The Engine Company is beginning to push their 1 ? handline down the hallway of a 2 story raised-ranch style house. The nozzle man is working the nozzle across the ceiling to push back the heat, smoke and unburned gases. He then lowers the nozzle to the floor to sweep it prior to moving further down the hall. He doesn't notice the lack of any stream impact noise as he moves the tip back and forth across the floor. As the nozzle team begins to move forward the rest of the burnt out floor collapses plunging the 2 firefighters into the basement.
When advancing a hose line in areas with little or no visibility we must rely on our other senses to help guide us. The one sense that fire and smoke will not totally distort is our sense of hearing. We need to listen to what is happening around us to gain information and direction. Under most situations a lot of information can be gained by listening to the water and how it reacts to the building and also how the building reacts to the water.
The most common incident the fire service deals with is the occupied private dwelling fire. This type fire can be very dangerous and actually kills more firefighters than any other type of fire we encounter. Private dwellings are normally constructed entirely from wood and can sustain heavy fire damage quite early in the fire. We must listen to the water throughout the attack for the subtle indicators that can alert us to this type damage.
While moving down a hallway, we should sweep the floor ahead of the nozzle team, listen to the water as it impacts the floor, as it will provide vital information. The lack of any impact noise could mean that the floor ahead is burned through. This would mean that the remaining floor joists around the burned through area are also heavily damaged. This is also true for stairways, if you find a stairway in a heavily damage area it is a good idea to sweep them with the stream to assure they are there and usable.
The lack of floor level impact noise could also indicate an open stairway down or even a shaftway. If you encounter the opposite, an increase in the impact noise while sweeping the floor, this situation too will give information useful to the nozzle team. An increase in impact volume can be a person lying in the hall or large a large amount of debris or junk. It can be the end of the hall, which means you will have to look for a doorway or some other type opening to continue. An increase in impact noise and a large amount of water splash back, could actually mean you have advanced into a closet, which seems so much bigger in smoke.
Once the floor has been swept the hose line must be returned to he ceiling to continue moving. The lack of any impact noise at ceiling level could mean an extremely high ceiling or a cathedral ceiling, which would dictate a much slower advance. This may also indicate that the ceilings are already down, which can be verified by the amount of debris encountered on the floor. If it is verified that the ceilings are down you should assume that the fire has been able to enter the attic space.
When hitting fire at chest or head level the sound of breaking glass would mean that you are out of the hall and actually in a room. If the impact noise alternates from hitting something to lack of noise then back again and continues that way you are probably encountering a bank of windows. By counting each time there is a lack of noise it could give you an idea of the size of the room your in. The absence of impact noise at this level could also mean a doorway or some other type opening. When encountering any of these situations we must be ready to react to each one accordingly by either slowing our rate of advance or changing our direction.