Truck Facts for Kids

A truck is a big motor vehicle that helps move things from one place to another. In the United Kingdom, people often call them lorries. The word "truck" comes from the Greek word "trochos", which means "wheel". Most trucks use a special type of fuel called diesel.

A Freightliner M2 dump truck.

Types of Trucks by Size
Different Kinds of Truck Bodies
Images for kids
See also

Types of Trucks by Size

Trucks come in many different sizes, from small ones that look like cars to huge ones that can carry tons of cargo.

Light Trucks

Light trucks are about the same size as cars. People use them for personal reasons, and companies use them for work. In the United States, a truck is called a light truck if it weighs less than 6,300 kilograms (about 13,000 pounds). These trucks are a bit heavier than vans or pickup trucks. You usually need a special driver's license to drive them.

Medium Trucks

Medium trucks are bigger than light trucks but not as big as 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 used for local delivery or public services like garbage collection or dump trucks are often this size.

Most medium trucks have two axles. One axle is at the front, and one is at the back. The back wheels might be "coupled," meaning two wheels are joined together. This helps the truck carry heavier loads.

Heavy Trucks

Heavy trucks are the largest trucks allowed on roads. In the U.K., they are called lorries. These trucks usually have three axles: one at the front and two at the back. The back axles have coupled wheels to help carry very heavy loads.

Often, heavy trucks pull trailers. There are two main types of trailers:

Full trailers have wheels at both the front and back. They also have their own brakes. They connect to the truck with a towbar.
Semi-trailers only have wheels at the back. The front part of the trailer rests on a special truck called a tractor unit. This connection is called a "fifth wheel." The tractor unit has the engine, but the semi-trailer does not.

Driving a heavy truck needs a special professional driver's license. People who drive trucks are often called truckers.

Sometimes, a semi-trailer can be turned into a full trailer by using a dolly. A dolly is a small trailer with just a set of wheels and a "fifth wheel" connection. It lets a semi-trailer be pulled by a regular cargo truck instead of a tractor unit.

A heavy truck pulling a trailer is often called a big rig or an eighteen-wheeler.

The biggest heavy trucks are the Australian road trains. These can have up to four semi-trailers connected to a tractor unit, like a train. They can carry up to 200 tonnes of cargo!

A light van
A medium car carrier
A heavy dump truck
A road train in Australia
An early Daimler truck from 1896

Different Kinds of Truck Bodies

Trucks have different body types depending on what they need to carry.

Box trucks or Dry vans have solid walls and a roof, making a closed space for cargo. They usually have doors at the back, and some have a side door.
Concrete mixers have a large drum on the back that spins. Spinning it one way mixes the concrete, and spinning it the other way pushes the concrete out. The concrete slides down chutes. Concrete is very heavy, so these trucks are built to be very strong.
Dump trucks carry things like sand, gravel, and dirt. Most have an open-top box that can lift up at the front. This makes the load slide out the back, "dumping" it on the ground.
Flatbed trucks have a flat body with no sides. There's a wall behind the cab to stop the load from hitting it. These trucks can be loaded from the side or top. The load is usually covered with tarps to protect it.
Garbage trucks pick up trash and recycling from homes and businesses. Older ones loaded from the back, but newer ones often load from the front or side.
Semi-tractors don't have a body for cargo. Instead, they have a "fifth wheel" that connects to a semi-trailer. The semi-tractor carries part of the trailer's weight and pulls it.
Tank trucks are made to carry liquids or gases. They usually have a long, round tank lying on its side. There are many types of tanks because different liquids and gases need special handling.
Wreckers are also called "tow trucks." They are used to lift and tow broken cars and trucks. They often have a crane with a strong cable. Some wreckers carry cars on a special flatbed.

A box truck
A concrete mixer unloading
A flatbed truck
A rear-loading garbage truck
Semi-tractors
A tank truck
A wrecker

A semi-truck with a "box" trailer. The blue parts show the axles, differentials, drive shafts, and fifth wheel.
1. Semi-tractor
2. Semi-trailer
3. Engine compartment
4. Cab
5. Sleeper (a sleeping area, not on all trucks)
6. Air dam (helps with air flow, not on all trucks)
7. Fuel tanks
8. Fifth wheel coupling (where the trailer connects)
9. Inside cargo space
10. Landing gear (legs for parking the trailer)
11. Tandem axles (two axles close together)

Images for kids

A truck made by SNVI in Algeria
A Daimler Motor-Lastwagen from 1898
A ROMAN dump truck in Brașov, Romania, 2013
A Japanese cement mixer truck
A Might-E Truck from Canadian Electric Vehicles
A Ford Ranger pickup truck
A Fuso Canter, 8th Generation in Taiwan.
A cement mixer is an example of a Class 8 heavy truck
In Pakistan, many trucks are colorful and decorated
A cabover truck
A cab beside an engine
A Cummins ISB 6.7L medium-duty truck diesel engine
A truck's rear suspension and drive axles
A truck's rear frame (chassis) section view
Inside a Mack truck
Inside a Mercedes-Benz truck
Inside a Navistar 9000
A DAF tractor with an auto-transport semi-trailer carrying Škoda Octavia cars in Cardiff, Wales
A truck cab filter housing with three filters
A trucking accident at Elst (Netherlands) in 2012
A Liebherr T 282B mining truck
A Sentinel steam wagon
A Piaggio Porter

Truck facts for kids

Contents