Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Principles of Vehicle Extrication > Chapter 9: Commercial/ Heavy Vehicles > Flashcards

Chapter 9: Commercial/ Heavy Vehicles Flashcards

1
Q

Medium trucks weigh between ____ and ____ pounds. Common examples are ____ and ____.

A
  • 13,000 and 33,000

* local delivery trucks and garbage trucks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Heavy trucks in the U.S. are defined as weighting ____

A

more than 33,000 pounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the most common type of truck?

A

Straight truck (ex. delivery truck)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Traits of straight trucks:

A
  • 2 or 3 axles, all attached to 1 frame.
  • Gross vehicle weight between 10,000 and 40,000 pounds
  • large boxy bodies
  • often used as delivery vehicles
  • may have flatbeds or large box bodies mounted to their frames.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

A ____ mounted on motorized tractors, serves as the attachment point for a semitrailer.

A

fifth wheel device

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The entire truck and semitrailer combination may weigh up to ____

A

140,000 pounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The tractors in tractor trailer combo’s may have ____ axles and may weight up to ____ pounds.

A
  • 2 or 3

* 18,000 pounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Tractor trailer combos can carry up to ____ of hazardous materials.

A

440 pounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Placard

A

Diamond-shaped sign that is affixed to each side of a structure or a vehicle transporting hazardous materials to inform responders of fire hazards, life hazards, special hazards, and reactivity potential. The placard indicates the primary class of the material and, in some cases, the exact material being transported.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Two most common types of cabs are:

A
  • conventional

* cab-over units

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

During extrication operations on trucks with air ride cabs, rescuers must ____.

A

crib between the frame and cab so if the air bleeds off the trucks cab, it does not lower and hinder extrication. Also capture the cab with chains or straps and isolate the power to secure the cab from any hazard if the air ride suspension were to inadvertently fill.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

On a cab over unit, where is the cab generally attached to the chassis?

A

In the center behind the cab (latch point), and by hinge at the front of each frame rail.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Rescuers access the sleeper unit by ____

A

forcing entry through the required exterior door

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Sleepers that are separate units must have ____

A

an intercom between the sleeper and the cab.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Often team drivers will have a sign indicating the driving team on the ____

A

driver door area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Fairing

A

An auxiliary structure or the external surface either attached to, or a part of the roof of a large truck that serves to reduce drag.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The cab roofs of most medium and heavy trucks are usually covered with the ____ on the vehicle, and is supported by ____.

A
  • lightest gauge metal or fiberglass

* two or more ribs running from front to rear.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

All trailers are one of two basic styles:

A
  • trailers or semitrailers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

A trailer is a ____ unit with wheels ____.

A
  • freestanding
  • front and rear
  • The front axle on a trailer is connected to a turntable that turns from side to side for better tracking. A trailer couples to a tractor of another trailer with a long tow bar, often called a dolly.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Semitrailers have wheels ____ and is supported by ____.

A
  • only in the rear
  • the tractor when locked into a fifth wheel, or by a pair of small wheels known as landing gear, that are attached to the underside of the trailer by two struts.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When not in use, a semi-trailers landing gear can be lowered by a hand crank that has two speeds:

A
  • Push in and crank for slow raising or lowering

* Pull out and crank for fast raising or lowering

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Some trailers are equipped with sliding axels that are used to ____

A
  • manage trailer loads
  • improve close quarters maneuverability
  • or allow loading and unloading of the trailer.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Low-load bed trailers and heavy equipment trailers often have a powered system to ____

A

slide entire axle assemblies along the track or frame rails of the low slung trailer. This action lowers one end or the trailer to the ground to drive the equipment, loading and unloading the trailer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The person charged with securing moveable trailer axles should ____

A

check each individual lock pin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Some trailers are also equipped with air suspension systems, Rescuers should ____ when stabilizing these trailers.

A

crib the trailer box or bed to the frame to prevent movement if suspension air is lost.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

The ____ of a box trailer is the area most easily penetrated because the covering material is thinnest and there are the fewest structural members.

A

roof

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Tanker trailer capacities can range from ____ to ____

A

200 to 14,000 gallons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Lowboy trailer (AKA heavy duty trailers)

A

Trailers that feature a low center deck area designed to carry large, heavy loads up to several hundred tons. These trailers often have two or three rear axels, all with dual tires on each hub, and can have additional sections with multiple axels to support especially heavy loads. Loads may be over 175 feet long and/or over width (greater than 8 feet). These trailers may overwhelm resources due to the large volume of material needed to stabilize them.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

The ____ and/or ____ provides the best points on medium and heavy trucks to perform stabilization.

A

frame and chassis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Truck batteries are either ____ or ____ systems supplied by ____ batteries. These batteries may be located ____

A
  • 12 or 24 volt
  • one or more banks
  • in more than one location on the truck
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The capacity of saddle fuel tanks can range from ____ to ____.

