A Guide to Tractor Trailers

Trucks move over 71% of the nation’s freight by weight. 11.49 billion tons of freight, primary shipments only, was transported by trucks in 2018, representing 71.4% of total domestic tonnage shipped. To carry the loads, these large trucks require a wide variety of trailers. Trailers are attached to the trucks as an extra carrier vehicle. They have no engine, only a chassis and wheels. This article reviews some of the basic types of trailers that operate in Texas and the United States. 

1. Flatbed Trailer 

Flatbed trailers are open-type trailers. Flatbed trailers are used to haul many kinds of materials. This type of trailer is the most common trailer being used today since it is very versatile. It can carry almost any type of product or material. Steel is the most common product they transport. The weight of flatbed trailers is around 100 pounds per foot of deck length. So, if the deck length is 16 feet, then it will weigh around 1600 pounds. The legal load for a flatbed trailer is 8.5 feet in height, 8.5 feet in width and 48 to 53 feet in length. The freight weight should not exceed 40,000 pounds. 

2. Dry Van or Enclosed trailer 

Products that don’t require a controlled temperature environment can be transported in a dry van. These are enclosed trailers that usually haul pallets or boxes of cargo. These freight containers are the most common in use. They are fully closed and sealed so the freight is protected from external influences. The goods inside are kept dry since these vans are weatherproof. The maximum freight weight for dry van trailers is 42,000 to 45,000 pounds. The maximum length of the dry van trailer is from 48 to 53 feet; its width is 8.2 feet, and the maximum height is 8 feet. 

3. Refrigerated or Reefer Trailer 

This type of trailer is temperature-controlled. Perishable and frozen food items are hauled in this type of trailer. The temperature inside of the trailer is controlled. Reefer trailers have a maximum freight weight of 42,000 to 45,000 pounds. The maximum reefer trailer length is 48 to 53 feet, its maximum width is 8.2 feet, and the maximum height is 8 feet. 

4. Drop Deck Trailer 

Drop deck trailers are also called step deck trailers. These are similar to flatbed trailers which are open space trailers. But a drop deck trailer can have a maximum freight height of 10 feet or less. Any goods that a flatbed could not carry, can be carried by a drop deck trailer. The maximum legal dimensions are 48 to 53 feet in length, the maximum width of 8.5 feet, and the maximum height is up to 10 feet. The maximum freight weight from drop deck trailers is 48,000 pounds. 

5. Lowboy Trailer 

A lowboy trailer has two drops in deck height. The first drop is after the gooseneck and the other one is right before the wheels. The deck becomes extremely low compared with other trailers. This type of trailer can haul heavy equipment such as bulldozers, industrial equipment, and more. The maximum freight weight for a lowboy trailer is 40,000 to 80,000 pounds. This depends on the number of axles used. The maximum well length is from 24 to 29 feet. Its maximum well height is from 18 to 24 inches, and the maximum width is 8.5 feet. The maximum legal freight height is from 11.5 to 12 feet, 

6. Conestoga Trailer 

The Conestoga trailer is designed with a sliding tarp system. This covers the cargo so that the items are not damaged underneath. Finish or moving parts of goods or equipment are protected with this tarp system. If the tarp is slid around the goods and equipment, they are protected from scratching and damage. The length of this trailer ranges from 48 to 53 feet. The maximum legal width is 8.2 feet and the maximum height is 8 feet. Its maximum weight capacity is up to 45,000 pounds. 

7. Power Only Trailer 

This type of trailer is used for towing other trailers. It usually comes with a fifth-wheel hitch. An overweight freight only allows four axles to be used. The maximum weight and dimensions of power only trailers depend on the type of trailer that is being towed. 

8. Removable Gooseneck Trailer or “RGN” 

Tall and heavy loads and equipment can be hauled by an RGN trailer. These trailers can carry loads of up to 150,000 pounds. This depends on the number of axles the trailer has. This type of trailer can have up to 20 axles. The maximum weight for an RGN is from 42,000 to 150,000 pounds. The maximum length is 29 feet with a width of 8.5 feet. The legal maximum height is 11.5 feet. 

9. Stretch Removable Gooseneck Trailer 

This trailer is similar to the RGN but its maximum length is 65 feet. This trailer can transport a great amount of load and equipment. The maximum freight weight for stretch RGN is from 42,000 to 150,000 pounds. The maximum width is 8.5 feet and the legal maximum height is 11.6 feet. 

10. Side-Kit Trailer 

The side-kit trailer has a wood side paneling and can carry loads that are not packed like gravel, dirt, and other unpackaged materials. The maximum height of a side-kit trailer is 8.6 feet, and the maximum width is 8.2 feet. The maximum load weight is 45,000 pounds. 

11. Belly Dumper Trailer 

To unload the payload, the belly dumper trailer opens its clam-shell type dumb gate at the bed’s bottom. This type of trailer is commonly used in road maintenance and agriculture. The belly dumper trailer typically weighs 12,500 pounds. It can haul 26 to 27 tons of aggregate per load. 

12. Converter Dolly 

Converter dolly trailers are used for towing trailers. It can usually haul two or more trailers behind one truck. This makes it possible to haul bigger loads. Dolly trailers are of different types and so have different weights. They typically weigh 400 pounds or more. Since the weight of the dolly trailer varies, its weight capacity also varies. But these types of trailers can carry very heavy loads.  

13. Specialty Trailer 

If you are hauling specific types of products or hazardous materials, then you should use a specialty trailer. With a specialty trailer, you can haul fuel and other liquid. But these types of trailers are under a lot of regulations. They can hold up to 200,000 pounds. The other dimensions are determined by state regulations.