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
Tunnel Railway Romney, Hythe and Dymchurch Railway. As the new railway would not be carrying heavy loads and would be travelling only a short distance, it was built as a narrow gauge railway, with a track gauge of . This allowed the new branch tunnel to be built to far smaller dimensions than the existing tunnel, at just high and wide. Although a cable haulage system had initially been considered, Ramsgate Olympia decided early in the line's planning to electrify the line. A third rail system was rejected due to concerns for the safety of the large numbers of children expected to