B's Flashcards 1501-2000
When do automatic snow chains lose their effectiveness?
When snow is deeper than 8 inches or when the vehicle is moving very slow or in reverse.
How much further does it take a vehicle to stop in snow or ice than dry concrete?
3 to 15 times more distance.
3 names for the ATC system for an apparatus that has tandem rear axles.
interaxle differential lock, power divider, or third differential.
Under normal operating conditions, the interaxle differential switch should be in the _____ position.
Unlocked
At what speed can an apparatus out run the siren?
50 mph
Siren projection distances
40 mph - 300 ft
60 mph - 12 ft or less
When more than one emergency vehicle is responding along the same route, units should travel at least ____ to ____ feet apart.
300 to 500 feet
Headlights should be turned ____ while responding.
ON
Warning lights combined with _______, reduce the effectiveness of the reflective trim on the firefighters protective clothing or vests.
On scene floodlights
Distance that microphones can hear sirens for preemption devices.
From a few hundred meters to 1/2 a mile.
What light system will microphone preemption devices have?
white (direction of travel) and blue (non-direction of travel) lights in each direction of travel, somewhere to the side of the regular traffic signals.
Which NFPA provides some specific direction on how driver/operator candidates should be tested?
NFPA 1002
NFPA 1451
Standard for a Fire Service Vehicle Operations Training Program
Alley dock dimensions
40 ft curb to curb
12 ft wide alley
20 ft deep
Station parking maneuver test as a substitute to the alley dock dimensions.
30 ft curb to curb
20 ft simulated apron
12 ft wide simulated garage door
The bay should be 10 ft longer than the vehicle
Number of markers and spacing for serpentine course.
At least 3 markers spaced 30 to 38 ft apart.
Which direction do you maneuver the serpentine course first?
Backwards
Confined space turn around dimensions
At least 100 ft long and 50 ft wide
What are the number of allowed direction changes for the confined space turn around?
Unlimited
What if the apparatus is small enough to complete a U-turn in the confined space turn around?
Make the dimensions smaller so backing is required
Speed for diminishing clearance maneuver.
Fast enough to require the driver to exercise quick judgement
Diminishing clearance dimensions.
75 ft long
Lane narrowing from 9 ft 6 inches to 8 ft 2 inches
Stopping dimensions for diminishing clearance.
50 feet after the last stanchion must stop within 6 inches of finish line
NFPA 1002 road test minimum elements. (9 things)
- Four left and four right turns
- A straight section of urban business or two-lane rural road at least 1 mile long
- One through intersection and two stopping intersections
- Railroad crossing
- One curve
- Limited access highway with on or off ramp and two lane changes
- A downgrade that requires downshifting or braking
- An upgrade that requires gear shift to maintain speed
- An underpass or low-clearance bridge.
Is testing a driver candidate subjective or objective?
Very subjective
Speed not to exceed when leaving the station.
10 mph
Determining the proper position for the attack pumper begins with what?
Sizing up the incident
How are later arriving units directed to location?
Based on SOPs or orders from the IC
Where to park during investigation mode?
Generally advisable to stop near the best access point into the occupancy, often the main entrance.
During “investigation” mode, where should the driver be?
Remain with the apparatus to make standpipe connections or pull attack lines and operate the pump
Considerations for apparatus positioning if fire is evident? (9 things)
- SOPs
- Method of Attack
- Exposures
- Rescue situations
- Water supply
- Wind direction
- Terrain
- Relocation potential
- Potential for building collapse (separate from the other 8)
What do you need to do if you position contrary to SOPs?
Let the incoming units know of the change
Whenever possible, attempt to position the apparatus _____ of the incident.
Upwind
Being upwind negates the need for what?
Drivers to wear SCBA
What is the one exception to positioning the apparatus uphill from the incident?
Wildland fires since the fire will spread uphill
What is the collapse zone equal to?
1.5 times the height of the building
When possible, position the apparatus at the _____ of the building.
Corners
What is the optimum position for aerial apparatus?
Corners
How far away can debris land when falling from a building?
