TABLE OF CONTENTS Story Summary Nature of Coal Coal Resources 19th Century 20th Century Late 20th and 21st Century The Miner’s Work Mining  Accidents Mining Community Future of Coal STORY SUMMARY   What is coal? Coal is a rock that can burn, and it is made from carbon, water, and minerals. It was formed millions of years ago when plants fell into peat swamps and were buried by heavy earth and rocks. Over a very long time, the weight of the rocks and heat in the ground turned the plants into coal. How old is it? Most of the world’s coal was formed 300–350 million years ago. New Zealand coals are much younger – they were made 30–70 million years ago.   Types of Coal Mines Kinds of coal There are different kinds of coal with varying properties that determine how it can be used. The kinds of plants that eventually turn into coal differ, as do the minerals in the coal. The most important factor is how deeply the original plant material is buried. It begins as peat and as it becomes more compressed it gradually changes into lignite, sub-bituminous coal, bituminous coal or even (if it is buried deeply enough) anthracite. Coal deposits There are coalfields in Northland, Waikato, Taranaki, the South Island’s West Coast, Otago, and Southland. Mining Europeans began mining coal in New Zealand in the 1840s.   At first, men went underground and dug out the coal with picks and shovels.           In the early 1900s, men used explosives and compressed-air machines in mines to cut coal from the seam. The coal was loaded into wagons and taken out of the mine. From the 1990s high-pressure water jets were used to cut the coal in some underground mines. Pneumatic (compressed air) locomotives were needed in highly flammable environments like coal mines   By the 2000s mining was usually opencast. Earth and rock covering the coal were scraped and blasted away. When the coal was gone, the land was generally restored. Accidents Underground mining was dangerous. Rocks fell, men were knocked over by the wagons carrying coal, there were explosions, and miners were suffocated by poisonous gases.   An explosion at the Brunner mine in 1896 was New Zealand’s worst industrial accident, with 65 people killed by toxic gas.     https://teara.govt.nz/en/speech/7453/brunner-mine-disaster-1896   In the 2000s mining was generally safer because of government regulations and inspections, and because opencast (rather than underground) mining methods were used. Explosions at the Pike River mine in 2010, which resulted in the deaths of 29 men, exposed ongoing safety issues for miners. (More about this soon)  The government set up Workplace New Zealand to be responsible for all workplace safety issues, with a designated High Hazards Unit covering industries such as mining and petroleum exploration. Trade unionism Many of the early miners came from Britain, where there was a tradition of trade unionism to improve miners’ working conditions. Many New Zealand mining towns became centers of strong union activity. Some of the union leaders later became members of parliament.   The nature of coal Origins Coal is a combustible rock formed from the altered remains of ancient vegetation laid down in peat swamps. It is mainly composed of organic matter (compounds of carbon), moisture, and minerals. The transition from peat to coal (coalification) occurs over millions of years as peat is buried and consolidated by the weight of overlying sediments. Three factors determine the properties of coal: type – variation in the original plant material and its subsequent alteration rank – difference in the degree of burial and subsequent coalification grade – variation in mineral matter. High-grade coal contains little mineral matter, whereas lower-grade coal contains more mineral matter, mainly from mud in the peat swamp. Changes in coal As coal becomes buried more deeply, it goes through a sequence of changes in rank: from peat to lignite, sub-bituminous coal, bituminous coal, semi-anthracite, and anthracite. This process results in irreversible changes in the chemical and physical nature of the coal, and there can be considerable variation within a coalfield. Geological age does not affect rank. From peat to bituminous coal there is a progressive loss of water and a proportionate increase in carbon. Lignite and sub-bituminous coal is relatively soft, with a brown, earthy appearance – these are often known as brown coals. Higher-rank coals are blacker, shinier, and have a higher proportion of carbon. As the rank increases, so does the heat (or calorific value) given out by the coal when it burns. It is difficult to make a fire from lignite because the moisture content is so high. Sub-bituminous coal burns well, and bituminous coal burns fiercely. The distinctive nature of New Zealand coal New Zealand coals have characteristics that distinguish them from coals found in other countries. Most of the world’s coals were formed in great swamps during the Carboniferous period, about 300–350 million years ago. New Zealand coals are much younger, having been formed mainly in the late Cretaceous and Tertiary periods, 30–70 million years ago, from more-evolved vegetation types containing flowering plants. Because the original vegetation is different, New Zealand coals have some unusual properties, giving them high value for specialized purposes. Mineral matter When coal burns, the ash that remains consists mainly of clay minerals, quartz, and sulfur compounds (mainly pyrite). Most New Zealand coals have an ash content of less than 4%, which is lower than most Carboniferous coals. A few seams have an exceptionally low ash content – less than 1%. Coal resources Government coal surveys and exploration by mining companies have established that New Zealand has an estimated 16 billion tonnes of in-ground coal.  However, 80% of this is lignite in Otago and Southland. Of the balance, much of the easily won coal is gone. The remaining amount that could be recovered is relatively quite small and depends on geological, engineering, economic, and environmental constraints. Estimated In-Ground Resource Coal is New Zealand’s most abundant fossil fuel and