Report - Evaluation of the Thermal Conditions and Smoke Obscuration of Live Fire Training Fuel Packages
As part of the DHS/AFG grant “Study of the Fire Service Training Environment: Safety, Fidelity, and Exposure,” FSRI conducted experiments to quantify the fire dynamics and fidelity of common training fuels. The study also compared common wood-based training fuels to innovative fuel packages and modern furnishings both in free burn and within a compartment.
The free burn cases were conducted under an oxygen consumption calorimeter to compare heat release rate (HRR) and total energy released. Below you will find an example of three pallets in a triangle configuration with a one bale of excelsior, prior to being burned in the UL Oxygen Consumption Calorimetry Laboratory.
The compartment burns were conducted in a metal container prop configured as a long hallway with a burn room at the end. The prop used for these experiments appears below.
The results of these experiments were then analyzed to provide fire service instructors with a quantitative comparison of potential fuel loads for live fire training along with considerations for improving the fire dynamics learning experience during both live fire training and fire dynamics demonstrations.
To design effective training evolutions, instructors should use these research results to compliment personal experience from both the training ground and the fire ground. Although this report covers a significant number of fuel loads to provide clarification to the efficacy of different fuels used in the fire training environment, future research is still needed to identify and analyze the effectiveness of additional training methods, both those used as interactive as well as demonstrative.
Training methods which utilize different structure types, lining materials, fuel types, as well as differing ventilation and suppression configurations may prove more or less effective than the methods evaluated in this study.
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.
The following training considerations are highlighted in this report:
- Fuel package design can take advantage of NFPA 1403 compliant fuels
- Training fuel packages do not need to be tended
- Obscuration can be increased without using synthetic fuels
- When using NFPA 1403 compliant wood based fuels, orientation and quantity are important for predicting fire size
- Select the fuel package for the intended lessons
- Wood-based training fuels can create hazardous conditions without transitioning to flashover
Abstract
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.
Research Project: Study of the Fire Service Training Environment: Safety, Fidelity, and Exposure
Report Title: Evaluation of the Thermal Conditions and Smoke Obscuration of Live Fire Training Fuel Packages
Report Authors: Jack Regan and Robin Zevotek
Download the Report: https://dx.doi.org/10.54206/102376/KARU4002
Release Date: March 21, 2019