Up to a block away from the base of the building
What should you do if debris is falling and you are unable to relocate the apparatus?
Cover with salvage covers
“Inside/Outside” method of positioning
If the building is less than five stories tall, engine companies are positioned on the side of the street closest to the building and aerial are positioned outboard of the engine.
Where should pumpers that are providing water for an elevated stream be positioned?
As close to the aerial apparatus as possible.
Pumpers will generally position _____ to the sprinkler or standpipe FDC.
As close as possible
Many departments have SOCs that require the ____ pumper to proceed directly to the FDC, others do not.
First-due
Should a pumper pumping an FDC give position priority to other apparatus?
Yes, aerials.
Which drafting sites should receive preference?
Ones accessible from a paved surface and require a minimum length of hose. Also ones that minimize the required lift.
In no case should the maximum lifts given in table 5.1 be exceeded if _____ is to be used.
Full pump capacity
At what amount of feet of lift will the pump meet its rated capacity?
10 ft
When drafting, an intake hose may be laid on a _____ to keep it off the bottom.
Ground ladder
When should an intake hose be attached to the engine when drafting?
Before the engine is in final position. After attached the engine is driven to final position.
How high should a dry hydrant used for drafting be off the ground?
15 inches
What should be the clearance around strainer used with a dry hydrant?
2 ft
Only hard intake hose that has been designed to withstand _____ should be connected to a fire hydrant
Positive pressure
Intake hose sections are commonly what length?
10-50 ft
When hooking to a hydrant do you judge the distance from the curb or hydrant?
Hydrant
If the wheels of the apparatus are turned a ___ degree angle the driver can easily adjust the distance to or from the hydrant by moving forward or backward.
45 degree
How many twists should you put in the hose if sexless couplings are not used?
2, no twists for sexless couplings
When using front or rear intake connections the vehicle should be aimed or angled in the direction of the hydrant, this angle should be…
45 degrees or less
What is one of the easiest ways to ensure the maximum possible flow through a hose?
Remove kinks
T/F The gated 2.5 inch intake connections to the fire pump can drastically limit total flow depending upon how the piping is arranged.
TRUE, a better way is to bring the lines into an LDH intake
Other names for a large diameter intake
Steamer or intake header
Define dual pumping.
When one hydrant supplies two pumpers (rarely used), position pumpers intake-to-intake
NFPA 1962
Standard for the Inspection, Care, and Use of Fire Hose, Couplings, and Nozzles and the Service Testing of Fire Hose
3 Reasons for Tandem Pumping operations (like relay pumping for a shorter distance)
- Supply high rise
- Very long hose lays
- Attack pumper is a short distance from the hydrant, but long distance from the fire
How far apart can the engines be for tandem pumping?
Up to 300 ft
How are pumpers connected when tandem pumping?
Discharge of water supply engine to intake of attack engine
T/F Wildland fire apparatus are seldom positioned in the same location for the duration of an incident
TRUE
What are the two most common functions of wildland apparatus?
- Providing structure protection
2. Making a direct attack on the fire
What is the highest priority for wildland firefighting after life safety?
Protection of structures
To facilitate a rapid exit, what should wildland apparatus do for driveways?
Back in from the last known turn around
In regards to wind, which side of a structure should a wildland apparatus be placed?
The lee side
Where should a wildland fire attack always begin?
From an anchor point that is a natural or man made barrier to protect from fire
Name some typical anchor points.
Roads, Lakes, ponds, streams, and previously burned areas
When a wildland apparatus is being operated from a stationary position, what should be deployed?
A charged 1.5 inch or 1.75 inch hose line
What is a concern when driving on the shoulders of railroad roadbeds?
Tire damage can result from the angular rock, the rock is prone to sliding, rollover, could be hit by train
When apparatus is used in a mobile attack, hose lines should be kept as _____ as possible.
Short
When a wildland fire is spreading rapidly upslope, where should the firefighters draw back to?
The flanks
Apparatus should not be driven into unburned fuels higher than the _____ without a spotter.
