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
Otford railway tunnel 8 original tunnels on the Illawarra line from Waterfall to Clifton. The Otford Railway Tunnel, the seventh after Waterfall, was the final major engineering project which permitted the linking up of the northern part of the Illawarra Line to the isolated southern part in 1888. The Otford Railway Tunnel opened on 3 October 1888. The single line connection was made at (old) Stanwell Park Station (now bypassed by the 1915 Stanwell Park Deviation). The tunnel was built of brick arched form and when built was the largest and steepest (5,985 feet long - 1824m - and 1 in 40 gradient)