Big rig trailer trucks are some of the most fascinating vehicles you will ever see on highways. They are big and powerful and it is a curiosity how these machines could support so much weight. 

A semi-trailer tractor typically weighs over 36,000 kilograms while a container trailer could weigh as heavy as over 32,000 kilograms. With that much weight, gravity is a constant threat for these vehicles but trucks can beat the earth’s pull thanks to these parts:

Suspension

There are two types of suspension systems in trucks used in big rig jobs: The leaf spring and the air. 

Big rig trucks are some of the most fascinating vehicles you will see on highways, but how could these machines support so much weight?

Leaf spring suspension

The leaf spring suspension is most commonly seen in smaller trucks but more heavy-duty ones are used in semi-trailer trucks as well. This traditional system is usually made out of steel and is bent in a curved shape that acts like a spring that flexes when pressure is felt. 

Big rig trucks are some of the most fascinating vehicles you will see on highways, but how could these machines support so much weight?

Air suspension

On the other hand, the air suspension uses air to imitate a spring-like action when there is pressure. This kind of suspension system is most commonly used in heavy-duty trucks that deal with insane amounts of weight. 

Axles

Big rig trucks are some of the most fascinating vehicles you will see on highways, but how could these machines support so much weight?

Trailer axles

The axles of a trailer truck used for big rig jobs are some of the toughest among vehicles. Their axles could support a Gross Axle Weight Rating (GAWR) of up to 18,000 kilograms. (The GAWR is the maximum distributed weight that an axle could support.) 

With tough axles and heavy-duty suspension, trailer trucks could do wonders. 

The Fifth Wheel

Big rig trucks are some of the most fascinating vehicles you will see on highways, but how could these machines support so much weight?

The fifth wheel

The fifth wheel is the horseshoe-shaped coupling tool at the back of a semi-trailer truck used for a big rig that connects the trailer to the tractor head. It has a unique locking mechanism that secures the connection between the truck and the trailer. The fifth wheel has a “jaw” which locks the kingpin located under the trailer to secure the connection. The only way to unlock the jaw and release the kingpin is by pulling a lever in the fifth wheel. 

Big rig trucks are some of the most fascinating vehicles you will see on highways, but how could these machines support so much weight?

Kingpin under a trailer

The combined strength and security of the fifth wheel and kingpin make the hauling possible. The jaw is even usually made of forged steel for great durability. 

The fifth wheel is also covered in grease for lubrication. 

Engine

Big rig trucks are some of the most fascinating vehicles you will see on highways, but how could these machines support so much weight?

A Cummins diesel engine

Diesel engines are a staple in heavy-duty big rig operations. Unlike gasoline engines that use spark plugs for combustion, diesel engines use air compression for heat, maximizing the power harnessed from a fuel. Thanks to this setup, diesel engines produce higher compression ratios and long drive strokes compared to gasoline engines. 

To move thousands of pounds of mass, you need a powerful engine that produces face-melting amounts of torque like a diesel engine. Today, virtually all heavy-duty semi-trailer trucks are equipped with diesel engines. 

Quality trucks, parts, and services for big rig operations

Autokid Truck Solutions offers high-quality semi-trailer trucks from Dongfeng. We also have an extensive directory of spare parts and reliable after-sales services to support your business’s big rig operations. Interested? Call us at +639176530000 or visit any Autokid branch near you.

Media used and attributions:
1. Leaf spring suspension (no changes made) by Jim Gill (public domain) via commons.wikimedia.org
2. Air suspension (no changes made) by Jonathan D Borgia (https://creativecommons.org/licenses/by-sa/4.0/) via commons.wikimedia.org
3. Trailer axles (no changes made) by Tennen-Gas (https://creativecommons.org/licenses/by-sa/3.0/) via commons.wikimedia.org
4. The fifth wheel (no changes made) by GeorgHH (public domain) via commons.wikimedia.org
5. Kingpin under a trailer (no changes made) by Sterkebak (https://creativecommons.org/licenses/by-sa/3.0/) via commons.wikimedia.org
6. A Cummins diesel engine (no changes made) by User:Bidgee (https://creativecommons.org/licenses/by-sa/3.0/) via commons.wikimedia.org