The Northland Line upgrade project will renovate the rail line between Swanson and Whangarei. Credit: KiwiRail.
The construction work on the project started in June 2020. Credit: KiwiRail.
The project includes the construction of a container terminal at Otiria. Credit: KiwiRail.

KiwiRail is upgrading the Northland Line to enable the line to carry freight around New Zealand and improve the efficiency and reliability of the line. The project will upgrade the line to meet the standards of the rest of New Zealand’s rail network.

The project is expected to start carrying freight between Whangarei and Auckland by the end of September 2020, with the entire upgrade anticipated to be completed by the second quarter of 2021.

KiwiRail is expected to employ 200 workers across Northland for the upgrade project in addition to 12 local staff for the ongoing maintenance of the line.

Need for Northland Line upgrade

The Northland Line is estimated to be more than 100 years old with freight services often disrupted due to lack of maintenance. Issues such as slope stability, flooding and derailments have caused frequent outages and disruptions on the line.

The line remained closed for more than a week in 2018 following two major derailments that required hundreds of thousands of dollars to repair. The line also has lower speeds and weight limits compared to the remaining network. In addition, due to the outdated tunnels of the line, it cannot carry the same containers as the rest of the network.

The upgrade will address these problems while providing stronger connections within New Zealand.

Northland Line upgrade details

The project will upgrade the Northland Line between Swanson and Whangarei by upgrading or replacing 54km of tracks. In addition, approximately 50,000m³ of ballast will be added and 50,000 sleepers will be replaced.

Five wooden and steel bridges on the line will be replaced with concrete structures. Drainage improvements will be made to avoid flooding and maintain stability of the rail line. These works will include the clearing of drains along 180km of track and upgrade of 950 culverts.

The project will stabilise slopes on nine embankments by performing widening and drainage improvements. The embankments will be monitored to check if further civil engineering is required.

Kauri to Otiria section upgrade

The upgrade project will reopen the mothballed Northland Line between Kauri and Otiria. The reopening of the Kauri to Otiria section will include 60km of track refurbishment, and replacement of approximately 8km of track, 20,000 sleepers, and 15,000m³ of ballast.

A new rail-road trade terminal will also be developed in Otiria, which will include a 4,000m² hard seal that can expand up to 15,000m². The terminal will have a handling capacity of 50,000-60,000 container movements per year. It will feature a container repair facility, and an export zone certified by the Ministry for Primary Industries.

The project will include the upgrade of 13 tunnels south of Whangarei to enable hi-cube containers to be carried on the line. The track for three tunnels will be lowered and track lowering and modifications will be performed for six tunnels. Further, track lowering and structural improvements will be performed for four tunnels. Approximately 5km of total track and ballast will also be replaced.

Marsden Point Line details

The Northland Line upgrade will also include the purchase of land along a new spur line between Oakleigh and Northport/Marsden Point for the future development of rail corridor. The spur line will enable the line to be connected to Northport, a deepwater port located at Marsden Point.

The development of the spur line will generate economic benefits, while enabling freight to be shifted from road to rail. The geotechnical studies on the designated route were completed in January 2019. KiwiRail is currently working on the preliminary design of the route and construction methods apart from the estimated costs and timeframes.


The Government of New Zealand announced a $109.7m regional investment in Northland Line from the Provincial Growth Fund (PGF) in January 2020 for the upgrade of the Kauri to Otiria section of the line.

The new investment is in addition to $94.8m announced in September 2019 for carrying out maintenance and remedial work on the Swanson to Whangarei section of the line.

Further, $2.2m was invested to undertake geotechnical evaluations along the route of the proposed spur line to Northport / Marsden Point in early 2019. KiwiRail will utilise $40m from the PGF investment to purchase land along the planned Marsden Point Line route.

Contractors involved in Northland Line upgrade

The contract for the replacement of two bridges was awarded to United Civil Construction, a civil engineering construction company.

Clements Contractors is responsible for providing all the ballast materials for upgrades to the track.

Busck Prestressed Concrete, a precast concrete manufacturer, is supplying concrete sleepers.

Project benefits

The Northland Line upgrade will decrease traffic congestion and road maintenance by reducing freight transportation by truck. Lesser road transportation will also help in reducing transport emissions as transportation by rail produces 66% lesser emissions compared to transportation by road.

The project will enable the speed limits on the line to be lifted thereby decreasing the travel time for rail freight to Auckland by 1.5 hours. It will decrease line outages and provide producers and manufacturers in Northland with an efficient transport alternative.

The new Otiria container terminal will enable containerised agriculture, meat, and wood products to be exported from Auckland or Tauranga.