Kurt Johannsen's 1942 road train moved 100 cattle with one driver

In the early 1940s, Kurt Johannsen — a bush mechanic born and raised around Alice Springs — was asked by a property owner why he could not build a truck that moved 100 head of cattle at a time. The tracks to outback cattle stations were narrow, unmade, winding and sandy.

Johannsen answered with the road train. Using a Diamond T 980 and bogies built from the wheels and axles of 23 surplus army gun trailers, he built three 13-metre trailers that tracked the prime mover's path. The 54-metre 'Bertha' carried 100 fully-grown cattle over bush tracks with a single driver, where the alternative was many trucks or many trips.

The self-tracking trailer was the key invention: each trailer steered itself along the ruts of the vehicle ahead, so a long train could still negotiate winding bush tracks. The Northern Territory government's Territory Stories archive calls Bertha 'the first ever road train'; 4X4 Australia credits Johannsen with the first successful example.

Trailers that follow the truck's own tracks

One engine and driver replaced several rigs and crews

Surplus army parts made the experiment affordable

Self-tracking bogies let a 54-metre train follow bush tracks

Cattle haulage proved the economics on real routes

When the road is the constraint, don't widen it: stretch the vehicle and make every axle follow the tracks the front wheels already make.

Johannsen grew the fleet to three prime movers and nine trailers, and road trains became the standard way to move cattle, fuel and freight across remote Australia. Bertha was restored and sits in the National Road Transport Hall of Fame in Alice Springs; Johannsen died in 2002 at 87.