Semi trucks are made up of a tractor that does the pulling and a trailer to carry freight. In your search for a used semi truck, consider the types of loads you'll be carrying and how versatile you want your unit to be. If you are an independent contractor picking up loads from various clients, you might want to think about just buying the tractor. On the other hand, if you run a specialized service, such as transporting cars, you will most likely need both tractor and trailer.
Heavy Duty Tractor Design
Semi trucks are considered heavy duty vehicles that can weigh in excess of 33,000 pounds. That's just for the tractor. In the United States, that is considered a Class 7 rig, and it requires a Class-B commercial driver's license to operate. Tractors use either gas or diesel fuel, with most truckers preferring the latter.
Cab Designs – The Most Noticeable Difference
Semi truck cab designs vary depending on the manufacturer and the intended use of the rig.
- The cab-over design is flush with the windshield, giving it a shorter wheelbase. These are popular for longer trailers, or for pulling two trailers at once because they have a smaller turning radius. The cab sits directly over the engine and in most models the cab flips up to allow service and repairs. The driver can easily see out and down from the cab's far forward position.
- The standard design has a nose which houses the engine compartment. Access to the engine is either from the side, or from swinging the "nose portion" down. The cab sits in back of the engine, which means the driver sits farther back from the front of the rig. Some drivers prefer the standard design because it puts more metal between them and any obstacle in the roadway.
- Sleeping compartments are available for both designs. Used mainly by long-haul truckers, these sleepers sometimes offer as many perks as RVs. Many models offer a comfortable bed, lots of storage space and spaces for a TV, mini-fridge and a microwave. Deluxe models may also have high-end sound and HVAC systems operated from a convenient panel.
- The driver compartments have the latest in high-tech electronics. In deluxe rigs, this may include a SmartNav system, a Garmin navigation system designed for high-clearance vehicles, Internet and Bluetooth connectivity. You might be able to find a used deluxe truck model that has similar features, or you can also do an after-market installation of your preferred items.
Considering That Trailer
Both tractor designs are fitted with a universal hitch, along with electrical and brake connections. This allows you to hook up to nearly any type of trailer. Two single tires are on the one front axle, while the back of the tractor usually has dual axles holding four tires each. The hitch fits squarely on the dual axles, carrying the tongue weight. The tongue is the part of the trailer that attaches to the hitch.
If you've decided that you only need, or want, a used tractor, then you simply go to a job, back up to a waiting trailer, and take it to its destination. This gives you the freedom to pull an enclosed trailer one way and a flatbed trailer or a refrigerated unit on a back haul. Back hauls allow you to make money on more of your driving miles, rather than the increased possibility of driving an empty rig to the next job.
The Car Hauler – A Specialty Semi
Specialty trailers, like car haulers, have ramps that are pulled out and down to allow cars to be driven on to the rig. Since these car hauler trailers have an extended area that sits over the cab, they are almost always paired with their own tractors. Large car haulers are still considered semis because most may be unhitched, even if it is more difficult. Loading these trailers takes a great deal of skill and knowledge of the various hydraulic functions that move the ramps.
For more information, contact a company like Arrow Truck Sales.