Although it happens to be rounded, the “fifth wheel” refers to a specialized hitch that allows for easy drop-and-hook on commercial carrier vehicles. It isn’t a wheel at all. The original fifth wheel concept comes from all the way in the horse-and-buggy era and is based on a coupline used on carriages and wagons to facility easy turning. Patented in 1916 by Hermann Farr and Charles H. Martin under the Martin Rocking Fifth Wheel Co., the improved hitch not only made travel on unpaved roads easier it led to an increase in semi-trailer sales.
According to Commercial Carrier Journal, “Without a fifth wheel, the modern distribution system would look quite different as drop-and-hook would not be easy. The semi-trailer increased the capacity of trucks, but it was the fifth wheel that brought the flexibility for drivers to keep moving while receivers unloaded the loads they just delivered.” While the look hasn’t changed much, newer fifth wheels rely on the engagement of a kink pin into a locking mechanism to form the main connection between tractor and trailer.
Today, fifth wheels are standard on all of Kalmar Ottawa models assuring order, control, and efficiency to trailer handling that is critical to fast-paced work environments.