The combustion within this compartment is of a high efficiency and the yields of soot and carbon monoxide (CO) are low (Pitts 1994). Match. The upper layer gases are elevated in temperature and have the ability to radiate heat downward onto the tops of contents throughout the compartment. It is important for reliability and validity that the industry develop processes to assist investigators to objectively identify fire patterns. Some experimental work has been conducted in this area as well as predictive calculations (Jahn et al. These myths have been dispelled by several studies, but their influence on using the geometric shapes as descriptors has justifiably persisted (NFPA 2014; Shanley et al. 2003). A two-dimensional fire pattern is expected to form on the vertical surface interface (i.e. Various types of fire patterns, such as; "V-shaped", "hour-glass", and "inverted cone", have come from common observation at actual fire scenes. The higher temperatures and higher velocities of smoke cause greater collection of soot deposits to form in certain locations within the compartment. This is the reason that many fire investigation texts commonly refer to fire moving up and outward (DeHaan and Icove 2011; Kennedy 1959; Kennedy (1977); Kirk 1969; Rethoret 1945). Such data include the patterns produced by the fire (NFPA 2014). A study conducted in 2012 examined the effect of carpet underlayment/carpet pad on post-flashover fire, floor patterns (Wood et al. This did not so much redefine the NFPA 921 coverage of the topic, but rather clarified the fire investigators interpretation process in identifying a fire pattern. The ventilation-controlled conditions did not result in any upper layer damage that was discernable, therefore it will not be considered here. 2009; Gorbett 2010; Gorbett et al. From this work, Ngu developed a tool based on a constant spring force and a force probe. One of the 11 NWCG categories of fire pattern indicators. 2009-DN-BX-K232. More recent research has identified heat flux values between 25 and 50kW/m2 reported at 1m away from more modern fuel packages, including king size mattresses, upholstered chairs and sleeper sofas (Madrzykowski and Kerber 2009). In this work, the authors outlined a system that described char as being on a range from Number 0 Char up to Number 10 Char, with number 10 char as representing the greatest level of damage. Scene photograph of suspected ignitable liquid pour (Wood et al. Annotated by Robert A. Corry Director, Fire Investigation Specialist American Re-Insurance.Classic "V" "Inverted Cone" on a Wall "Inverted Cone" on an Object. This study also developed a simplified grid system out of tent pole stakes to decrease scene processing time. National Institute of Standards and Technology, NIST Monograph 179, Gaithersburg, MD, Posey E, Posey J (1983) Using Calcination of Gypsum Wallboard to Reveal Burn Patterns. Fire Safety Journal 40:528554, Barnott A, Hardman R, Hoff N (2013) An Improved Method for Measuring Depth of Calcination in Fire Investigations. The three compartments were similarly constructed measuring 11ft, 5in. The Schroeder study (1999), however, was the first to quantify the depth of calcination and its relationship within fire investigations. 13). Ultimately, the locations of damage and fire patterns are compared to the causal factors from the physics of the fire, alternative causes and background information. 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. Test one used only Class A fuels, while the eight remaining tests used gasoline as the first fuel ignited. Such patterns can provide clues as to the origin, cause or propagation path of the fire. California Privacy Statement, All of the early texts indicate that fire tended to rise and that a pattern may exist from this damage, but most did not use the term pattern nor did they give any guidance on what a pattern was (Rethoret 1945; Kennedy 1959; Kirk 1969). This project consisted of 10 separate full-scale tests to produce the first scientifically controlled and recorded research into the formation, growth and investigation of patterns produced in fires. This same damage near the drywall seams was identified in the Claflin study (2014) (Fig. They appear between the affected area and adjacent, less-affected areas (NFPA 2014). Both of these misconceptions have fallen into disrepute and are no longer prevalent within the current profession (Bieber 2014). The study concluded that 73.8% without measurable data and 77.7% with measurable data accurately determined the area of origin. In the face of non-systematized approaches to solving complex problems, the current state of fire investigation, many other professions have turned to decision support frameworks, tools or methods. 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. A U-shaped burn pattern found on the top of floor joists, caused by fire burning down through the floor. Every fire investigation text, including NFPA 921, uses shapes to describe the characteristics of the lines of demarcation associated with plume-generated patterns. NFPA (2014) refers to this as fire pattern generation and provides a list of them including plume-generated, ventilation-generated, hot gas layer-generated and suppression-generated. To accomplish this goal, the authors suggested that the area of origin could be identified through the use of damage by both (1) retracing the fires path by the forces bearing on it and (2) retracing or reconstructing the path of the fire by the effects produced. In 1992, NFPA 921s first edition identified most of these old indicators as misconceptions. Kirk being one of the few texts at the time that opposed this idea when declaring flammable liquids never carry fire downward (Kirk 1969). 