Railway electrification in New Zealand Railway electrification in New Zealand Railway electrification was initially adopted by the New Zealand Railways in New Zealand for long tunnels; the Otira Tunnel, the Lyttelton Rail Tunnel and the two Tawa Tunnels of the Tawa Flat Deviation. Electrification of Wellington suburban services started with the Johnsonville Line and Kapiti Line out of Wellington from the 1930s. Auckland suburban services were electrified in 2014–15. Electrification of long distance services on the North Island Main Trunk (NIMT) dates from 1986, although KiwiRail is now considering diesel operation of the NIMT. New long tunnels e.g. the Rimutaka Tunnel and the Kaimai Tunnel
Rimutaka Tunnel five-span 91 metres (300 ft) bridge across the Mangaroa River and two underpasses near Maoribank. There is a tunnel of 539 metres (1767 ft) near Maoribank, but on the eastern side where two short tunnels (220 metres (11 chain) and 180 metres (9 chain)) had been proposed through a spur it was cheaper to lengthen the line by 140 metres (7 chain) and have open cuttings. The construction of the Rimutaka Tunnel consumed: The first locomotives to work through the tunnel were the 560 kW DG class - the tunnel was too long for steam locomotives, making the Wairarapa Line