In order to talk about advancements in coal mining we must first look at how coal was mined before mechanism. Pre the industrial revolution in the 17th century, nearly all coal was being mined by hand, be it from being picked up on beach outcrops which lead to the ‘coal seekers' which consisted of men, women and sometimes children to mine away at the beach to uncover the seam which they followed inland, much like surface mining of today but on a much smaller scale. This method was called a ‘horizontal adit' mine which is a nearly horizontal passage that gently slopes away from the surface into a mine for access or drainage. Another method was a ‘bell pit' which is where a shaft is created to reach the coal, then the coal is excavated and removed by means of a bucket (see figure 1), much like a water well, only it was powered by horses, unfortunately this method of mining was extremely dangerous as no supports were used, which often lead to cave-ins of falling rocks and earth. Although the ‘bell pit' was successful at the time something needed to be done on the safety issue, so when mining began to develop this was the first problem that needed to be solved, therefore a new method was introduced, the ‘room and pillar' method (see figure2), this method used the same structure as a ‘bell pit', the bottom of the pit was squared off to create a room, they added another room next to it, then another and so on, what was between the rooms were called pillars, which consisted of untouched coal, these were the supports to hold up the roof, therefore avoiding cave-ins. The ‘room and pillar' method was used throughout the centuries, and is still in use today but in another aspect of mining (continuous mining).
Like the ‘bell pit' method, ‘room and pillar' mining also had a problem, it left behind a huge amount of coal. A new method had to be found that would incorporate the safety of ‘room and pillar' mining but also to mine the valuable coal that was being left behind, with this in mind, ‘longwall' mining was introduced. A team of miners excavated the coal with picks and shovels cutting down one side of the seam called a ‘face', while other miners erected timber supports as they moved forward (see figure 3). What was left behind them was used as space for waste stone and spoil, a passageway was left open through the centre of this for access.
Thomas Newcomen, in 1792 developed the first successful steam engine to drain the mines (see figure 4). Later a simple design for ventilation was also added by digging a second shaft, by placing a fire at the bottom of it, so enabling the hot updraft of the fire to pull fresh air down the first shaft and through the mine. To ventilate all parts of the mine, a complicated system of trapdoors was needed, failures of this led to many deathly explosions. Humphrey Davy was credited with the invention of the safety lamp in 1815 called the ‘firedamp' (see figure 5), this allowed miners to light up what they were working on, reducing the dangers of explosions by igniting the methane gas which was present as they used to use a lit candle.
George Stephenson, developed a steam pump engine that pulled the buckets of coal from the coal face to the pit bottom; he also improved the underground coal railways. James Watt, greatly improved the Newcomen engine to create the separate condensing engine; this was much more powerful and could help with weights and drive mechanisms. Richard Trevithick further improved the steam engines to use high steam pressure (see figure 6); this meant that both coal and men could be easily raised from mine to surface.
A more recent invention circa 1930 was that of the ‘Meco-Moore cutter loader' (see figure 7); this was invented by M Moore and further developed by an engineering company. It was designed so that it could work along the coal seam to shear and undercut it; this then was transferred to a conveyor belt, which brought the coal to the entrance of the mine. It was among one of the first machines to do both, cutting and loading. Of course this not only increased productivity it also increased safety.