What are the common types of B-couplings, how do they work and where are they used?
In several of the earlier parts of the course we have referred to fifth-wheel turntable couplings.
We explained that fifth-wheel couplings are used to connect prime movers and semi-trailers together.
Fifth-wheel couplings are also called B-couplings.
B-couplings are used in combinations involving a prime mover and one or more semi-trailers. They may also be used in other larger combinations involving a converter dolly.
There are two parts to this coupling.
The turntable part fitted to the towing vehicle is called a fifth-wheel.
The fifth-wheel may be mounted on a prime mover, on a converter dolly or to the back of a semi-trailer.
The second part of the coupling is called a kingpin and is fitted underneath the semi-trailer.
After ensuring everything is lined up and the locking mechanism on the fifth-wheel is set, the towing vehicle is reversed under the trailer to engage the fifth-wheel and kingpin.