There are two types of trailers: full trailers and semi-trailers.
What does each type of trailer do? How each of them is being used? And how does a semi-trailer differ from a full trailer?
Below, in this article, you'll find out what's the difference between these types of trailers.
What is a semi-trailer
Semi-trailers are used in the trucking industry to haul long-distance freight.
The main distinctive characteristic of these types of trailers is that it doesn't have front axles. That means that the rear axle supports only half of the semi-trailer's weight. The other half of the weight requires some type of support.
Because of that characteristic, there are two methods to support the first half of the semi-trailer's weight.
- The first option is when the semi-trailer is attached to the back of the tractor attaching its kingpin to the tractor's fifth wheel.
- The second option is when the semi-trailer is not in use, it uses the landing gear to support its weight.
A semi-trailer is combined with a tractor to form a semi-trailer truck.
What is a full trailer?
In comparison with a semi-trailer, the full trailer's front and back axles support its entire weight.
To be pulled, the full trailer needs to be towed by a tractor vehicle.
The trailer uses a drawbar with a hook to attach it to the tractor's hitch.
The full trailer is used in factories, ports, terminals, and warehouses for short-distance transportation.
The main differences between a semi-trailer and a full trailer
Below are the major differences between a semi-trailer and a full trailer.
1. Axle position and weight support
- A semi-trailer has no front axles. So, spreading the correct tractor-trailer weight per axle is important to stay legal. They’re on the rear part of the vehicle to support half of its weight. The other half of the weight is supported by the back of the truck. Knowing how to distribute the weight on a semi-trailer is key to avoiding overweight issues.
- Full trailers have both front and rear axles that support the entire weight of the trailer.
2. Connection type
- The semi-trailer connects to a semi-truck by its kingpin. The kingpin is made of heavy metal. It’s a cylinder in shape, and it is located underneath the front end of the trailer. It’s the mechanism that locks the trailer to the truck.
- A full trailer is connected to the truck by its front hook attaching it to the tractor's hitch.
3. Dimension and capacity
- 48 to 53 feet long.
- 8.5 feet wide.
- 13 feet high.
They can carry up to 45,000 pounds.
The standard dimension of a full trailer is:
- 10 to 26 feet long.
- 8.5 feet wide.
- 13 to 14 feet high.
And they carry 33,000 pounds.
Typically, semi-trailers are longer than full trailers and can carry heavier loads.
In terms of logistics, semi-trailers are more popular than full trailers.
- Semi-trailers are used for long-distance hauling. They are easier to handle, to move, and to load and unload faster. Also, they are used to transport heavier and larger loads.
- Full trailers are normally used for short-distance to transport cargo to factories, ports, terminals, and warehouses. Most often, they deliver in different locations unloading cargo in the different drop-off points.
Between the two, semi-trailers are more popular, are most often used, and there are more semi-trailer manufacturers on the market.
But each has its advantages and disadvantages.
Full trailers are perfect for transporting lightweight goods in volume. They’re easy to drive and have low operational costs. Loads are usually local goods. There are times when a commercial driver’s license is not required.
Semi-trailers are ideal for heavier and larger loads. During snow and rain, they provide better traction than full trailers. Doing a reverse is also easier for semi-trailers because they only have a single turning point at the coupling. A full trailer has two turning points making it harder to reverse. The trailer, being detachable, allows easy loading and unloading. In case the truck or the trailer needs repair, it’s easy to attach another unit any which way.
In general, semi-trucks are ideal for long-hauls while full trailers are better for local goods transport. Full trailers have fewer maintenance costs but semi-trailers offer a lot of opportunities to earn higher.