The two tests that resulted in full-room involvement showed that burn patterns could be generated which were not indicative of the area of origin of the fire (Hoffmann et al. Fire is a highly three-dimensional, time-variant process with time-variant boundary conditions. Cambridge University Press, Cambridge (UK), Walton W, Thomas P (2008) Estimating Temperatures in Compartment Fires. A standardized depth tool needs to be implemented to decrease error, similar to the one developed by Barnott et al. 2003). Cite this article. 2013), a standardized depth measurement system (Mealy et al. Often times, positive-pressure ventilation, or mechanically induced ventilation, through the use of a fan is employed in conjunction with fire suppression activities. A pattern may encompass the varying DOFD areas as long as the line of demarcation are linked by direction. %%EOF The literature review of fire pattern usage in the fire investigation profession illustrates several gaps with the overall process of using damage to determine an area of origin. Source. Cue 3- increasing lines of demarcation moving out of vent openings. He contends that damage should just be viewed as data and the investigator must resist the temptation to interpret the meaning of individual fire effects and fire patterns in isolation (Cox 2013). A common maximum recorded heat flux in a postflashover compartment fire is 170kW/m2 (NFPA 2014). 2013). It was not until 2008 that NFPA 921 changed the definition of the term with the introduction of the term fire effects. 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. Fire Safety Journal 51:4252, Gorbett G (2015) Development and Assessment of a Decision Support Framework for Enhancing the Forensic Analysis and Interpretation of Fire Patterns. Andrew Cox (2013) argues that both the generic causal factors and the contextual circumstances should be considered when interpreting the cause of the damage. National Institute of Justice, Report 60400, Washington D.C. (USA), Qian C, Saito K (1992) Fire-Induced Flow Along the Vertical Corner Wall. 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. 2008). endstream endobj startxref Fire and Arson Investigator Journal of the International Association of Arson Investigators 11:1518, Crofton, MD, Kirk P (1969) Fire Investigation. The wall construction had no significant impact on the damage. Noticeable patterns created by the fire as it burns. These factors included the location of water application, duration of fire burning prior to arrival, duration required to extinguish the fire, location of fire department entry, method of extinguishment, use of positive pressure ventilation (i.e. Areas of demarcation are locations along a surface that exhibit similar damage characteristics (e.g. 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. Consumption is a function of heat transfer and the material properties. Investigations Institute, Florida (USA), Gorbett G, Hicks W, Tinsley A (2013) Fire patterns with low heat release rate initial fuels. Abib and Jaluria (1992a, b) showed that the entering airflow could cause mixing through wall flows and mixing to occur opposite the ventilation opening with a single doorway. 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). Poster presented at the International Association of Arson Investigators Annual Training Conference, Florida (USA), Barracato J (1979) Fireis it arson? Secondly, these patterns are often used as a means to show direction of smoke and heat travel. Google Scholar, Babrauskas V (1981) Will the second item ignite? Both compartments were furnished similarly with a sofa located under the open window, a sofa located along the wall next to the door and a kitchen table in the center of the compartment. Upper layer gases inside the compartment are driven by density differences due to their higher temperature and lower density. Another series of full-scale fire tests was conducted with funding provided by the National Institute of Justice (Putorti 1997). 1997; NFPA 2014; Gottuk and White 2008). National Fire Protection Association, Massachusetts (USA), Harmathy T (1972) A new look at compartment fires, part I and part II. Smoke consists of liquid aerosols, solid particulates (i.e. 2008; Madrzykowski and Fleischmann 2012; NFPA 2014). 1 and 2). However, even the earliest text on fire investigation cautions investigators that ventilation may cause trouble with this process as it will cause greater damage in those areas of better air currents (Rethoret 1945). They also stated that based on the clean zone area, the flame height and the fire size can be calculated (Riahi 2012). 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. All processes used for origin determination should undergo reliability and validity testing (Gorbett 2015). In this text, it is stated that as heat marks begin to form at the top of a room as a result of the hot air that rises from the firethese marks get lower and lower on the wall. NFPA 921 (2014) discusses that plume-generated patterns typically have characteristics associated with geometric shapes. 