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. 2013). American Psychiatric Association, Washington, DC, Eaton T (1987) Underfloor Fires. A thermocouple tree was located at the area of origin. Attributing a fundamental interpretation to an observation, specifically one that ties the underlying physics to an observation, is a major key to accurately determining the true fire scenario and area of origin. 2006; Hopkins et al. Interscience Communications, London (UK), Houck M, Siegel J (2006) Fundamentals of Forensic Science. 1997; Hicks et al. Carman attributed the failure to the lack of understanding by the investigation profession of the differences between pre- and post-flashover fire behavior and resulting damage. Fire Patterns (2 of 2) Analyze fire patterns within the context of all the patterns. The literature on using fire patterns to determine an area of origin should be classified into four areas that will assist in guiding future research, including: Assessing the varying Degrees of Fire Damage (DOFD) along the surfaces of the compartment and contents (i.e. 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 majority of these texts stated that the investigator should consider the damage to be caused by an ignitable liquid if the investigator would visibly observe damage to the floor in the shape of a puddle, have hard-edged burn marks in the shape of a pour, or the damage had the appearance of trailers (i.e. A few of the studies also indicated that truncated cone patterns, specifically V-patterns, were located away from the true origin causing confusion for the investigators (Hoffmann et al. The statistics can be found in Additional file 1 associated with this review paper. Fire and Arson Investigator Journal of the International Association of Arson Investigators 15:1619, Crofton, MD, Theobald C (1968) The Critical Distance for Ignition From Some Items of Furniture. From this work, the researchers used gravimetric measurements of these filters to demonstrate and validate an analytical model for smoke deposition based on thermophoresis. Privacy 1983; Kennedy and Kennedy 1985; Cooke and Ide 1985). These tests evaluated many aspects of fire investigations, including the presence of ignitable liquid residue after extinguishment, fire patterns, depth of calcination and the fire dynamics of an under-ventilated compartment. First Asian Conference on Fire Science and Technology, China, Quintiere J (1995) Compartment Fire Modeling. 2008; Hopkins et al. Key aspects of a decision support framework include identification of decision objectives, attributes (criteria) which are important to the decision problem and the weighting (importance) of the attributes to the decision given the uncertainty and variability in the data and relationship between the attributes. Thus, different locations within the compartment may be receiving different temperatures at different times throughout the fire. increases. Wood stud wall with varying DOFD char damage, Depth of char contour plot of wood stud wall depicted in Fig. 2003). Their method encouraged investigators to use fire patterns to arrive at an origin, but upon arriving at their hypothetical area(s) of origin required the investigator to provide some measure of accuracy in the form of a radius of error. Kirk was the next to put forward a general process on how to identify the area of origin based on damage. As the smoke exits the opening, it expands in volume and rises. The participants were provided a diagram of the room and photographs of the contents, walls and ceiling. 12). 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. The fundamental items within the definition that may assist in better defining the term fire pattern is that patterns are something that happens in regular and repeated ways with characteristic features. Smoke consists of liquid aerosols, solid particulates (i.e. 14, 4th edn. 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). This test was conducted as part of a conference where the participants of the conference were to evaluate the fire scenes for origin. Fire patterns are formed when the products of combustion come into contact with a vertical or horizontal surface such as a wall, floor, ceiling, or home furnishing. The authors would like to thank Bill Hicks for providing pictures taken during fire testing. 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] In this graph the axes would be availability of intuition (being th Y-axis) and level of expertise (being the X-axis), instead of the skill level (being the Y-axis) and time (being the X-axis). 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. In 2013, Andrew Cox published an article proposing a new methodology for the assessment and interpretation of compartment fire damage through the use of what he termed the origin matrix (Cox 2013). Notice, however, none of these documents came out and directly stated that an investigator could not identify an ignitable liquid from a floor pattern based on observation, they only warned that it cannot always be reliably identified (NFPA 1992). Gorbett, G.E., Meacham, B.J., Wood, C.B. Many of the studies contend that this process assists investigators in determining the correct area of origin (Shanley et al. Fire and Arson Investigator Journal of the International Association of Arson Investigators 1:2526, Crofton, MD, Putorti A (1997) Full Scale Room Burn Pattern Study. 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. 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