South Island main trunk
The South Island’s main trunk line was completed in the late 1870s. Christchurch was connected to Timaru in 1876 and to Dunedin two years later, cutting travel time between Christchurch and Dunedin to around 11 hours. The final section between Dunedin and Invercargill was opened, amid much fanfare, in January 1879. More than six decades later, in 1945, the main trunk line was extended north to Picton.
North Island main trunk
The central North Island posed greater challenges to rail-builders than the South Island’s eastern plains. A main trunk railway between Auckland and Wellington was discussed from the 1860s, but progress was slow. By 1880 Auckland’s southern line reached Te Awamutu, and there were isolated sections of line between Wellington and Wairarapa, and in Taranaki, Manawatū and Hawke’s Bay. Further progress was blocked by rugged mountains, dense forests and the Māori stronghold of Te Rohe Pōtae (the King Country).
Despite these challenges, exploratory survey work began in 1882. Two years later a Parliamentary committee opted for a central route rather than western or eastern alternatives. The government also reached a crucial agreement with Ngāti Maniapoto leaders to open up the King Country to the railway.
On 15 April 1885 politicians and Māori leaders ceremonially ‘turned the first sod’ of the central section by the Pūniu River, near Te Awamutu. It would take 23 years to complete the 680-kilometre North Island main trunk (NIMT). Progress was slow in the 1890s, but work intensified after 1900.
Working on the line
Life was hard for the men who built the North Island main trunk line. The work was dangerous and their makeshift shantytowns offered few comforts. G. G. Stewart, then a railways cadet but later the publicity manager, visited Raurimu in the winter of 1908 and found that ‘[c]ontinuous heavy rain, with occasional hail, sleet and snow, much fog, miry clay, and a tangled bed of wild undergrowth knitting together the forest giants, made a tough job for the workers’.1
The Raurimu spiral and viaducts
By 1904 the northern and southern sections had reached Taumarunui and Taihape. South of Taumarunui, the steep climb up to the Waimarino plateau was accomplished via the famous Raurimu spiral, which featured two tunnels, three horseshoe curves and a complete circle. Towering steel viaducts bridged deep ravines at Makatote, Hāpuawhenua, Mangaweka, Makōhine and elsewhere.
Closing the gap
By May 1908 only the 24-kilometre gap between Makatote and Ōhakune remained. The Public Works Department rushed to complete the line by August so a Parliament Special train could carry MPs to Auckland to greet the US Navy’s visiting Great White Fleet – a journey of more than 20 hours.
The opening of the NIMT
The NIMT was formally opened on 6 November 1908, when Prime Minister Sir Joseph Ward drove home the final spike at Manganuioteao. In December the government took control of the private Wellington and Manawatu Railway Company, whose line then became part of the NIMT.
From February 1909 regular express trains linked Auckland and Wellington in 18 hours.
The NIMT’s importance
The completion of the NIMT was a major landmark in New Zealand’s history. It fostered economic and population growth in the North Island, opening up Pākehā access to the Māori-dominated interior, and accelerating the destruction of the great forests that once covered much of the island. For most New Zealanders, the NIMT was a proud symbol of progress, ushering in a golden age of rail transport in the first half of the 20th century.
The NIMT was a steam railway until the 1950s (apart from the Wellington–Paekākāriki section, which was electrified in 1940). The electrification of the whole NIMT was proposed in the late 1940s, in response to post-war coal shortages, but the government opted instead for diesel propulsion. The idea was revived during the oil shocks of the 1970s, and electrification of the central section between Hamilton and Palmerston North was approved in 1980.
This project involved the erection of more than 10,000 concrete poles. Many tunnels had to be ‘daylighted’ or opened up by having the covering earth removed. Others needed their floors lowered to accommodate overhead wires. The electrification was completed in 1988, at a cost of around $250 million. Diesel trains continue to operate on the Auckland–Hamilton and Palmerston North–Wellington sections.