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
Yimbun Railway Tunnel HC Stanley; the steel and concrete Harlin Rail Bridge over Maronghi Creek at Harlin; and the Yimbun Railway Tunnel. Approximately two dozen timber rail bridges are still intact, although their condition varies greatly. Yimbun Railway Tunnel is located between and from Wulkuraka station along the former Brisbane Valley Branch Line formation and is sited beneath a saddle between two knolls. Yimbun Railway Tunnel is a semi-elliptical, concrete-lined, straight tunnel that is long and has a gradient of 1:165 against north-bound traffic. It has an earthen floor and is approximately high at its apex. Both portals feature the date "1910". The