Rail Network Rebuild
The Rail Network Rebuild (RNR) programme was completed in January 2026. The five-year-year rebuild delivered critical upgrades to ready the network for the City Rail Link (CRL) to open in the second half of 2026.
The modernised network will support shorter journey times, fewer delays and trains every 4-5 minutes at peak.
RNR replaced old foundations under tracks and upgraded drainage, allowing more reliable train journeys and a more resilient network. It focused on upgrading priority areas across the network, enabling an efficient rail network that can accommodate more trains per hour on every line that the CRL will bring.
RNR teams worked night and day, wherever possible, to make the most of full and partial network closures to complete vital renewals and upgrades. They removed existing rail and dug down up to a metre to replace aging rock foundations under the tracks, sleepers and ballast, and upgraded drainage to improve the network’s performance in weather events.
Watch these videos to hear RNR team members talk about their work.
How RNR was delivered
Most of RNR's final stages were delivered in extensions to scheduled rail closures. Train services have been typically suspended during major holidays so our teams can safely work on the tracks and inside tunnels.
This approach means relatively short, sharp closures and less ongoing disruption when passengers and freight suppliers need the network most.
The four-week 2025-26 Summer Rail Upgrade completed the final stages of the Rail Network Rebuild. There is some contingency during network closures from February to April 2026 to be used for a small amount of tidy-up and auxilliary works.
Find out where our teams are working and what we are doing here.
The Rail Network Rebuild programme delivered a decade’s worth of work over 18 months, enabling more efficient and smoother train services.
KiwiRail thanks Auckland commuters, passengers, our rail corridor neighbours and freight customers for their patience with these disruptions as we safely delivered the huge amount of RNR work needed to modernise the network.
KiwiRail Key Auckland Upgrade Projects
Rail Network Rebuild related documents proactively released under the Official Information Act.
Components of RNR
The Rail Network Rebuild is challenging work:
- Rail lines, sleepers and turnouts, which allow trains to switch between tracks, lifted away
- Existing foundations, compacted gravel that forms the base of the rail line, and ballast, the rocks the tracks sit on, dug out
- New foundations brought in and compacted to form a firm and resilient base
- New ballast brought in and compacted
- New drainage installed to prevent future deterioration of foundations
- The rails, sleepers and turnouts put back, aligned for safe and smooth train running.
This video shows how we replace the foundations under rail tracks.
Wherever possible we’ll also do proactive maintenance – such as replacing sleepers and trimming vegetation that would otherwise need to be dealt with in the coming years – and using the line closures to complete other rail related projects.
All railways require ongoing maintenance but we are planning ahead and trying to avoid the need to come back and cause further disruption in the future.
These photos illustrate some of the different types of work that go into the Rail Network Rebuild.
This work removes rail and digs out the original foundations, adds stabilising mesh, installs and compacts new formation, then replaces the rails, sleepers and ballast. This example at Sylvia Park includes adding a new crossover, which will improve flexibility on the network.
Using technology to get the job done quickly
To renew foundations quickly, KiwiRail is using a range of specialist machines and technology. These include:
Panel lifter
The panel lifter can pick up and put down up to 75 metres of straight sections of track and sleepers at a time.
Stabiliser
Stabilisers shake and consolidate the track formation, to ensure new formation is stable.
Tamper
Tamper machines measure the track placement, lift it, and pack the ballast underneath to hold it in place. It helps create a smoother ride for passengers and freight.
Rail grinder
Rail grinders smooth irregularities in the tracks and restore their profile, so they last longer. It also helps to improve the ride for passenger and freight services.
