Volume I, National Bureau of Standards, NBSIR 802054, Gaithersburg, MD, Raiffa H (1968) Decision Analysis. The walls and ceiling were lined with gypsum wallboard. 2003). 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. 12). The concept of fire patterns for this review has been broken into four components that better assist in evaluating their effectiveness in determining an area of origin. Photograph of a Conical-Shaped Fire Pattern along a concrete block wall (fire origin was located under the stack of wooden pallets-fire test conducted at EKU by author). Babrauskas (2005) lists several unpublished tests of holes through wood floors and provides a summary of these tests. increases. Paper presented at the International Symposium on Fire Investigations. They found that that floor patterns caused by ignitable liquids might be minimal because they can easily be destroyed and because the short duration of exposure due to fuel consumption. The greater the distance between the base of the plume and the surface of the wall or content surface will result in a substantially decreased heat flux to the surface (Qian and Saito 1992). Another series of full-scale fire tests was conducted with funding provided by the National Institute of Justice (Putorti 1997). The use of depth of char and relating this depth to duration of burning has fluctuated as to its usefulness in fire investigations since the mid-1950s. Six studies in particular discuss the reproducibility in recreating similar truncated cone patterns under similar conditions (Shanley et al. This damage is commonly reported as heat or smoke deposition reported to be found throughout a structure at varying heights on the walls of a room between areas of no damage and smoke or heat damage. Incident heat flux to wall, floor, or ceiling surfaces is dependent on the HRR of the fuel and standoff distance between the flame plume and the surface of interest. Magnitude refers to the degree of damage to the material. 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. Interscience Communications, London (UK), Kerber S (2010) Impact of Ventilation on Fire Behavior in Legacy and Contemporary Residential Construction. J of Forensic Sci. 1997). The compartment size, ventilation opening and setup were similar to the 2008 work. doi:10.1128/AEM.02526-07, Jowsey A (2007) Fire Imposed Heat Fluxes for Structural Analysis. As this smoke collides with cooler surfaces, it may deposit out of the heated gases onto wall, ceiling and content surfaces. Two tests were completed with television sets placed on a wood stand next to an upholstered chair. Society of Fire Protection Engineers, Technology Report 828, Heskestad G (2008) Fire Plumes, Flame Height and Air Entrainment. 2008). The most common definition of a pattern is something that happens in a regular and repeated way, combination of qualities forming consistent or characteristic arrangement and frequent or widespread incidence (Pattern 2015). The fire plume and the various heat fluxes generated by it are one of the primary means of damage production in the early stages of a fire due to this great temperature difference and highly turbulent flows. Fire patterns are the result of a fire or its. Paper presented at the Fire and Materials 2009 Conference. 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. There are a few misconceptions that have been promulgated over the years associated with V-patterns. long lines of damage appearing to spread the fire from one location to another). Smoke contains particulates, liquid aerosols and gases (NFPA 2014). 7, 8 and 9). The literature was received from different databases, primarily ScienceDirect (2012), International Symposium on Fire Investigations conference proceedings, Fire and Arson Investigator-Journal for the International Association of Arson Investigators and fire investigation textbooks. The ignition varied where four tests had a 2ft (0.61m) diameter pan of Isopropyl Alcohol (IPA) used to ignite a small electrical appliance adjacent to the television set, two tests were ignited by applying the IPA fueled fire directly to the television set and the last two non-full room involvement tests were ignited with the use of newspaper sheets under the cushion and on the floor in front of the upholstered chair. 2026 Plaza Dr. PO Box 8637 Benton Harbor, MI 49023 Voice: (269) 925-2200 Fax: (269) 925-2204 E-Mail: firefind@firefindings.com Fire Safety Science 10:641654, Riahi S, Beyler C, Hartman J (2013) Wall smoke deposition from a hot smoke layer. Annotated by Robert A. Corry Director, Fire Investigation Specialist American Re-Insurance.Classic "V" "Inverted Cone" on a Wall "Inverted Cone" on an Object. 1997). Furthermore, this process has not been widely tested for reliability or validity. The bulk of this research can be found within the SFPE Engineering Guide, Assessing Flame Radiation to External Targets from Pool Fires (SFPE 1999). For example, an investigator would assign a number 5 char level to a piece of wood that had the number of cracks occurring up to 2 per centimeter with widths approximately the thickness of a five-cent piece (Keith and Smith 1984). The damage caused by this upper layer is often times referred to as hot gas layer-generated fire patterns or heat and smoke horizons (NFPA 2014; DeHaan and Icove 2011), but in this work it will be described as upper layer-generated patterns (ULG patterns). National Fire Protection Association, Quincy (USA), NFPA (2002) Recommendations of the Research Advisory Council on Post-fire Analysis A White Paper. Shanley et al. Dissertation, Worcester Polytechnic Institute, Gorbett G, Chapdelaine W (2014) Scientific Method Use, Application and Gap Analysis for Origin Determination. 