City Rail Link (CRL) is New Zealand’s largest transport infrastructure project, transforming how people move around Tāmaki Makaurau Auckland.
As part of Link Alliance, Tonkin + Taylor worked alongside industry-leading partners to help deliver a 3.45 km twin-tunnel underground rail link beneath Auckland’s city centre. The project connects Waitematā Station with the redeveloped Maungawhau Station, creating a modern rail network with three new stations, increased capacity, and more reliable journeys. By combining engineering, planning and environmental expertise, we helped deliver infrastructure that supports Auckland’s growth, improves public transport, and creates lasting benefits for communities for generations to come.

A transformative rail project for Auckland

City Rail Link is a 3.45 km twin-tunnel rail link extending up to 42 metres beneath Auckland’s City Centre. Once operational, it will transform Auckland’s rail network by allowing trains to travel through Waitematā Station in both directions, rather than terminating there. This creates a more efficient network, reduces journey times, and provides a sustainable transport solution for New Zealand’s largest city.

The project includes:

  • Waitematā Station, transformed into a two-way through station
  • Te Waihorotiu Station, a new underground station in midtown Auckland
  • Karanga-a-Hape Station, connecting the Karangahape Road precinct
  • Maungawhau Station, a redeveloped station connecting the East West and Onehunga West lines

Together, these stations improve connections across Auckland and support future urban growth and development.

Services

  • An alternative underground route of the rail alignment via Albert Street ridge (a value engineering approach adopted by AT)
  • ECI phase technical advice
  • Assessment of potential settlement effects on surrounding structures along the entire CRL alignment
  • Geotechnical peer review of the main temporary and permanent civil retention and breakthrough works
  • Preliminary design of alternative solutions, monitoring requirements and input into the construction methodology for the enabling works during the tender design phase
  • Geotechnical advice and support during the ECI phase, including alternative retention designs and value engineering improvements
  • Additional geotechnical site investigations
  • Preparation of the Groundwater and Settlement Monitoring Contingency Plan
  • Planning services involving coordination and preparation of the construction management plans required as part of the resource consent
  • Spaceproofing and layout planning of the running tunnels and platforms for all utilities and rail systems
  • Full detail design of the underground civil works
  • Geotechnical structures for the NASL connections
  • Leading and coordinating the design development and detailed design of the package as well as the delivery of various interim and enabling works packages
  • Running Safety In Design, design coordination and consultation workshops
  • Designer responses to Road Safety Audits
  • Design reviews and reports
  • General coordination with interfacing packages
  • Signals design, signage, and markings design
  • Vehicle tracking assessments and street design
  • Planning and consenting advisory
  • Engineering Geology
  • Environmental management
  • Contaminated Land
  • Air quality

Clients

  • Auckland Transport
  • City Rail Link

Year

  • 2012 – current

Link Alliance

Tonkin + Taylor was a member of Link Alliance, alongside City Rail Link Ltd, Vinci Construction Grands Projets, Downer, Soletanche Bachy International, WSP and AECOM. Working collaboratively across the alliance, we provided multidisciplinary engineering, planning and environmental services throughout the project’s design and delivery. Our teams helped solve complex technical challenges while supporting safe, efficient construction in one of New Zealand’s busiest urban environments.

Delivering complex underground infrastructure

City Rail Link presented significant engineering and planning challenges, requiring careful coordination across multiple disciplines and organisations. Our specialists worked closely with alliance partners to develop practical solutions for complex underground construction, supporting the delivery of:

  • 3.45 km of twin rail tunnels beneath Auckland’s city centre
  • Te Waihorotiu Station, a 300 metre-long underground station constructed using top-down cut-and-cover methods
  • Karanga-a-Hape Station, featuring two 33 metre-deep shafts and mined platform tunnels
  • Deep portals and rail connections to the North Auckland Line
  • Mechanical, electrical, fire, hydraulic and rail systems
  • Public realm upgrades surrounding all stations

This collaborative approach helped manage technical risk and deliver infrastructure that integrates seamlessly with Auckland’s existing transport network.

Creating long-term benefits for Auckland

City Rail Link is more than a rail project. It is a long-term investment in Auckland’s future, delivering lasting benefits for the city and its people.

Key benefits include:

  • Unlocking the full capacity of Auckland’s rail network
  • Faster journeys and reduced travel times across the city
  • Increased rail capacity during peak periods
  • Improved access to jobs, education and recreation
  • Reduced congestion on roads and bus networks
  • Better connections between communities
  • Opportunities for urban regeneration around stations
  • Encouraging greater use of sustainable public transport
  • Supporting Auckland’s continued economic growth

The project also leaves an enduring social legacy through workforce development, skills growth and stronger partnerships across the infrastructure sector.

Partnering with mana whenua

Partnership with mana whenua has been central to the City Rail Link from the outset, helping shape a project that reflects the history, identity and future of Tāmaki Makaurau. Working alongside the eight iwi of the City Rail Link Mana Whenua Forum, the project has integrated te ao Māori, cultural values and local narratives into the design and delivery of the new rail network. This is reflected in the station names, architecture, public spaces and the stories woven throughout the project.
The Mahi Ōkawa (formal blessing), led by tangata whenua Ngāti Whātua Ōrākei, marked an important milestone as the project entered its final readiness phase. It recognised not only the completion of a significant piece of infrastructure, but also the enduring partnerships, trust and shared commitment that have helped bring the City Rail Link to life.
For Tonkin + Taylor, being part of a project delivered in partnership with mana whenua has reinforced the value of collaboration in achieving better outcomes for communities, infrastructure and place, and in creating lasting benefit. It is a legacy we are proud to have helped shape.

A collaborative approach

Projects of this scale are only possible through strong partnerships. Link Alliance brought together local and international expertise to deliver one of the country’s most complex infrastructure programmes. Working alongside clients, contractors, designers, operators and mana whenua helped ensure better outcomes and that the City Rail Link reflects both the engineering ambition and cultural significance of the places it connects

City Rail Link will soon welcome passengers, marking a new chapter for Auckland’s public transport network and the communities it serves.

City Rail Link

Explore More Projects

LEAD Alliance Housing Development Programme, Auckland

LEAD Alliance Housing Development Programme, Auckland

Drury South Crossing Precinct

Drury South Crossing Precinct

Waterview Connection

Waterview Connection

Te Ara Tupua Horo Rangi Shared Pathway

Te Ara Tupua Horo Rangi Shared Pathway

Pukeahu War Memorial Park

Pukeahu War Memorial Park

previous arrow
next arrow

How can we help?

Get in touch with a Tonkin + Taylor representative today. Our friendly and knowledgeable team make it easy to find the right solution to suit your specific needs.

Get In Touch