N: Road trains of the Outback


The juggernauts that replaced
bullock teams  and camel convoys

The need to transport goods over great distances across inhospitable country in the outback where there were no railway lines made Australia the ideal place for the development of road trains.

Australian road trains are long trucks. Really long.

Their development over 75 years has been critical to the survival of far flung places on the vast Australian continent.

The Guinness World Record for hauling the longest road train was set near Clifton on the Darling Downs in southern Queensland by Brisbane man John Atkinson, who drove a single Mack prime mover 140m in 50 seconds, pulling 112 heavy-haulage trailers. The record-breaking road train was 1,474.3 metres long – that’s a truck and trailer combination measuring almost 1.5 km.

The record-holder

That of course is not the standard road train configuration you will see in Australia – it was a record attempt, after all.

But road trains are an important contributor to the movement of freight across land to this day, despite the growth of freight railways and they have been so since the first one appeared in the mid-19th Century.

Early road trains consisted of traction engines pulling multiple wagons.

In war time as far back as the Crimean War, a steam traction engine was sometimes called in to haul multiple wagons through difficult terrain and conditions. They were also used in the second Boer War and other conflicts up to World War I.

Mack superliner road train

Today, road trains comprise a prime mover (tractor truck) towing a series of trailers. They are used in Australia, Argentina, Mexico, the US and Canada to carry freight to and from places not serviced by rail or freight that’s not suited to rail travel.

In Australia, they are most commonly seen in Western Australia, Central Australia and the Northern Territory, especially on the Stuart Highway north of Alice Springs, and the Victoria/Great Northern Highway between Katherine and Broome. Not all their routes are sealed roads, however and great clouds of red desert dust usually will signal that a road train is on the move in the outback.

The invention of the road train can actually be attributed to Great Britain.

The AEC Government Road train built in the 1930s by Hardy Motors, a subsidiary of AEC, for the British Overseas Mechanical Transport Directing Committee was intended for heavy transport in remote regions of the British Empire.

The AEC government road train - in its preserved version and at work in 1934.

The road train consisted of an eight-wheel drive tractor and two eight wheeled trailers. The first and last axles on the tractor steered in opposite directions giving good manoeuvrability. The trailers were self-tracking – the front and rear bogies turned in opposite directions. Thus, wheels on all twelve axles would follow each other in the same set of wheel tracks for better off-road ability.

Three AEC road trains were built, one going to Africa and one to Russia.

The third 8×8 was despatched to South Australia in April 1934 where it was operated by the State Government to transport freight into the Northern Territory, replacing the Afghan camel trains that had been trekking through the desert since the late 19th Century.

It comprised a 130 hp AEC 6-cylinder diesel truck connected with 2 Dyson self-tracking trailers.

The large radiator cooling the engine was mounted behind the “cab” and provided with a large pusher fan. A smaller fan drew air through the engine bay.

The brakes were unusual in acting on the rear trailer most strongly and so on down to the tractor.

In April 1934 the Government road train set off from Adelaide via Oodnadatta to Alice Springs. Arriving on 19 May, the trip of 1,100 mi (1,770 km) took more than three weeks. The AEC usually pulled two or three trailers. It was powered by a 130 hp (97 kW) diesel engine and travelled at 20-30 mph (32-48 km/h). It is estimated to have travelled off-road over 1.2 million miles (2 million km) in the Northern Territory from 1934 to 1946.

Today, road trains are quite common in outback Australia and an Australian, Kurt Johansson, is credited as the inventor of the modern version.

As noted on Jeremy Clarkson’s Australian episode of Motorworld on the BBC, Johansson, after transporting stud bulls 200 mi (320 km) to an outback property, 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 of thousand pounds and inspired by the tracking abilities of the Government road train, Johansson began construction. Two years later he hit the road with his Diamond T.

Bertha at work

Johansson’s first effort used a US 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 be steered, able to negotiate tight and narrow tracks and creek crossings. Freighter Trailers went on to build self-tracking trailers for Johansson and other customers as major innovators in transport machinery for Australia.

