ABS (Antilock Braking System) Computer, sensors and solenoid valves which together monitor wheel
speed and modulate braking
force if wheel lockup is sensed during braking. Helps the driver retain
control of the vehicle during
heavy braking on slippery roads.
AFV (Alternative Fueled Vehicle) Vehicle powered by a fuel other than gasoline or diesel.
Air brake
A brake which is operated by air. The air brake is operated by
use
of air lines, valves, tanks, and an air compressor.
Air Ride Suspension Suspension
which supports the load on air-filled rubber bags rather than steel
springs.
Compressed air is supplied by the same engine driven air compressor and
reservoir tanks which
provide air to the air brake system.
Air spring System
A system whereby the container and plunger are separated by air under
pressure
When the container and plunger
attempt to squeeze together, air compresses and produces a spring
effect.
Air Tank
A reservoir for storing air for use in the air brake system
Without
this storage tank there would not be enough
air for braking when needed.
Ammeter
A gauge which registers the output of the alternator or generator.
ATC (Automatic Traction Control)
Usually an optional feature based on ABS, it prevents spinning of the
drive
wheels under power
on slippery surfaces by braking individual wheels and/or reducing
engine
throttle. Also called
ASR, an acronym sometimes loosely translated from the German as
anti-spin
regulation.
Axle Structural component to which wheels, brakes and suspension are
attached.
Drive axles are those with powered wheels.
Front axle is usually called the steer axle.
Pusher axles are unpowered and go ahead of drive axles.
Rear axles may be drive, tag or pusher types.
Tag axles are unpowered and go behind drive axles.
BBC Distance from a truck's front bumper to the back of its cab.
Bill of Lading A shipping document or or shipping paper for a particular
shipment.
It contains an itemized list of goods in the shipment.
It serves as a contract of shipment and a receipt for the goods.
Blind Spot Areas around a commercial vehicle that are not visible to the
driver
either through the windshield,
side windows or mirrors.
Bobtail Tractor operating without a trailer.
Bogie (also spelled bogey) Assembly of two or more axles, usually a pair in tandem.
Balloon Freight
The term used when a driver is hauling cargo that is very light in
weight
compared with the cubic space occupied.
Brake Horsepower (bhp)
Engine horsepower rating as determined by brake dynamometer testing.
(see
Horsepower)
Bridge Formula A bridge protection formula used by federal and state governments
to
regulate the amount of
weight that can be put on each of a vehicle's axles, and how far apart
the axles (or groups of axles)
must be to legally carry a given weight.
Bulk Freight
Freight that is not in packages or containers. It is normally
hauled
in tanks or grain trailers.
Cabover (Cab-Over-Engine, COE)
Truck or tractor design in which the cab sits over the engine on the
chassis.
Cargo Weight Combined weight of all loads, gear and supplies on a vehicle.
Cartage Company Company that provides local (within a town, city or municipality)
pick-up and delivery.
Cast Spoke Wheel Wheel with five or six spokes originating from a center hub. The
spoked
portion, usually made of
cast steel, is bolted to a multiple piece steel rim.
CB (Citizens Band Radio) Two-way radio for which no license is required by the Federal
Communications
Commission (FCC).
Long beyond its heyday in the '70s, CB is still used by truckers and
motorists
for everything from
traffic condition reports to emergency calls to idle chatter. Click
here for the FCC Rules.
CDL (Commercial Driver's License)
License which authorizes an individual to operate commercial motor
vehicles
and buses over
26,000 pounds gross vehicle weight. For operators of freight hauling
trucks,
the maximum size
which may be driven without a CDL is Class 6 (maximum 26,000 pounds
gross
vehicle weight).
CE (CF, LP)
Distance from back of a truck's cab to the end of its frame.
CG (Center of Gravity) Weight center or balance point of an object, such as a truck body.
Calculated to help determine
optimum placement of truck bodies on chassis.
Chassis Weight (Curb Weight, Tare Weight)
Weight of the empty truck, without occupants or load.
