When is it time to pull out? The old adage of 20 minutes was considered to be the norm. This is really for two reasons. The building construction for that day did not consider light weight trusses, no gang plates, no I-beam floor joists; one bottle lasts about that long. There were many reasons for the “rule of thumb”. In today’s buildings we can not operate by rules of thumb. Think about it this way…dispatched to a SFD at 2300 arrive to find light smoke showing at 2305 and place your crew into operations. Attack lines are deployed, force entry, search initiated. Locate fire in attic at 2310 and start putting water on the fire. At 2312 the roof suffers catastrophic failure pinning your crew inside. WHY? We are well within our 20 minute time frame… no one is ready for a new cylinder we are only 7 minutes into suppression activities. The time frame starts when the fire starts not when we are dispatched.
The transition from offensive to defensive is some times a tough pill to swallow. As the IC we do not want to give up the structure. This is a must… the loss of a building is a much easier call than the loss of a whole crew. As the OIC we must look for the cues that the fire building is giving us. From the exterior take notice to the message that the building is presenting. Is there brick veneer…do you have smoke or water coming out of the mortar joints? Is the roof crew yelling at you that the roof is untenable? I am going to try to use the term “spongy” with caution. Newer construction methods now build roof systems that “bounce” and newer members may confuse this to be “spongy”. Educate yourselves on the difference. From the exterior any building shift or movement is another cue to the OIC that a failure is imminent. A rapid change in the smoke conditions is another read.
From the interior of the structure officers need to pay attention as well. A partial ceiling collapse may be an indication to truss member failure. Like the roof if the interior floor is soft this is a sign of imminent collapse. As a crew working on the inside the two most dangerous situations that you can be in are working above a fire and working below a fire. We must recognize these two killers. Fire below can be identified by heavy heat, smoke, and embers coming from ground floor openings. When inside notice the construction type and know that with ordinary construction there will e fire cuts made in the joists and rafters of buildings. These are made to make the building collapse into itself and not out on the street. Again the constructions industry thinking of themselves and not of the fire service. Also in the basement or cellars of these structures often there will be a post screw support jack to aid old dilapidated support beams. We already know the effects of fire on steel.
1. Smoke/Air split in opening = fire on same level
2. Smoke doesn’t lift in large opening = fire below
3. Smoke surges then disappears = fire above
Look for the fastest smoke from the most-restrictive opening – that’s probably where the fire is.
The decision to act defensively may not be a popular one. The aggressive nature of our type A personalities tells us to never give up and a defensive posture is seen as just that… giving up. I gave it to you before: “Civilian lives are best protected from offensive positions. Fire fighter lives are best protected from defensive positions.” Like Chief Norman (FDNY ret.) says if we put the fire out the problem goes away. Nowhere does he mention from what mode this is accomplished! When we arrive and find that the conditions are advanced, wind becomes an issue, or there is a delay in the response of other companies place you and your crew in the safest position possible. I would rather pound nails in wall studs than a firefighter’s coffin.
Crews it is essential that when the order to abandon ship is given abandon ship! We can replace equipment a lot easier than we can you.
As always stay safe!