Why two semi-trailer brake
There is a tractor front brake, the other is a trailer brake.
Two hand you see there are two modes of some is divided into front and rear but that almost no Trailer main car and motorcycle is now a handbrake left when the emergency brake
A semi-trailer is a trailer that is placed behind the center of gravity of the vehicle (when the vehicle is uniformly loaded) and equipped with a coupling device that can transfer horizontal and vertical forces to the tractor. Semi trailers are generally three axle semi trailers, and their types are divided into eleven meters, warehouses, semi trailers, thirteen meters hurdles, low flat, semi trailers and many other species. The utility model relates to a heavy transportation vehicle which is connected with a semi-trailer head through a traction pin.
