The trailer of a semi is commonly referred to as a semi-trailer.
The trailer of a semi is commonly referred to as a semi-trailer.
● No Front Axle: Unlike full trailers, a semi-trailer has no front axle. Instead, it relies on the rear wheels and the connection to the tractor unit (the truck) for support.
● Hitching Mechanism: The front of the semi-trailer rests on the tractor unit via a fifth wheel coupling (also called a "kingpin" or "turntable") that allows the trailer to pivot when the truck turns.
● Detachable: A semi-trailer can be detached from the tractor unit, allowing the truck to be used with different trailers as needed.
● Cargo Capacity: Semi-trailers come in various configurations, such as flatbeds, dry vans, refrigerated units (reefers), and tankers, each designed to carry different types of cargo.
The combination of a tractor unit and a semi-trailer is often called a "semi-truck," "tractor-trailer," "18-wheeler," or simply "semi."