Clearance Lights
The lights that are on top of the Front and rea of the Semitrailer.
CNG
Compressed natural gas.
COFC (Container On Flat Car) Method of moving shipping containers which involves transporting
them
on railroad flat cars.
Common Carrier
Freight transportation company which serves the general public. May be
regular route service
(over designated highways on a regular basis) or irregular route
(between
various points on an
unscheduled basis).
Compensated Intracorporate Hauling
Freight transportation service provided by one company for a sister
company.
Container (Shipping Container)
Standard sized rectangular box used to transport freight by ship, rail
and highway. International
shipping containers are 20 or 40 feet long, conform to International
Standards
Organization (ISO)
standards and are designed to fit in ships' holds. Containers are
transported
on public roads atop a
container chassis towed by a tractor. Domestic containers, up to 53
feet
long and of lighter
construction, are designed for rail and highway use only. Consignee
The receiver. The company taking in your freight. The place you deliver
your load to.
Container Chassis Single purpose semitrailer designed to carry a shipping container.
Contract Carrier Company that transports freight under contract with one or a
limited
number of shippers.
Conventional
A style of truck with the engine compartment located in front of the
cab
or driver’s compartment. Conventional spring system
A system which uses the conventional front and rear suspension springs.
Converter Dolly (Dolly) Auxiliary axle assembly equipped with a fifth wheel (coupling
device),
towed by a semitrailer and
supporting the front of, and towing, another semitrailer.
Cube (Cubic Capacity)
Interior volume of a truck body, semitrailer or trailer, measured in
cubic
feet. Dedicated Run
A run that typically always goes to the same place, on nearly the same
schedule. Many
drivers would love to get a dedicated run. As a result, you usually
have
to wait awhile
before it's offered/available to you.
Dead-Heading Operating a truck without cargo.
Demountable Rim Multi-piece steel wheel rim assembly which is bolted to a spoke
hub.
Demountable rims are still in
use, though they have been replaced in many applications by the simpler
disc wheel.
Disc Wheel Single piece rim/wheel assembly of stamped and welded steel or
forged
aluminum, anchored by 8
or 10 nuts to a hub. A "Budd wheel" is a ten-hole, stud piloted disc
wheel;
a design originated by
the Budd Corporation.
Displacement (Piston Displacement) Sum of the volumes swept by an engine's pistons as they travel up
and
down in their cylinders.
Based upon bore (diameter of cylinder) and stroke (distance traveled by
piston). Expressed in liters
or cubic inches.
Doubles (Twins, Twin Trailers)
Combination of a tractor and two semi trailers connected in tandem by a
converter dolly.
Driveline All the components which together transmit power from the
transmission
to the drive axle(s).
These consist of at least one drive shaft (propeller shaft) with a
universal
joint at each end.
Drive train (Powertrain) All the components, excluding engine, which transmit the engine's
power
to the rear wheels:
clutch, transmission, driveline and drive axle(s).
DRL (Daytime Running Lights)
System that automatically turns on a vehicle's low beam headlights when
the parking brake is
released and the ignition is on. Drop & Hook
This means that you take your empty trailer into a shipper's facility
and
drop it. You then
pick up a trailer that has already been loaded. It saves an enormous
amount
of time and
most drivers find a company that has a high percentage of drop &
hook
to be a big advantage. (less dock time.)
EDI (Electronic Data Interchange) The business-to-business interconnection of computers for the rapid
exchange of a wide variety of
documents, from bills of lading to build tickets at auto plants.
Exempt Carrier Company which transports commodities exempted from Interstate
Commerce
Commission (ICC)
economic regulation.
Fifth Wheel Coupling device attached to a tractor or dolly which supports the
front
of a semitrailer and locks it
to the tractor or dolly. The fifth wheel's center is designed to accept
a trailer's kingpin, around
which the trailer and tractor or dolly pivot in turns.
Fingerprint a load
If the driver must "fingerprint" a load, it means he/she must unload it
themselves. Not a
terribly popular option to most drivers.
