There are different types of semi-trailers that can accommodate a wide range o freight.
A semi-trailer is not simple a full trailer. It can have different semi-trailer dimensions or configurations.
If you need to transport frozen goods, then you might need to go with reefer trailers.
If you want to transport tall or wide freight, then you might need to go with flatbed trailers.
Or, if you need to transport goods that require protection from rain, sun, or dust, then you might need to go with dry van trailers.
Below is a list of different semi-trailer types and their uses.
Different types of semi trailers
1. Flatbed trailers
Flatbed trailers are the most commonly used thanks to their versatility.
These types of semi trailers are open from the top and sides which makes the loading and unloading process quick and easy. A crane can pick up/unload the load from the top while a fork lifter can load/unload the load from the sides.
Flatbed trailers are used to transport steel coils, lumber, industrial commodities, large equipment, large machinery, building materials.
Since the flatbed trailer doesn’t have a container covering the load, it might need a trap to cover the transported cargo.
2. Step Deck trailers
Step deck trailers are similar to flatbed trailers. Both trailers are open and have a deck.
The only difference between these types of trailers is that the step deck trailers have two deck levels, which allows them to carry loads taller than those carried by flatbed trailers.
Commonly shipped material is large equipment, building material, and large machinery.
3. Extendable Flatbed trailers
Extendable flatbed trailers are similar to flatbeds. The only difference extendable trailers have is their ability to stretch to accommodate loads that are too long to be shipped on standard flatbed trailers.
Extendable flatbed trailers don’t have a container and they are open from the sides and on the top.
4. Stretch Wingle-Drop deck
Step Deck trailers are a flatbed type of trailer with a drop in the deck of the trailer. In this case, the deck of the trailer has a top-level and a low level. These kinds of trailer are designed to ship freights that cannot be carried on a standard type of flatbed trailer, which is usually due to height restrictions.
5. Extendable Double Drop trailers
Extendable double drop trailers are used to haul unusually long loads that are can’t be transported by standard double drop trailers.
This is done thanks to the extendable middle section of the deck trailer adapting it to non-standard shipping needs.
With extendable double drop trailers, you can transport taller and shorter products at the same time. The taller products can be adjusted on the lower deck, also known as the “well”, and shorter products can be placed on the upper deck.
Depending on the weight of the load, the extendable double drop trailer may have 2 to 3 axels.
Common things carried on this type of trailers are heavy and long equipment and construction material.
6. Dry Vans or Enclosed trailers
Dry van trailers are one of the most popular trailer types in the freight transportation industry.
Almost anything from clothing to electronics, plastic, packaging, paper, dry grade food, batteries, etc is transported with a dry van.
What makes it so versatile is its enclosed container that protects the transported freight from external factors.
Also, the transported products in a dry van trailer can be organized on shelves or in storage cabinets.
The trailer is loaded and unloaded on the rear of the trailer while parked at a standard dock.
When learning to operate a dry van, the most important tasks a driver needs to know is backing up the tractor-trailer and the rules of tractor-trailer weight per axle distribution.
7. Refrigerated or Reefer trailers
Refrigerated trailers or also known as reefers are used to transport material goods that need to be kept under cool temperatures such as frozen foods, pharmaceuticals, or ice creams.
Though these types of trailers look similar to enclosed trailers, they have added proper insulation and cooling system installed inside, which adds additional fuel costs.
8. Lowboy trailers
A Lowboy trailer is a semi-trailer with two drops in the deck - one right behind the gooseneck and the second one is just before the wheels. As a result, this type of trailer sits close to the ground.
The drop construction frame of a lowboy trailer allows them to ship huge heavy-duty construction equipment that is usually heavier and weighs more than the cargo shipping limit of other types of trailers.
A Lowboy trailer with two axels can legally haul around 40000 pounds. However, the weight limit can be increased to 80000 pounds by adding the required number of axels accordingly (weight of the trailer and weight of the load added together).
Note: you would need additional permission from the authorities before carrying such heavy and over-sized loads on a lowboy trailer.
9. Removable Gooseneck trailer (RGN)
RNG trailer’s main feature is its drop in the middle of the trailer, known as “well”, which allows carrying tall objects.
The gooseneck or the front end detaches from the trailer allowing it to drop on the ground creating a ramp through which large machinery can drive directly onto the trailer. Once the large machinery is on the trailer, the detached portion of the trailer is reattached.
Depending on the carried weight, these types of trailers can use from 3 to 20 axles.
10. Stretch RGN trailers
The main feature of Stretch Removable Gooseneck Trails is its ability to stretch the deck accommodating long loads that standard RNG trailers can’t.
Apart from the extendable deck, extra axels can be added to balance the carried heavy load.
11. Specialized trailers
Specialty types of trailers are built to be used for purposes only and are not available otherwise.
For example, you can’t use a trailer specialized to carry large quantities of liquid to carry medications or food. Each kind of load needs to carried by a specialty trailer.
Using a specialty trailer require to have a permit and the drivers must have a special license allowing them to carry such loads.
13. Side-kit Trailers
A side-kit trailer is similar to a flatbed trailer but it additionally has removable sides and a tent covering the trailer from the top.
This type of trailers is used to transport material that can’t be packaged in containers such as granular material like crops, powder, gravel, coal.
This is especially important when shipping crops that require being protected from moisture and dirt during transportation.
14. Conestoga Trailer
Conestoga trailers are the type of trailers that provides an easy flatbed like loading and unloading experience and protects the load from wind, dust, dirt, and rain like dry van trailers do.
This feature Conestoga trailer is possible due to the installed tarp-on-frame system that is attached to the sides of the flatbed through the top. This tarp-on-frame system is moved to expose the flatbed trailer, which makes it possible to load or unload the trailer from the sides with a forklift or from the top by a crane.
Conestoga trailers are used to haul sophisticated machinery or large items that need to stay in excellent condition.
15. Power-Only Trailers
Power only trailers are used to transport an entire trailer from one location to the other location. It attaches the trailer to its tail and tows it to the desired location.
A power only trailer comes with a fifth-wheel hitch, pintle hitch, a ball, and a hitch.
Only four axles are allowed when the freight is overweight.
You might want to check semi-trailer brands.