Forecasts indicate passenger numbers at Brisbane Airport will grow to 47+ million by 2040, so Brisbane Airport Corporation (BAC) is investing $1.8 billion in capacity-related infrastructure to service this predicted demand. Central to this is the construction of Brisbane’s new runway system which is set to open this year after an eight-year planning and construction process. Part One of our chat with Paul Coughlan, Project Director of the New Parallel Runway Project, explores the technical aspects of the runway, including the innovative pavement materials used, and new developments in lighting and line-marking.

Costing approximately $1.1 billion, Brisbane Airport’s new runway is one of the largest aviation construction projects in Australia. It is a key piece of infrastructure that will enable Brisbane Airport to better meet the demands of the community it serves, now and for future generations.

The project consisted of a 3.3km runway, more than 12km of taxiways, navigational aids, airfield infrastructure and hundreds of hectares of airfield landscaping.

Work on the site began back in 2012, with the major stages of construction now complete. The runway is on track to commence operations on 12 July 2020, despite the current impacts of the COVID-19 pandemic on the airline industry. On completion, Brisbane Airport will have the most efficient runway system in the country, effectively doubling its current capacity.

BAC partnered with BMD Group, CPB Contractors, Jan de Nul and McConnell Dowell to deliver the new runway. In total, up to 675 people worked directly on the project during the peak period, with 90 per cent of project employees living in South East Queensland.

Aside from the hundreds of construction jobs already created, it has been estimated that by 2035 the new runway will lead to the creation of 7,800 new jobs and contribute an additional $5 billion in annual economic benefit to the region. For travellers, this project will also lead to a greater choice in airlines, destinations and flight times.

Eight years in the making

Eight years sounds like a long time to build a runway, but this complex project was constructed on difficult ground conditions which added an extra layer of work in order to create a flat, solid and reliable base. The new runway is located at sea level on what was historically the Brisbane River delta. As a result, the underlying soil is made up of very soft, waterlogged mud and silt.

Every development at the airport has been through a process of engineered compression to form a solid base before building up. Typically, this involves placing sand (or similar material) on the site to compress the soils below to the required firmness.

On the new runway site, 11 million cubic metres of sand was dredged from an approved location in Moreton Bay and placed on the site at varying heights depending on the softness of the underlying soils. It was left to settle and compact over a four-year period (2014-2018).

Paul Coughlan, Project Director of the New Parallel Runway Project at Brisbane Airport Corporation, said one of the key project challenges was locating such a large volume of sand within Moreton Bay without adversely impacting the environment.

“We did extensive mapping of seagrass, the dugong areas, the turtle areas, and the commercial and recreational fishing areas, and prepared a comprehensive Environmental Impact Statement (EIS) for presentation to the public prior to the Australian Government’s consideration for approval,” Mr Coughlan said.

“Overall, the scientific studies indicated that large-scale sand extraction in northern Moreton Bay was highly unlikely to result in major environmental impacts.”

Mr Coughlan said that the commercial dredging contractor advised using very fine sand – 250 microns. The sand was extracted from the Middle Banks area of Moreton Bay with a trailer suction hopper dredge, transported to a designated mooring site in the Brisbane River and pumped to the runway site via a 5km purpose-built pipeline.

“The sand was vital to provide a stable platform to enable the construction of the runway pavements,” Mr Coughlan commented.

During the four-year process, some areas of the site settled as much as three metres. While this process was underway, the project team moved onto finalising the design and layout of the runway pavements.

“During the pavement design phase, we spent a lot of time analysing all the rock quarries within 60km of Brisbane, because transport cost is always one of the biggest challenges,” Mr Coughlan said.

“For instance, we required 1.2 million cubic metres of rock. It wasn’t just a matter of finding a quarry with suitable rock, but also identifying the transport routes to the airport. We obviously didn’t want a lot of heavy trucking going through community and school areas.

“It was like assembling a recipe and choosing ingredients that had the right quality and the right cost while minimising community disruption. Once we had all the ingredients, building the pavement was reasonably straightforward.”Innovation in pavement production

Mr Coughlan said that the new runway features a flexible asphalt pavement, which is particularly suited to the poor ground conditions at the airport.

