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
Wairarapa Line North Island Main Trunk section between Wellington and Palmerston North. The line originally included the famous Rimutaka Incline, which used the Fell mountain railway system to cross the Rimutaka Range between Upper Hutt and Featherston. In the mid-1950s, the line between Petone and Featherston was substantially realigned, with the line diverted to the east of the Hutt River between Petone and Haywards to serve new housing developments in northern Lower Hutt, and the construction of the Rimutaka Tunnel to replace the Rimutaka Incline. Part of the former route west of the Hutt River has been retained as the Melling Branch.