The bumper or running board
You should not drive the apparatus into smoke where crews are operating. If you must drive through smoke what should you do?
Sound the horn and siren intermittently, use warning and headlights, and drive slowly
What are personnel assigned to squad/rescue apparatus commonly assigned?
Extra manpower or truck company functions in the absence of an aerial apparatus
Positioning of rescue apparatus.
As close to scene as possible without blocking access to other apparatus, leave a clear exit path in case needed at a second incident
Volunteer fire officers may use their ____ as command vehicles.
Personal vehicles
Ideally, the command vehicle should be positioned near a _____ of a building so the IC is afforded ____.
Corners; a view of two sides of the building
How many cylinders do cascade systems typically have? (A range)
4 to 12 large cylinders
Where do smaller jurisdictions carry cascade systems or breathing air compressors?
Rescue apparatus or in some cases Aerial apparatus
The position of mobile air supply apparatus is much the same as ______.
Rescue vehicles
Breathing air compressors have _____ that prevent their use if the incoming air is contaminated.
Filter sensors (interlocks)
Which NFPA lists having an EMS unit on fire and hazmat incidents as a requirement.
NFPA 1500
On incidents where there are victims requiring medical intervention, the IC should establish a _______ .
Triage and treatment area
When there are no immediate medical problems to handle EMS should…
Be in standby mode and locate where firefighter rehab is being conducted
Who initiates level 2 staging?
The IC or Operations section chief when requesting additional resources
How many units needed where level 1 staging may be initiated?
2 companies or more
How far away should units stage with level 1 staging?
At least one block away
Who generally becomes the Staging Area manager?
The company officer of the first company to arrive at the staging area
The staging manager communicates the resource availability and resource needs to the ______ or the ____.
Planning section or IC
How quickly should companies be ready to respond when in Level 2 staging?
Within 3 minutes
According to the Manual of Uniform Traffic Control Devices, emergency vehicle lighting should be….
used as needed to reach the scene, but once on scene its use should be reduced as much as possible.
At least ______ lane next to the incident should be closed when operating on the highway.
ONE
Consider positioning additional apparatus ______ feet behind the shielding apparatus to act as an additional barrier.
150 to 200 feet
Departments that commonly respond to highway incidents tend to prefer…
top-mounted pump panels
Control zones are not necessarily ____ and can be ____ as the incident changes.
Static; adjusted
Decon is usually located…
Within the warm zone in the decon corridor
It may require ______ for a fully loaded train to come to a complete stop.
hundreds of yards
More than ____ percent of the calls to which most fire departments respond are emergency medical incidents.
60 percent
Apparatus positioning on EMS incidents is important from a ____ and _____ standpoint.
Tactical and safety
How much does water weigh when it is near is freezing point?
62.4 lb/cf
How much does water weigh when it is near is boiling point?
60 lb/cf
For fire protection purposes water is assumed to weigh
62.4 lb/cf or 8.3 lb/gal
As an extinguishing agent, water depends on the following: (4 things)
- Specific heat
- Latent heat of vaporizations
- Exposed surface area
- Specific gravity
How much more heat does it take to raise water one degree compared to CO2?
5 times the amount of heat
Each pound of water requires an additional _____ of additional heat to completely convert to steam.
970 BTU
How many BTUs will one gallon of water absorb to convert to steam?
9,346 Btu
How much does water expand when converted to steam?
1700 times
Adequate ventilation must be provided when making a direct or combination attack with a fog stream because…
Without ventilation there is a high possibility of steam or even fire rolling back on hose teams
3 signs of adequate application of a water fire stream into a room:
- Fire is extinguished or reduced in size
- Visibility may be maintained
- Room temperature is reduced
Water has _____ surface tension that makes it difficult to penetrate dense items.
High
First principle of pressure
Fluid pressure is perpendicular to any surface to which it acts
Second principle of pressure
Fluid pressure at a point in a fluid at rest is the same intensity in all directions
Third principle of pressure
Pressure applied to a confined fluid from without is transmitted equally in all directions
Fourth principle of pressure
The pressure of a liquid in an open vessel is proportional to its depth
Fifth principle of pressure
The pressure of a liquid in an open vessel is proportional to the density of the liquid
Sixth principle of pressure
The pressure of a liquid on the bottom of a vessel is independent of the shape of the vessel
What is a common method of measuring atmospheric pressure?
