Chapter 4 COAL MINING in Nanaimo
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Chapter 4 COAL MINING in Nanaimo The single most dangerous action you can take on this tour is failing to pay attention while travelling on the route. Do NOT read the following chapter while actively moving by vehicle, car, foot, bike, or boat. NANAIMO COAL MINING Driving Tour Simon Priest, local resident and student of history DANGER: Do not enter coal mines (abandoned or active) without special permission and training to go underground. For this tour, stay on marked trails and roadways. “Lost” or unknown mine openings can be covered with wood that has rotted or vegetation that has overgrown the gap. One wrong step off the beaten path and you could end up at the bottom of a deep shaft. Stay out of mines, remain alert! As recently as 1969, two boys exploring a mine tunnel near Harewood, decided to sleep there overnight without telling anyone where they had gone. Thought to be lost forever, their bodies were discovered in 1980 as they had died in their sleep from breathing deadly gases that had accumulated in the mine! Sedimentary layers including black coal GEOLOGY: Sedimentary rocks are formed by the deposition of materials that are later fused together under pressure. If the deposited materials are mostly sand, then sandstone results from pressure. If these materials are mostly coral, then limestone can result. Small pebbles are pressed into concrete-like conglomerate. Mud makes shale. Deposited animal or plant matter forms coal under heavy pressure. The Nanaimo Basin (lowlands between the surrounding half circle of mountains) has all of these layers in varying combinations. All of these were believed to be formed underwater about 65 - 85 million years ago. The materials were washed out by rivers into the deeper waters and compressed under the weight of that water and layers on top to form rock. As waters receded, and this sedimentary rock was pushed up by geological forces, it became dry land. In some places near Nanaimo, seams or layers of black coal can easily be seen in between the other sedimentary layers. The discovery and sharing of this exposed coal on the surface led to Nanaimo’s mining growth during the last half of the nineteen century. MINING: The extraction of coal was conducted through surface and/or underground mining. Surface mining involved open-pit stripping of layers (removing overburden above to get to the coal below). In Nanaimo, this approach was used first, where coal was obviously seen at the surface. After removing the maximum coal possible, or encountering too much overburden to remove safely or profitably, the head miner would then decide to go underground. Either a shaft would be dug vertically, or a drift would go horizontally into a hill side, or an angular slope would descend toward an exploratory pocket. Underground workers would remove all the coal in the layer sandwiched between other layers of sandstone and conglomerate. Since large unsupported gaps would be created by this method, early mines would collapse. Later methods saw the use of pillars and posts to reinforce the gap. Pillars of coal would be left in place or timber posts were added with additional wood to support the ceiling layer. When the farthest limit of a mine was reached, due to ventilation or economic shortcomings, the workers would retreat; removing the pillars behind them and the tunnel may or may not have collapsed. Normally workers would chip away at the front face of underground operations using hand tools such as pick and shovels. To accelerate their efforts, holes were drilled into the active face and explosives were used to shatter the coal and facilitate its easy removal by hand. Temporary rail beds were built into tunnels to move coal from the face to the shaft by shuttle cars. Raising the coal up the shaft and out of the mine would be accomplished with skip elevators suspended from cables that ran over a large pulley (headframe) to a winch powered first by animals and later by steam from water boiled with fired coal. Horse-drawn coal cart and “pit pony” in underground mine, circa 1890s COAL: For Nanaimo, coal is an important sedimentary rock, composed of carbon with some impurities (hydrogen, sulfur, nitrogen). In the presence of oxygen (forming 20% of the air we breathe), the carbon in coal will burn to produce heat and carbon dioxide. The heat is extremely useful for creating steam to generate electricity and for industrial manufacturing of iron and steel. Carbon dioxide is a greenhouse gas that contributes to climate destabilization and the overall warming of the planet. Nevertheless, coal is a fossil fuel commodity that the world continues to mine and exploit despite its obvious impacts. While coal types range from anthracite (90%+ carbon), through bituminous (70-90% carbon), to lignite (50-70% carbon), all three types are present on Vancouver Island. However, coal