Chapter 16 Flashcards
Chapter 16
All aerial apparatus should meet the design requirements of?
NFPA 1901
The two most common materials for construction of aerial ladders are
Heat-treated aluminum alloy and steel
aerial ladders designed and built with?
K-bracing
An aerial apparatus is unique because it is
Equipped with one of several varieties of aerial devices
The three main portion of an aerial ladder to which most firefighters and drivers are commonly refers to are
1•base rails(beams)
2•top rails(handrails)
3•rungs
A device that transfers the center of gravity of an apparatus and prevented from tipping as the aerial device
Stabilizer
The function of the hydraulic system is to provide power for operating
Various hydraulic components needed to stabilize the apparatus and operate the aerial device
Hydraulic system has four main components
1• actuators: Transformers power into
mechanical force
2• Hydraulic fluid: The medium by which the
system transmits force
3• hydraulic pump: power by a PTO
arrangement off the
vehicle’s main engine
4•Hydraulic reservoir: supplies the hydraulic
fluid that move in and
out of the system
one of the most important valves is the _____
SELECTOR VALVE
One of the most important valve in the system is the
Selector valve also known as the transfer or diverter.
By blocking the flow to the system that in use
Selector valve act as an interlock to prevent stabilization and aerial device systems from operating at the same time
Hydraulic cylinder use for elevation and telescopic control of the aerial device and for operating to stabilizers are
Double acting
Double acting cylinders are capable of receiving oil under pressure from both sides of the piston
So that force can be created in either direction
Hydraulic motors convert energy in the system into
Rotary motion
NFPA 1901 categorizes aerial devices into three categories
1• aerial ladders
2• elevating platforms
3• water towers
the supporting beams of the ladder are of aerial truss construction,which provides
the required strength for this work application
trusses consist of an assembly of (pg.543)
bars or rods to from a rigid framework
A properly designed truss permits tension and compression stresses
To be distributed over the length of the ladder for maximum strength with minimal weight
Aerial apparatus
Fire fighting vehicle with a hydraulically operated ladder,elevating platform, or similar device for the purpose of placing personnel and/or water stream elevated positions
What is the general term used to describe the Hydraulically operated ladder are elevating platform attached to a specially designed fire apparatus
Aerial device
What NFPA establishes requirements for the dimensions of sections and structural members of the aerial ladder
NFPA 1901
The function of the hydraulic systems is to
Provide power for operating the various hydraulic components needed to stabilize the Apparatus and operate the aerial device
Force is created on the fluid by
By a hydraulic pump
The pump used for hydraulic system is either
1• A load sensing piston pump
2• Rotary vane pump
3• Rotary gear positive-displacement pump
Hydraulic fluid is used because it is practically
incompressible,and is allows force to be transmitted over relatively large distance with little loss of power.
Depends on the manufacture of the a aerial apparatus the fluid maybe under pressure of
3500 psi
Normally hydraulic pressure is from
850-3000 psi
Stabilizing cylinder take much of the Apparatus weight off the suspension
Providing a solid, Stable base for operating the aerial device
What is used to elevate an aerial device
Hoisting cylinders
Hoisting cylinders are equipped with integral safety valves that
Lock or hold oil in the cylinder in the event of a leak or a blowout
Aerial ladder apparatus is
The most common type of aerial fire apparatus operated in North America
The working height for an aerial ladders is measured from the ground
to the highest ladder rung with the ladder at maximum elevation and extension
The main uses of the aerial ladders are
1• rescue 2• ventilation 3• elevated master stream applications 4• Gaining access to upped level of an emergency scene
Aerial ladders are also an excellent resource for
Exposure protection and above ground fire fighting
It is also a common to used aerial device to
Access lower floors or rescue areas,when expediency or safety is a factor.
