Greening the Tracks: Link Alliance's Sustainable Rail Network Transformation

28/11/2023

Downer is one of seven companies that form Link Alliance, delivering the main stations, tunnels and systems for Auckland’s game-changing City Rail Link (CRL).

The CRL project has ambitious carbon reduction targets and to meet these Link Alliance embarked on several pioneering initiatives.

The integration of decarbonisation into Link Alliance decision-making has estimated a projected 60,500 tCO2-e reduction in total carbon footprint over the CRL’s 100-year design lifespan. This represents a significant 19% reduction, effectively lowering the anticipated carbon payback time to less than six years once the CRL is operational. Upon reaching operational status, the CRL is expected to reduce Auckland's transport emissions annually by a substantial 28,000 tCO2-e.

A key sustainability initiative was to utilise Building Information Modelling (BIM), in collaboration with Revizto, to help deliver a holistic approach to sustainability and efficiency for the project.

The Problem and Solution:

Link Alliance is required to quantify and reduce the project's embodied carbon emissions, a task traditionally undertaken manually during the final stages of design. This process is usually time-consuming, leaving little room for designers to make impactful changes.

Link Alliance proactively introduced a robust BIM platform, Revizto, to monitor the carbon footprint in real-time. The BIM model was able to incorporate data from over 100 design packages, which allowed the team to assess the environmental impact of different design decisions promptly.

This integration facilitated efficient design outcomes and provided a visual context for the project's stakeholders.

Benefits and Beneficiaries:

The initiative resulted in a more streamlined and sustainable design process, ensuring efficient use of resources, materials, time, and energy.

Designers, sustainability teams, and commercial departments benefitted from this approach, gaining insights into progress against the initial 15% reduction target, and in fact doing better than the target to reach a 19% reduction. The real-time collaboration enabled proactive decision-making and alignment among various stakeholders, ensuring the project's success.

Incorporating Revizto and BIM:

Revizto's features, such as Multiple Search Sets, Multistamping and Issue Tracking, and Custom Properties, empowered the Alliance to democratise data across disciplines.

BIM, coupled with Revizto, enabled 4D modelling, allowing visualisation of different construction stages, and facilitating efficient sequencing and design changes. This integration minimised errors, streamlined workflows, and ensured the project's adherence to sustainability goals.

Next Steps and Future Development:

This has paved the way for extending the process into the construction phase, further enhancing tracking, and ensuring the final design's environmental impact positively contributes to the project's goals. Through collaboration with the programming team, crucial alignment with construction schedules with the design, has enabled accurate comparisons between planned and actual material usage.

Conclusion:

The Link Alliance's innovative approach showcases the industry's potential for sustainable transformation. By addressing environmental concerns in real-time, the project not only met its contractual obligations but also set a precedent for efficient, sustainable, and collaborative rail infrastructure development in New Zealand.

This initiative indicates a significant step toward a greener future for the country's transport networks, emphasising the power of digital engineering in mitigating environmental impact while ensuring project success and holistic sustainability outcomes.