From 1900 to 1914 New Zealand coal production more than doubled to 2.25 million tonnes, a figure it would not consistently exceed until the Second World War. This dramatic increase was due to the demands of steamships and railways, the export-driven growth of dairy factories and freezing works, and the development of municipal gasworks that used coal to produce domestic gas.
The most spectacular growth came in Buller, where the Westport Coal Company developed major deposits at Millerton and Stockton. By 1914, one-third of New Zealand’s coal came from the Buller mines.
State Coal Mines
The Grey River fields saw falling production in the Brunner area, but in 1901 Richard Seddon’s government created State Coal Mines to challenge the Union Steam Ship Company’s coal monopoly and improve safety. The first state mine was at Seddonville in Buller. The state’s Point Elizabeth mine, established near Rūnanga in 1904, revived mining in the Grey River valley. By 1914 the area was producing a quarter of the country’s coal, and the West Coast, in all, contributed three-fifths.
Further south, the Kaitangata field remained static (contributing less than 13% in 1914) as Dunedin lost its economic pre-eminence. Production expanded in the Huntly area, where dairying and the industrial and domestic demand of Auckland provided strong local markets. Production quadrupled between 1900 and 1914 to reach 15% of the national total. During the First World War a new bridge across the Waikato River opened up areas for mining in the hills to the west – at Pukemiro, Glen Afton and Rotowaro.
In the interwar years the West Coast suffered as ships turned to oil in place of coal. By the mid-1930s the Waikato fields were producing as much coal as the West Coast fields. The economic depression encouraged a revival of small-scale mining as miners, laid off from the large operations, developed cooperatives and reopened abandoned workings. By mid-1930 there were several hundred such operations.
Second World War
The outbreak of war in 1939 gave a new value to coal. From 1942, coal mining became an essential industry and miners were prohibited from changing jobs. The Labour government began taking over pits, especially if they looked like failing. By 1942 all the mines in the Grey River valley and Waikato had been nationalised. By the late 1940s state-owned mines were producing over half of New Zealand’s coal, and in 1948 coal deposits were nationalised – a decision reversed by the new National government two years later.
Another important development in this period was the beginning of opencast mining on a substantial scale. In this method, coal is mined from the surface rather than from underground workings. At the start of the war only 2% of coal was mined in this way. By 1945 the figure was over 16%. In 1960, when coal production reached a post-war peak of over 3 million tonnes, 37% came from opencast mines. By 1979, when production had fallen to under 2 million tonnes, opencast mining contributed 69%.
The fall in the 1960s and 1970s was particularly severe on the West Coast, partly because bituminous coal, once the fuel of ships and trains, was no longer in demand, as ships had switched to oil and the railways were in decline. In addition, gas was increasingly being replaced by hydro-electric power and eventually by Māui natural gas, while household use of coal in 1972 was a quarter of the 1949 level. Twelve significant mines closed between 1967 and 1974.
There was evidence of decline in coal mining everywhere – the number of mines fell from 216 in 1953 to 78 in 1973, while the number of miners fell from over 5,000 to about 1,500, almost half of whom were aged over 45. In the same period, the Grey River valley workforce fell to a quarter, the Buller workers to a third. Denniston, which once had a population of 1,308, had only four people living there in 1981.