“We used asphalt on the existing runway, which has been there more than 30 years, and it performed really well,” Mr Coughlan said.

“Despite putting a lot of effort into surcharging and stabilising, at Brisbane Airport we get continual settlement. We’re forecasting over the next 40 years that we’ll have average settlements of 200mm after the new runway opens, compared to 300–400mm that has occurred on the existing runway since it opened some 30 years ago. Asphalt is better at adjusting to those subtle changes.”

In addition to pavement material innovations, the lighting at the runway was also forward-thinking, with BAC using LED lighting in the airfield as well as the Dryandra Road underpass.

“The Dryandra Road underpass is one of the first major underpasses where we changed the lighting specifications after we had started construction, as a result of industry developing LED lights that could meet all the visibility requirements in that underpass,” Mr Coughlan said.

“In terms of the airfield, we’ve also made sure that we’re running a full LED system out there. In due course, we’ll start to upgrade our existing runway and taxiway system to have LED lighting.”

The LED lights are much more energy efficient, which not only saves money, but also reduces carbon emissions and demand on the wider network.

“For example, the system can actually detect how much light is coming into the Dryandra Road underpass and adjust the LED lights accordingly, which uses a lot less power,” Mr Coughlan said.

“From a resilience point of view, the whole world is moving to LED lighting. The suppliers of the old HPS lights will probably start to phase them out over the next five to ten years, and we didn’t want to have to retrofit more modern lighting in a decade’s time.

“We’ve also heard from pilots that LED lighting is less harsh on the eyes. While it’s a very distinct light glow and beautifully sharp, it doesn’t cause squinting or a glint in the eye.”

One of the final steps in the pavement production process is line-marking, and Mr Coughlan said that the new runway utilised several innovations to improve the effectiveness of this process.

“Traditionally, a surveyor would go out with what we call a chainman, and mark everything out with a little spray can before the line-marking took place. Our contractor trialled – for one of the first times at an airport in Australia – a robot,” Mr Coughlan said.

“The operator used an iPad to mark out every line in the system, and with our satellite technology and GPS these days being so accurate, the tiny robot just went to work. What would typically take about five weeks to mark out only took a week.

“The second innovation is the paint itself. We’re using what’s called glass beading, which gives the paint more fluorescence. It offers enhanced visibility for the pilots, particularly at night or when it’s raining, which can make it challenging for the pilots to really see where the lines are.”Biggest learning during construction

Looking back over eight years of work, Mr Coughlan said that some of the most significant things he learnt during the project revolved around the delivery framework, relationships between designers and contractors, and collaboration and communication.

“When I look back, number one, my board and senior management backed us to have a client delivery team. So, we actually decided that we would project manage this whole delivery ourselves. We made sure we had really good skillsets in our team, covering all the major design and construction areas,” Mr Coughlan said.

“I think the relationship framework that we set up with the designers and contractors was outstanding. We decided that right from day one we would have a governance framework that really drove collaboration. One of the outstanding successes that we’ve heard back from our contractors over the eight years, is the relationship framework that BAC, its design engineers, and the contractors operated to. That to me was one of the main contributors to this project being successful.”

Mr Coughlan said the project also set some of the highest safety achievements for contractors while minimising disruption to airport operations, which all came back to having good communication measures in place across the entire project.

“We never disrupted the airport. We were building this right adjacent to live airfields, and we had no outage as a result of this construction. If you look at our on-airport tenants, we always made sure that they were aware if construction work was going to be occurring and updated them about what it would involve, and if things were taking longer than anticipated, or finding a few challenges, which you always do. It was about really opening up those communication lines.

“It comes down to collaboration and communication. I think if you can get everyone aligned on what success means, and as I said, it means different things to different parties. I think that’s what pleases me the most; it is we didn’t just see this as just let’s get this thing built on time, on budget, to the quality. It meant a lot more than that,” Mr Coughlan said.

 

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