Fire Officer Handbook of Tactics Part 2 Flashcards
Basic components for CAFS
-foam concentrate supply-injection device (Class A 0.3-0.6%, Class B 3-6%)-source of compressed air to inject into solution
Claims have been made that a CAFS stream can knock down a fire in ___ the time of a conventional hoseline using only ___ the water
1/41/3
Current disadvantages of CAFS
fairly complex system that requires maintenance-not seen as cost effective-reliability of components
Can be used to extinguish gasoline truck fire from greater safety
Bent applicator - supplied with AFFF or using dry chem from an extinguisher after removing the fog head
Characteristic of AFFF that makes it ideal for fighting gasoline truck fires as opposed to protein foam
does not require a great deal of aeration so less splashing than high velocity types
An innovative way to fight fires involving the undercarriages of many of the heavier motor vehicles
using a bent applicator
Uses for the piercing applicator (3)
car fires (hood/trunk), cockloft, deep-seated fires in baled materials
Putting the proper size hoseline at the required place in the least possible time with the most efficient use of personnel is the job of the
engine company
Even a flimsy hollow-core wooden door has some containment value if
it is closed
A unit that only responds to single-story homes built on slabs will probably be able to use ___ hose to good advantage, while units that face larger homes and those with basements or cellars may require ___
1 ½-in1 ¾- or 2-in hose
Ensuring that the proper volume of water is available at the required location on the fireground
Water supply
1 cu ft of water weighs about ___ and is equal to about ___ gallons
62.5 lbs7.5
Fluid pressure is ___ to the surface on which it acts
perpendicular
The pressure in a confined body of water at rest is the ___
same at all points
The pressure of a fluid in an open container is ___
proportional to its depth
For every foot of height that the water rises, it exerts ___ of force. This is known as ___
.434 psihead pressure
The pressure of water in an open container is independent of the shape and volume of the container. It depends solely on ___
depth
The pressure a fluid exerts is proportional to the ___ of that fluid
density
If the intake of the pump is ___ above the surface of the liquid at any time, it will be physically impossible to draft
34 ft (33.9 ft)
Pressure on a confined fluid is transmitted ___ throughout that fluid
equally (this is why fire hose can be tested in multiple sections)
Most common resistance to water flow
friction loss - mostly caused by turbulence of the water
Low flow where there is almost no turbulence and all water molecules move along quite smoothly
laminar flow
Factors involved in supply capabilities (3)
capacity of the pump-capacity of the supply source-capacity of the hose
Items that should be known by pump operators and company/chief officers before the incident
rating of the pump-discharge characteristics of nozzles-capacity and length of hoselines-general idea of areas water supplies
Having a hydrant in front of the house does not ensure
adequate water supply
Static pressure is no indicator of the ___ of water available at a hydrant
volume
Low flowing pressure often indicates that the pumper should be placed ___. This is a good policy for all but the ___.
near the hydrant rather than near the fireinitial-arriving engine company
Minimum residual pressure that should be allowed is
10 psi except when drafting
Occurs when there isn’t enough water in the pump to supply the demand
cavitation
Two possible actions to take to keep pressure from going below 10 psi
reduce the discharge flow (not desirable)-increase the supply with another source (may not be possible)
At a house fire, ___ takes priority over ___, due to the potential life hazard and the relatively small fire area and light fire loading
speed of water deliverygpm deliverd
Inline pumping (pumping at the house vs from the hydrant) for private dwelling fires has the advantage of speed which is ideal, but still has the disadvantage that
maximum flows aren’t available
Centrifugal pumps will deliver increasingly ___ flows as the pressure is ___
lower increased
For relay pumping, the problem isn’t always best solved by a bigger pump. It might be more cost-effective to correct the___
hose size (diameter) of the water supply line
Drawback of automatic nozzles, particularly on master stream devices
Stream looks just as good at different gpm levels so you may not be delivering enough water
It would be prudent to restrict the use of 4” hose to pumpers of ___
1,000 gpm capacity or less
One of the advantages of LDH
allows for rapid deployment and return to service with minimum personnel
Using LDH to take advantage of its low friction loss is normally best accomplished by using the the hose as
an inline supply
The most versatile, most highly maneuverable master stream on the fireground today
tower ladder
One of the most common reasons for deploying a master stream
fire has extended into the cockloft
Telescoping boom vs articulating boom devices for taxpayer fires
Telescoping booms are superior since the front of the building may contain power lines
Advantages of platform (tower ladder) vs ladder pipes for (2)
-capable of flowing 1500 gpm vs 800 gpm-range of motion of the stream (most pronounced when operating stream through windows)
One easy way to take much of the difficulty out of water supply is to use ___ in conjunction with pressure gauges
flow meters
One complicating factor in the use of flow meters is
manually adjustable nozzles that allow nozzle operator to manually select a wide range of flows
Most satisfactory method to supply large flows is to use
large hose
If LDH isn’t available, the next best option is to use
multiple lines
Even more important [regarding water supply] is to understand that it is ___ that puts it out, not the pressure at which it is applied
the amount of water that is applied to the fire
