No stone, or boulder, left unturned to clear highway

Of all the damage caused by ex-Tropical Cyclone Jasper, arguably the most imposing was the 300-tonne boulder that cut the Captain Cook Highway near Rex Lookout between Cairns and Port Douglas.

The monster rock was deposited on the road after more than a metre of rain fell in less than a week following the coastal crossing of Jasper on 13 December 2023 just north of Port Douglas.

The record deluge triggered significant landslips, severely damaging the road at multiple locations and closing a 27-kilometre section of the highway between Buchan Point and Oak Beach. 

Motorists who would normally use the highway to travel from Cairns to the idyllic tourist mecca of Port Douglas were forced to detour through an inland route via Mareeba and Mount Molloy, adding roughly an hour of travel time and 80 kilometres to the trip.

Transport and Main Roads (TMR) crews faced the massive challenge of repairing the road to allow freight and other critical supplies to move between Cairns and Port Douglas, and doing so in time for the recommencement of school.

Once deemed safe to attend the highway, TMR crews reviewed the damage and made urgent repairs to restore access to affected communities.

These assessments also revealed the enormity of the task ahead to get the road fully operational once again.

More than 120 landslips and areas of coastal undermining had to be cleared, and about 50 culverts were either blocked with debris or required repairs.

And, of course, that boulder.

Dealing with a boulder the size of the one at Oak Beach – estimated at 300 tonnes – was a first. 

Logistical challenges, including removing the boulder without causing further damage to the road and transporting materials to a temporary stockpile, meant conventional removal methods were off the table.

But Queenslanders are renowned for rising to a challenge, and TMR crews proved equal to the occasion, leaving no stone unturned to reopen the highway.

TMR brought in ‘shot firers’, experts typically seen in the mining and quarrying industries, to skilfully manage the use of explosives to break the rock into manageable pieces without damaging the road.

Parts of the boulder lodged in the slope adjacent to the road were extracted using an excavator with a rock breaker mounted on a constructed ramp and platform to carefully control fragmentation and fall.

The entire process was carried out in an impressively swift four weeks. 

With emergency roadworks complete, the Captain Cook Highway between Buchan Point and Oak Beach reopened earlier than expected on 20 January 2024, just five weeks after the major landslips blocked access.

Approximately 65 pieces of heavy machinery, 15 trucks and close to 100 personnel swung into action to remove tens of thousands of tonnes of mud and debris from the road.

All of the smaller landslips were cleared prior to the road reopening, with about 75 per cent of the larger landslips cleared and ready for stabilisation activities should they be required. 

Road users can now travel between Cairns and Port Douglas via the coastal route, although several single-lane sections remain under traffic control.

Damage assessments and geotechnical investigations will continue over the coming months, and a significant program of reconstruction works will be required across the region.

Assistance will be provided through the jointly funded Commonwealth-state Disaster Recovery Funding Arrangements (DRFA).