A road train or roadtrain is a trucking concept used in remote areas of Argentina, Australia, Mexico, the United States and Canada to move bulky loads efficiently. The term "road train" is most often used in Australia. In the U.S. and Canada the terms "triples," "Turnpike doubles" and "Rocky Mountain doubles" are commonly used for longer combination vehicles (LCVs).A road train consists of a relatively conventional tractor unit, but instead of pulling one trailer or semi-trailer, the road train pulls two or more of them. These should not be confused with land trains, which are relatively lightweight vehicles used for moving passengers. Australia has the largest and heaviest road-legal vehicles in the world, with some configurations topping out at close to 200 tonnes (440,000 lb). The majority are between 80 and 120 t (180,000 and 260,000 lb).
Road trains are used for transporting all manner of materials, with livestock, fuel, mineral ores and general freight the most common. Their cost-effective transport has played a significant part in the economic development of remote areas, with some communities totally reliant on a regular service. Overtaking a road train can be quite difficult. Patience, assistance from the driver, and large amounts of either clear road or horsepower are required. On the unsealed outback roads the road trains create huge amounts of dust that need to be reckoned with when overtaking.
HISTORY.... In the 1930s, the Government of South Australia operated a fleet of AEC 8x8 military trucks to transport freight and supplies into the Northern Territory, replacing the Afghan camel trains that had been trekking through the deserts since the late 1800s. These trucks pulled two or three 6 m (18 ft) Dyson four-axle self tracking trailers. With 130 hp (100 kW), the AEC's were grossly underpowered by today's standards, and drivers and offsiders routinely froze in winter and sweltered in summer due to the truck's open cab design and the position of the engine radiator behind the seats. Australian Kurt Johansson is recognised as the inventor of the modern road-train. After transporting stud bulls 200 miles (320 km) to an outback property, Johansson was challenged to build a truck to carry 100 head of cattle instead of the original load of 20. Provided with financing of a couple thousand pounds and inspired by the tracking abilities of the Government roadtrain, Johansson began construction. Two years later his first road train was running.
Johansson's first roadtrain consisted of a US Army WW2-surplus Diamond-T tank carrier, nicknamed "Bertha", and two home-built self tracking trailers. Both wheelsets on each trailer could steer, and therefore could negotiate the tight and narrow tracks and creek crossings that existed throughout Central Australia in the earlier part of last century. Freighter Trailers in Australia viewed this improved invention and went on to build self-tracking trailers for Kurt and other customers, and went on to become innovators in transport machinery for Australia. This first example of the modern roadtrain, along with the AEC Government Roadtrain, forms part of the huge collection at the National Road Transport Hall of Fame in Alice Springs,Northern Territory. ……………Wikipedia……