Fixed Tandem
Assembly of two axles and suspension that is attached to the chassis in
one place, and cannot be
moved fore and aft.
For-Hire Carrier Company in the business of transporting freight belonging to others.
Freight bill
Document for a common carrier shipment. Gives description of the
freight, its weight, amount of charges,
taxes, and whether collect or prepaid. Bills paid in advance are
called prepaid freight bills. Bills collected at destination
are called collect.
GAWR (Gross Axle Weight Rating)
Maximum weight an axle is rated to carry by the manufacturer. Includes
both the weight of the axle
and the portion of a vehicle's weight carried by the axle.
G.B.L.
Government Bill of Lading.
GCW (Gross Combination Weight) Total weight of a loaded combination vehicle, such as a tractor
semitrailer
or truck and full
trailer(s).
Geared Speed Calculated vehicle speed at the engine's governed rpm in each
transmission
gear, or (commonly) in
top gear.
Gear Ratio
Number, usually expressed as a decimal fraction, representing how many
turns of the input shaft
cause exactly one revolution of the output shaft. Applies to
transmissions,
power takeoffs, power
dividers and rear axles. Example: If 2.5 revolutions of an input shaft
cause one revolution of the
output shaft, the gear ratio is 2.5:1.
Governor
A device for regulating a supply of fuel that keeps the same, maximum
speed
regardless of the load.
Grade Steepness of a grade, expressed as a percentage. Example: A vehicle
climbing a 5% grade rises 5
feet for every 100 feet of forward travel.
Gradeability Vehicle's ability to climb a grade at a given speed. Example: A
truck
with a gradeability of 5% at 60
mph can maintain 60 mph on a grade with a rise of 5%.
GVW (Gross Vehicle Weight)
Total weight of a vehicle and everything aboard, including its load.
GVWR (Gross Vehicle Weight Rating)
Total weight a vehicle is rated to carry by the manufacturer, including
its own weight and the
weight of its load.
Hazmat
Hazardous materials, as classified by the U.S. Environmental Protection
Agency (EPA). Transport
of hazardous materials is strictly regulated by the U.S. Department of
Transportation.
Headache Rack
Heavy protective barrier mounted behind the tractor's cab. Designed to
prevent "headaches"
caused by load shifting forward from the trailer and crushing the cab.
Home Time Policy
Most companies profess to have a "Home Time Policy". It is more or less
what they try to
do in regards to getting drivers home. Some of the more popular
"policies":
1.) You earn
one day home for every day you spend on the road. 2.) You earn 3 days
for
spending 2
weeks on the road. 3.) You are home every weekend. This usually means
you'll
probably
be home sometime on Friday and have to leave out sometime on Sunday.
Every
company
is different, of course, so if home time is important to you, be sure
to
ask any potential
employer!! This is a source of problems for many drivers. They are told
one thing by a
recruiter and it works differently when they start to deal with their
dispatcher.
Also keep in
mind that there will be times that you just won't make it home. Freight
will just not be flowing
right. The weather will be bad. Your equipment will break down. Give a
carrier a chance to
"do right" by you in regards to home time but if it is a constant
difficulty
- and it's an issue
that matter to you - you may have to look elsewhere. Just don't jump
ship
too soon.
Horsepower (hp) Measure of power (the amount of work that can be done over a given
amount of time). One
horsepower is defined as 33,000 foot-pounds of work in one minute.
Example:
Lifting 33,000
pounds one foot in one minute, or lifting 3300 pounds ten feet in one
minute.
Hours-Of-Service
U.S. Department of Transportation safety regulations which govern the
hours
of service of
commercial vehicle drivers engaged in interstate trucking operations.
Hydroplaning
When the tires lose contact with a wet road surface.
Interstate Commerce commission (ICC)
The federal body charged with enforcing Acts of congress affecting
interstate
commerce.
