B-double

Origin: So-called -"double" in Australia partly because of industry concerns about negative public attitudes to road trains. The "B" refers the load sharing axle group of the bridge "B" lead trailer with a 5th wheel coupling at the rear (between the trailers)- followed by a 5th wheel/turntable connected semitrailer as the second in the configuration. B-Doubles were initially developed in Canada, as B-Trains. The Australian freight road industry was able to persuade Governments to call them B-Doubles. This was to reduce potential confusion with road trains and also help overcome some public oppositi. Origin information sourced from Wiktionary contributors (CC BY-SA 4.0).