Truck Facts for Kids

A truck (or lorry in British English) is a motor vehicle used to transport goods. The word "truck" comes from the Greek word "trochos", which means "wheel". Most trucks use diesel fuel.

Freightliner M2 dump truck.

Sizes of trucks
Body types
Images for kids
See also

Sizes of trucks

Light trucks

Light trucks are trucks the size of cars. They are used by individuals and also companies. In the United States, a truck is a light truck if it weighs less than 6,300 kg (13,000 lb). Light trucks are only a little heavier than vans or pickup trucks, but require a special driver's license.

Medium trucks

Medium trucks are heavier than light trucks but lighter than heavy trucks. In the United States, a truck is a medium truck if it weighs between 6,300 kg (13,000 lb) and 15,000 kg (33,000 lb). Trucks that are used for local delivery and public service (dump trucks, garbage trucks) are normally around this size. Medium trucks have usually two axles: one at front and one at rear. The rear wheels may be coupled (that is: two wheels hitched together) to enable heavier load, but they may also be single.

Heavy trucks

Heavy trucks are the heaviest trucks that are allowed on the road. In the U.K. they are known as lorries. Usually heavy trucks have three axles: one at front and two at rear, and the rear axles have coupled wheels to enable heavy loads. Often heavy trucks pull trailers. They can be either full trailers which have both front and rear axles or boggies and their own brakes, and are connected to the towing truck with a towbar, or semi-trailers, which are attached to a special kind of a truck called tractor unit with a turntable coupling ("fifth wheel"). A semi-trailer is a kind of trailer which has wheels only in the back and the front rides on the back of the tractor unit. The tractor unit has an engine and the semi-trailer does not. Driving a heavy truck requires a professional driver's license. Truck drivers are called truckers.

The laws of various countries say what kind of vehicle combinations are allowed. A semi-trailer can be converted into a full trailer with using a dolly. A dolly is a small trailer which has only a bogie (= set of wheels), fifth wheel coupling for the semi-trailer and a towbar. Using a dolly, the semi-trailer can now be hitched to an ordinary cargo-carrying truck and does not need a tractor unit.

A heavy truck-trailer combination is often called big rig or eighteen-wheeler.

The largest heavy trucks are the Australian road trains which may have up to four semi-trailers coupled to a tractor in a train-like fashion and may carry up to 200 tonnes of cargo.

Light van
Medium car carrier
Heavy dump truck
Road train in Australia
Daimler-Lastwagen, 1896

Body types

Box trucks or Dry vans ("tilts" in the UK) have walls and a roof, making a closed cargo room. The rear has doors. Some have a side door.

Concrete mixers have a turning drum on back. Turning it one way mixes the concrete. Turning it the other way pushes the concrete out. The concrete goes down "chutes" (like large pipes with an open top). On most trucks the concrete comes out the back. Some new types have the concrete goes over the cab and down chutes in the front. Concrete is very heavy and hard to mix. Concrete mixers have to be very heavy duty.

Dump trucks ("tippers" in the UK) carry sand, gravel, and dirt. Most dump trucks have an open-top box bed with an opening "tail-gate" door on the back. The body lifts up at the front. The load falls out the tailgate and is "dumped" on the ground behind the truck.

Flatbed trucks have a flat body with no sides. There is a wall between the cab and the body. The load will not move forward and hit the cab. The truck can be loaded from the side or top. Nothing covers the load. Some trucks have sides that can be taken off or folded down. Many times the load is covered with tarps.

Garbage trucks pick up garbage and trash from homes and some businesses. Most were loaded from the rear. Now some load from the front or side. The same type of truck is often used for recycling.

Semi-tractors ("artics" in the UK) have no bodies. They have a "fifth wheel" that carries weight. A semi-trailer has no front wheels. The front of the trailer goes on the fifth wheel. The semi-tractor carries weight from the trailer and pulls the trailer

Tank trucks ("tankers" in the UK) are designed to carry liquids or gases. They usually have a round tank that is long (a cylinder) lying on its side. There are many types of tanks because there are many liquids and gases. Most tankers are built for only one liquid.

Wreckers ("recovery lorries" in the UK and sometimes "tow trucks" in the US) are used to lift and tow broken cars and trucks. They usually have a boom with a cable. Cars are often carried on special flatbeds.

Box truck
Concrete mixer unloading
Flatbed
Rear loading garbage truck
Semi-tractors
Tank truck
Wrecker

Semi-truck with "box" trailer. Blue is the axles, differentials, drive shafts, and fifth wheel.
1. Semi-tractor
2. Semi-trailer
3. Engine compartment
4. Cab
5. Sleeper (not on all trucks)
6. Air dam (not on all trucks)
7. Fuel tanks
8. Fifth wheel coupling
9. Inside cargo space
10. Landing gear - legs for parking trailer
11. Tandem axles

Images for kids

Freightliner M2 dump truck
SNVI made in Algeria
Daimler Motor-Lastwagen from 1898
A ROMAN dump truck in Brașov, Romania, 2013
A Japanese cement mixer truck
Might-E Truck from Canadian Electric Vehicles
A Ford Ranger pickup truck
Fuso Canter, 8th Generation in Taiwan.
A cement mixer is an example of a Class 8 heavy truck
In Pakistan the majority of trucks are colorful and decorated
A cabover truck
Cab beside engine
Cummins ISB 6.7L medium-duty truck diesel engine
A truck rear suspension and drive axles overview
A truck rear frame (chassis) section view
Inside a Mack truck
Inside a Mercedes-Benz truck
Inside a Navistar 9000
DAF tractor with an auto-transport semi-trailer carrying Škoda Octavia cars in Cardiff, Wales
Truck cab filter housing using a contiguous series of pre-, HEPA, and charcoal panel filters
Trucking accident at Elst (Netherlands) 2012-03-23
Liebherr T 282B mining truck
A Sentinel steam wagon
A Piaggio Porter

Truck facts for kids

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