Reading the fire with Vatra Dornei’s firefighters
I have, like any person, a normal fear of fire, so the idea of entering a closed room where a fire is burning raised my pulse. It was an experience that made me respect more the work the firefighters do and understand the effort and risks assumed each day by these people so they can be better prepared when they are needed.
Those who welcomed me into their team and taught me the secrets of fire were the firefighters from Vatra Dornei Fire Department, whom I accompanied during their everyday training.
The day started with a preparatory technical meeting, a daily routine which aims to show to all the personnel of the subunit exactly how a fire manifests itself, the phases it goes through, from the initiation phase to the widespread burning and all the other phenomena occurring during the fire. The information is used primarily for the personal protection of the firefighters, and also to better fight the fire. The theoretical part is followed by the practical study conducted in the fire study room, where the entire evolution of a fire is recreated, from initiation to regression.
Together with the team that I accompanied during the day, I attended the technical meeting, where the plan of the fire study room was presented. The locations of the materials to be burned were presented, also the places of each firefighter, or, in my case, journalist. One at a time, the place, role, and actions of each serviceman were explained, and also of those offering support, like secondary teams and SMURD (paramedics). Given the fact that several objects were placed at different distances from the fire, so we can see all the phenomena occurring during the fire, their places were also marked.
Once the presentation of all the objects and personnel inside the fire study room was concluded, the explanation of the rules to be followed by all the participants at the exercise started. As I saw later on the field, during the training session, only one person gives the commands, the leader on the training session. Everyone has to listen to him and no one on the field commands over him. Were explained to me the commands used during the exercise, how to move inside the fire study room, the communication methods between the members of the team, and how to react to different situations, different types of teams participating in the intervention and the evolution stages on the fire, that we were to encounter in the fire room.
After completing the theoretical part, we started the practical part, which for me began with donning the protective suit and the rest of the equipment consisting of a mask and oxygen tube and helmet. Once in the fire room, I could see all the stages that were presented to me in the theoretical session. After initiating the fire, the next step that I could see was vaporization that occurs at around 100° C, when water contained in any material vaporizes. I could see after that the layering the smoke, which, from the top of the room, started to descend, arranging itself in layers and stabilizing at a height of 80 cm from the ground, called neutral zone, where the best visibility is.
Pyrolysis or decomposition of the material into gas was the next phenomenon that I have seen, which occurs around the temperature of 200o C when the materials break down into gases. These gases create the next phenomenon, flame over, also known as angels of fire. At around 400° C temperature, the gases from the pyrolysis arose and start lighting up and I could see on the ceiling as tongues of fire appeared. The flames grew in intensity and began to unite, to blend together, coming up above us, appearing in the form of waves of fire, a phenomenon known as rollover, and a stage of a fire that firefighters studying very carefully.
This is the last step before the most dangerous phenomenon of a fire, the flashover, which is the transition from the localized burning to the general one when the whole room catches fire and the room is engulfed in flames. The phenomenon occurs at temperatures above 600º C. Because the transition from rollover to flash over is very short, ranging between 5 and 15 seconds, knowing each phenomenon is very important, and firefighters can anticipate these steps by “reading the fire”. For that, firefighters must take into account five elements.
The first thing the firefighters notice when they arrive at a fire is the smoke, by its color they can know how much it’s loaded with unburned gas, of pyrolysis, which provides information about the amount of fuel inside the fire and the degree of risk to which the firefighters expose themselves. Another thing the firefighters learn to read is the color of the fire, indicating the level of oxygen and temperature of the fire. They also look after the number of openings (windows, doors) and their location, and the firefighters will try not to create new openings during the intervention to don’t supply the fire with oxygen. Another element to consider is the heat, which can be determined according to the stages in which the fire is and specific phenomena observed. Another indicator is the sound, each fire is accompanied by a series of sounds, such as cracking, which indicates the degree of danger.
By reading these elements firefighters can predict the stage in which the fire is and plan ahead for its extinction. For example, if the firefighters reach the fire at the stage of flame over they can intervene offensive by starting the attack on the fire to put it down. If they have reached the stage of rollover they will act defensively, with more cautious, acting with water jets to cool down the fire and respecting more safety features.
In addition to preparing for interventions to fight a fire, the firefighters prepare for other types of interventions that they are called at, the most common being the rescue of persons (and of various animals) fallen in wells and other confined spaces. The rescue teams work in three teams of two men each – one coordinating team consisting of a rescuer and the coordinating firefighter (that coordinates all the teams participating in the intervention and whose commands are obeyed by all participants), and two teams for lowering and retrieving the rescuer and the victim.
Also during the daily training, the firefighter exercise how to save themselves in cases of fires in tall buildings, when the stairwell is collapsed or filled with smoke, and the only way out is through a window. Using ropes and harnesses, that each firefighter carries, they have to rescue themselves and help their colleagues. They practice rappelling, rope recovery, and the funicular descent technique that is used in interventions where the victims cannot be evacuated using the stairs.
In addition to firefighting training, the firemen also have a daily routine of physical training, meant to increase their capacity to cope with long-term interventions, especially when using a breathing apparatus in order to dose the effort and use an oxygen tank as long as possible.
