KiwiRail is unwrapping its Christmas gift early, in the form of upgrades and improvements to the Auckland railway networks.

A variety of rail projects will be chugging ahead between December 26 and January 23, which will see all rail services replaced by buses for three weeks.

While general maintenance will be carried out across all rail lines, the focus over Christmas will be to extend electrification from Papakura to Pukekohe, continue construction on a busy line between Westfield and Wiri, and replace track in the complex entry to Britomart Station.

SIMON MAUDE/STUFF

Auckland's rail network will shut down over the festive season for upgrades to the tracks. (File photo)

There will also be general track repairs done for lines across the metro area.

KiwiRail’s capital projects and asset development manager David Gordon said the plan behind shutting down all rail for three weeks was to get multiple projects completed over a short time period.

“We thank all stakeholders, commuters and especially our neighbours for their patience while we carry out this important work,” he said.

“Our teams will be progressing the $1.5 billion suite of projects which will enable a world-class rail service for Auckland Transport’s passenger trains and greater capacity for freight trains.”

The works would be done during both day and nighttime, rolling out track machines such as tampers, ballast cleaners and rail grinders as more than 1000 people work on the projects.

AUCKLAND TRANSPORT/SUPPLIED

A variety of rail projects will be chugging ahead between December 26 and January 23, and all rail services will be replaced by buses for the first three weeks. (File photo)

From January 17 to 23, buses will replace trains on the Western Line, and between Newmarket and Britomart for other services.

KiwiRail said its upgrades would not impact on the transport of freight. Temporary truck services would be set up to replace freight trains travelling to Hamilton and Whangārei, during portions of the upgrade timeline.

The Ports of Auckland would see its freight service re-routed during the upgrades, with the line running through its inland depot at Wiri through Newmarket, instead of the usual Eastern Line along the waterfront.

KiwiRail teams would also carry out rail works in Northland, Mount Maunganui, and Wellington over the Christmas period.