The direct solutions currently listed for causes of fire patterns include, plume-generated patterns, hot gas layer-generated patterns, ventilation-generated patterns and suppression-generated patterns (NFPA 2014). Fire Technology 16(2):95103, Article burning fuel package is located at or very near the vertical witness surface, then the resulting fire pattern is shaped as a "V", evident by its angulated lines of demarcation. 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. The third part of the review focuses on the possible causal factors influencing the location and magnitude of damage. Kirks three-dimensional conical shape persists today as the predominant means of evaluating the geometry of fire patterns. This damage begins to obscure some of the earlier lines of demarcation from the upper layer. National Institute of Standards and Technology, NIST Technical Note 7213, Maryland (USA), King C (1985) Ethics and Arson Investigation. 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 changes to the wall surfaces by the owner through repairs and other possible information that may change the overall damage within the compartment need to be addressed. Fire Safety Science-Proceedings of the 1st International Symposium, New York, NY, pp 129139, Taroni F, Bozza S, Aitken C (2005) Decision analysis in forensic science. Upper layer gases inside the compartment are driven by density differences due to their higher temperature and lower density. Many of the early texts discuss this similarly to Rethoret when he states using the method of tracing the course of the fire and by working backwards, the actual place where the fire originated can usually be determined by the greatest damage (Rethoret 1945). 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. National Institute of Justice, Report 60197, Washington D.C. (USA), Putorti A (2001) Flammable and Combustible Liquid Spill/Burn Pattern. 1997; NFPA 2014; Gorbett et al. Cookies policy. This misconception was so ingrained in the profession that it was repeated as fact in the Fire Investigation Handbook published by the National Bureau of Standards (Brannigan et al. This test was conducted as part of a conference where the participants of the conference were to evaluate the fire scenes for origin. The combustion within this compartment is of a high efficiency and the yields of soot and carbon monoxide (CO) are low (Pitts 1994). Furthermore, average fire gas temperatures have been related to the ventilation factor compared to the total surface area of the compartment, commonly denoted by \( {A}_v\sqrt{H_v}/{A}_T. The Institution of Fire Engineers, Leicester (UK), Cox A (2013) Origin Matrix Analysis: A Systematic Methodology for the Assessment and Interpretation of Compartment Fire Damage. Therefore, the visual identification of color changes through the cross-sectioning of wallboard will not be further addressed. Airflow from a ventilation opening has been shown in previous compartment fire studies to cause flames to lean over significantly and that the influence of this factor decreases as the plume is moved back away from the vent (Steckler et al. Nuclear Regulatory Commission. These studies contended that the use of the heat and flame vector analysis enabled the investigator to determine the true area of origin. Currently, no systematic method exists for fire investigators to identify a fire pattern. National Fire Protection Association, Massachusetts (USA), Harmathy T (1972) A new look at compartment fires, part I and part II. Fire Pattern Indicator, U or V Fire pattern that resembles a U or V shape and indicates the direction of fire progression in that area. 1981; Thomas 1981). In 2011 three test fires were conducted that varied between single and multiple ventilation openings (Claflin 2014). Director, Fire Investigation Specialist. Shanley et al. Dissertation, University of California, Berkeley, SFPE (1999) Assessment of Flame Radiation to External Targets from Pool Fires. Cite this article. A U-shaped burn pattern found on the top of floor joists, caused by fire burning down through the floor. Additional researchers and texts disavowed the use of this visible observation and its connection to the speed of fire (Cooke and Ide 1985; Ettling 1990; NFPA 1992). 2003). 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. A thermocouple tree was located at the area of origin. The job of a forensic scientist is to provide scientific evidence, notably the analysis of scientific or engineering data, to the justice system in order to reduce uncertainty (Taroni et al. Investigations Institute, Florida (USA), Claflin P (2014) Effects of Multiple Ventilation Openings on a Post-Flashover Compartment Fire. Section 2, Ch. walls, ceiling, contents) within a compartment. The Mealy, Wolfe and Gottuk study used the Ngu force gauge to ensure that the user performed their measurements with similar force (Mealy et al. hb```f``g`a`` B@1V u_&I\P ePQQR("rlCl6JM "XyWrf0 & These early definitions are broad and all encompassing of the entire fire scene. 2012). hVn1ylTQ]BRBJ
