This is our semi tractor. She pulls several kinds of trailers, depending on the job.
A semi tractor is the pulling unit in a tractor trailer combination, the most common thing that you see on the roads. It is commonly referred to as a truck. Tractors have a large diesel engine that can pull a lot of weight. The standard tractor is licensed for 80,000 pounds. There are some that haul far more. A tractor itself is just a powerhouse.
The most common way of attaching a trailer is a fifth wheel. This is a large plate with a slot in the middle. Trailers have a pin that slides into this slot, and is locked in place by a large jaw. This allows the tractor to pull, turn, and control the trailer. There is a light cord that is plugged into the trailer, powering the trailer lights and syncing up the lights on the back of the tractor with the lights on the back of the trailer. The last thing that connects the tractor to the trailer is 2 air lines. A trailer has 2 air systems, one is used for braking and sometimes for actuating the trailer in some way, depending on the trailer. The second is emergency brakes. This is a fail safe, if something happens to the common air, so a driver can get stopped safely. These tractors can have many names depending on their configuration .
Some tractors are called a day cab. These are just a cab with the controls and seats. Some tractors are equipped with a sleeper. This is a compartment that gives a driver a bed in the truck. Sleepers can be very small, like a cot, and others have full sized beds, TV’s and even bathrooms!
A semi truck is also called a tractor, a power unit, a truck or a semi. These are all different names for the same piece of equipment.
- A semi tractor is a power unit that has a fifth wheel plate that allows it to connect to a trailer. There are many types of trailers, which we will discuss later.
- A full sized semi truck has a motor that is big enough to haul 80,000 lbs or more in the US.
- Semi trucks run on diesel fuel. Most trucks average between 5 and 6 miles per gallon. It takes a lot of fuel to pull these big loads all over the country.
- Most trucks have 10 tires per truck. The traction provided by all these tires is vital both for moving and stopping these vehicles. Trucks can add axles in order to haul more weight in some states.
- Some units have a bedroom on the back. This is caller a sleeper. A sleeper allows a driver to rest when other options are not feasible.
- Driving a semi truck requires a special license called a CDL (commercial driver’s license). Semi trucks and their drivers are subject to random inspections at designated ports along roadways, as well as by roaming compliance officers.
- Drivers are subject to hours of service rules set up by the federal government. These rules often change and can be very convoluted.
- Semi trucks require special insurance, licensing, markings, paperwork, as well as being taxed specifically.
- Driving a semi requires a person willing to be away from home for long periods of time, willing to deal with inclimate weather, willing to jump through bureaucratic hoops, willing to be alone for many hours everyday while staying alert.
What is a semi tractor? It is a large piece of equipment that requires a certain kind of person to run it capably.
For now, just remember that a tractor is a pulling unit that can be hooked to many different trailers. The trailer actually determines what job you can do…a tractor just provides the power to do the job. And sometimes a place to live while you are doing it.
