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 tunnel. Detailed surveys were completed in 1938/1939, but the project was again postponed due to World War II. After World War II it became a matter of urgency to consider a replacement. The H class locomotives were showing their age, the Incline was in bad shape, and maintenance costs were increasing. Between September 1945 and July 1947 four options were considered. It was accepted that no contour line could be the solution and that a tunnel under the Rimutaka Ranges was the only satisfactory answer. The adopted route was the shortest route, a tunnel between Mangaroa and Lucena’s Creek gully.