North Island Main Trunk

The North Island Main Trunk (NIMT) is the main railway line in the North Island of New Zealand, linking Wellington, the capital, and Auckland, the largest city, via Paraparaumu, Palmerston North, Taihape, National Park, Taumarunui, Te Kuiti, Hamilton, and Pukekohe.It is 681 kilometres (423 mi) in length, of New Zealand rail gauge of 1,067 mm (3 ft 6 in). Most is single track with frequent passing loops, with double track most of the distance between Wellington and Waikanae, and between Hamilton and Auckland. The main exception to the latter is the 13 kilometres (8.1 mi) of single track from Te Kauwhata to Amokura, which uses CTC, whereas the rest uses Double line automatic signalling. Around 460 kilometres (290 mi) of the line is electrified in three separate sections: 55 km at 1500 V DC between Wellington and Waikanae, and 412 km (256 mi) at 25 kV AC between Palmerston North and Te Rapa (Hamilton) and 34 km (21 mi) between Papakura and Britomart (Auckland CBD), electrified in the 2010s.The first section of what became the NIMT opened in 1873 in Auckland. Construction of the Wellington end began in 1885, and the line was completed in 1908 and fully operational by 1909. The line is credited for having been an economic lifeline for the young nation, and for having opened up the centre of the North Island to European settlement and investment. In the early days, a passenger journey could take more than 20 hours; today, the Northern Explorer takes approximately 11 hours.The NIMT has been described as an ""engineering miracle"", with numerous engineering feats such as viaducts, tunnels and a spiral built to overcome large elevation differences with grades suitable for steam engines.