What is a marginal fire attack?
A marginal or transitional attack is used to focus tactics on saving lives. In a transitional attack, hose lines are used to protect crews for rescue support, not for fire extinguishment. The purpose is to accomplish a known rescue and get out, which may force a change in the two-in-two-out thinking mentality.
What is the difference between positive pressure attack and positive pressure ventilation?
Now, before we get too far into this article, let’s clarify the distinction between PPA and PPV: PPA is defined as using a fan to pressurize a building before the fire is knocked down, while PPV uses a fan to pressurize a building after the fire is knocked down.
What is positive pressure attack?
A Positive Pressure Attack (PPA) is a coordinated attack for fire control and/or victim rescue involving mechanical positive pressure ventilation for smoke removal before fire knockdown.
What is the goal of positive pressure ventilation fire fighting?
Positive Pressure Ventilation (PPV) is a firefighting technique that involves the use of high-powered ventilation fans to remove smoke, heat and other combustion products from a burning building so firefighters can perform tasks within the structure in a more tenable atmosphere.
What is the Charlie side?
Alpha, Bravo, Charlie, Delta – these terms are used to designate the sides of a structure. Generally speaking, the “alpha” side is the front of the structure, the “bravo” side is the left side of the structure, “charlie” is the back of the structure and “delta” is the right side of the structure.
What do firefighters call each other?
My friend, a former longtime firefighter, was in the hospital some months ago. I went to visit him when I found out he was ill, and we chatted.
How do PPV fans work?
The positive pressure (PPV) fan is the most commonly found fire service fan. It works by forcing air into a structure, creating a “higher pressure” inside the structure which forces the interior air to the “lower pressure” outside the structure through an exit portal.
What is the primary risk of using a positive pressure ventilation PPV fan in a compartment fire?
Positive pressure tactics have the ability to move fire and fire gases (this is the ventilation part). This also can cause a rapid increase in fire development. Attempt to place the ventilation opening between your firefighters and the fire or between the fire and trapped victims.
How do you set up positive pressure ventilation?
Typically, a PPV fan is placed about 1.2 m to 3.0 m (4 ft to 10 ft) outside the doorway of the structure. It is positioned so that the “cone of air” produced by the fan extends beyond the boundaries of the opening. With the doorway within the cone of air, pressure inside the structure increases.
What is a disadvantage of hydraulic ventilation?
What are disadvantages of hydraulic ventilation? 1. Increased water damage.
What are the complications of positive pressure ventilation?
Among the potential adverse physiologic effects of positive-pressure ventilation are decreased cardiac output, unintended respiratory alkalosis, increased intracranial pressure, gastric distension, and impairment of hepatic and renal function.
Why do firefighters wait to use water?
Using water is one common method to extinguish a fire. Water extinguishes a fire by cooling, which removes heat because of water’s ability to absorb massive amounts of heat as it converts to water vapor. Without heat, the fuel cannot keep the oxidizer from reducing the fuel in order to sustain the fire.