IVHS (Intelligent Vehicle Highway Systems) Blanket term for a wide array of technologies, including electronic
sensors, computer hardware and
software and radio communications. The purpose of IVHS is to increase
efficiency
of use of
existing highways, reducing travel time, fuel consumption, air
pollution
and accidents. There are
five functional areas:
Advanced Public Transportation Systems (APTS)
Advance Traffic Management Systems (ATMS)
Advance Traveler Information Systems (ATIS)
Advanced Vehicle Control Systems (AVCS)
Commercial Vehicle Operations (CVO)
A more recently coined term, Intelligent Transportation Systems (ITS),
encompasses both IVHS
and modes of transportation other than highway, such as rail.
Jackknife
To place the trailer at a very sharp angle to the tractor.
Jack-Rabbit Start
The sudden or quick release of the clutch that causes immediate
movement
of the vehicle
JIT (Just-In-Time) Manufacturing system which depends on frequent, small deliveries of
parts and supplies to keep
on-site inventory to a minimum.
Kingpin (axle) Pin around which a steer axle's wheels pivot.
Kingpin (trailer)
Anchor pin at the center of a semi trailer's upper coupler which is
captured
by the locking jaws of a
tractor's fifth wheel to attach the tractor to the semitrailer.
Landing Gear Retracting legs which support the front of a semitrailer when it is
not coupled to a tractor.
Layover
Any off-duty period away from home.
LCV (Long Combination Vehicle) In general, vehicles longer than a standard doubles rig (tractor
and
two 28ft semi trailers).
Examples of LCVs which are permitted in some U.S. western states and
eastern
toll roads: Twin
48ft trailers; triple 28ft trailers.
Lessee
Company or individual which leases vehicles.
Lessor
Company which leases vehicles.
Lift Axle
Extra, unpowered axle needed only when the vehicle is loaded, allowing
it to meet federal and state
vehicle weight standards. The lift axle is mounted to an air spring
suspension
that raises the axle
when it is not required.
Line haul
The movement of freight from one point to another. It does not
include
pickup and delivery services
LPG
Liquefied Petroleum Gas, e.g., Propane Butane.
Logbook Book carried by truck drivers in which they record their hours of
service
and duty status for each
24-hour period. Required in interstate commercial trucking by the U.S.
Department of
Transportation. Click here for Logbook
info.
Lowboy Open flat-bed trailer with a deck height very low to the ground,
used
to haul construction
equipment or bulky or heavy loads.
LTL (Less-Than-Truckload) A quantity of freight less than that required for the application
of
a truckload (TL) rate; usually
less than 10,000 pounds.
LTL Carrier Trucking company which consolidates less-than-truckload cargo for
multiple
destinations on one
vehicle.
Minnie
Any shipment under 100 pounds.
Motor Carrier Act
A law passed in 1935 which brought the interstate commerce Commission
(ICC)
into the truck
regulation business.
Motor Vehicle
Any vehicle driven or pulled by mechanical power. It is used on
the
highways for hauling property or
passengers as determined by the federal highway Administration. No Touch
Means the driver does not have to "touch" the load -- doesn't have to
fingerprint...doesn't
have to do any of the unloading.
Odometer
A device that measures the distance of travel in miles. This
device
is attached to the speedometer
O, S & D Dept.
Overage, shortage and damaged. Someone in your company is in charge of
OS & D. You
must call in if you have any of these conditions with your load before
leaving the receiver --
and in some cases, you must call before even pulling out of their dock.
Overage
Extra freight from what should have been shipped.
Overdrive Gearing in which less than one revolution of a transmission's input
shaft causes one turn of the
output shaft. The purpose of overdrive is to reduce engine rpm in high
gear for better fuel
economy. Example: A transmission with an overdrive top gear has a ratio
of 0.70 to one. Turning
the input shaft 0.7 revolutions causes 1.0 revolution of the output
shaft.
Owner Operator Trucker who owns and operates her/his own truck(s). Click
here for Owner Operator info.
Pancake
A brake diaphragm housing on each set of dual wheels on a semitrailer
and
on most tractors.
P&D Pickup and delivery.
Payload Weight of the cargo being hauled.
