Mixed manifest train from Wellington to Auckland has just descended the 2.5% grade of Raurimu Spiral. This is about half way along the 675Km long North Island Main Trunk. The central section from Hamilton to Palmerston North was electrified in the 1980's.
Trains on 3' 6" (1.067m) track from Whangarei to Bluff with virtually heritage rebuilt EMD and GE locomotives still the mainstay power. The network was privatized in 1990's and operated by Toll until 2008 when state owned KiwiRail was established.