The world has become a giant interconnected web of goods and materials all needing to move from place to place. Making sure everything moves safely and is accounted for takes industrial-strength know-how. It also takes specialized equipment that isn't too specialized.
The tractor and trailer, or truck as you know it, provides the best in general and specialized versatility. The tractor provides the power and you pick one of many types of trailers for the cargo.
Read on to learn more about the different trailers and what each class of equipment for trucks brings to your transportation needs.
When you think about it, the best way to transport anything is in a box. Boxes hold multiple items safely and are easy to stack and organize. Even things that don't fit in a box get thought of as boxed units.
Any object that can be transported in one piece becomes its own box, it might have an odd shape, but it contains everything in one unit.
This is the type of crucial thinking you need to make trucking logistics function.
Consider each trailer on this list a specialized box and it all comes together quickly.
The most common image when one thinks of a semi-trailer belongs to the dry van. This is a long rectangular box on wheels.
Dry vans are enclosed, protecting cargo from weather and other elements. They are best used with a raised dock for quickly loading and unloading.
Some models come with a lift gate that allows them to be used from ground level – these are very common in the LTL world and not so common in the FTL world.
A dry van that allows an intermodal shipping container to attach to it blurs the line between flatbed and van. They are considered dry vans for regulatory purposes.
The other typical square trailer seen on the roads is the reefer. These take the same shape and basic cargo capacity of a dry van but add a refrigeration unit.
They also have to adhere to rigorous airflow regulations designed to keep the internal temperature stable even as the external changes. Reefers draw their power from a combination of batteries, generation through the tractor's power, and diesel fuel.
Between the refrigeration unit and the extra fuel, reefers cannot haul as much weight as a dry van. Reefers can be used to keep products frozen, fresh, or heated to protect from freezing.
Unloading and repacking the trailer at warehouses and depots can put the cargo at risk. Produce, in particular, suffers from traveling too far and has led to more advancements on the sending and receiving ends than on the transportation side.
More an alternative loading method on the dry van than anything else, the Conestoga trailer uses a tarping system to cover its rectangle.
This allows cargo to be loaded along the each side which upgrades loading and unloading times – big benefit to drivers. Many flatbed and step deck drivers have transitioned from their old equipment to Conestogas because of the ease of “tarping”.
Another big benefit to a conestoga is that you have many of the bells and whistles of a dry van, however, it's built off of the chassis of a flatbed so therefore you can haul greater weights. It's a perfect piece of equipment for heavy machinery that needs side loaded/unloaded and for freight that is challenging to tarp.
The second most common type of trailer is the flatbed. These workhorses of the transportation industry are open, allowing varying sides of cargo to be loaded from either side or the rear.
Straps, chains, and other bindings secure the cargo from movement better than a dry van.
Flatbeds are not entirely flat, they actually bow along their length, allowing them to support heavier loads without breaking.
As cargo can be loaded and unloaded from multiple angles, flatbeds are useful for delivering cargo to multiple sites.
A side-kit (also known as a covered wagon) is a variation of a flatbed trailer with sides made of wooden panels attached to the bed. This leaves the top open to be covered with a tarp to protect freight from all elements.
This allows for easy loading and rapid unloading of certain types of cargo. Large, long, but irregular objects get loaded onto this type of trailer.
The step deck is a version of a flatbed designed to haul taller loads. There are two different beds on the trailer, the upper-deck and the lower-deck. The upper-deck is the same height as a flated and the lower deck is typically a foot and a half lower. The upper-deck is usually above 1/4 of the trailer and the lower-deck is the remainder.
Like flatbeds, step decks may be kitted out with side panels or even a conestoga siding. The important part is the two different levels of bed.
The double drop is a specialized piece of equipment that is typically used to carry very tall or heavy pieces. The bed has three different levels of elevation and sometime has additional axles.
Double drops have a unique design allowing them to piecemeal various types of freight on the trailer.
The removable gooseneck (RGN) trailer is another used for oversized freight. The front hitch is removable, which turns the entire trailer into a ramp for loading equipment.
The number of axles on RGN can ranges from 2 to 20 or more and are often custom-built for specific purposes.
No matter what type of cargo you deal with, one of these types of trailers will fit your needs. The history and evolution of transportation offer a lot of insight into why each was designed and how they found their niches.