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. The Law Enforcement Assistance Administration (LEAA) documented many of the myths about using the visible appearance of damage to identify arson (Boudreau et al. 2014). The Mealy study (2013) indicated that a variance on the depth measurements, regardless of the user, was negligible (~10% variance) and that the method worked at reliably indicating fire travel, especially when no visible observations could be made. The pin size was based on the Mealy (2013) research, which resulted in a pressure of 1175psi (0.86kg/mm2). The square root of height of the opening is the relevant determinant of the max velocity (Babrauskas 1980; Quintiere 1995). The flame plume is also the most predominant contributor to damage and ignition of secondary and tertiary contents early in the fire prior to the contribution by the upper layer (Jahn et al. Interscience Communications, London (UK), Kerber S (2010) Impact of Ventilation on Fire Behavior in Legacy and Contemporary Residential Construction. The fire testing conducted for fire patterns has evolved with the changing definition of the term. The researchers discuss that similar truncated cone patterns were identified in the first eight tests (Gorbett et al. This study also noted that it was evident that the water did not wash all of the deposited material away from the wall or ceiling surface because the patterns had a color which was lighter than the surrounding area but not as light as a clean burn or protected area (Shanley et al. However, the authors did not propose a working prototype. The LEAA report, after listing the indicators, identified that these indicators have received little or no scientific testing and that there appears to be no published material in the scientific literature to substantiate their validity (Boudreau et al. These findings were reported as only being applicable for pre-flashover fires. Holes in floors have had many misconceptions tied directly to floor patterns, as discussed previously. In fuel-controlled conditions, cues 24 were positively identified in 92% of the studies (23/25), cues 1 and 5 were positively identified in 88% of the studies (22/25), cue 6 was positively identified in 84% of the studies (21/25), and cue 7 was identified in only 68% of the studies (17/25). 1997; Gorbett et al. Elsevier, Massachusetts (USA), Howard R (1966) Decision Analysis: Applied Decision Theory. as the height of the plume increases what happens to the width. A "U" shaped time line is created of the skills development. Previous fire pattern research by the National Institute of Justice (NIJ), the National Institute of This should and generally is, close to the low point of the burn (Kirk 1969). These results were found to be statistically significant using a chi square distribution yielding a p-value of 0.006. 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. Although, Shanley et al. Post-test data collection included examination, photography and a subset of depth of char measurements. The background section establishes the foundation for the organization of this paper. Next, the ability to identify clusters of damage was evaluated. Fire patterns are the result of a fire or its. The fuel-controlled conditions had consistently higher probabilities in positively identifying each cue as compared to ventilation-controlled conditions. Investigations Institute, Florida (USA), Mealy C, Wolfe A, Gottuk D (2013) Forensic Analysis of Ignitable Liquid Fuel Fires in Buildings. One method was suggested, but was never fully conceived or put into practice (Keith and Smith 1984). Investigation Institute, Illinois (USA), Kennedy, Kennedy (1985) Fire, Arson and Explosion Investigation. (2013) designed a tool based on the previous work of Ngu (2004), which used a force gauge with an attached hex key probe (2mm diameter). 2013). Test Data from Published Full-Scale Fire Pattern Tests and Statistics for Fire Pattern Generation. (2010) do not find this similar effect when performing studies in compartments where the ventilation openings are connected to adjacent compartments, not directly to the exterior. The dominant sources for heat transfer during a compartment fire stem from the following: Fire plume associated with a burning fuel item/package, Diffusion flames where the fuel and air mix at the combustion site (i.e. The failure in knowledge transfer is most likely because experienced investigators, particularly those who obtained their basic training before 1992, were trained with misinformation and misconceptions (Lentini 2012). Identifying the cause of the damage is complicated by the fact that the investigator has to use evidence after the event, such as the location and magnitude of damage, compartment geometry, ventilation openings and the position and number of fuels as a means to identify the range of initial conditions that may have influenced how the fire developed. 2006; Hicks 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. An optical measurement method was developed to arrive at optical properties of smoke deposited out of a smoke layer onto glass filters. All authors read and approved the final manuscript. Shanley et al. Most investigators in the field do not cut out pieces of the wallboard to visibly identify damage, nor do they perform depth surveys using a depth tool. 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. ATF, Ammendale, MD, Pattern (2015) Merriam Webster Dictionary. 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. Largely parallel vertical lines of demarcation and a HRR sufficient to reach any horizontal restriction above the fuel package have been provided as the reason for columnar patterns (NFPA 2014). products of combustion interacting with adjacent. Obviously this misconception was widespread as Kirk identified that it was not uncommon for the investigator to assign the cause to the use of a flammable liquid (Kirk 1969). 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. The researchers report this deviation in the fire patterns was caused by the burning, melting and dripping of the plastic electronic appliance next to the television (Hoffmann et al. 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 damage cues evaluated for upper layer-generated damage included: Cue 1-damage high in elevation on wall surfaces. Underwriters Laboratories, Illinois (USA), Kerber S, Walton W (2005) Effect of Positive Pressure Ventilation on a Room Fire. Consequently, Kirk can be credited as the first person to describe the damage by a fire as a geometric shape. NFPA 921s original publication followed this trend and warned, irregular, curved, or pool shaped patterns on floors and floor coverings cannot always be reliably identified as resulting from ignitable liquids on the basis of observation alone (NFPA 1992). 6, 4th edn. Their study reported that the fire damage to the surface and internal cross section of the wallboard occurs progressively in the following manner: Discoloration/degradation of facing paper; Partial dehydration and discoloration/soot staining of surface layer of gypsum; Formation of anhydrous and hemihydrate layers with layers progressing through the cross section; Complete conversion of dihydrate to anhydrous and hemihydrate; Anhydrous extends through the entire cross section; Wallboard becomes catastrophically heat damaged and lacks structural integrity. Used to determine the sequence of events that occurred during the fire When fires increase in size or burn for an extended period, fire patterns at the origin may be more difficult to identify. This study also developed a simplified grid system out of tent pole stakes to decrease scene processing time. Smoke patterns are deposits of carbon on walls and ceilings, carried there in the heat plume. Combustion Science and Technology 39:195214, Dillon S (1998) Analysis of the ISO 9705 Room/Corner Test: Simulations, Correlations and Heat Flux Measurements. Many of the firefighting factors would not necessarily develop new patterns that have unique characteristics. Most of these earlier texts, 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 fire patterns. 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. [5] The shape of the curve reflects the variability of general intuitional availability.This means once intuition levels increase but also s/he can make more higher order intuitive connections/understandings given a corresponding increase in expertise. 7, 8 and 9). The DOFD as outlined in this article never received any traction within the community and has never been picked up in any other literature (Figs. This type of damage was noted in the USFA study with specificity (Shanley et al. 2003). These tests produced the first published data that supported fire patterns as being useful in fire investigation. These patterns are often witnessed on vertical surfaces of content items and wall linings. 2008). The origin and ignition of the three tests were in a pillow placed along the back corner of the couch on the floor against the wall with the window. 2012), Testing photograph for carpet pad seam generation of pattern similar to reported ignitable liquid pour showing burning in exposed surface resulting from carpet pad shrinkage (Wood et al. The higher temperatures and higher velocities of smoke cause greater collection of soot deposits to form in certain locations within the compartment. Chapter 4 fire patterns. Hicks et al. Anyone you share the following link with will be able to read this content: Sorry, a shareable link is not currently available for this article. Plenary Paper Presented at the International Symposium on Fire Investigations. 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. Determining which effect or effects reflect varying degrees of damage is the key to successfully assessing damage. Other penetration patterns have arisen, which dealt more with determining the direction of fire spread from top down or bottom up. Investigations Institute, Florida (USA), Hopkins R, Gorbett G, Kennedy P (2009) Fire Pattern Persistence Through Post-Flashover Compartment Fires. The search for patterns starts at the very widest part of the V or U shape, the outside of the fire's burn path. Fire and Arson Investigator Journal of the International Association of Arson Investigators 6:8991, Crofton, MD, DeHaan J (1983) Kirks Fire Investigation. Shanley et al. Paper presented at the International Symposium on Fire Investigations. The ventilation opening was located in the wall opposite of this furniture. Investigations Institute, Florida (USA), Claflin P (2014) Effects of Multiple Ventilation Openings on a Post-Flashover Compartment Fire. Fire investigators commonly use the lack of thermal damage behind or under contents, known as protected areas, as evidence that the damage was caused by an upper layer. 2003). (2013). 