As most firefighters know, choosing the turnout gear system that best matches desired performance can be complicated. Help is just a click away.
Researchers at thereleased a free software tool in June called TOGS or Turnout Gear Selector. The system helps firefighters decide which turnout gear systems to purchase based on what they need.
“Our goal was to help firefighters evaluate and select the turnout ensemble that best meets their needs,” said Hayden Brown of NIST's Building and Fire Research Laboratory.
TOGS allows the evaluation of 41 available ensembles. There are nine different outer shells, five moisture barriers, eight thermal liners and seven face cloth materials. Data on performance attributes of these ensembles are based on performance tests conducted and published by DuPont in its Internet-based EZ Spec Machine.
TOGS ranks all turnout coat and pants ensembles by their user-weighted performance test scores to identify which ensemble system has the best overall performance independent of cost. These results help departments determine which ensembles warrant a request for bids.
TOGS also helps users understand tradeoffs between performance attributes.
“For example, a better thermal protection performance score may be due to more insulation,” Hayden said. “Therefore, even though TPP is higher, such a system will be heavier and perhaps stiffer. TOGS helps the user take all tradeoffs into account when making decisions.”
In related research, firefighters also know that skin can be burned by turnout gear, even after a fire.
During the time the heated protective fabric is cooling after exposure to intense heat, fabric temperatures remain high enough to inflict burns. New research is being conducted to help equipment makers better understand the heat and moisture transfer in turnout gear and other protective clothing.
“Improving our knowledge in this area will help manufacturers design improved clothing and help firefighters understand the expected performance and limitations of their protective clothing,” said David Torvi, an assistant professor of mechanical engineering at the University of Saskatchewan in Canada.
Torvi has developed a heat-transfer model that can predict inherently flame resistant fabric temperatures and skin burn injuries during this cooling phase.
In a paper that appeared in Fire Technology in January, Torvi describes the heat transfer model, including methods used to calculate the apparent heat capacity and the convection heat transfer coefficient as the fabric cools. The new model has been validated using data from benchtop tests of Kevlar/PBI fabric specimens. Parametric studies using the model demonstrate the importance of selected thermal properties and boundary conditions on fabric temperatures and benchtop test results.
Torvi said the new feature that was added to this model is the ability to predict temperatures after an exposure to fire.
“This is especially important for firefighters as it is expected that their clothing can be heated during an exposure to fire, and that this stored heat energy in their garments can continue to heat the skin well after the exposure to fire ends,” he said.
During this work, Torvi was only able to compare the model to temperature measurements of the thin fabrics used in the outer layer of firefighters' clothing. Future work is planned to expand the model to treat the multiple-layer fabrics used in turnout gear.
While the model is intended for research purposes and to help better understand the physics of heat and moisture transfer in protective clothing, Torvi expects results to be useful to manufacturers and the fire service.
The TOGS software is available for download www2.bfrl.nist.gov/software/TOGS/.