KiwiRail has started geotechnical investigations along a section of the route of the proposed rail link to Northport at Marsden Pt.
KiwiRail acting chief executive Todd Moyle said the scoping work would inform the business case for Northland rail currently being developed by the Ministry of Transport for the link from Oakleigh, south of Whangārei, to the deep-water port.
"We've held a designation for this rail spur for several years, and are very pleased to be now taking steps to determine how the line would be built, Moyle said.
"These investigations will provide us with more detailed information about the design and potential construction methods for the link, as well as costs and timeframes. To begin with, we'll be working at Mata Hill over the next few weeks, using a drilling rig to take samples from a number of locations. These will bore up to 30 metres into the ground to remove samples for analysis.''
He said KiwiRail was also investigating what associated works would be needed on the North Auckland Line to allow for more freight to be carried by rail in Northland.
"The Government has indicated its strong support for the value rail delivers in the regions and the benefits it brings for New Zealand by taking trucks off the road, improving safety and reducing carbon emissions, Moyle said.
"The work we are doing in Northland is one of a number of projects underway to ensure we deliver stronger connections for a better New Zealand."
The corridor for the rail link has been designated by the Northland Regional Council.