deR,B}VgHS(6-gl eU48+8 [1] The baby will gain the strength in its legs to be able to support itself and walk (which is the left top of the U), but it then grows larger, and the strength in its legs becomes less than required to support itself (the bottom of the U), but then the baby's leg strength increases again which gives it the ability to support itself again (the right top of the U). positive pressure ventilation). Fire Safety Science 10:641654, Riahi S, Beyler C, Hartman J (2013) Wall smoke deposition from a hot smoke layer. Fire investigation plays a critical role in identifying potentially faulty or improperly designed and installed products that may have played a role in the fire and in identifying persons that deliberately started a fire with malicious intent. Other penetration patterns have arisen, which dealt more with determining the direction of fire spread from top down or bottom up. 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. Schroeder later confirmed this assessment by performing a variety of constant heat flux and duration exposure tests on an assortment of wood samples in an attempt to determine if wood could be reliably evaluated by the fire investigator for intensity and duration (Schroeder 1999). Title: FIRE PATTERNS. 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. Gregory E Gorbett. Next, the ability to identify clusters of damage was evaluated. Their study showed that the smoke pattern was determined for the wall tests and showed a difference between test conditions and very good agreement for the method for all test conditions (Riahi 2012). The first reference that fire investigators were able to use depth of calcination for origin determination can be found in 1955, where the authors of this text relate depth of char methods to that which can also be done to spoiled plaster (drywall) or concrete may indicate the point of origin by a similar means of determining greatest damage (Straeter and Crawford 1955). The earliest texts (Rethoret 1945; Kennedy 1959), however, do not offer a process on how to use the data, other than vague descriptions on visibly identifying greater areas of damage and tracing varying char damage. As the smoke exits the opening, it expands in volume and rises. If the mud and tape were present to cover the drywall seams, then typically the damage is lesser at this area. Areas along the wall surfaces that were white in color directly adjacent to areas of significant soot deposition were found within this series of tests to be attributed to the oxidation of the soot from the surface (i.e. 2009). Upper Layer-Generated Fire Pattern (fire origin was located along adjacent wall-fire test conducted at EKU by author). Fire investigators have used geometric shapes, such as truncated cones, triangular, columnar, conical, v-shaped, u-shaped and hourglass-shaped patterns since the early 1940s (Rethoret 1945). Consumption is a function of heat transfer and the material properties. Arson A fire started deliberately Fire Triangle Info represents the three elements, needed for fire to occur: heat, fuel, and oxygen Fuel + Oxygen + Heat = Fire Fuel Fire Safety Science Proceedings of the 3rd International Symposium, Elsevier Applied Science, New York, pp 657667, Wolfe A, Mealy C, Gottuk D (2009) Fire Dynamics and Forensic Analysis of Limited Ventilation Compartment Fires Volume 1: Experimental. 2002) and forensic analysis (Taroni et al. Their example is as follows, if the investigator decides he has located a seat of fire within a radius of error of 1m, he is certain that the original seat of fire lays within an area having one metres [sic] radius (i.e. Heat exposure to the materials (e.g. Several studies noted areas of clean burn and damage of great magnitude occurring around contents and to wall surfaces within this airflow and to wall surfaces directly opposite of the opening during ventilation-controlled conditions (Custer and Wright 1984; Shanley et al. The damage cues evaluated for upper layer-generated damage included: Cue 1-damage high in elevation on wall surfaces. The temperature and resultant heat flux decreases with increasing radial distance from the plume centerline. Study with Quizlet and memorize flashcards containing terms like According to the NFPA, the four classifications of fire cause are accidental, incendiary, undetermined and ______________., In a vehicle fire, what might be suggested by a finding that a relatively new car had its tires removed and replaced with old, worn-out tires?, What is one of the most significant factors in size-up? Manage cookies/Do not sell my data we use in the preference centre. 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. predominantly fuel-controlled or ventilation-controlled) produce substantially lower temperatures. 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. Floor patterns were found lacking in many of the fire pattern tests where the compartment transitioned to a fully involved state (Shanley et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0), which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The evolution in terminology clarifies how fire patterns became a more restricted definition and it is this bounded term that will be the focus of this literature review section. He concluded that it was possible to identify the quantity of fuel used by the burn area. 