Not just what and how, but why!
My last post (Gas Explosions) examined flammability and ignition of fuel/air mixtures as related to gas explosions. Deflagration of a fuel/air mixture can result in a significant energy release, when confined, this results in a significant pressure increase. Pressure If a confined gas is heated, pressure will increase as indicated in Gay-Lussac’s Law. Gay-Lussac’s Law: … Read more
Extreme fire behavior can be categorized as a step event which results in a sustained increase in heat release rate or a transient event that results in a brief increase in heat release rate. Transient events involve combustion of unburned combustion and pyrolysis products. The speed of this combustion process can vary widely depending on … Read more
Two incidents recently point to the hazards presented by explosions which may occur during firefighting operations. Pittsburgh, PA On March 25, 2009, firefighters in Pittsburgh, Pennsylvania were operating at a fire in a three-story apartment building of ordinary construction when an explosion occurred on Floor 2 while WPXI was videotaping fireground operations. Watch the video … Read more
In Fire Gas Ignitions and Language & Understanding: Extreme Fire Behavior, I pointed out the ambiguity in definition of terms related to extreme fire behavior. In the structural firefighting context, the term extreme fire behavior is used to identify phenomena that result in rapid fire progression and present a significant threat to firefighters. Rapid fire … Read more
Application of the B-SAHF (Building, Smoke, Air Track, Heat, & Flame) organizing scheme for critical fire behavior indicators to photographs or video of structure fires provides an excellent opportunity to develop your knowledge of fire behavior and skill in reading the fire. This post uses a short video clip from Providence, RI to provide an … Read more
On March 24, 1994 Captain Drennan and Firefighters Young and Seidenburg of the FDNY were trapped in the stairwell of a three-story apartment building by rapid fire progression that occurred as other companies forced entry into the fire apartment on the floor below. The FDNY requested assistance from National Institute for Standards and Technology (NIST) … Read more
Fifteen years ago tomorrow, three members of the Fire Department of the City of New York (FDNY) lost their lives while conducting search in a three story apartment building located at 62 Watts Street in Manhattan. Captain Drennan and Firefighters Young and Seidenburg were trapped in a stairwell by rapid fire progression that occurred as … Read more
Language is Important Language has a substantial influence on what and how we think. “What a man cannot state he does not perfectly know, and conversely the inability to put his thoughts into words sets a boundary to his thought” (Newbolt, Bailey, Baines, Boas, Davies, Enright, et al., 1921, p. 20). While the authors of … Read more
My last post examined National Institute for Standards and Technology (NIST) tests of wind control devices to mitigate hazards presented during wind driven compartment fires (Fire Fighting Tactics Under Wind Driven Conditions). Heat release rate (HRR) data from Experiment 1 (baseline test with no wind) and Experiment 3 (wind driven) illustrates the dramatic influence of … Read more
Continuing examination of NIST’s research on Firefighting Tactics Under Wind Driven Conditions, this post looks at the results of experiments involving use of wind control devices and external water application. In my last post, I posed several questions about wind control devices to “prime the pump” regarding wind driven fires and potential applications for use … Read more