An elevating platform leveling system is required
So that the platform position is horizontal to the ground at all times
The required minimum floor area of a platform is
14 square feet
Platform must have a rail completely enclosing the floor area with no opening under the railing greater than
24”
Kick plate is required at floor level and should be
4”
All elevating platforms are required to have two operator control stations
- one at street level
- one in the platform
The controls at street level must be able to
Override the platform controls
To protect Firefighter on the platfrom from radiated heat
A heat protective shield is built in
The term quint is derived from
the descriptive phrase quintuple fire apparatus or quintuple combination pumper
The features established by NFPA 1901 that a quint must have are
1• fire pump 2•water tank 3•supply attack hoses 4•ground ladders 5• aerial device our platform
The top section of many aerial devices are
Extended and retracted by cables and pulleys
Turntable
Rotational structural component of the aerial device.
The primary function of the turntable is to
Provide continuous rotation on a horizontal plane
Turntable should be inspected regularly for wear(periodically based on manufacturers torque specification)
True
The operator control panel is positioned to the side of the aerial device to
Better enable operator to see the tip and any personnel operating there
Interlock
A safety device that prevents a component from functioning when another component is functioning
Rotation interlock (Short jack)
The aerial device will not rotate over the side of the Apparatus where the stabilizers are not fully extended
There are two types of pre-piped waterway systems
1•Bed ladder systems
2•Telescoping waterway systems(most common type)
The telescoping piping system consist of
Three or four sections that decrease in diameter(minimum internal diameter is 4”)
Most telescoping that existing are capable of flowing up to
1000 gpm
Detachable a ladder pipes should not have a
Horizontal range of movement exceed and 15° in either direction
Inverter is a step up transformer that convert
The vehicle’s 12 or 24 volt D.C. current into 110 or 230 volt AC current.
Vehicle mounted generators can be powered by a (pg.574)
Variety of fuels or power take off (PTO)
It is common for fire department aerial apparatus to carry
A variety of extrication equipment
The most commonly used tools are
Hydraulic power extrication tools
Hose distance 100 feet or greater from the hydraulic pump
May have a negative effect on tool operation
The variety of ground ladders on aerial apparatus is dictated by
1• NFPA 1901
2• Insurance industry
3•AHJ
The driver/operator must also know the procedures for
Inspecting, testing, and maintaining ground ladders
The driver/operator should be familiar with the
Location,operation, inspection and servicing each types of forcible entry equipment carried on the Apparatus
Smoke ejectors are placed in windows, doors, or roof opening for drawing out heat, smoke,and gases
By creating a lower pressure inside the fire building
Positive pressure ventilation fans are used to
Increase the air pressure and a structure and thus force out the by products of combustion
Driver/operator. will be expected
To inspect and test devices on regular basis
Power equipment should be started daily and inspected
True
All equipment, whether required or not
Must be tested periodically to the applicable NFPA standard
Once the general inspection of the Apparatus as being completed
The driver/operator should make a visual and operational inspection of the aerial device
Check the fluid in the hydraulic reservoir
When the system is cold,unless otherwise specified by the manufacture
The device may be inspected in the stowed position
But extended is the preferred method
Perform and operational inspection of the aerial device
When the visual inspection is complete
The operational inspection serves two purposes
1•to ensure that the aerial device is in proper working condition
2•Serves as a review of the aerial device operation for the driver
By operating the aerial device at least once every work period
The driver/operator will be more prepared to operate efficiently under emergency conditions
A full visual inspection may require the aerial to be placed in a
full horizontal position at full extension
Department SOP’s should identify each interlock
And provide a procedure and how to ensure that each is functioning safely
The main hydraulic system should be disengaged and the control valve must be open before turning on the pump to prevent
Deadheading,when testing the emergency power unit
Apparatus test are grouped into two basic categories
1• preservice test
2• Service test
All test conform to the most current edition of NFPA 1911 and 1901
True
deadheading
Operating a hydraulic pump without allowing flow through the system; this generate tremendous heat and pressure and can damage components
Service test are conducted on
At least yearly basis while the apparatuses is in service
Nondestructive testing is conducted every
Five years
Nondestructive testing is conducted after
1• accidents
2•Unusual stresses and loads
3•Major repairs or overhauls
The best guarantee that the Apparatus will perform within its design limitation is
An organized system of Apparatus testing and regular maintenance
The insurance industry requires apparatus testing in order for the community to
To Receive full insurance rating credit, and this ultimate affect the insurance rates for customers in the jurisdiction
Functions should be performed in sequence
1• elevate
2• rotate
3• extend
what is the term for the bottom section of the aerial ladder?
