Four years ago, Toowoomba and the Darling Downs was devastated by floods. It is a testament to the region’s resilience that it is now becoming a major hub for infrastructure projects.
The $1.6 billion Toowoomba Second Range Crossing, which will provide a second highway crossing of the Great Dividing Range, is set to begin construction this year. One of the features on the new highway which commuters will inevitably notice is the Brisbane West Wellcamp Airport, located 16km west of Toowoomba and 130km west of Brisbane.
The airport is the brainchild of Wagners, the family-operated civil construction company with interests in contract crushing, fly ash and environmentally friendly concrete and cement. Aside from being the first greenfield public airport development in Australia since Melbourne Airport opened in 1970, Brisbane West Wellcamp Airport is also the country’s first privately funded aerodrome.
From the outset, Wagners built a 2.9km by 45m wide asphalt runway capable of accommodating 747 style of aircraft and two regional airlines – QantasLink and Regional Express Airlines – began flights respectively from November 2014 and January 2015.
Although the runway and the terminal building were completed in mid-2014, construction of an industrial precinct is ongoing. The Wellcamp Business Park will feature landscaped streets, parklands and modern buildings and is likely to accommodate aviation training and maintenance services, transport logistics, warehouses, corporate offices, factory outlets and retailers.
To provide aggregate for the runway and other infrastructure, Wagners set up its own quarry at the airport site. It also brought in blasting specialist Sequel Drill & Blast (trading in the southern states as Impact Drill & Blast). The target was to extract more than eight million tonnes of basalt to provide rock fill for under the runway and aggregates for concrete, asphalt and other building materials.
Sequel Drill & Blast’s work at Wellcamp Airport commenced in July 2013 and has been ongoing. “To be successful getting awarded this job, we presented a solid and detailed expression of interest to Wagners,” Sequel’s general manager Xavier Montaner explained. “We were awarded the contract to deliver a complete Rock on the Ground service and we were responsible for the process to design, drill, load and fire each shot.”
Working to tight deadlines, every week Sequel Drill & Blast had to “safely and effectively put on the ground an average 230,000 tonnes of rock”. To achieve that, Montaner estimated that the group had to drill 7500 metres of rock. Overall, more than 40 shots have been fired on-site.
“The main challenge has been drilling and blasting material that could be processed on site in very large shots so economies of scale could be achieved and minimise disruptions during the construction of the airport,” Montaner elaborated. “We also had to design blasting with the aim of producing a rock size specification of less than 500mm. We successfully achieved this.”
Montaner said that full-time resources on-site were two to three Sandvik DP1100i drill rigs, working 24 hours a day for the majority of the project. A standard shot required between four and five drilling operators working Monday through Friday and four qualified shotfirers on the day of the shot. “All shots had to be within the industry’s standard requirements,” he added. “Vibrations had to be below 5mm per second and air pressure below 115dB. We’ve achieved these targets in each one of the 44 shots fired so far.”
The biggest of the 44 shots delivered 448,000 tonnes of basalt. Montaner explained that it required the drilling of 551 holes, the equivalent of 11,068 metres. All holes were 102mm. “The blast required the loading of 108 tonnes of explosives,” he said. “This is probably the largest shot that has ever been fired in an Australian quarry.”
As of February 2015, Montaner said Sequel had drilled and blasted 8,024,347 tonnes of basalt over 18 months. The average shot size was 182,000 tonnes.
Montaner added that Sequel has enjoyed an “excellent” working relationship with Wagners. “Both organisations have showed a high level of professionalism and commitment during the execution of the project,” he said. “Robert Payne, Sequel’s southern Queensland and northern New South Wales operations manager, was leading the project and he had a deep understanding of Wagners’ requirements. We were able to deliver ahead of schedule many times. Each shot was timely and carefully designed, drilled, loaded and fired by our team.”
While Sequel Drill & Blast’s involvement at Brisbane West Wellcamp has wound down, Montaner did not rule out other work there. “There’s a good chance that more drill and blast work may be required and we would be delighted to be part of it,” he said.