The statistics can be found in Additional file 1 associated with this review paper. What are the 4 elements of extinguishment? repairs of the drywall performed). The temperature and resultant heat flux decreases with increasing radial distance from the plume centerline. Since the beginning of organized fire investigation in the late 1940s, fire investigators have relied on fire patterns as their basis for determining the fire origin (Rethoret 1945). 1983; Kennedy and Kennedy 1985; Cooke and Ide 1985). Typically, flashover occurs at a =1.0 (Wieczorek et al. \This type of structured approach to reaching better decisions has been applied in various fields, from business and economic decisions (Clemen and Reilly 2001), to building and fire safety analysis and regulation (Donegan 2008; Meacham 2000), diagnostic support within the psychological, psychiatric and medical professions (Boorse 1976; DSM-IV-TR 2000), failure analysis (Benner 1975; Ericson 1999; Vesely et al. (2013). Items were scorched at distances greater than 0.191.2m depending on the material and heat source. Fire Safety Journal 4:281292, Babrauskas V (2005) Charring rate of wood as a tool for fire investigations. Interscience Communications, London (UK), Hopkins R, Gorbett G, Kennedy P (2008) Fire Pattern Persistence Through Post-Flashover Compartment Fires. This includes the spring housing and rear slider block. In March of 1997 four full-size compartment test fires were conducted in furnished bedrooms (Milke and Hill 1997). It is called "U" shape development because of the shape of the letter U in correlation to a graph, skills developed in the "U shaped" fashion begin on a high position on a graph's Y-axis.The skills start out at a high performance level . This was the first time that investigators were encouraged to assign some reliability to their origin conclusion, however, the authors failed to provide guidelines on how specifically to arrive at the initial origin hypothesis. Finally, the study was conducted with a variety of digital cameras and they found that the optical properties were not dependent on the camera used. Section 5, Ch. The combustion of a fuel through diffusion flames is inherently oxygen limited by the diffusion reaction and the availability of only 21% of oxygen in air in well-ventilated fires. A fundamental principle of decision analysis is that people do not always have all the data or information needed to make a good decision. This is of particular concern with respect to the importance of being able to identify and properly weigh potentially subtle differences from one fire scene to the next, some of which could have significant bearing on the development of the fire and the interpretation of the evidence. 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. Protected Surface: Body "Clean Burn" "Rundown Burn" Ignitable Liquid Pour Pattern. It was not until 2008 that NFPA 921 changed the definition of the term with the introduction of the term fire effects. This causes the plume to widen horizontally in the upper layer causing damage to the intersecting surfaces. Combustion that fire investigators will most commonly encounter is predominantly diffusion flames. The test was conducted in a single compartment measuring 14ft by 12ft by 8ft high (4.26m3.66m2.4m) that resembled a residential bedroom with one open doorway to the exterior. Therefore, determining if and when the fire transitions from a fuel-controlled to a ventilation-controlled condition is an important distinction. National Institute of Justice, Report 60197, Washington D.C. (USA), Putorti A (2001) Flammable and Combustible Liquid Spill/Burn Pattern. Fire patterns are the principal artifacts that fire investigators use to trace the origin and development of a fire. Many of the suppression factors would not necessarily develop new patterns that have unique characteristics. 2004). The Posey study reported that an investigator could visibly identify subtle color changes in individually cut cross-sections of the wallboard and prescribe the DOFD associated with the color changes.
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A pattern requires that the degree of damage between varying materials and along the same material reflect a similar intensity/duration of exposure to the byproducts of combustion. Building Research Institute of Japan., p 27, Keith, Smith (1984) Analysis of Char Patterns Known as Alligatoring. Fire Technology 39:207224, Hopkins R, Gorbett G, Kennedy P (2007) Fire Pattern Persistence Through Post-Flashover Compartment Fires. Although, Shanley et al. Fire investigators are instructed to visually and measurably identify these areas and lines of demarcation. 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). 2013). Investigations Institute, Florida (USA), Hicks W, Gorbett G, Hopkins M, Kennedy P, Hopkins R, Thurman T (2008) Full-Scale Single Fuel Package Fire Pattern Study. Paper presented at the International Symposium on Fire Investigations. Investigations Institute, Florida (USA), Mealy C, Wolfe A, Gottuk D (2013) Forensic Analysis of Ignitable Liquid Fuel Fires in Buildings. If the burning fuel package is located away from the witness surface, the resulting fire pattern is shaped as a "U", However, he found that much higher charring rates apply to floors and to any other wood members where charring is affected by the presence of gaps or joints. magnitude of damage, type of fire effect, color, texture) and are in close proximity to each other. Science 185:11241131, Kawagoe K (1958) Fire Behavior in Rooms. 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 Mealy, Wolfe and Gottuk study used the Ngu force gauge to ensure that the user performed their measurements with similar force (Mealy et al. Ngu (2004) performed similar experimental work as Schroeder (1999). DeHaan elaborated on the characteristics associated with this damage as being generally level, that is, of uniform height from the floorchanges in the level indicate points of ventilation and the level will often drop markedly in the vicinity of the point of origin (DeHaan 1983). (2010)). 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). Two tests were completed with television sets placed on a wood stand next to an upholstered chair. In these texts the authors stressed that the investigator should evaluate low burns for possible ignition sources, but did not necessarily link the damage to ignitable liquids. The burning during ventilation-controlled conditions is often times detached from a fuel item (i.e. Hughes Associates, Maryland (USA), Bieber P (2014) Anatomy of Wrongful Arson Conviction: Sentinel Event Analysis in Fire Investigations. %%EOF