Peddle Run
Truck route with frequent delivery stops.
Pigtail Cable used to transmit electrical power from the tractor to the
trailer.
So named because it is coiled
like a pig's tail.
Piggyback Semitrailer built with reinforcements to withstand transport by a
railroad
flatcar.
Pintle Hook Coupling device used in double trailer, triple trailer and truck
trailer
combinations. It has a curved,
fixed towing horn and an upper latch that opens to accept the drawbar
eye
of a trailer or dolly.
Placard
A sign showing the type of hazardous materials loaded in a vehicle. Click
here for HAZMAT Placard info.
Ply Rating (PR)
Relative measure of tire casing strength. (see Load Range)
Powertrain (Drivetrain) All the components, including engine, which transmit the engine's
power
to the rear wheels: clutch,
transmission, driveline and drive axle(s).
Private Carrier Business which operates trucks primarily for the purpose of
transporting
its own products and raw
materials. The principle business activity of a private carrier is not
transportation.
PSI (Pounds Per Square Inch) In trucking, unit of measurement for tire air pressure, air brake
system
pressure and turbocharger
boost.
PTO (Power Takeoff) Device used to transmit engine power to auxiliary equipment. A PTO
often drives a hydraulic
pump, which can power a dump body, concrete mixer or refuse packer.
Some
designs mount to a
standard opening on the transmission, while others attach at the front
or rear of the engine.
Pull Trailer Short, full trailer (supported by axles front and rear) with an
extended
tongue.
Pup Trailer Short semitrailer, usually between 26 and 32 feet long, with a
single
axle.
Relay (Relay Driving) Common practice in the less-than-truckload industry, in which one
driver
takes a truck for 8 to 10
hours, then turns the truck over to another driver, pony express style.
Reefer
Refrigerated trailer with insulated walls and a self powered
refrigeration
unit. Most commonly used
for transporting food.
Retarder device used to assist brakes in slowing the vehicle. The most
common
type of retarder on
over-the-road trucks manipulates the engine's valves to create engine
drag.
(This type is
commonly referred to as "Jake Brake" because the predominant
manufacturer
is Jacobs Vehicle
Equipment Co.) Other types of retarders include exhaust retarders,
transmission-mounted
hydraulic
retarders and axle-mounted electromagnetic retarders.
RFG (Reformulated Gasoline)
Gasoline blended with pollution reducing additives. Common in the
Milwaukee
metro area. Rider Policy
A policy the company might have that allows someone, not employed by
the
company, to
ride along with you. Typically limited to certain times of year (April
to November) and limited
to age of rider. The Policy might also stipulate the person must be an
immediate family
member only.
Rolling Radius Tire dimension from center of the axle to the ground; measured with
tire loaded to rated capacity.
Used in calculating geared speed.
Rodeo or roadeo
A series of skill execises that are to be done within a limited amount
of time. Measures a drivers’s skill in maneuvering
his vehicle.
RPM (Revolutions Per Minute) Measure of the speed at which a shaft spins. Most often used to
describe
engine crankshaft
speed. Indicated by a tachometer.
Runaway Truck Ramp
Emergency area adjacent to a steep downgrade that a heavy truck can
steer
into after losing
braking power. Usually two or three lanes wide and several hundred feet
long, the ramp is a soft,
gravel-filled pathway which absorbs the truck's forward momentum,
bringing
it to a safe stop.
Depending on the surrounding terrain, the ramp may be level or run up
or
down hill.
Running Gear
A trailer’s axles’s bearings, seals, brakes. Wheels, tiers,
springs, and spring hangers anr the parts which make up the
running gear. Saddle tank
The fuel tank on a truck or tractor.
Semitrailer Truck trailer supported at the rear by its own wheels and at the
front
by a fifth wheel mounted to a
tractor or dolly.
Setback Axle Front steering axle moved rearward from the generally accepted
standard
position. Advantages:
Shorter turning radius and more of a vehicle's weight shifted to front
axle.
Shipping Weight "Dry" weight of a truck including all standard equipment, but
excluding
fuel and coolant.