Today, road trains in Australia usually comprise at least three trailers.

The maximum weight for a loaded American semi-trailer is 80,000 pounds (36,287 kg) spread over 18 conventional wheels. Out in the wide-open spaces of Australia however, some “road trains” weigh more than 300,000 pounds (136,077 kg).

Australian road trains are most often seen carrying livestock or fuel.

Volvo NH15 Road Train
Photo: Sibylle Dreyer, Wiki

Another form of Australian road trains are the multi-unit haulers that work in the mining industry.

Jim Cooper, who arrived in Australian from New Zealand in 1970, established a transport business operating out of Darwin. His Gulf Transport grew into the Gulf Road Trains of Australia Group with more than 100 road trains running across Australia. The Cooper family also established the Brisbane-based Powertrans company in 2001 to give Gulf RTA a major advantage in mine haulage, underground and surface.

The Gulf RTA Group became a subsidiary of BIS (Brambles Industrial Services) in 2010.

The Pit Hauler system

Powertrans developed and built the Pit Hauler system – various combinations of trailers and power plants that could move mined material over longer distances and at greater speeds than the massive dumper trucks traditionally associated with surface mining.


Road trains can be very intimidating on the roads due to their sheer size. Road trains and other heavy vehicles need more space on the road and take longer to stop.

The Northern Territory Government offers this advice:

  • be patient – do not cut in front of road trains, especially when they are slowing down at traffic lights or turning.
  • do not overtake a turning road train, give them space and time.
  • keep your distance when travelling behind road trains on unsealed roads and use your headlights.
  • slow down and pull off the road and drive slowly on the shoulder of the road when approaching an oncoming road train on a single lane highway.
  • don’t drive in convoys, especially if you are towing a caravan.

When a road train starts to overtake your vehicle:

  • Maintain your speed.
  • Keep left and don’t move off the road.
  • Only slow down once the road train moves out to pass.
  • When the road train has passed flash your headlights to let the driver know that it is safe to move back in.

Before overtaking a road train:

  • Stay well back when behind a road train.
  • Make sure the driver can see you in one of the cab’s mirrors – if you can’t see the mirror the driver probably can’t see you.
  • Be certain you can see enough clear road space ahead.
  • Only overtake when you are confident you can safely do so.

When overtaking:

  • Signal, move out and pass quickly but sensibly.
  • Don’t move back in until you see both the road train’s headlights in your mirrors and don’t slow down.
  • You must allow more time to stop safely when driving behind a heavy vehicle or road train. Road trains take longer to stop.

It is recommended that travellers in the outback carry a UHF radio. This enables communication with the road train so you know where they are and also can be used in the case of an emergency.

US gets in on the act

The US government of the 1950s had the Texan company LeTourneau design wheeled land trains which could operate without the need for railway lines. Warfare at the time involved destroying rail links so the US Government decided it should have a massive roadtrain on standby.

LeTourneau came up with the TC-497 Overland Train. The first version was the LCC-1.

The US Army road train

A 600 hp (441.3 kW) diesel-powered generator in the cab sent power to all of wheels on both the cab and the four cargo trailers. The wheels were just over 10 ft (3 m) tall and very wide, to allow smoother-off road travel.

LCC-1 was so impressive that the Army contracted for a larger version, the Overland Train Mark II. It included a steering system that turned the wheels on the individual cars. Power could be increased by adding extra power cars along the train.

Lighter and smaller gas turbine engines supplied the power instead of a traditional diesel. The Mark II had a much larger six-wheeled cab that was 30 ft (9 m) tall. The smaller engine allowed the interior to support a crew of six with sleeping quarters, toilets and a galley. An additional two power cars and 10 cargo cars were built for testing. The train now stretched over 570 ft (173.7 m). On flat ground it could carry 150 tonnes of cargo at about 20 mph (32 km/h).

Only parts of these monsters survive, most having been sold for scrap.

Not a road train, but a car-carrier in China.
It is one trailer with side-by-side cars on top.

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