Firefighter I · NFPA 1010 6.3.7, 6.3.8, 6.3.10, 6.3.19
Fire streams & fire attack for Firefighter I
Four Firefighter I JPRs end with water on a fire: an interior structure fire (6.3.10), a passenger vehicle (6.3.7), stacked or piled Class A materials outdoors (6.3.8) and a ground cover fire (6.3.19). They share one body of knowledge, what a nozzle does at a given pressure and how to tell that the stream is working.
Smooth-bore (solid stream): 50 psi on a handline, 80 psi on a master stream.
Fog: 100 psi on a handline or master stream; 50–75 psi for a low-pressure fog handline. Fog nozzles come with fixed, manually adjustable or automatic (constant-pressure) flow.
Broken stream (piercing and cellar nozzles): pressure depends on the design.
The same outline sorts streams by flow: low-volume under 40 gpm, handline 40 to 350 gpm, master stream over 350 gpm.
What interior attack (6.3.10) asks for
Stream principles: pressure, friction loss, elevation loss and gain, vaporization and the heat water absorbs, water hammer.
Nozzles: solid, fog and broken-stream designs, operating valves (ball, slide, rotary), reach, nozzle reaction and the air a stream pulls along with it.
Advancing lines: into a structure, up and down stairways, from a standpipe and up a ladder.
Reading the result: changes in smoke, heat and flame after a direct, indirect or combination attack, and the T, Z and O patterns.
Attack lines and teams: line sizes from 1½ to 3 inches, the backup team, attack at grade, above grade and below grade, and coordination with ventilation.
Hidden fire: opening walls, floors and ceilings to find what is still burning.
Vehicles, outdoor piles and ground cover
Passenger vehicles (6.3.7): approach uphill and upwind, at about a 45-degree angle to the car. Alternative fuels on the outline include E85, compressed and liquefied gases, high-voltage electric systems, fuel cells, biofuels and hydrogen. Energy-absorbing bumpers, gas struts on hoods and hatches, airbag systems and batteries are the hazards named; locked compartments must be opened and every one overhauled.
Stacked and piled materials, small outbuildings, containers (6.3.8): water adds weight, piles can shift or fall, and complete extinguishment is slow. Lines range from booster or reel lines up to 2½ inches, and signs of the area of origin and of arson are preserved for investigators.
Ground cover (6.3.19): know the parts of the fire (origin, head, heel, flanks, fingers, spot fires, islands, pockets, the green and the black, the perimeter) and the safety rules taught with it: the Ten Standard Firefighting Orders, the Eighteen Watch Out Situations and LCES.
Where foam fits at Firefighter I
At Firefighter I, foam appears in one place: 6.3.8, as an agent on stacked and piled Class A materials, where it smothers by blanketing, cools, and lowers the surface tension of water so it soaks in. Choosing a concentrate for an ignitable-liquid fire, proportioning it and keeping a foam blanket on the fuel is a Firefighter II task (7.3.1 in the TCFP outline).
Fire attack errors candidates repeat
Snapping a nozzle shut. Closing a valve fast sends a pressure surge back through the hose and pump; 6.3.10 names preventing water hammer as a required skill.
Ignoring nozzle reaction. More pressure and more flow push back harder, and a line that gets away from its crew is a hazard of its own.
Treating the fire as finished at knockdown. Hidden fire in walls and floors is part of 6.3.10 itself, and overhaul continues in salvage and overhaul.
Getting water to the nozzle, from hydrant to hose lay, is on hose and water supply. The fire stages and warning events to watch for during attack are on fire behavior.
Which stream types should a Firefighter I candidate know?
Solid streams from smooth-bore nozzles, fog streams from fog nozzles, and broken streams from piercing or cellar nozzles. A fog nozzle can also be set to a straight stream, which is one of its patterns, not a solid stream.