I've driven west from Mount Isa numerous times, heading to Camooweal and points in the Territory. The first time I drove it was in 2002 when the Mount Isa to Camooweal stretch was mostly just one lane. But otherwise it was a fine road to Tennant Creek, and since those times even the Queensland section has improved out of sight. Around 50km west of Mount Isa there is a caravan resting site with a monument commemorating the opening of the site in 1995 and also a section of the older original road still visible. Nearby, as cars and trucks zoom past at 110kph, interpretative signage tells the history of the road, built as a wartime project.
The signage notes the preserved old road shows the design standards of the 1940s. The road hugs the natural surface crossing floodplains and crests. The sign said the adjacent modern road, the Barkly Highway, built in 1994 is a stark contrast. The sign also acknowledges the site was built on Kalkadoon land, who formed part of the workforce in war times.
Before World War II, the road between Mount Isa and Camooweal was little more than a droving track. The track followed the 1897 telegraph line and meandered from waterhole to waterhole across ridges and black soil plains. That might have sufficed for moving cattle but was hopeless for moving war materiel. By 1940 Australian governments finally had to look seriously at the problem of getting soldiers, equipment and supplies to Darwin, where the threat of the Japanese was all too real. In 1940 the Queensland Main Roads Commission was given the task of building a road west from Mount Isa to Tennant Creek, where other crews were building another road north from Alice Springs.
Engineers designed a new route, 10km shorter than the Telegraph route and work started in earnest in January 1941. But progress was slow. There was not enough money allocated to the project and there were chronic shortages of manpower and equipment. Nevertheless pressing concerns of war meant traffic used whatever sections were available as soon as they were built and by year's end 1000 vehicles a day used the road, adding to its wear-and-tear.
It wasn't until May 1942 that the new Allied Works Council took over management of the road, With Commonwealth funding and machinery borrowed from across Queensland, the road took shape. Work continued around the clock to gravel the road, By October they had completed important bridges over Spear Creek and the Buckley, Georgina and Rankine rivers meaning jeeps could avoid hazardous boggy causeways. But heavy use still meant constant maintenance and by end 1943 the road was almost five metres wide, which it remained to war's end.
Former World War II serviceman Alex Tanner writes of the building of the road in his 1995 book The Long Road North. As the title suggests, his focus was on the Stuart Highway, which linked Alice Springs with Darwin but the Barkly is also part of his story. Tanner notes the incredulity of local cattlemen who scoffed at the idea of putting an all-weather road over the treacherous black soil plains or sealing the stretches of shifting bulldust which grinds down to fine powder with the slightest of traffic. Nevertheless the power of bulldozers and graders made it happen.
Creeks were a major problem requiring reinforced concrete fords over larger creeks while smaller ones were kerbed and gravelled, as there was not enough time to install pipe drains. They pulled down trees with soft-tempered steel wire rope as Diesel-powered Caterpillar angledozers and trailbuilders worked 24 hours a day to clear the land ahead of the formation graders. Hurricane lamps were used at nighttime to keep the line in the dark. Problems included ever-present dust, flies, snakes and anthills which regenerated on the road as quickly as they were pulled down. Tanner noted it was a four day journey from Alice to the Isa and on the last day "winding gullies cut deeply into the soft rock and the road traced a circuitous way in and out of gullies and narrow creek flats" before finally in the late afternoon of the fourth day "the curling smoke from the mine stack at Mount Isa, hanging in the still afternoon sky, pointed the location of the dusty little mining town."
The December 1941 Pearl Harbor attack brought the US into the war and the Americans were given the use of the railroad to Mount Isa and the new East-West road springing up to Tennant Creek. By early 1942, 56 trains a week were arriving in the Isa and American troops were stationed there until April 1943. The road west was thrashed by the huge increase in traffic with 2500 personnel and 1500 vehicles regularly using the road. Tanner said the mainly Black American jeep drivers were not disciplined when it came to speed limits and accidents were common. Crews were admonished for travelling 50mph "grossly excessive over the newly constructed gravel surface" while trucks overturned in the treacherous bulldust. The Mains Roads Commission had to rebuild the entire Queensland section in 12 months. A plan to build a pipeline from Isa to Birdum in NT to transport fuel was ruled out as impractical.
Initially the east-west road was unsealed but it was always Queensland's intention to seal it. Based on the north-south experience the Allied Works Council decided the most appropriate technique was emulsified bitumen. A better method would have been "straight" bitumen heated in a continuous mixer but the quantities of fuel required made that prohibitive with very few trees along the line. Emulsified bitumen was a more liquid product which penetrated into the gravel base rather than forming a carpet over it. They applied a primer coat of crude tar which sank into the gravel. A "tack" coat of emulsified bitumen was followed by a machine-rolled "penetration" coat and finally a seal coat with finer grit, rolled and drag broomed.
The high water content needed for emulsified bitumen was a transportation problem with so few natural water supplies. They solved this by mixing the bitumen and emulsion at Mount Isa using the least amount of water, then transporting the rest to dumps along the road where the balance was added from available bores. The emulsified bitumen was carried in 44 gallon drums to 400 ton dumps spread at 32km intervals. The final cost of the road was £1,020,700, a very substantial amount at the time. But the end product was testament to the army's work. The legacy of the road was that it was unaltered for another 20 years improving the lives of North West Queenslanders and making the the Territory - and the rest of the state - accessible.