Australia’s largest road infrastructure project
Brisbane’s $4.8B Airport Link was Australia’s largest road infrastructure project. It incorporated three discrete projects:
- Airport Link (APL) – a privately financed toll road including Australia’s longest road tunnel (at 6.2km) and a total of 11km of main road tunnel and ramps
- Northern Busway – a 3km, two-lane, two-way, bus-only roadway, including 1.5km of cut-and-cover and mined tunnels
- EWAG – a grade-separated interchange, including:
- A four-lane flyover
- A high capacity interchange
- Widening of the East-West Arterial to three lanes each way.
Complex engineering requirements
Construction methods included:
- Tunnelling through soft ground, using earth pressure balance tunnel-boring machines
- Mined tunnel sections through variable strength rock
- Sections of drill and blast excavation through hard rock
- Constructing caverns up to 14 metres high, 30 metres wide and 150 metres long where ramps intersected the mainline tunnels
Independent review and certification
APP was appointed as the Independent Verifier and Financier's Engineer, working across the design, construction and initial operations and maintenance phases of the project, in association with Hyder Consulting (now Arcadis).
As Independent Verifier, our role was to certify that the design and construction were carried out in accordance with State project documents.
As Financier's Engineer, APP:
- Certified monthly payments to the D&C contractor
- Reported on the program, identifying possible delays and proposed amelioration measures.
The project presented significant challenges:
- Technical complexity, traffic management, urban, environmental and community considerations
- Scale: more than 20,000 drawings to certify, and payment certificates of over $100 million per month across the three projects
- Organisational complexity: three discrete projects with separate owners and contracts.
We overcame these by establishing a strong pool of senior and experienced staff with diverse technical knowledge, to resolve disputes and verify that design and construction compliance was being achieved at all stages.
We also appointed a dedicated completions manager 12 months before contractual completion, to ensure the smooth execution of construction close-out, certification and commissioning of control systems.
We maintained clarity and focus on each of the three concurrent projects by managing them separately, employing separate design review and construction document systems.