| Popis: |
Firefighters routinely conduct live fire training in an effort to prepare themselves for the challenges of the fire ground. While conducting realistic live fire training is important, it also carries inherent risks. This is highlighted by several live fire training incidents in which an inappropriate fuel load contributed to the death of participants. NFPA 1403: Standard on Live Fire Training Evolutions was first established in response to a live fire training incident in which several firefighters died. Among the stipulations in NFPA 1403 is that the fuel load shall be composed of wood-based fuels. The challenge of balancing safety with fidelity has led instructors to explore a variety of different methods to create more realistic training conditions. A series of experiments was conducted in order to characterize common training fuels, compare these training fuels to furnishings, and examine the performance of these training fuels in a metal container prop. Heat release rate (HRR) characterization of training fuels indicated that wood-based training fuels had a constant effective heat of combustion. Depending on the method used, this value was between 13.6 and 13.9 MJ/kg. This indicates that, even in engineered wood products, wood is the primary material responsible for combustion. In order to further explore the conclusions from the HRR testing, additional experiments were conducted in an L-shaped metal training prop. The results of these experiments highlighted a number of considerations for firefighter training. Thermal conditions consistent with “realistic fires” could be produced using NFPA 1403 compliant fuels, and in fact the thermal conditions produced by larger wood-based fuel packages were more severe than those produced by fuel packages with a small amount of synthetic fuel. The fuel package used in training evolutions should reflect the training prop or building being used, the available ventilation, and the intended lesson. Fuel load weight and orientation are both important considerations when designing a fuel package. The training considerations drawn from this report will help to increase firefighters’ understanding of fire dynamics, and help instructors better understand fuel packages and the fire dynamics that they produce. |
