Flashcards in Aerial Chapter 3-Types And Construction Deck (31):
How is the working height of the aerial measured?
The working height is measured from the ground to the last rung at the max elevation and extension.
What is the range of fully-extended lengths (working height) of North-American made aerial ladders?
50 feet to 135 feet
NFPA 1901 defines an aerial device in three different categories. What are they?
Aerial ladders (most common)
What are IFSTA's two categories of aerial ladder apparatus?
Aerial ladder platforms
What are IFSTA's two categories of elevating platform apparatus?
Telescoping aerial platforms
Articulating aerial platforms
What is the primary function of the turntable?
To provide continuous rotation of the aerial device on a horizontal plane.
What are the main uses of aerial ladders?
Elevated master stream
Gaining access to upper floors on an emergency scene
The ladder can be mounted on what three types of vehicles?
Two-axle single chassis vehicle
Three-axle single chassis vehicle
Three-axle tractor trailer type vehicle
What is the footplate (kickplate)?
A 4 inch metal plate that runs around the bottom edge of an elevated platform to prevent the firefighter's feet from slipping off the edge of the platform.
What is the minimum jackknife angle of a tillered truck used to increase stabilization of the apparatus?
Mechanical device with a passageway that controls the flow of a liquid or gas.
Define check valve.
Automatic valve that permits liquid flow in only one direction.
Define relief valve.
Pressure control device designed to eliminate hazardous conditions resulting from excessive pressures by allowing this pressure to bypass the intake side of the pump.
Define counterbalance valve.
Valves designed to prevent unintentional or undesirable motion of an aerial device from position.
What is the normal range of hydraulic pressure?
850 psi to 3,000 psi
What is a trunnion?
In a hydraulic cylinder, the pivoting end of the piston rod that is connected to the anchor ear by the heel pin.
Describe the auxiliary hydraulic pump.
Usually a 12-volt DC, electrically operated pump connected to the battery. Used when there is a loss of main engine power. Should only be used to bed the ladder. Should be used only intermittently because it can overheat. One minute on, one minute off.
Hoisting cylinders are equipped with what to lock and hold oil in the cylinder in the event of a leak or blowout?
Integral safety valves or integral control valves
How can the ladder be lowered in the event of a leak or hydraulic blowout?
Manually by bleeding the pressure from the cylinder through a bleed-down valve.
What are the extension and retraction cables made of?
Usually corrosion-resistant aircraft quality cables made with a very high strength steel called plow steel. The are resistant to abrasion.
The ladder control levers on the control pedestal should be in what order (from left to right)?
Extension, rotation, elevation
What are the two types of pre-piped aerial waterways
Bed ladder systems: one non-telescoping pipe attached to the bed section
Telescoping waterway: extends directly to the tip of the fly section. The piping that goes through the turntable is equipped with a continuous swivel joint that allows 360 degree rotation while flowing water. Capable of flows up to 1000 gpm.
When using a detachable ladder pipe system, how should it be secured to the ladder?
It should be in the center of the ladder to avoid unnecessary torsional stress and should be secured at a minimum of two or three locations on the ladder.
Elevating platforms generally have a higher load capacity than aerial ladders. The max flow capacity is generally what for a platform?
2000 gpm rather than 1000 gpm for a ladder
In addition to master streams, water towers may also have a piercing nozzle. What type of stream does it deliver and at what gpm?
Broken stream at up to 300 gpm
What is the most common type of electric cord reel cord on an aerial apparatus?
12-gauge, 3- wire type
They must be adequately insulated, contain a ground wire, be waterproof, and have no exposed wires.
When is a junction box used?
When multiple connections are needed.
What are the four possible power sources for extrication equipment?
Two or four-cycle gas engines
Apparatus mounted PTO systems
What is loss control?
The practice of minimizing damage and providing customer service through effective mitigation and recovery efforts before, during, and after an incident.
What is the required minimum floor area of the aerial platform?
14 square feet