Single-Source Leasing Service in which companies can lease drivers and trucks from the
same
source, rather than having
to procure them from different companies.
Sleeper
Sleeping compartment mounted behind a truck cab, sometimes attached to
the cab or even
designed to be an integral part of it.
Sliding Fifth Wheel
Fifth wheel mounted to a mechanism that allows it to be moved back and
forth for the purpose of
adjusting the distribution of weight on the tractor's axles. Also
provides
the capability to vary
vehicle combination lengths.
Sliding Tandem (Slider) Mechanism that allows a tandem axle suspension to be moved back and
forth at the rear of a
semitrailer, for the purpose of adjusting the distribution of weight
between
the axles and fifth
wheel.
Space Cushion
An area around a vehicle which would allow a driver time to avoid an
accident.
Speedability Top speed a vehicle can attain as determined by engine power,
engine
governed speed, gross
weight, driveline efficiency, air resistance, grade and load.
Spread Axle (Spread Tandem)
Tandem axle assembly spaced further apart than the standard spacing of
54 inches. The U.S.
federal bridge formula favors trailer axles with an eight or nine foot
spread by allowing higher
weight than on tandems with standard spacing.
Spotter
A terminal yard driver who parks vehicles brought in by regular
drivers.
It I is also a supervisor who watches the activities of the
driver on the road.
Synchronized Transmission
Transmission with built-in mechanisms to automatically "equalize" the
speed
of its gears to allow
smooth shifting without the need to double clutch.
Tachometer
A decive inside the cab of a vehicle to show the engine RPM.
Tandem Axle (Tandems) Pair of axles and associated suspension usually located close
together.
Team (Driver Team)
Team of two drivers who alternative driving and resting.
TEU (Twenty Foot Equivalent Unit)
Standardized unit for measuring container capacity on ships, railcars,
etc.
TL (Truckload)
The quantity of freight required to fill a trailer; usually more than
10,000
pounds.
TL Carrier
Trucking company which dedicates trailers to a single shipper's cargo,
as opposed to an LTL (Less
Than Truckload) carrier which transports the consolidated cargo of
several
shippers and makes
multiple deliveries.
Tractor Truck designed primarily to pull a semitrailer by means of a fifth
wheel mounted over the rear
axle(s). Sometimes called a truck tractor or highway tractor to
differentiate
from it from a farm
tractor.
Tri-Axle Truck, tractor or trailer with three axles grouped together at the
rear.
Tridem Group of three axles on a truck, tractor or trailer. Tridems are
most
common on European
semi trailers.
Trip Leasing Leasing a company's vehicle to another transportation provider for
a single trip.
Trip Recorder (On-Board Computer) Cab-mounted device which electronically or mechanically records
data
such as truck speed, engine
rpm, idle time and other information useful to trucking management.
Truck Vehicle which carries cargo in a body mounted to its chassis,
rather
than on a trailer towed by the
vehicle.
ULEV
Ultra low emissions vehicle.
Upper Coupler Load bearing surface on the underside of the front of a
semitrailer.
It rests on the fifth wheel of a
tractor or dolly and has a downward-protruding kingpin which is
captured
by the locking jaws of
the fifth wheel.
VIN (Vehicle Identification Number) Assigned by the manufacturer, this number is unique to each vehicle
and appears on the vehicle's
registration and title.
VMRS (Vehicle Maintenance Reporting Standards) Set of codes developed to facilitate computerized tracking of parts
and labor used in equipment
repair. Established and maintained by the American Trucking
Associations.
Walking Beam Suspension Type of truck and tractor rear suspension consisting of two beams,
one at each side of the chassis,
which pivot in the center and connect at the front to one axle of a
tandem
and at the rear to the
other axle.
Waybill
A list of goods sent by a common carrier with shipping directions.
WIM (Weigh-In-Motion)
Technology for determining a vehicle's weight without requiring it to
come
to a complete stop.
Yard Jockey Person who operates a yard tractor.