Auckland’s long-awaited City Rail Link (CRL) has officially opened, marking one of the most significant rail infrastructure milestones in New Zealand’s history and transforming the way people travel across the country’s largest city.
The opening of the CRL introduces New Zealand’s first underground railway, delivering a major step change in rail capacity, connectivity and journey times across Auckland. The project comprises two 3.45km twin tunnels, significant upgrades to two existing underground stations and the construction of two brand-new underground stations, creating a faster and more resilient public transport network for the region.
Global engineering consultancy Mott MacDonald has been involved in the programme since 2012, providing technical expertise throughout the project lifecycle. Its role spanned concept and reference design, consenting, procurement and delivery, while acting as principal technical adviser across multiple engineering disciplines.
Working alongside project partners, the company coordinated specialists covering rail systems, stations, civil engineering, structural engineering, utilities, safety and systems integration. Drawing on experience gained from major underground rail programmes including London’s Elizabeth Line, Sydney Metro and the Melbourne Metro Tunnel, the team combined international best practice with a detailed understanding of Auckland’s rail network, local ground conditions and regulatory requirements.
In the final stages of delivery, Mott MacDonald supported City Rail Link Limited during testing and commissioning activities. This included overseeing systems integration testing to ensure control, fire, safety and communications systems operated as designed.
The consultancy also played a key role in establishing testing criteria, agreeing methodologies and supporting safety assurance processes. Alongside this, it assisted Auckland Transport and KiwiRail with asset readiness and handover activities, helping facilitate the transition of ownership from the project delivery partners to the organisations responsible for operating the railway.
Beyond its engineering achievements, the City Rail Link has become an international benchmark for sustainable infrastructure delivery. The project secured two Leading As-Built Infrastructure Sustainability ratings from the Infrastructure Sustainability Council (ISC), following two Leading IS Design ratings awarded in 2017.
The ISC also recognised the development as the world’s first infrastructure project to successfully embed Māori cultural values within its sustainability framework, establishing a new precedent for future transport and infrastructure schemes globally.
Peter Taylor, technical director for major projects at Mott MacDonald, said:
"City Rail Link is a once-in-a-generation investment that changes how Auckland moves, grows and connects. The opening marks the culmination of more than a decade of involvement in one of New Zealand’s most ambitious infrastructure projects. We are proud to have supported the project from its earliest stages through to opening day, bringing specialist underground rail expertise to New Zealand and supporting the delivery of a rail system that will benefit Aucklanders for generations."
Stretching from Waitematā Station in central Auckland to Maungawhau Station in Mount Eden, the City Rail Link converts Auckland’s rail network from a traditional terminus operation into a more efficient rapid transit system. As population growth continues, the railway is expected to significantly increase network capacity, improve accessibility to the city centre and support sustainable urban development for decades to come.
Image credit: Mott MacDonald