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. These tests produced the first published data that supported fire patterns as being useful in fire investigation. The average velocity of natural buoyancy driven flows or natural ventilation through the bottom of a door during ventilation-controlled conditions is approximately 1.52.0m/s (3.44.4 mph) (Kerber 2010; Quintiere and McCaffrey 1980). 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. (0.91m2.1m). as the height of the plume increases what happens to the width. Each fire was said to have only burned for 2min in full room involvement. \) This relationship points out that there are higher gas temperatures reached in the fuel-controlled burning but the duration of burning is shorter because much of the heat energy is transferred out of the room by the air/fire gas exchange (Drysdale 2011). 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. Door openings to the exterior were identified as being the most influential to damage. The fire testing conducted for fire patterns has evolved with the changing definition of the term. [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). The related lines of demarcation are ensuring that the area being called a pattern have associated boundaries or lines of demarcation. Fire patterns identified on the floor have been a common theme within fire investigation as being a possible indicator that flammable or combustible liquids were used within the fire (Smith 1983; Beyler 2009). Dissertation, The University of Edinburgh, Kahneman D, Tversky A (1974) Judgment under uncertainty: heuristics and biases. Hicks et al. Therefore, the walls, ceiling and floor surfaces are now receiving an elevated heat flux, in addition to the already burning fuel receiving greater feedback, increasing its own HRR and other fuels becoming involved. Secondly, these patterns are often used as a means to show direction of smoke and heat travel. It was not until 2008 that NFPA 921 changed the definition of the term with the introduction of the term fire effects. 2003). 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. 1985). Scene photograph of suspected ignitable liquid pour (Wood et al. Cue 3-increased magnitude of damage around opening within 2 times the opening width (2wv). This was also observed on walls opposite door openings (Shanley et al. 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). 2014). 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. Cox provided a process for better interpreting the compartment fire dynamics that is still under development and has not undergone a major field test for user application. The velocity of this air inflow also influences this mixing. Thus, the total percentage of participants choosing the correct area increased 3.9% with the inclusion of measurable data as part of the given. Many of the firefighting factors would not necessarily develop new patterns that have unique characteristics. Given the history of using fire patterns within the fire investigation profession, it was reasonable that they would also be included in the first edition (1992), and all subsequent editions of NFPA 921 Guide for Fire and Explosion Investigations. In 2005 and 2008, three studies were completed in conjunction with a training seminar to analyze burn pattern development in post-flashover fires (Carman 2008). Gorbett, G.E., Meacham, B.J., Wood, C.B. The pin size was based on the Mealy (2013) research, which resulted in a pressure of 1175psi (0.86kg/mm2). 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. Also, the lines of demarcation are not parallel to the floor or ceiling, but are at an angle representing the buoyant flow, usually with characteristic geometric shapes (Fig. 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. The following statistics were accumulated while performing the literature review and summarized here for ULG fire patterns. Characteristics of the damage linked with ventilation-generated patterns during ventilation-controlled conditions are large surface areas of damage, increased magnitude of damage, damage found near unsealed drywall seams and angled lines of demarcation located around the ventilation opening or directly opposite of a door opening. 1977). They appear between the affected area and adjacent, less-affected areas (NFPA 2014). Use of damage in fire investigation: a review of fire patterns analysis, research and future direction. Many plastic materials will burn. A compartment (3.7m3.7m2.4m) with a single doorway ventilation opening located in the center of a wall was used for this series of tests. As the fire continues to grow, the pattern becomes . A subset of replicate tests was also performed. Each test fire was conducted for 10min, with the door opened at 5min. American Re-Insurance. Heat related damage patterns at a fire scene yield clues as to where a fire originated. The room burns produced patterns that were both consistent with the origin as well as burn patterns and V-patterns that were inconsistent with the origin. Putorti (2001) performed a series of experiments that evaluated the damage to a variety of floor surfaces (carpet, wood and vinyl) with varying volumes of ignitable liquids used in the open. 13). Correspondence to 2009). Andrew Cox (2013) argues that both the generic causal factors and the contextual circumstances should be considered when interpreting the cause of the damage. As such, fire investigators have written about the use of visible and measurable observations related to varying damage to wood for as long as fire investigation has been in existence (Rethoret 1945). The elements of the fire pattern definition are further explained here: distinct area of damage or cluster of fire effects the area of damage must be clearly distinguishable from other areas of damage through the identification of line(s) of demarcation. Also, the study illustrated that drywall seams, if no tape and mud was applied, would present areas of clean burn damage during ventilation-controlled conditions (Mealy et al. Varying degree of fire damage to gypsum wallboard-visible damage results, Varying degree of fire damage to gypsum wallboard-contour plot of the depth of calcination results of Fig. These tests demonstrated similar findings as Carmans tests (2008) that significant heat flux and clean burn occurs on the wall directly across the room from the doorway. 