Posts Tagged ‘fire behavior’

Earlier this month the Loudoun County Department of Fire, Rescue, and Emergency Management releases a report flashover in a single family dwelling which resulted in injury to six firefighters and one EMS provider. Four firefighters received serous burn injuries, two sustained other traumatic injuries, and the EMS provider experienced minor respiratory distress. This extremely detailed report examines the multiple factors adversely influencing the sequence of events resulting in these injuries.

• Lack of supplemental information to responding companies regarding the location of the fire within the building
• Limited situational awareness based on lack of a 360^o size-up and failure to recognize key fire behavior indicators pointing to potential of a first floor fire
• Working above the fire by initiating fire attack on Floor 2, based on the assumption that this incident involved an attic fire based on fire behavior indicators visible from Side A
• Limited staffing on the first arriving units and delay in arrival of additional resources taxed the capability of the initial companies operating at the incident, negatively influencing situational awareness
• Building construction, lack of compartmentalization in the open floor plan dwelling, and significant fire load contributed to fire development and occurrence of flashover and a partial collapse on Floor 2

However, the investigation also pointed to a number of factors that positively influenced the outcome of the incident.

• Quick and appropriate response to escape from the building once conditions deteriorated and water supply was lost to the attack line
• Rapid placement of ladders to provide secondary egress from Floor 2
• Immediate acknowledgment of the Mayday and recognition of the need to abandon the building
• Completion of Mayday: Firefighter Down curriculum and Flashover training
• Stability of dimensional lumber supporting Floor 2 allowing members on the interior time to escape
• Performance of personal protective equipment, limiting the extent of injuries

The investigators took a broad based, systems approach in examining this incident. Read this report and evaluate the applicability of the lessons learned to your own organization. The next several posts will examine fire behavior, situational awareness, and tactical factors in this incident and recommendations made by the investigative panel

Ed Hartin, MS, EFO, MIFireE, CFO

While fire investigators are the target audience for this course, it provides a good overall look at the influence of ventilation on fire behavior regardless of your interest in compartment fire behavior. The instructional presentation is particularly strong in its examination of building and environmental factors (e.g., wind and temperature differential effects), drawing heavily on Dr. Stefan Svensson’s text Fire Ventilation.

While solid in its examination of influences on ventilation, this course fails to adequately address the influence of unplanned and tactical ventilation on fire behavior. The course outlines potential positive effects of tactical ventilation, but discussion of potential for ventilation induced extreme fire behavior is limited to a brief mention of potential for backdraft in ventilation controlled conditions. In addition, there was no discussion of the potential impact of incorrect tactical ventilation such as establishment of positive pressure with no outlet or inadequate outlet area or failure to coordinate tactical ventilation with fire control. These issues are of more immediate concern to firefighters than investigators, the potential influence on fire behavior (and subsequent investigation) may be significant. A more detailed discussion of fuel and ventilation controlled burning regime and the potential influence of ventilation under each of these conditions would be a useful addition.

The use of multiple choice questions in the mid course and final assessment was generally effective in checking learner comprehension of the concepts presented. However, there were a few problems with the two assessment instruments. The mid-course assessment included one question addressing a topic covered in the second segment of the course. In the final assessment there were two true-false questions in which both answers are arguably correct (although it was fairly easy to discern which answer was “correct” based on course content. In addition, there were a number of questions in the final assessment that would accurately assess learner understanding if worded differently.

Overall, this is a worthwhile training program for compartment fire behavior instructors and others interested in compartment fire behavior. However, as always you should maintain a critical perspective. This training program is offered (free) at http://www.cfitrainer.net

Ed Hartin, MS, EFO, MIFireE, CFO