Joke Time…


The boss of a big company needed to call one of his employees about an urgent problem with one of the main computers.

 

He dialed the employee’s home phone number and was greeted with a child’s whispered on the first ring, “Hello?”

 

Feeling put out at the inconvenience of having to talk to a youngster the boss asked, “Is your Daddy home?”

 

“Yes.”, whispered the small voice.

 

“May I talk with him?” the man asked.

 

To the surprise of the boss, the small voice whispered, “No.”

 

Wanting to talk with an adult, the boss asked, “Is your Mommy there?”

 

“Yes.” came the answer.

 

“May I talk with her?”

 

Again the small voice whispered, “No”

 

Knowing that it was not likely that a young child would be left home alone, the boss decided he would just leave a message with the person who should be there watching over the child.

 

“Is there any one there besides you?” the boss asked the child.

 

“Yes”, whispered the child, “A policeman.”

 

Wondering what a cop would be doing at his employee’s home, the boss asked, “May I speak with the policeman?”

 

“No, he’s busy” whispered the child.

 

“Busy doing what?” asked the boss.

 

“Talking to Daddy and Mommy and the Fireman” came the whispered answer.  

 

Growing concerned and even worried as he heard what sounded like a helicopter through the ear piece on the phone the boss asked, “What is that noise?”

 

“A hello-copper.”, answered the whispering voice.

 

“What is going on there?”, asked the boss, now alarmed.

 

In an awed whispering voice the child answered, “The search team just landed the hello-copper!”

 

Alarmed, concerned and more than just a little frustrated the boss asked, “Why are they there?”

 

Still whispering, the young voice replied along with a muffled giggle, “They’re looking for me!”

Open air fire…


For fires in the open, the seat of the fire is sprayed with a straight spray: the cooling effect immediately follows the “asphyxia” by vapor, and reduces the amount of water required.  A straight spray is used so the water arrives massively to the seat without being vaporized before.  A strong spray may also have a mechanical effect: it can disperse the combustible product and thus prevent the fire from starting again.


The fire is always fed with air, but the risk to people is limited as they can move away, except in the case of wildfires or bushfires where they can be surrounded by the flames.  But there might be a big risk of expansion.


Spray is aimed at a surface, or object: for this reason, the strategy is sometimes called two-dimensional attack or 2D attack.


It might be necessary to protect specific items (house, gas tank) against infrared radiation, and thus to use a diffused spray between the fire and the object.


Breathing apparatus is often required as there is still the risk of breathing in smoke or poisonous gases.

Use of water…


Often, the main way to extinguish a fire is to spray with water. The water has two roles:

  • in contact with the fire, it vaporizes, and this vapour displaces the oxygen (the volume of water vapour is 1,700 times greater than liquid water); leaving the fire with not enough combustive agent to continue, and it dies out;
  • the vaporization of water absorbs the heat; it cools the smoke, air, walls, objects in the room, etc., that could act as further fuel, and thus prevents one of the means that fires grow, which is by “jumping” to nearby heat/fuel sources to start new fires, which then combine.

 

The extinction is thus a combination of “asphyxia” and cooling. The flame itself is suppressed by asphyxia, but the cooling is the most important element to master a fire in a closed area.


Water may be accessed by pressurized fire hydrant, pumped from water sources such as lakes or rivers, delivered by tanker truck, or dropped from aircraft tankers in fighting forest fires.

Suppressing the fuel and the energy…


The first method is to remove fuel for the fire by, for example, cutting off the domestic gas supply and moving combustible objects from the path of the fire.  When the activation energy is still present, it is also useful to switch it off; this will not stop a fire, but will help in controlling a starting fire and will prevent a new fire from occurring.


The first action is thus to cut off the domestic gas and electricity, and switch off working machines (motors).  It is also important to turn off ventilation and air conditioning, as they supply oxygen which supports combustion and can dangerously change the behavior of the fire.

Reconnaissance and reading a fire…


The first step of fire operations is a reconnaissance to search for the origin of the fire (which may not be obvious for an indoor fire, especially when there are no witnesses), and spot the specific risks and the possible casualties.  Any fire occurring outside may not require reconnaissance; on the other hand, a fire in a cellar or an underground car park with only a few centimeters of visibility may require a long reconnaissance to spot the seat of the fire.


The “reading” of the fire is the analysis by the firefighters of the forewarnings of a thermal accident (flashover, backdraft, smoke explosion), which is performed during the reconnaissance and the fire suppression maneuvers. The main signs are:

 

·        hot zones, which can be detected with a gloved hand, especially by touching a door before opening it;

 

·        the presence of soot on the windows, which usually means that combustion is incomplete and thus there is a lack of air;

 

·        smoke goes in and out from the door frame, as if the fire breathes, which usually means a lack of air to support combustion;

 

·        spraying water on the ceiling with a short pulse of a diffused spray (e.g. cone with an opening angle of 60°) to test the heat of the smoke;

 

o       when the temperature is moderate, the water falls down in drops with a sound of rain;

o       when the temperature is high, it vaporises with a hiss.

 

Ideally, part of reconnaissance is to consult an existing Preplan for the building.  This would provide knowledge of existing structures, fire fighter hazards, and can include strategies and tactics.