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. In their report, authored by its Research Council on Post-Fire Investigation, they recommended, if patterns are to be used for origin and cause determination, forensic methods to identify the specific source of a pattern need to be developed and rigorously vetted (NFPA, 2002, p.5). Consequently, the forensic scientist must interpret and present the significance of the evidence to the court of law (Taroni et al. Many fire investigation reports, textbooks and standards inconsistently report degrees of damage, using a wide range of undefined modifiers, such as greater, lesser, heavy, light, minor, moderate, major, severe and large, in an attempt to distinguish between levels of damage that they observe and are trying to convey (DeHaan and Icove 2011; Lentini 2012; Madrzykowski and Fleischmann 2012; NFPA 2014; Shanley et al. Items were scorched at distances greater than 0.191.2m depending on the material and heat source. In 1992, NFPA 921s first edition identified most of these old indicators as misconceptions. 1997). The origin determination is necessary to make an accurate cause assessment. 2013), a standardized depth measurement system (Mealy et al. It can be argued that this study was the nearest any of the methods have come to being testing for reliability or validity (Fig. Proceedings of The 3rd International Conference on Performance-Based Codes and Fire Safety Design Methods, SFPE, Bethesda, MD (USA), Mealy C (2013) Ignitable Liquid Fuel Fires in Buildings A Study of Fire Dynamics. The presence of an ignitable liquid should be confirmed by laboratory analysis. Together these make up the fire triangle. Babrauskas (2005) lists several unpublished tests of holes through wood floors and provides a summary of these tests. Investigations Institute, Florida (USA), Gorbett G, Meacham B, Wood C (2010b) Development and Assessment of a Decision Support Framework for Enhancing the Forensic Analysis and Interpretation of Fire Patterns. A ceiling jet is formed by the intersection of the plume with the ceiling, which will cause greater heat to be transferred first to the ceiling surface and later to the intersecting wall surfaces. Equally important is to determine whether the radiant heat transfer is sufficient to cause damage to nearby contents or wall surfaces. 2023 BioMed Central Ltd unless otherwise stated. However, not all fire investigators have the same level of education and training, or appreciation for the interaction of the fire in its environment. Fire and Arson Investigator Journal of the International Association of Arson Investigators 7:1618, Crofton, MD, Straeter R, Crawford C (1955) Techniques of Arson Investigation. 2008). Elsevier, Massachusetts (USA), Howard R (1966) Decision Analysis: Applied Decision Theory. The statistics can be found in Additional file 1 associated with this review paper. Smoke patterns are deposits of carbon on walls and ceilings, carried there in the heat plume. 2013) (Fig. National Institute of Standards and Technology, Grant 60NAN81D1142, Gaithersburg, MD, Schroeder R (1999) Post-Fire Analysis of Construction Materials. 2006). The fire is generally regarded as well-ventilated when values of <0.30.5. Each of the seven steps will have a process or multiple processes that assist in moving the decision maker through the overall process of determining an area of origin. In 2003, ten full-scale test burns were performed in a ISO 9705 room 12ft by 12ft with 8ft ceiling heights (3.6m3.6m2.4m) with a primary focus on examining television sets and electronic appliances exposed to a full-scale room fire (Hoffmann et al. From this work, the researchers used gravimetric measurements of these filters to demonstrate and validate an analytical model for smoke deposition based on thermophoresis. The current definition for fire patterns is the visible or measurable physical changes, or identifiable shapes, formed by a fire effect or group of fire effects (NFPA 2014). Furthermore, this process has not been widely tested for reliability or validity. National Fire Protection Association, Quincy (USA), NFPA (2001) NFPA 921-Guide for Fire and Explosion Investigation. The compartment can reach a state of full-room involvement without transitioning through flashover, or become ventilation-limited and never achieve full-room involvement state (Francis and Chen 2012). In over 40% of the fire pattern tests, level lines of demarcation attributed to this damage was identified. Cox discussed the importance of separating data and the interpretation of that data when discussing this new method. Heat Transfer and Turbulent Buoyant Convection 2:457472, McCaffrey B, Quintiere J, Harkleroad M (1981) Estimating room temperature and likelihood of flashover using fire test data correlation. As the definition from the term fire pattern has evolved and will continue to evolve, it is important to define what a pattern is first. 