallboard were exposed to various heat fluxes at varying durations using the ASTM E1354, Cone Calorimeter radiant heater. Surface effect is the result of the nature and material of the surface which contains the fire pattern, affecting the actual shape of the lines of demarcation displayed, or increasing J Forensic Sci 50(4):894905, Taroni F, Aitken C, Garbolino P, Biedermann A (2006) Bayesian Networks and Probabilistic inference in Forensic Science (Statistics in Practice). Another problem is that the shapes discussed are assuming an idealized fire plume that is shaped as a cone, which is a gross oversimplification. Cue 3- increasing lines of demarcation moving out of vent openings. Fire and Arson Investigator Journal of the International Association of Arson Investigators 63:2440, Utiskul Y (2007) Theoretical and Experimental Study on Fully-Developed Compartment Fires. 1997; Gorbett et al. Location and elevation are essentially further describing proximity. The other difficulty for forensic scientists investigating fires is that the observations of damage after the fire may often times be independent of the path taken by the fire making it difficult to identify where the fire started. Interscience Communications, London (UK), Hopkins R, Gorbett G, Kennedy P (2008) Fire Pattern Persistence Through Post-Flashover Compartment Fires. The pin size was based on the Mealy (2013) research, which resulted in a pressure of 1175psi (0.86kg/mm2). Paper presented at the International Symposium on Fire Investigations. This misconception persists despite the warnings from both the fire science and fire investigation communities (Shanley et al. Dissertation, The University of Edinburgh, Kahneman D, Tversky A (1974) Judgment under uncertainty: heuristics and biases. Match. The loss of mass from a material is typically dependent on the material and the exposure to heating. The terminology associated with fire patterns and their use in origin determination has evolved over the past 80years, so the first task was to identify any separations within the work to better organize the presentation of the literature. The gauge is capable of reading measurements to 0.0005 (0.01mm). The authors suggested that the investigator could evaluate the items involved and the differences of flammability of combustibles along the route of travel may explain the route of travel or spread (Straeter and Crawford 1955). These studies focused on fire pattern reproducibility, pattern persistence through flashover, the use of fire patterns in origin determination and the influence of initial, low HRR fuel on fire pattern production. It is suggested from this literature review that the overall reasoning process for evaluating fire damage for determining an area of origin consists of the following seven steps (Gorbett 2015): Identifying the value in further analysis of a surface or compartment; Identification of the varying degrees of fire damage (DOFD) along the surfaces of the compartment and contents; Identifying clusters and trends of damage (fire patterns); Interpreting the causal factors for the generation of the fire patterns; Testing the hypothetical area(s) of origin; and. Currently, investigators have no reliable method for identifying varying DOFD for charring. As the fire continues to grow, the pattern becomes . In the early days of fire investigations a common rule among fire investigators was that the visible observation of large shiny blisters of wood char indicated fast fires and that small dull blisters indicated a slower fire, which assisted investigators to conclude that a fire was incendiary or not (Boudreau et al. Fire and Materials 5(3):130141, Thomas I, Bennets I (1999) Fires in Enclosures with Single Ventilation Openings Comparison of Long and Wide Enclosure, Fire Safety Science Proceedings of the Sixth International Symposium, Thomas P, Heslden J (1972) Fully Developed Fires in Single Compartments, A Co-operative Research Program of the Conseil International du Batimen (CIB Report No. In the early stages of a fire and through fuel-controlled conditions, the production of the incomplete combustion byproducts (HCN, CO, UHCs) is typically minor. Nuclear Regulatory Commission. A U-shape could indicate that there was a "pool of origin" rather than a point of origin, such as might be caused by, say, a puddle of gasoline. When lacking a systematic approach to solving complex problems, many professions have turned to decision support frameworks, tools or methods, the intent of which are to guide the decision by asking questions and helping to assess the weight or importance of variables. Mealy et al. He found that the damage from the flame plume would extend approximately the width of the fuel for 100kW fires that did not have a ceiling jet form and 3 times the width of the fuel with 300kW fires that did have flame extension under the ceiling. Is nadir, but to remain consistent with these texts apex will be used of... Reflect varying degrees of damage had been proposed or adopted of this is! 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