CityRailLink Auckland UndergroundRailway RailEngineering

New Zealand's first underground railway begins passenger service

*Auckland's City Rail Link has opened as New Zealand's first underground railway, connecting the city through two 3.45 km twin tunnels. Source: Rail Technology Magazine*

New Zealand has opened its first underground railway, with Auckland's City Rail Link beginning passenger service on 13 September.

The project transforms Auckland's rail network through two 3.45 km twin tunnels linking Waitemata Station in the city centre with Maungawhau Station in Mount Eden. It also delivers two new underground stations at Te Waihorotiu and Karanga-a-Hape, alongside major upgrades to Waitemata and Maungawhau.

The City Rail Link changes Auckland's railway from a terminus-based system into a more connected rapid transit network. The new configuration is designed to increase rail capacity significantly, with the system planned to accommodate up to 54,000 passengers per hour during peak periods.

The scale of the opening was immediately visible. Around 90,000 rail boardings were recorded across Auckland on the first Monday following the public opening.

Delivering the project required much more than constructing tunnels. The programme combined underground excavation, station construction, structural works, rail systems, utilities, fire engineering, communications, safety systems and integration with the existing operational railway.

Around 500 BIM models were reportedly combined into a federated model, giving multidisciplinary teams a shared digital representation of the project. This allowed designers to identify conflicts between systems and improve coordination across stations, tunnels and operational infrastructure.

Virtual reality simulations, scenario testing and workshops were also used to assess normal, degraded and emergency operating conditions. These exercises informed details such as emergency wayfinding, accessibility arrangements and control-room layouts.

Testing and commissioning were particularly important because individual systems had to operate together before passenger service could begin. Control, fire, safety and communications systems were subjected to integration testing, while asset readiness and handover processes transferred completed infrastructure to the organisations responsible for long-term operation.

The significance of the City Rail Link extends beyond the tunnels themselves. By connecting previously terminating rail lines through central Auckland, the project removes an important operational constraint and allows trains to continue through the city rather than entering and leaving through the same terminus.

This provides the basis for greater service frequency, shorter journeys and improved access to central Auckland as the region grows.

The project has also received two Leading As-Built Infrastructure Sustainability ratings from the Infrastructure Sustainability Council, following earlier Leading IS Design ratings. Its sustainability framework also incorporated Maori cultural values into infrastructure planning and delivery.

Sources: megaproject.com, globalconstructionreview.com, railtechnologymagazine.com