A

50 to 300 gallons each.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Many vehicle saddle tanks are interconnected by a ____. At one or both ends of this is a ____ that can be used to ____

A
  • a small tube that equalizes the volume of fuel in both tanks.
  • small valve
  • isolate the tanks from one other if one tank is leaking.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Truck battery systems are usually parallel wired together to produce ____

A

a higher amperage flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

When isolating a trucks electrical system, the ____ cable should be either disconnected or double cut first, followed by the other cable.

A
  • negative (ground)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

PTO shafts can rotate at more than ____ and can easily entangle rescuers or bystanders. Isolate mechanical power by ____.

A
  • 1000 rpm

* locking/ tagging out the piece of equipment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

In trucks air brake systems, compressed air is used to apply the brakes under normal operation. Under abnormal operation, such as a complete loss of air pressure in the braking system, ____

A

heavy duty springs automatically apply the rear brakes.

37
Q

The trailers air system is connected to that of the tractor by a breakaway valve at the rear of the cab, commonly called a ____

A

glad-hand connection

38
Q

The flexible air line connecting the tractor and trailer is often supported on a vertical stand sometimes called ____

A

a pogo stick

39
Q

Both trucks and trailers with airbrakes have air brake chambers mounted under each axle. The double chambers (called ____) under the rear axles contain ____. These ____ for parking or if there is a loss of air pressure.

A
  • piggyback chambers
  • large compressed springs
  • apply the brakes mechanically
40
Q

The parts of each double chamber are held together with a metal clamp. Loosening this clamp can ____.

A

release a spring that has sufficient force to cause serious injury or death. Never loosen the clamp on an air brake chamber.

41
Q

Most medium and heavy trucks have ____ suspension systems.

A

conventional heavy duty leaf or coil spring suspensions.

42
Q

On truck with air suspension bags, each axle has ____ air bags, and an on board compressor which maintains the pressure in each bag as high as ____.

A
  • 2

* 120 psi

43
Q

Major concerns for rescuers regarding auxiliary lift axles include the ____. When a vehicle impacts the hinge locations or damages the lifting mechanism, the 6000 to 10,000 pound axle could potentially fall on the impacting vehicle or rescuers. The lift axle should be ____

A
  • rear lift axle, specifically the stringer type. (auxiliary lift axles that are located only behind the drive axles, operate in a fold down manner)
  • secured forward of the affected area, with chains and chain binders.
44
Q

The fifth wheel allows the trailer or rotate more than ____ from center in both directions. The fifth wheel turntable can pivot approximately ____ front to rear.

A
  • 90 degrees

* 15 degrees

45
Q

A ____ on the ____ side of the tractor opens the jaws to allow the trailer to be uncoupled from the tractor.

A
  • pull handle

* drivers side

46
Q

By definition, busses are designed to carry more than ____ passengers. School buses are divided into what four types?

A
  • 10

* A,B,C,D

47
Q

Type A school bus

A

The smallest type of school bus, capable of carrying up to 36 passengers. They are a standard SUV or van conversion built on a heavy duty, van type front section chassis. The entry/exit door is located behind the front wheels, and the bus has a driver side door. Type A comes in 2 varieties. A1 and A2. A1 busses have a GVWR of 10,000 pounds or less, while A2 busses have a GVWR of 10,000 pounds or more

48
Q

Type B school bus

A

Capable of carrying up to 36 passengers, these busses are either a conversion or their body is constructed on a front-section vehicle chassis. The entry/exit door is located aft (in front of) the front wheels. Has a GVWR of more than 10,000 pounds

49
Q

Type C school bus

A

The typical school bus most think of, capable of carrying up to 78 passengers. The body is installed on a flat-back cowl chassis. Entry/exit door is behind the fender and the engine compartment protrudes from the front of vehicle. Have a GVWR of more than 10,000 pounds with an average weight of 20,000 to 30,000 pounds.

50
Q

Type D school bus

A

Full size vehicles capable of carrying up to 90 passengers. Entry/ exit door is located forward of the front wheels, no driver side door. Roof hatches may be provided, engine could be in front or rear of the vehicle. has a GVWR of more than 10,000 pounds and many weight more than 30,000 pounds.

51
Q

Bus conversions can often be identified by ____

A

blacked out windows, and customized paint schemes.

52
Q

Regardless of the type of bus door, the most common way to open or secure it closed is with ____

A

the manual control arm mechanism.

53
Q

Air operated doors on school buses have the main operating switch located ____. There will also be an emergency backup release mechanism in the ____.

A
  • left of the driver on the instrument console

* exit stairwell inside the vehicle.

54
Q

A school bus may not have an air override release mechanism for the doors if ____

A

there are two similar doors located along the same side of the bus.

55
Q

Rear exit doors on school buses are secured by ____. The main latch is ____. The other latches if present are located ____.

A
  • one or three point latching mechanism
  • at the edge of the door near the control handle
  • on the top and bottom of the door, engaging the bus body and floor assembly.
56
Q

Nearly all transit bus doors are ____

A

two pieces and center opening

57
Q

Exterior emergency releases for commercial bus doors:

A
  • In the right front wheel well
  • Under or to the left of the door on the outside of the vehicle
  • Directly below the center of the windshield.
58
Q

Emergency exit windows on school buses can be identified by ____

A

the hinges located along the top side of the window frames.