2013). Several researchers supported this analysis but questioned the practical application of such a method (Schroeder 1999; Kennedy et al. They focused on under-ventilated fires, the fire growth associated with these types of fires and their forensic analysis. Contact Us: NWCG Comments & Questions | USA.GOV | Notices | Accessibility | Copyrights | Linking Policy | Records Management | FAQs, M-581, Fire Program Management Course Steering Committee, M-582, AA Advanced Wildland Fire Course Steering Committee, Committee Roles and Membership Information, Course Steering Committee Guidance & Templates, International Association of Fire Chiefs Roster, National Association of State Foresters Roster, Alternative Pathways to NWCG Qualification, Wildland Fire Leadership Development Program. 14). 2008). Next, the ability to identify clusters of damage was evaluated. CRC Press, Boca Raton (USA), Madrzykowski D, Fleischmann C (2012) Fire Pattern Repeatability: A Study in Repeatability. The final two tests were performed after multiple television sets and electronic appliances were placed on wood stands and on the floor in a burn room containing an upholstered chair and area rugboth of these tests were allowed to progress into full-room involvement and were not extinguished until 4min past flashover (Hoffmann et al. 98 0 obj <>/Filter/FlateDecode/ID[<91F1DAB77B67D07957F283104A2F7883><83C49AA1AA664D4BAE5EBD1CBF89369B>]/Index[80 32]/Info 79 0 R/Length 87/Prev 597082/Root 81 0 R/Size 112/Type/XRef/W[1 2 1]>>stream A thermocouple tree was located at the area of origin. The first use of the term pattern was in 1969 by Kirk when discussing the normal behavior of heated gases. However, not all fire investigators have the same level of education and training, or appreciation for the interaction of the fire in its environment. debris fall down). f&dUCk|Q89Z(` RJ fire patterns); Interpreting the causal factors for the generation of the fire patterns; and. Department of Fire Protection Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA, 01609, USA, Gregory E Gorbett,Brian J Meacham,Christopher B Wood&Nicholas A Dembsey, Department of Fire Protection and Paramedicine Sciences, Fire, Arson and Explosion Investigation Program, Eastern Kentucky University, 521 Lancaster Avenue, Richmond, KY, 40475, USA, FireLink, LLC, 1501 Main Street, Suite 17, Tewksbury, MA, 01876, USA, You can also search for this author in As such, fire origin determination is largely a matter of fire pattern recognition and interpretation (NFPA 2014). 2013). Thermocouple data and total heat flux gauges were used as instrumentation for all three burns. Duxbury, California (USA), Cooke R, Ide R (1985) Principles of Fire Investigation. There are a total of 17 fire effects listed in NFPA (2014) that serve as the base list of observations for fire investigators (Table1). The most recent example of this failure resulted in the execution of Cameron Todd Willingham by the State of Texas on the basis of an investigation that relied on poor understandings of fire science and investigators that failed to acknowledge or apply the contemporaneous understanding of the limitations of fire indicators (Beyler 2009). Heat damage to the surface linings and the contents within the compartment after the fire is frequently the most readily visible and measurable. 4 2012). 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. 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. American Society of Mechanical Engineers, Heat and Mass Transfer in Fire and Combustion Systems, HTD 223:1119, Abib A, Jaluria Y (1992b) Penetrative convection in a partially open enclosure. 2004). 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). 2013; Wolfe et al. Consumption is a function of heat transfer and the material properties. Lines of demarcation are the borders defining the differences in certain heat and smoke effects of the fire on various materials. The cumulative heat exposure should be considered the leading factor in the creation of damage. 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. Fire Clues: Heat Shadows - Occur when heavy furniture shields part of a wall; can help determine the origin point. (1997)) described the phenomenon that ventilation to the room was able to change the truncated cone shape expected from the flame and fire plume by leaning or pushing of one side of the pattern away from the source of ventilation (Shanley et al. 2010). Soot deposited in rooms away from the room of origin have a fairly uniform soot deposition on all surfaces extending from floor to ceiling (Wolfe et al. Investigations Institute, Florida (USA), Gorbett G, Hicks W, Tinsley A, Kennedy P (2010a) Fire Patterns with Low Heat Release Rate Initial Fuels. The first component evaluated is the ability to assess the varying degree of fire damage along the surfaces of the compartment and contents. As vertical and horizontal surfaces intersect this 3-D fire plume, truncated conical shaped patterns have been shown to form (NFPA 2014). 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. 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.