The suburb of Oaklands Park in Adelaide's south has a vibrant central hub with plenty of community activity, particularly around the retail outlets, healthcare facilities, primary school and busy railway station.
Cutting through this busy local hub was a level crossing used by up to 40,000 vehicles every day, with boom gates stopping traffic for up to 25% of the peak periods. Trains were also speed-restricted in and out of the station due to uncontrolled pedestrian and cyclist movements across the rail corridor. For these reasons, the level crossing was flagged by the Department for Infrastructure and Transport (the Department) to be removed.
The complex and constrained site, encompassing an existing operational metropolitan railway line and major arterial roads and intersection, required a design solution that focused on minimising the impact on rail services and the public during construction.
Arup worked with the Department, McConnell Dowell and Mott MacDonald in an Alliance to deliver a solution that removed the level crossing by locating the new station’s platforms below street level. This allowed trains to pass underneath the traffic it had once interrupted and as a result, opened the area to pedestrians and cyclists, unlocked the roads for drivers and created a more connected community precinct.
40+years traffic congestion solved
24%average improvement in commuter peak travel times
19monthsdesign and construction
Removing the level crossing at Oaklands not only eased traffic congestion but renewed a precinct. It is a perfect example of how good design and collaboration is a key ingredient to creating outstanding infrastructure. ”Liam O’Donohue Victoria and South Australia Infrastructure Leader
Minimising disruption within a complex and constrained environment
The station site was immediately adjacent to an existing operational metropolitan railway line and surrounded by major arterial roads and intersection, making it critical that the design and staging minimised impacts on rail and road services and the public and local businesses during construction.
The key elements were:
Constructing the new station offline, with the adjacent existing station remaining functional for the duration of the project, having minimal impact on station users.
Lowering the Seaford rail line underneath Morphett Road with a top down construction approach, allowing the new rail line to be constructed offline and adjacent to the existing live rail.
Designing the bridge construction to be undertaken in halves.
This staged construction of the road bridge and off-line construction methodology enabled the fully commissioned station to be stitched onto the live network through only one main 24-day closure of rail services. Previous local rail projects saw lines closed for months at a time whereas Oaklands Crossing only required a few weeks.
Roads continued to flow, the previous station continued operation and the final occupation was kept to an absolute minimum.
Through detailed planning and ongoing collaboration with key stakeholders, Arup as part of the Alliance was able to successfully minimise disruptions to road users and Adelaide Metro train passengers. ” Jon Whelan Executive Director, Transport Project Delivery, Department for Infrastructure and Transport
Creating a successful place for people
By removing the level crossing, the station precinct now encourages walking, cycling and the use of public transport in what was previously a precinct dominated by vehicles. The greatly improved pedestrian and bicycle connectivity, safety and accessibility has resulted in a station precinct that encourages safe transport across all modes.
The deliberate decision to create a place for passengers and the general public to gather, saw the station precinct cutting narrowed and green space maximised at ground level both north and south of the station. The design also made it possible to retain a pre-European Remnant River Red-gum tree, which now forms a significant placemark in the upper plaza level of the station.
Working with COX Architects and ASPECT Studios to improve the local landscape and the daily lives of those who use it. The station is now easily accessible and has excellent passive surveillance to make it feel safe both day and night. By designing infrastructure to meet and respond to the needs of the people who use it, we have helped create a place for passengers and the general public to gather, enjoy and orientate themselves.
When clever design and creative construction come together you get successful projects like Oaklands. That’s why we enjoy working with Arup. ” Mario Russo General Manager SA/WA, McConnell Dowell
The universal use of 3D design tools
Universal adoption of 3D design tools was key to the project’s success, helping to create a truly collaborative approach across all disciplines. Each discipline designed and modelled using 3D software, and models were shared daily and combined weekly for coordination and clash detection. This process enabled the complex and potentially competing demands from each discipline to be evaluated against each other, optimising the design as the project progressed.
The design was communicated to the construction team through a combination of conventional drawings and 3D models, which helped to minimise additional requests for information during the site phase.