Compare the weight of the atmosphere with the weight of mercury
Absolute zero pressure is called a ______.
Perfect Vacuum
______ is stored potential energy available to force water through pipes, fittings, fire hose, and adapters.
Static pressure
Is residual pressure measured at the flowing hydrant?
No, a different hydrant than the one flowing
_____ refers to the centerline of the pump or the bottom of a static water supply source above or below ground level
Elevation
Pressure drop is of little consequence to about _____.
2,000 ft
Above sea level, atmospheric pressure decreases approximately _____.
0.5 psi for every 1,000 ft
In fire hose, the following cause friction loss: (6 things)
- Movement of water molecules against each other
- Linings in the fire hose
- Couplings
- Sharp bends
- Change in hose size or orifice by adapters
- Improper gasket size
The friction loss in old hose can be as much as ____ greater than the friction loss of new hose.
50 percent
First principle of friction loss
Friction loss varies directly with the length of pipe.
Second principle of friction loss
When hoses are the same size, friction loss varies approximately with the square of the increase in velocity of flow.
Third principle of friction loss
Friction loss varies inversely as the fifth power of the diameter of the hose
Fourth principle of friction loss
For a given flow velocity, friction loss is approximately the same, regardless of the pressure on the water.
A pressure of _____ is required to reduce a given volume of water by _____.
30,000 psi; one percent (this is why water is considered incompressible)
When the diameter of a hose _____ the area of the hose opening increases approximately ____ times.
Doubles; Four
The velocity where water velocity is so great that the agitation from friction causes a degree of turbulence.
Critical velocity
Typically hose larger than ____ cannot be used for handlines.
3 inches
When referring to water hammer, high-volume systems should be equipped with _____.
Dump valves
Who are considered experts in water supply issues?
Water department officials
T/F In cities the domestic/industrial water demand exceed that required for fire protection.
True. The opposite is true for small or rural towns.
List of ways water can be treated. (6 things)
- Coagulation
- Sedimentation
- Filtration
- Chemicals
- Bacteria
- Other organisms
To ensure sufficient water, _____ or more primary feeders should run from the source of the supply to the high risk or industrial areas of the community by 2 separate routes.
TWO
Residential water main sizes for fire hydrants and cross mains
6 inches to hydrant; 8 inches for cross mains spread not more than 600 ft apart
Business and industrial water main size recommendation
8 inches
Valves in the water system should be operated _____ to keep them in good condition.
Once a year
Valves in private fire protection systems are usually the _____ type.
Indicating
Public water distribution systems usually are equipped with ____ type valves.
Non-indicating
Common materials for underground pipes (6 things)
- Cast Iron
- Ductile iron
- Asbestos cement
- Steel
- Plastic
- Concrete
Unstable or corrosive soils usually get which type of pipe?
Steel or reinforced concrete
How is maximum daily consumption (MDC) calculated when designing a water system?
Max total water used during any 24 hour interval within a 3 year period
Max daily consumption is usually how many times the average daily consumption?
1.5 times
Peak hourly rate is normally how many times the normal hourly rate?
Two to Four times
Most commonly, private water supply systems receive their water from?
Municipal systems
4 things that a fire stream is influenced by after it leaves the nozzle and is passing through space.
Velocity, gravity, wind, and friction with air
4 things that influence the condition of the stream when it leaves the nozzle.
Operating pressure, nozzle design, nozzle adjustment, and nozzle orifice condition
T/F No nozzle is capable of delivering any other stream than for which it was designed.
TRUE, a fog nozzle can deliver a straight stream, but not a solid stream
How long is the cylinder shape at the end of a smooth bore nozzle?
one to one and one-half the diameter
Pressure for solid stream handlines.
50 psi
Pressure for solid stream master streams.
