Road train

The first identified road trains operated into South Australia's Flinders Ranges from the Port Augusta area in the mid-19th century.

[4] In 1900, John Fowler & Co. provided armoured road trains for use by the British Armed Forces in the Second Boer War.

[6] A road train devised by Captain Charles Renard of the French Engineering Corps was displayed at the 1903 Paris Salon.

[9] In the 1930s/40s, the government of Australia operated an AEC Roadtrain to transport freight and supplies into the Northern Territory, replacing the Afghan camel trains that had been trekking through the deserts since the late 19th century.

At 130 hp (97 kW), the AEC was grossly underpowered by today's standards, and drivers and offsiders (a partner or assistant) routinely froze in winter and sweltered in summer due to the truck's open cab design and the position of the engine radiator, with its 1.5 m (4 ft 11 in) cooling fan, behind the seats.

[10] After transporting stud bulls 200 mi (320 km) to an outback property, Johannsen was challenged to build a truck to carry 100 head of cattle instead of the original load of 20.

[11] Johannsen's first road train consisted of a United States Army World War II surplus Diamond-T tank carrier, nicknamed "Bertha", and two home-built self-tracking trailers.

Both wheel sets 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 the 20th century.

[12] The term road train is used in Australia and typically means a prime mover hauling two or more trailers, other than a B-double.

[16] In South Australia, B-triples up to 35.0 metres (114 ft 10 in) and two-trailer road trains to 36.5 metres (119 ft 9 in) were only permitted to travel on a small number of approved routes in the north and west of the state, including access to Adelaide's north-western suburban industrial and export areas such as Port Adelaide, Gillman and Outer Harbour via Salisbury Highway, Port Wakefield Road and Augusta Highway before 2017.

[14] A project named Improving Road Transport for the Agriculture Industry added 7,200 kilometres (4,500 mi) of key routes permitted to operate vehicles over 30 m (98 ft 5 in) in 2015–2018.

Darwin is the only capital city in the world where triples and quads are allowed to within 1 km (0.62 mi) of the central business district (CBD).

[16] Strict regulations regarding licensing, registration, weights, and experience apply to all operators of road trains throughout Australia.

Road trains are used for transporting all manner of materials: common examples are livestock, fuel, mineral ores, and general freight.

Their cost-effective transport has played a significant part in the economic development of remote areas; some communities are totally reliant on regular service.

Some of the heaviest road trains carrying ore are multiple unit with a diesel engine in each trailer, controlled by the tractor.

In order to reduce emissions and running cost, trials are made with road trains powered by batteries.

[28] In Finland, Sweden, Germany, the Netherlands, Denmark, Belgium, and some roads in Norway, trucks with trailers are allowed to be 25.25 m (82.8 ft) long.

[35] In July 2024, after 5 years of testing, HCTs have been permitted on Spanish territory, with lengths of up to 32 meters (105 ft) and 70 gross tonnes.

[36] Since 2016, Eoin Gavin Transport, Shannon and Dennison Trailers, Kildare have been trialling 25.25 metres (82.8 ft) B-doubles on the Irish motorways.

the regulations tend to be more severe and strict to avoid overloading and accidents, to adhere to the federal rules of transportation.

Cons mainly include very tricky reversing due to the multiple articulation points across two different types of coupling.

B-doubles are more heavily regulated, but routes are made available by state governments for almost anywhere that significant road freight movement is required.

However, because of their length and low accessibility into narrow streets, these vehicles are restricted in where they can go and are generally used for terminal-to-terminal work, i.e. wharf to container holding park or wharf-to-wharf.

The rear axle on each trailer can also pivot slightly while turning to prevent scrubbing out the edges of the tyres due to the heavy loads placed on them.

[46] The B-train principle has been exploited in Australia, where configurations such as B triples, double-B doubles and 2AB quads are permitted on some routes.

Alternatively, a BA triple sees this configuration reversed, consisting of a B-double with a converter dolly and standard trailer behind it.

In South Australia, larger road trains up to 53.5 metres (175 ft 6 in) (three full trailers) are only permitted on certain routes in the Far North.

In some parts of Australia, 'super quad' road trains up to 60 metres (196 ft 10 in) are permitted, consisting of four standard trailers connected via three converter dollies.

Converter dollies must have a sign affixed horizontally to the rearmost point, complying to the same conditions, reading "LONG VEHICLE".