The upgrades to the North Auckland Line includes an 8m-deep excavation near Ranganui, Kaiwaka, where 21,000 cu m of unsuitable, saturated soil had to be excavated and will be replaced with more suitable foundations.
The upgrades to the North Auckland Line includes an 8m-deep excavation near Ranganui, Kaiwaka, where 21,000 cu m of unsuitable, saturated soil had to be excavated and will be replaced with more suitable foundations.
The North Auckland Line has been closed by slips since the end of January 2023, when the region was hit by the Auckland Anniversary floods. Cyclone Gabrielle compounded damage to the line.
But good progress means civil works are set to be complete in the next few months, followed by testing, with the aim of a mid-year reopening, Northland rail upgrade programme director Eric Hennephof said in KiwiRail’s latest newsletter.
While the railway has been closed, KiwiRail has also upgraded the line from Whangārei to Kauri to take heavier, 18-tonne trains. It has also upgraded the Whangārei rail yard for greater freight volumes and fewer flood risks.
The line upgrade - completed from Swanson to Whangārei just days before the severe weather hit - will allow the line to run the same locomotives as used in the rest of the North Island and to run longer trains, Hennephof said.
In the newsletter, he thanked everyone for their patience, especially rail customers.
“We remain committed to reopening the North Auckland Line and making sure it can better stand up to future weather events,” he said.
But one rail proponent, Alan Preston from Save Our Rail Northland, said it would have been useful to have more details from KiwiRail about the closure, such as a map of where the slips were located.
He was concerned the long closure of the railway benefitted road-based freight, which had opportunities in the face of no competition.
Preston said rail needed to be prioritised as a transport alternative in New Zealand, which is the world’s most car-dependent nation and relies on importing millions of dollars worth of petrol each day - a supply chain that is not only vulnerable but produces about 17 per cent of the country’s greenhouse gases.
The upgrades to the North Auckland Line including working around a kāhu (swamp harrier) nest, found near the line in Wellsford in December.
“This is a perilously irresponsible and dangerous way to plan a remote island nation’s infrastructure,” he said.
But Whangārei Mayor Vince Cocurullo said both road and rail were important in Northland’s infrastructure.
He sees a four-lane highway between Auckland and Whangārei as a high priority as the highway would deal with the majority of traffic, even once a railway connection to Marsden Point was built.
But Cocurullo said rail was also important for heavy traffic and large volumes, and he believed KiwiRail had made steady progress on repairing the line.
Many people did not realise how difficult it was to fix a slip on rail line that needs to be perfectly level, as opposed to a road, which can have more give, he said.
KiwiRail’s latest update revealed some of the difficulties involved with the upgrade, including access to the slip sites, with contractors having to rely on long road trips due to the rail line being out of action.
Working around native bush was another difficulty, with KiwiRail engaging ecologists, erosion control specialists and the Department of Conservation to ensure native flora and fauna were protected.
In late December, the team had to work around a kāhu (swamp harrier) nest in dense grass close to the rail line near Wellsford, the newsletter said.
Marsden Pt link out of steam?
While $40 million from the Provincial Growth Fund was set aside to buy land needed for a rail link to Northport at Marsden Pt, a business plan for its construction has still not been approved.
In the October, 2023 hearing into Northport’s expansion, KiwiRail’s David Gordon said 73 per cent of the land needed to build the line has been bought, excluding iwi land, the coastal marine area and port land.
Engineering and geotechnical design had been funded to help inform the business case, but he admitted key issues were yet to be decided, with an impact of hundreds of millions of dollars.
Examples of these key issues included whether cut material could be used as fill elsewhere, and what height the corridor should be built relative to flood levels and assumed sea level rise.
Denise Piper is a news reporter for the Northern Advocate, focusing on health and business. She has more than 20 years in journalism and is passionate about covering stories that make a difference.