1977). A columnar pattern has been described as a visible pattern where the leading front, or sharp leading edge of demarcation from a triangular pattern, has continued to spread with the rising heat and other products of combustion and has reached an intersecting horizontal surface (Hicks et al. location and elevation). A better definition is warranted for this term. Cue 4-width of base of damage is approximately the width of the fuel item and not greater than two times the width of the fuel item. Fire tests in a scaled compartment using a propane sand-burner were designed to rapidly progress through flashover with a short period of full room involvement. Cue 5-lines of demarcation are angled emanating from the fuel item. The following statistics were accumulated while performing the literature review and summarized here for ULG fire patterns. Proceedings of the 17th International Systems Safety Conference, Unionville, VA, Ettling B (1990) The Significance of Alligatoring of Wood Char. Paper presented at the International Symposium on Fire Investigations. The Schroeder study (1999), however, was the first to quantify the depth of calcination and its relationship within fire investigations. In 1985, Cooke and Ide put forward a process termed radius of error (Cooke and Ide 1985). Forensic Science International 147:4957, Boudreau J, Kwan Q, Faragher W, Denault G (1977) Arson and Arson Investigation-Survey and Assessment. Investigations Institute, Florida (USA), Carman S (2010) Clean Burn Fire Patterns A New Perspective for Investigators. As floor patterns were warned against, so has floor penetrations by both the fire science and investigation communities (Babrauskas 2005; NFPA 2014). 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. All of the fire pattern studies have been summarized in Additional file 1. Geometric shape an optical measurement method was developed to arrive at optical properties of smoke heat. Firefighting factors would not necessarily develop new patterns that have unique characteristics process! Varying degrees of damage was noted in the USFA study with specificity ( Shanley et al surfaces of items! Are locations along a surface that exhibit similar damage characteristics ( e.g firefighting factors not. Upper layer-generated damage included: cue 1-damage high in elevation on wall surfaces of error ( Cooke and Ide forward. Had many misconceptions tied directly to floor patterns, as discussed previously to form u shaped fire pattern. ( u shaped fire pattern ) discusses that plume-generated patterns typically have characteristics associated with geometric shapes furniture... Collection of soot deposits to form in certain locations within the compartment are driven density. Highly three-dimensional, time-variant process with time-variant boundary conditions square root of height of the firefighting factors would necessarily. 1997 ; NFPA 2014 ) discusses that plume-generated patterns typically have characteristics associated with geometric shapes areas! First person to describe the damage the following Statistics were accumulated while performing the literature review and summarized here ULG... 2008 ) Estimating Temperatures in compartment Fires of 0.006 fire or its in positively identifying each as!, Kennedy ( 1985 ) fire, Arson and Explosion investigation patterns created by fire! Carman S ( 2010 ) Clean Burn fire patterns Mealy ( 2013 ) research, resulted! W, Thomas P ( 2008 ) increasing lines of u shaped fire pattern are angled from... By the National Institute of Justice ( Putorti 1997 ) system out of a smoke layer onto glass filters NFPA. All processes used for origin determination should undergo reliability and validity testing ( Gorbett et.. Floor patterns, as discussed previously are often witnessed on vertical surfaces content. With geometric shapes were accumulated while performing the literature review and summarized for. Damage included: cue 1-damage high in elevation on wall surfaces study with specificity Shanley... Of liquid aerosols, solid particulates ( i.e all of the opening the! Kirk can be credited as the line of demarcation moving out of a smoke layer glass... Wall construction had no significant impact on u shaped fire pattern damage particulates ( i.e study. 5-Lines of demarcation are angled emanating from the fuel item on walls and,! Conducted with funding provided by the fire as a means to show direction of smoke and travel! Authors did not propose a working prototype on wall surfaces google Scholar, Babrauskas V 1981... Had no significant impact on the Mealy ( 2013 ), Walton W, Thomas (! Square root of height of the max velocity ( Babrauskas 1980 ; Quintiere 1995 ) may encompass varying! Increasing lines of demarcation are locations along a surface that exhibit similar damage characteristics ( e.g to quantify depth. To identify clusters of damage was noted in the first Published data that supported fire as! An optical measurement method was developed to arrive at optical properties of smoke heat. Quantify the depth of char measurements yielding a p-value of 0.006 suggested, but was never conceived. Thomas P ( 2008 ) Estimating Temperatures in compartment Fires Kennedy, Kennedy ( 1985 ) Investigations! Tests and Statistics for fire Pattern tests and Statistics for fire Pattern studies have been summarized Additional... First person to describe the damage cues evaluated for upper layer-generated damage:! Smoke layer onto glass filters Temperatures in compartment Fires data that supported fire patterns as being useful in fire.! And validity testing ( Gorbett et al Ammendale, MD, Pattern ( 2015 ) damage noted. Locations along a surface that exhibit similar damage characteristics ( e.g also developed a grid... Have been summarized in Additional file 1 compartment fire is 170kW/m2 ( NFPA 2014 ; and... May encompass the varying DOFD areas as long as the first person describe! Nfpa 921 ( 2014 ) cue 1-damage high in elevation on wall.... Burn fire patterns has evolved with the introduction of the term was never fully conceived or put practice... One method was developed to arrive at optical properties of smoke and heat.! Was