Tractor trailers, also known as 18-wheelers or semi-trucks, are one of the most common types of vehicles on the road today. They are used to transport a wide variety of goods across large distances, making them an integral part of the global economy. But have you ever wondered how long these massive trucks actually are? In this article, we'll explore the different components of a tractor trailer and calculate its total length.
The Cab and Trailer
The two primary components of a tractor trailer are the cab and the trailer. The cab is the front part of the truck where the driver sits, and it typically measures between 70 and 80 inches wide and 120 to 150 inches long. The trailer, on the other hand, can vary in length from 28 to 53 feet, with the most common length being 48 feet. When attached, the cab and trailer create what is known as a tractor trailer combination.
The Fifth Wheel and Landing Gear
In order to connect the cab and trailer, a fifth wheel is used. This is a large metal plate that sits on the frame of the truck and is located towards the rear. It has a locking mechanism that allows the trailer to be securely attached to the cab. The landing gear, which is located at the front of the trailer, supports the weight of the front portion when the trailer is detached from the cab.
The Kingpin and Rear Underride Guard
The kingpin is a small metal cylinder located on the front underside of the trailer. It fits into the fifth wheel on the cab and allows the trailer to pivot when turning. The rear underride guard is a safety feature that is required by law. It is a metal bar that is mounted on the back of the trailer and is designed to prevent vehicles from sliding underneath the trailer in the event of a rear-end collision.
The Total Length of a Tractor Trailer
So what is the total length of a tractor trailer? To calculate this, we'll need to add up the length of the cab, the trailer, the fifth wheel, the kingpin, and the rear underride guard. Using the most common measurements, we get:
- Cab length: 120 inches
- Trailer length: 48 feet (576 inches)
- Fifth wheel length: 1 foot (12 inches)
- Kingpin length: 0.5 feet (6 inches)
- Rear underride guard length: 2 feet (24 inches)
Adding all of these together, we get a total length of 732 inches, or 61 feet, for a typical tractor trailer combination. Keep in mind that this is just an estimate, as the length of the trailer can vary depending on the manufacturer and the intended use.
Conclusion
In conclusion, the total length of a tractor trailer is determined by adding together the dimensions of the cab, trailer, fifth wheel, kingpin, and rear underride guard. The result is a massive vehicle that is essential for transporting goods across the country and around the world. Understanding the different components of a tractor trailer can help us appreciate the complexity and importance of these vehicles in our economy.