Australia’s long, remote roads are traversed by giant multi-trailer semi-truck combos, and here’s why these iconic heavy-duty beasts are called B-doubles.
The reason why some semi-trucks are called ‘B-doubles’ in Australia can be traced to the country’s National Heavy Vehicle Regulator (NHVR) and its classes of heavy vehicles in the Heavy Vehicle National Law (HVNL). The HVNL, in its own words, « .provides for three classes of heavy vehicle as a means of managing access for different types of heavy vehicles. » B-doubles fall under Class 2 heavy vehicles in the HVNL.
According to these Australian regulations, « B-double means a combination consisting of a prime mover towing 2 semitrailers, with the first semitrailer being attached directly to the prime mover by a fifth wheel coupling and the second semitrailer being mounted on the rear of the first semitrailer by a fifth wheel coupling on the first semitrailer. » In other words, a B-double is a semi-truck with two trailers, both of which are connected to it using fifth-wheel couplings.
The origin of the B-double truck goes back to Bob Pearson, who has been called the ‘father of the B-double.