59
Q

The ____ window of a school bus, the ____ colored frame can be removed and the opening used as an emergency exit.

A
  • center

* silver

60
Q

Rear windows and windshields on school buses are ____ and are mounted with ____

A
  • laminated safety glass

* removable rubber gaskets.

61
Q

Transit buses most commonly have windows made of ____

A

laminated safety glass.

62
Q

All modern commercial motor coaches are designed with ____, some of which can be removed in emergencies. Emergency exit windows are identified by ____.

A
  • single piece side windows that do not open

* being set in metal frames that are hinged at the top.

63
Q

Since 1977 school bus seat backs have been required to be ____

A

24 inches high.

64
Q

All type A school buses under 10,000 pounds must have ____

A

lap belts

65
Q

What are the two basic types of school bus construction?

A
  • Integral construction - The body and chassis are formed as a unit. The manufacturer assembles the vehicle starting with the frame and chassis and proceeds item by item to the finished vehicle.
  • Body on chassis - The body and chassis are manufactured as separate units and joined by the bus manufacturer.
66
Q

____ forms the basic structure of the entire bus. It dictates how the vehicle will respond during a collision and forms the basis of the protective envelope designed to provide occupant safety and survival.

A

The skeletal system

67
Q

Running horizontally along the base of each sidewall of a school bus is a framing element referred to as a ____

A

collision beam

68
Q

Finish panels of ____ are typically mounted on the exterior and ____ on the interior of the sidewall frame members of a school bus.

A
  • 20 gauge steel

* 22 gauge steel

69
Q

____ of 16 gauge steel run the full length of the sidewalls are intended to minimize penetration during a collision and can also be used for ____.

A
  • Rub rails

* identifying occupant location from the exterior.

70
Q

One rub rail will indicate the ____ level, if a second rail is present, it will identify the ____.

A
  • Seat cushion level

* floor level

71
Q

The skeletal framework of the school bus roof commonly consists of 11-14 gauge steel frame members called ____ spanning the structure from side to side.

A

roofbows

72
Q

Within the frame of roofbows are 14-16 gauge girders (known as ____) funning from ____, strengthening and spacing the bows.

A
  • stringers

* front to rear

73
Q

Rescuers can determine the location of the roofbows and stringers on school buses by____.

A

The rows of rivets used to secure the roof panels.

74
Q

Forcible entry through the floor of a school bus is ____. Floors should ____ as a primary entry point.

A
  • difficult and time consuming

* not be considered

75
Q

In general, transit buses are of ____ construction.

A

integral body

76
Q

Unlike other types of buses, roof panels in a commercial bus ____

A

may not be riveted to every structural member.

77
Q

On commercial buses structural roof members are generally separated by about ____ on center. Panels are often riveted to _____, therefore there will be a structural member ____.

A
  • 24 to 26 inches
  • every other structural member
  • in between every set of rivets.
78
Q

On type A and some type B school buses, the batteries are usually located ____

A

in the engine compartment

79
Q

On most type B, C, and D school buses the batteries are located ____

A

in a separate compartment on the drivers side of the vehicle.

80
Q

School buses with an electric lift have a separate battery located ____. Disconnecting this battery will not ____

A
  • in a separate compartment on the drivers side of the vehicle
  • interrupt power to the engine.
81
Q

The batteries for nearly all transit buses are located

A

in a compartment on the drivers side of the vehicle, just forward of the rear wheels.

82
Q

In commercial buses the location of batteries vary based on the manufacturer, but many are found ____. Regardless of the battery location, all manufacturers place ____

A
  • just after the front wheels on the passenger side of the bus
  • an electrical disconnect switch in the battery compartment.
83
Q

On type C and D school buses rescuers may need ____ to access the battery compartment door. This is located ____.

A
  • a hex key or Allen wrench

* usually inside the school bus near the driver’s area

84
Q

If a bus engine is still running, rescuers should ____ prior to disconnection or disabling the batteries.

A
  • shut it off
  • this can be accomplished with the ignition key or switch, or by shutting off the fuel supply valve on alternate fuel vehicles. Some buses may also have engine stop switches on the drivers console, or in the rear engine compartment. These switches are usually clearly marked and located in the top left of right corner of the engine compartment.
85
Q

LNG must be stored in a ____

A

double walled vacuum insulated pressure vessel

86
Q

What are the two primary hybrid propulsion system configurations for hybrid buses?

A
  • series - the internal combustion engine runs a generator that provides power for the battery and electric motor.
  • parallel - the electric motor and the internal combustion engine are both connected to the vehicles transmission to individually or simultaneously propel the vehicle.
87
Q

Pantograph

A

Mechanical linkage device which maintains electrical contact with a contact wire and transfers power from the wire to the traction unit of electric buses, locomotives and trams.

88
Q

Electric buses with high voltage batteries typically store them ____

A

on the top of the bus

89
Q

Kneeling

A

Ability of some buses to lower the front end of the bus to curb level for ease of passenger boarding.

Principles of Vehicle Extrication (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions