Have you ever seen a huge truck on the highway and got scared of it right away? If your answer is yes, don’t worry, we won’t judge you. As we all have been there at some point thinking of these heavy load trucks being out of control on the highway (mostly thanks to the Final Destination movies!).
Even though getting close to some of the tandem axle trucks can be scary while on the road, the truck is perfectly stable and controllable with the axle system and braking mechanism. However, many are curious to know what is tandem axle.
If you are also one of those who hasn’t got a clue, then let me hint you with the famous Sci-fi character of the Transformers franchise named as Optimus-Prime. Familiar with the character? Then you know what is tandem axle truck.
What is a Tandem Axle Truck?
Tandem axle truck or trailers is a type of vehicle that uses two sets of axles which are situated one behind the other. The extra set of axles and tires on these types of vehicles allow them to carry heavy load while being stable on highways and motorways.
A tandem axle is mostly found on the rear of the typical 18-wheeled tractor. Most of these trucks use eight tires and wheels on the drive axles. This type of truck is able to support an incredible amount of weight as well as provide improved traction and stability even on poor road conditions.
How Does Tandem Axle Work?
Most of the heavy-duty trucks have what is referred to as tandem axles. To simply explain how this works it is important to understand that when the differential or power divider lock is engaged, each axle drives the vehicle despite the other axle having traction or not.
The engine of the vehicle directly sends power to the lead axle and the trailing axle receives its power through a short drive shaft that extends from the rear of the lead axle. The presence of this type of axle allows the driver to select drive power from the front axle only and can also be activated by a switch which divides the power between the two drive axles.
The tremendous strength that the tandem axle truck showcases makes it a good fit to be used as a dump truck, cement mixing truck and tankers. This type of truck is equipped with huge spring packs that are specially designed to carry the heavy load for transportation.
A tandem axle truck that is used in a dump truck application are required to not only support the truck’s heavy weight when loaded but also, they help to stabilize the truck when the dump-box is raised high into the air to unload. This type of tandem axle is also best for tankers. The sloshing of the liquid in the tank is sometimes able to rock the truck and it’s tires off of the road. In such cases, a weaker suspension system would likely fail to perform well.
What is a Double Axle Truck?
Tandem axle is also known as double axle truck. These types of trucks are especially built to lift and transport heavy loads without losing stability on the road. Most of the double axle trucks are fitted with a set of 18 wheels which tremendously helps improve the traction of the vehicle.
How Many Wheels Does Tandem Axle Truck Have?
There are many different types of trucks that use different types of suspension and axle mechanism. Some are called semi-trucks, 10-wheelers, bogey-trucks and trailers. However, the tandem axle truck are we are talking about are mostly fitted with a set of 18 wheels that are efficiently divided into 5 axles.
What is the Weight of Tandem Axle Truck?
A tandem axle truck is built to lift and transport heavy weight and thus itself has a large weight of its own which helps it acquire stability and traction on the road. A typical single axle medium-duty truck (commonly known as semi-truck) weighs around 10,000 pounds more or less. However, a tandem axle truck can weigh up to 17,000 pounds to 23,000 pounds.
How Much Weight Can These Trucks Haul?
The Federal laws clearly state and oftenly regulate gross vehicle weights and axle loads on interstate and motor highways. There are a predefined set of rules and regulations that you are required to follow when it comes to use tandem axle trucks for heavy-load transport and hauling. The heaviest permitted gross vehicle weight is up to 80,000 pounds. The maximum weight of a single axle is 20,000 pounds, with around 34,000 pounds as the upper limit of a tandem axle truck.
The most common tandem axle dump trucks can carry up to 13 tons per load. However, the thing to keep in mind is that the federal and state bridge laws also govern payload weights. If you are not certain about the amount of weight a truck is permitted to lift, check your truck’s weight rating for how much payload it can carry. You can also look at its gross axle, vehicle, and combined weight ratings for more details. Note that the maximum permitted loads can vary between city streets freeways and motorways.
Which Axle Drives on Tandem Axle?
All tandem axle trucks have axles with differential assemblies. Some are fitted with a standard differential and the others are paired with a power divider. However, there may be some confusion in determining which differential axle is active at any given moment. But in truth, both axles are driving the truck. When there is no loss of traction, both axles drive the truck. The differential or power divider lock can be engaged at any time which permits each axle to drive the truck. Depending on the truck’s design, it may also be equipped with wheel differential locks that independently allow the wheels to turn regardless of existing traction conditions.
