Tranz Metro Ganz Mavag units on Upper Hutt to Wellington service near Woburn. The system was electrified at 3000V DC from late 1940's. The distant Rimutaka Ranges were a formidable barrier for railways. A rare Fell center rail incline at 6.6% gradient (1 in 15) operated from 1878 until a 8.5Km long tunnel opened in 1955.
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.