80 psi
Solid stream nozzle discharge formula in GPM.
GPM = 29.7 * d^2 * sqrt(NP) for L/min change the coefficient to 0.067
Flow from a 1-inch smooth tip at 50 psi
210 gpm
The line bounding an outward surface; the outward boundary of an object distinguished from its internal regions
Periphery
A turning or state of being turned; a turning from a straight line or given course; a bending; a deviation.
Deflection
To strike or dash about or against; clashing with a sharp collision; to come together with force
Impinge
Most constant flow nozzles use a _____.
Periphery deflected stream
Most constant flow nozzles are designed to operate at ____ psi, but some special designed nozzles can operate at ____ or ____ psi.
100 psi; 50 or 75 psi for things like high rise firefighting
Adjustable flow nozzles are usually designed to discharge the selected flow at ____ psi.
100 psi
The minimum flow setting for interior firefighting operations is _____ gpm.
95-100 gpm
Automatic nozzles are also referred to as ____. (2 things)
Constant pressure nozzles or multi purpose nozzles
The automatic nozzle serves as a ______ for the pumper as lines are opened or shut down.
Pressure regulator
High pressure fog nozzles operate at pressures up to ____.
800 psi
High pressure nozzles are best suited for fighting _____ fires.
Wildland
High pressure nozzles generally only discharge ____ gpm.
8-15 gpm
What is generally the max gpm that can be flowed through a handline?
350 gpm
What psi is a fog master stream generally operated at?
100 psi
4 basic categories for master streams
- Monitor
- Turret pipe
- Deluge set
- Elevated master stream
Difference between monitor and deluge set
With a monitor the stream direction and angle can be changed while water is being discharged
If a ladder pipe is used on an aerial up the rungs, how do you adjust horizontally?
The entire ladder must be redirected as to not put extra stress on the ladder
The power system to operate the master stream may be ____.
Electric, hydraulic, or pneumatic
Are any special nozzles, such as a cellar nozzle required to be carried per NFPA 1901?
NO
What has better reach and penetration, broken stream or fog stream nozzles?
Broken stream because they typically have bigger droplets
What is another term for a cellar nozzle?
Distributor
If a cellar nozzle is not equipped with a shutoff, an _____ should be placed at a convenient location back from the nozzle.
In-line shutoff
Can a cellar nozzle be used for an attic fire?
YES
General dimensions of a piercing nozzle.
3-6 ft long of 1.5 inch diameter pipe
The chimney nozzle is designed to be placed on the end of a _____.
Booster hose
At a nozzle pressure of 100 psi, the chimney nozzle only produces ______ gpm.
1.5 - 3 gpm
Nozzle reaction clearly illustrates ____.
Newton’s Third Law of Motion
Practical working limits for velocity of fire streams are within _____. These limiting velocities are produced by nozzle pressures that range from ____.
60-120 feet per second; 25-100 psi
In most cases, ____ psi is used as the nozzle pressure for solid stream handlines equipped with up to ____ inch nozzles.
50 psi; 1.5 inches
Nozzle pressure for handlines can be raised to ____ without becoming unmanageable.
65 psi
Fixed master streams can be operated at higher pressures up to ____ psi, if needed. But aerial master streams should only be at ____ psi for solid stream and ___ psi for fog stream so as not to damage the ladder.
100 psi max; 80 psi for solid and 100 psi for fog
Calculation for solid stream nozzle reaction. (NR in pounds)
NR = 1.57 * d^2 * NP (coeff of 0.0015 for newtons)
Rule of thumb to calculate solid stream nozzle reaction.
NR = Q/3
Calculation for fog stream nozzle reaction.
NR = 0.0505 * Q * sqrt(NP)
Rule of thumb to calculate fog stream nozzle reaction
NR = Q/2
Name the 6 ways that a driver can determine pressure loss and pump discharge pressure while on the fireground.
- Flowmeters
- Hydraulic calculators
- Pump charts
- Hand method
- Condensed Q formula
- GPM flowing
Flowmeters are particularly advantageous when supplying which type of nozzles?
Automatic nozzles