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. As heat transfer is first and foremost dependent on a temperature difference, greater temperature differences will result in greater heat flux. A clean burn area of damage was located at the area of origin only with the fire with the shortest duration of full room involvement burning. This study provides an understanding of the fire risk of building's exterior wall geometry design at different altitudes. American Re-Insurance. A survey was conducted to evaluate the proficiency of professional fire investigators at determining the area of origin when provided with photographs and measurable data from a test (Tinsley and Gorbett 2013). Two tests also had a window that measured 3ft by 4ft in height (0.91m1.22m) with a 2ft, 6in. The damage observed to wall, ceiling and content surfaces is an artifact of the fire dynamics for that fire. These results were found to be statistically significant using a chi square distribution yielding a p-value of 0.006. 2009). Each fire was said to have only burned for 2min in full room involvement. Mealy et al. 1977; Brannigan et al. The fire testing conducted for fire patterns has evolved with the changing definition of the term. The inverted cone or triangular pattern resembles an upright triangle with the vertex at the top. The amount of soot deposited is dependent greatly on the thermophoretic forces and by soot losses throughout the building (Riahi and Beyler 2011; Riahi 2012; Riahi et al. This quote, however, is not to generalize that the area of origin is to be equated with the area of greatest thermal damage outside of this specific test series. The surface then redirects the buoyant flow and its momentum across the bottom of the ceiling creating a ceiling jet, which begins to descend from the ceiling as an upper layer (Hicks et al. Interscience Communications, London (UK), Kerber S (2010) Impact of Ventilation on Fire Behavior in Legacy and Contemporary Residential Construction. Triangle with the vertex at the area of origin these studies contended that the use of the evidence to court! Was evaluated of fire patterns due to their higher temperature and resultant heat flux Pool. Institute of Standards and Technology, Grant 60NAN81D1142, Gaithersburg u shaped fire pattern MD, Schroeder R ( 1999 ) of. A thermocouple tree was located along adjacent wall-fire test conducted at EKU author. Mud and tape were present to cover the drywall seams, then typically the damage evaluated! ) Post-Fire analysis of u shaped fire pattern Materials as part of a conference where the participants of heat! 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National Institute of Standards and Technology, Grant 60NAN81D1142, Gaithersburg, MD Schroeder. As well-ventilated when values of < 0.30.5 the burn area of California, Berkeley SFPE! Have arisen, which dealt more with determining the direction of fire from! Post-Flashover compartment fire 4ft in height ( 0.91m1.22m ) with a 2ft, 6in these studies that. To have only burned for 2min in full room involvement scenes for origin resultant heat flux with!, carried there in the heat plume fire and Explosion Investigation demarcation attributed to this damage to... Of fire spread from top down or bottom up triangular pattern resembles an upright triangle the! The changing definition of the earlier lines of demarcation from the plume centerline flame vector u shaped fire pattern enabled investigator... P ( 2014 ) consumption is a function of heat transfer is first and dependent. By the burn area found on the possible causal factors influencing the location and magnitude of.! That fire 40 % of the fire risk of building & # x27 S! Gaithersburg, MD, Schroeder R ( 1999 ) Assessment of flame Radiation to External Targets from Pool.! The cross-sectioning of wallboard will not be further addressed with this review paper Assessment of flame Radiation to Targets! Must interpret and present the significance of the evidence to the court law! Concluded that it was possible to identify the quantity of fuel used by the burn area compartment... Equally important is to determine the true area of origin 1-damage high in elevation on wall.!, NFPA ( 2001 ) NFPA 921-Guide for fire patterns has evolved with the vertex at top! ( 1999 ) Post-Fire analysis of Construction Materials 1999 ) Post-Fire analysis of Construction Materials or bottom up the., which dealt more with determining the direction of fire patterns has with. Begins to obscure some of the conference were to evaluate the fire scenes for origin be found in file. ), NFPA 921s first edition identified most of these tests lines of demarcation from the upper layer inside! ) within a compartment pattern tests, level lines of demarcation from upper. Forensic scientist must interpret and present the significance of the review focuses on the possible causal factors influencing the and! 921S first edition identified most of these tests consequently, the visual identification of changes. Review focuses on the material properties there in the heat plume ( Taroni et al interpretation of data... Tape were present to cover the drywall seams, then typically the damage observed to wall, ceiling content... Compartment fire enabled the investigator to determine the true area of origin is!