Base
what is a base rail?
the lower chords of the aerial ladder to which the rings, trusses, and other portions of the ladder are attached
which types of valves control the flow of hydraulic fluid from an aerial apparatus hydraulic system to the hydraulic cylinders?
actuator valves
which of the following is the function of aerial device hoisting cylinders?
elevate the aerial device from its stowed position
the operator’s control pedestal usually stands about ___ feet high
3.5’
most ladder pipes should be operated from an aerial positioned between ___ degrees
70- 80°
portable lights generally range from
300-1000watts
fixed lights generally have a capability of ___ per light
500-1500 watts
hose distances of ___ ft or greater from hydraulic tool pumps may have a diminishing effect on tool operation
100
during an air brake test with the engine off, transmission in neutral, full air tanks, and parking brake released, air pressure should not drop more than 3 psi after
1 minute
what is the final step in a walk-around inspection
performing a functional test on apparatus systems
in the context of aerial apparatus inspection, free play is the distance an activation device will move
Definition
while the system it is a part of is inactive
While the system it is a part of is inactive
for a building less than five stories tall, where should aerial apparatus park
On the outside of the engine
Quints may be customized to accommodate differences in
1• geography
2•type of occupancy and construction
3•Water supply
NFPA 1911 specify for breathing air systems on aerial devices should be tested
Annually testing of the breathing air system and the equality of the stored air
Though historically,some manufacturers of telescoping water Towers have equipped them with ladders, the affixed must meet the requirements of_____to be truly be considered an aerial
NFPA 1901
counterbalance valves
Prevent unintentional or undesirable Motion of the aerial device from its established position
type of hydraulic pumps in aerials
rotary vane or rotary gear
pressure of hydraulic fluid in aerials
3500 psi or more
what supplements hyrdaulic reservoirs ability to condition fluid
filters and exchange type oil coolers
where are hydraulic reservoir coolers usually located
In front of the vehicles radiator
valve that controls flow of oil from hydraulic system to the hyrdraulic cylinders
Actuator valve
how is structural members of ladder connected
rivets, welded for steel, heliarced for aluminum alloy
normal hydraulic pressure
850-3000 psi
what may need shut off before engaging aerial PTO
Jake brake
what stresses are created when aerial rungs are not parallel to ground
lateral and torsional
Lateral and torsional
How much weight should the topmost portion of the aerial ladder fly most be cable of supporting when the ladder is extended st any elevation within it normal range
250 lbs
How fast would a 110 feet or less ladder need to lower stabilizers and raised to it’s maximum elevation and rotated 90 degrees per NDPA 1901
120 seconds or less
Depending on the manufacturer of the aerial device, the pump used for the hydraulic system is either
A load sensing piston pump, rotary vane pump or rotary gear positive-displacement pump
Cooler, usually located in front of the vehicle’s radiator,
remove heat from the fluid as it returns to the reservoir from the hydraulic system
Most manufacturers use steel tubing and aircraft type
.
steel-braided hose
Hose must be rated to withstand pressures
.
at least four times greater than normal operating pressure
what is a check valves
prevent fluid from flowing
backward through a component and acts as a safety feature in the event that a leak develops in the system
Hydraulic motors convert energy in the system
into
rotary motion
There are two rotary motor systems of the apparatus.
One rotates the aerial device through a ring and pinion drive and the other operates a winch drive (in older aerial apparatus) to extend and retract the aerial device
The auxiliary pump is typically
a 12-volt DC, electrically operated pump connected directly to the vehicles battery, back up unit that helps bring down ladder
The end of the piston rod outside the cylinder
is fitted with a trunnion that is anchored to the aerial device or to the turntable, depending on the make of the apparatus
Aerial ladder truss
- assembly of bracing bars or rods in triangular shapes that form a rigid framework for the aerial device
The supporting beam of the ladder are of ____ _____ ______Construction, which provides the required strength for this work application
Aerial ladder truss
The end of the piston rod outside a cylinder is fitted with a____ that is anchored to the aerial device or to the turntable
TRUNNION
Aerial ladders made in North America, the extended length ranges from
50-137 ft
