Mott MacDonald celebrates the opening of New Zealand's first underground railway

Auckland welcomes a new era of rail transport as City Rail Link opens

The City Rail Link (CRL) has officially opened, marking a historic milestone for Auckland and New Zealand with the launch of the country's first underground railway. The transformational project connects Auckland's rail network through two 3.45km twin tunnels encompassing major upgrades to two existing underground stations and two completely new underground stations, creating a faster, more connected and higher-capacity public transport system for the region.

Mott MacDonald has played a key role on the project since 2012, providing technical leadership through concept and reference design, consenting, procurement and delivery. As principal technical advisor, the company coordinated a multidisciplinary team of specialists across rail systems, stations, civil, structural, utilities and safety disciplines.

Drawing on experience from major rail and underground systems including London’s Elizabeth Line and Australia’s Sydney Metro and Melbourne Metro Tunnel, the local team combined this knowledge with a strong understanding of Auckland’s network, ground conditions, regulatory environment and community expectations.

More recently, Mott MacDonald supported City Rail Link Limited during testing and commissioning, overseeing systems integration testing to verify that control, fire, safety and communications systems performed as intended. As part of this, the company helped establish test criteria, agree testing methodologies and oversee safety assurance processes. In addition, it assisted both Auckland Transport and KiwiRail through asset readiness and handover, facilitating the transfer of asset ownership from Link Alliance and City Rail Link Limited to the organisations responsible for operation.

Beyond its engineering achievements, CRL has set new benchmarks for sustainability and cultural integration. The project became the first infrastructure development to achieve two Leading As-Built Infrastructure Sustainability ratings from the Infrastructure Sustainability Council (ISC), following two Leading IS Design ratings in 2017. The ISC also recognised it as the world's first project to embed Māori cultural values into its sustainability framework.

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 downtown Auckland to Maungawhau Station in Mount Eden, the City Rail Link transforms Auckland's rail network from a terminus system into a more connected rapid transit network. As the city grows, the project enables significant increases to rail capacity in Auckland and will transform access to the city centre.