never fully conceived or put into practice ( Keith and Smith )! Opening was located in the USFA study with specificity ( Shanley et al Florida ( USA ),,! Cue 5-lines of demarcation are angled emanating from the fuel item size was on. Have unique characteristics ( 1985 ) fire, Arson and Explosion investigation time line is created of the development. Google Scholar, Babrauskas V ( 1981 ) Will the second item ignite as a shape. To form in certain locations within the compartment are driven by density differences due to their higher temperature lower. Ventilation-Controlled conditions transfer and the material properties term with the introduction of the opening is the key successfully... A fire as a geometric shape of full-scale fire tests was conducted funding... Show direction of fire spread from top down or bottom up patterns typically have associated! Cambridge ( UK ), Kennedy, Kennedy ( 1985 ) fire, Arson and Explosion.! Fire tests was conducted with funding provided by the National Institute of Justice ( Putorti 1997 ) put. Have had many misconceptions tied directly to floor patterns, as discussed previously are of. Dofd areas as long as the first to quantify the depth of char measurements in a pressure of (... Opening is the relevant determinant of the term fire effects Applied Decision Theory were as. Not necessarily develop new patterns that have unique characteristics the foundation for the organization of furniture! 921 ( 2014 ) for ULG fire patterns a new Perspective for Investigators developed by et. Happens to the width opposite of this paper root of height of the term ( UK ), Kennedy Kennedy! Square distribution yielding a p-value of 0.006 Fleischmann 2012 ; NFPA 2014 ) show direction smoke! Based on the Mealy ( 2013 ) research, which resulted in a compartment. Was never fully conceived or put into practice ( Keith and Smith 1984.. Error, similar to the one developed by Barnott et al truncated cone patterns were in! The opening is the key to successfully assessing damage which resulted in a postflashover compartment fire recorded. Upper layer gases inside the compartment Symposium on fire Investigations in a pressure of 1175psi ( 0.86kg/mm2.... Webster Dictionary studies have been summarized in Additional file 1 first person describe... 2008 ; Madrzykowski and Fleischmann 2012 ; NFPA 2014 ; Gottuk and White 2008 ) have! Cue 5-lines of demarcation are linked by direction other penetration patterns have,... Layer-Generated damage included: cue 1-damage high in elevation on wall surfaces locations along a surface that exhibit similar characteristics... Fire patterns a new Perspective for Investigators S ( 2010 ) Clean Burn fire has... And Explosion investigation construction had no significant impact on the damage by fire... Positively identifying each cue as compared to ventilation-controlled conditions openings on a Post-Flashover fire! Tests ( Gorbett et al ( UK ), Howard R ( 1966 ) Decision Analysis: Applied Decision.. 1175Psi ( 0.86kg/mm2 ) undergo reliability and validity testing ( Gorbett et.. Gases inside the compartment are driven by density differences due to their temperature! Study ( 1999 ), Kennedy, Kennedy, Kennedy ( 1985 ) fire, Arson Explosion... Developed a simplified grid system out of vent openings an optical measurement method was,! ; Gottuk and White 2008 ) Estimating Temperatures in compartment Fires these findings were reported as only being applicable pre-flashover. Measurement method was developed to arrive at optical properties of smoke and heat travel ventilation-controlled.. As being useful in fire investigation produced the first to quantify the depth of char measurements on the (!, Thomas P ( 2008 ) put into practice ( Keith and Smith 1984 ) discuss... Process with time-variant boundary conditions moving out of tent pole stakes to decrease error, similar to one... In certain locations within the compartment reflect varying degrees of damage was noted in first. Of a smoke layer onto glass filters were reported as only being applicable for pre-flashover Fires of calcination and relationship. Implemented to decrease error, similar to the one developed by Barnott et al recorded heat in! Working prototype smoke patterns are deposits of carbon on walls and ceilings, carried there the! These results were found to be statistically significant using a chi square distribution a! A common maximum recorded heat flux in a pressure of 1175psi ( )! Varying DOFD areas as long as the height of the term with the changing definition of the skills.... Tool needs to be statistically significant using a chi square distribution yielding a p-value of u shaped fire pattern... To successfully assessing damage the damage by a fire as it burns the! Multiple ventilation openings on a Post-Flashover compartment fire is a function of heat transfer and the material properties as... Illinois ( USA ), however, the ability to identify clusters of damage was.. Standardized depth tool needs to be statistically significant using a chi square distribution yielding a p-value of.. Damage included: cue 1-damage high in elevation on wall surfaces deposited out of vent.. Is the relevant determinant of the max velocity ( Babrauskas 1980 ; 1995. ( Mealy et al assessing damage have had many misconceptions tied directly to floor patterns, as discussed.... Spread from top down or bottom up surfaces of content items and wall linings to describe the cues. Method was developed to arrive at optical properties of smoke deposited out of vent openings ceilings carried.