works in Nanaimo, Wellington, Comox (to the north), and Extension (to the south) mined bituminous coal, with low moisture content and high volatility (from vaporized hydrocarbons), making it perfect for industrial use. Bituminous Coal Nanaimo coal was mined from three distinct layers or strata, which did not overlap or intersect. These were named for the locations of the initial surface mines: the Newcastle Seam, the Douglas Seam, and the Wellington Seam. While roughly horizontal, these seams were folded by the earth’s pressure to look like a potato chip underground. Most seams were on a slight slant, so they reached the surface at some point as an exposed seam or outcrop. The distances of sedimentary layers between coal seams were fairly regular. The diagram below shows approximate spacing for initial operations on Newcastle Island. Note that the average thickness of a coal seam meant that workers could not stand upright in the mine. …The [Newcastle] seam occurs 244 metres to 305 metres above the Wellington Seam and on average 18.3 metres below the Douglas Seam. The seam has the most restricted distribution of the three producing seams in the Nanaimo Coalfield…. The seam occurs in the area underlying Newcastle and Protection Islands, beneath the town [of] Nanaimo, and is thought to extend towards south Wellington…. The seam averages 0.9 to 1.2 metres in thickness where worked but thicknesses range from 0.5 to 2.4 metres. The seam is high volatile bituminous with lower carbon and higher oxygen and ash contents than the Wellington and Douglas seams. The coal has mainly been sold as steam coal. The seam is underlain by flaggy or shaly sandstone and overlain by sandy shale to fine conglomerate…. Mineable coal was worked from the Brechin mine to the No. 1 mine for a distance of approximately 2 miles along strike and for about one mile down dip. The seam extends beneath Newcastle and Protection Islands and for some distance seaward. The strata generally strike northwest to northeast and dip shallowly predominantly to the northeast and southeast…. The Douglas Seam (20 metres above the Newcastle Seam) outcrops at the Brechin mine but has not been worked. At the Protection mine the Douglas Seam is approximately 1.5 metres thick under a hard faulted roof rock. Below this seam is the 1.2 metre thick Newcastle Seam. Both seams were mined out under the Northumberland Channel at this mine.... MINFILE No. 092GSW045, Record Summary for the Brechin Mine (#9) on Newcastle Island From the Ministry of Energy, Mines, and Petroleum Resources, British Columbia government http://minfile.gov.bc.ca/Summary.aspx?minfilno=092GSW045 (retrieved February 25, 2019). The Industrial Terminology of Coal Mining TERMINOLOGY: Please get familiar with the above diagram, because you will see some sites on this tour where these industrial terms are frequently used: • Strip mine – open pit where coal and its covering layer of overburdened rock was scraped away. • Coal mine – location where coal was removed through a vertical shaft, horizontal drift or angular slope dug into the ground. • Tunnel or level – location where a piece of the mine extended away from its shaft, drift or slope and into the seam or layer of coal. • Pillar or post – location where pillars of coal were left in place or wooden posts were added to reinforce tunnels or levels and prevent their collapse from the weight of the rock above. • Ventilation – location where a minor shaft, slope or drift was added to provide air circulation in the tunnels or levels below ground. • Front face – location where the coal was being broken up, sometimes with explosives, and removed by workers using individual shuttle cars or a connected chain of cars. • Sump – location where coal was stored temporarily at the bottom of a shaft or slope before being extracted by rail cars or a skip (elevator). • Headframe – location where a structure of wood, steel, or reinforced concrete, was used to suspend and support a pulley for a cable running between the winch and skip. • Tipple – a sorting facility, where ore was tipped into, rock was screened out, and then the remaining coal was sifted on the basis of size for delivery into rail carriages. • Colliery – location where coal was mined (from one or more mines) and processed by crushing and/or washing with water before transport by railway and ocean-going ship. Rough map of Nanaimo’s coal mining regions (shapes approximate underground workings). TIMELINE: The historical timeline of coal mining in Nanaimo can be traced through several periods, each corresponding to a geographic region. As shown on the above map, exploration proceeded generally south along two routes: the combined Douglas + Newcastle seams and the singular Wellington seam. Aside from several minor players, two strong influences arose as major competitors in the Nanaimo coal mining market and they changed names over the years as shown in the timeline below.