The fire pattern studies revealed that the upper layer damage is very difficult to identify after the fire has transitioned into ventilation-controlled conditions. A substantial degree of damage is often times found directly adjacent to or opposite of window and door openings. 2010). Wood has been and remains a common material used for construction of structures and contents. Figure 1 is a schematic representation of how such a pattern is created, and Figure 2 shows a triangle-shaped pattern produced by a test fire. SFPE Handbook of Fire Protection Engineers, NFPA, MA, Wieczorek C, Vandsburger U, Floyd J (2004) An evaluation of the global equivalence ratio concept for compartment fires: data analysis methods. 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). Fire and Arson Investigator Journal of the International Association of Arson Investigators 32:8184, Crofton, MD, Fitch R, Porter E (1968) Accidental or Incendiary. A hypothesis of pseudo chimney effect is provided. Specifically, the hypothesis that carpet pad seams could mimic the floor fire patterns previously attributed to ignitable liquid pours was examined. The investigator has always been tasked to evaluate damage from lesser to greater with minimal advice related to any meaning that exists for the lack of damage or the lesser damaged areas (Rethoret 1945). The same proponents of identifying pour patterns as being indicative of an ignitable liquid, also promulgated that holes in floors were indicative of ignitable liquids being used (Battle and Weston 1960; Fitch and Porter 1968; Barracato 1979; Smith 1983; Harmer et al. Fire Technology 8(3):196217, Harmer R, Nolan T, Moss R, Thaman R (1983) Liquid Burn Patterns on Linoleum. Schroeder was able to illustrate that a crystalline change would occur within the gypsum wallboard when heated by using an x-ray diffraction technique. Six tests were completed with television sets placed inside a wood entertainment center. 2010). fire patterns); Interpreting the causal factors for the generation of the fire patterns; and. Kirks (1969) text was the first reference that indicated investigators could use this data for more than just direction of damage when he explained investigators make measurements with the idea of determining the length of time the fire burned at this point. Match. by 11ft, 9in. 2013). Photograph of a Plume-Generated Fire Pattern (fire origin was located at the base of this damage-test conducted at EKU by author). They also suggested that the level of heat lines on the walls may be traced back from the termination point toward the beginningordinarily they will be lower and lower on the walls as you approach the areas where the greatest heat was generated (Straeter and Crawford 1955). The authors stated that fire leaves its fingerprints and that each finger of flame leaves its effects and the study of these effects will help you pick the spot where it burned first (Straeter and Crawford 1955). Fire Safety Journal 38:709745, Lentini J (2012) Scientific Protocols for Fire Investigation. Poster presented at the International Association of Arson Investigators Annual Training Conference, Florida (USA), Barracato J (1979) Fireis it arson? 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. The forces bearing on the fire were identified in this text as (a) combustibles involved, (b) openings and ventilation, (c) winds and drafts, (d) explosions and (e) variations from normal burning. 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. Straeter and Crawford (1955) text identified that the point of deepest char in the wood is likely to be the point of origin of the fire. Drysdale (2011) indicates that the average compartment temperatures are highest near the cross over between fuel-controlled and ventilation-controlled. Assessing the historical and current semantics of the fire investigation literature, the use of fire patterns to determine an area of origin, for purposes of the current paper, can be grouped into four areas of literature that need to be reviewed, including: Assessing the varying degrees of fire damage (DOFD) along the surfaces of the compartment and contents (i.e. National Fire Protection Association, Quincy (USA), Ngu C (2004) Calcination of Gypsum Plasterboard under Fire Exposure. The second part isolates the work conducted on identifying fire patterns and the characteristics associated with these trends within the damage. Every fire investigation text, including NFPA 921, uses shapes to describe the characteristics of the lines of demarcation associated with plume-generated patterns. Consequently, the forensic scientist must interpret and present the significance of the evidence to the court of law (Taroni et al. National Fire Protection Association, Quincy (USA), NFPA (2001) NFPA 921-Guide for Fire and Explosion Investigation. The importance of fire patterns is clearly reiterated in Section 6.1.1 by stating the major objective of any fire scene examination is to collect data as required by the scientific method. Given these findings, damage cues 1, 2 and 4 are used as the most accurate damage cues for classifying a fire pattern generated by ventilation. 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). 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. It can be argued that this study was the nearest any of the methods have come to being testing for reliability or validity (Fig. In addition, they may not know where or how to obtain additional information, or how to judge the value of the information in the context of the overall decision. These photographs and annotations are provided to illustrate the burn pattern indicated. If the burning fuel package was located at or very near the vertical witness surface, then the expected fire pattern is shaped as a V, evidenced by its angulated lines of demarcation. 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). 2006; Hicks et al. 1997; NFPA 2014; Gorbett et al. Mann and Putaansuu (2010) exposed samples of gypsum wallboard to three levels of heat flux for three different durations and noted visible changes, as well as depth of calcination changes with a variety of probing instruments. 4. Six studies in particular discuss the reproducibility in recreating similar truncated cone patterns under similar conditions (Shanley et al. Saito (1993); Williamson, et al. 2013) (Fig. Several researchers supported this analysis but questioned the practical application of such a method (Schroeder 1999; Kennedy et al. et al. 2003). However, if the fire pattern is incorrectly assigned as a plume generated pattern, then the entire origin hypothesis will most likely be incorrect (Carman 2008). predominantly fuel-controlled or ventilation-controlled) produce substantially lower temperatures. 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