Cutting the Coal

Movements in the earth's crust have caused coal seams to be inclined rather than horizontal and this, together with the effects of volcanic, glacial and climatic action, has exposed the edges of most seams. The exposed edge of a seam is called "the outcrop" or "basset edge". The earliest coal workings were on these outcrops, the coal being dug where it was exposed. Evidence of shallow coal was often found on river- banks.

The combustible properties of coal were probably first recognised in ancient China. In Britain it has certainly been used since Roman times, if not before. The earliest written records of coal mining date from the later medieval period when coal was dug from the soil by peasants, who regarded it rather as a specialist form of agriculture. Once the surface deposits were gone, there were two ways of proceeding. On hills it was usual to drive tunnels (or drifts) into the seam for a short distance. On flat ground shallow pits rather like wells were sunk down to the seam. The coal was then dug from around the pit bottom by sharp- pointed picks until the sides of the pit were in danger of collapsing, when the pit was abandoned and another dug nearby. 

Seen in section, such a pit is shaped like a "bell", so we call them "bell pits". At depths of more than about 20 feet (6 m), labour was economised by heading out into the seam, and it was found that connecting two or more shafts together allowed air to flow, so enabling them to honeycomb the seam with a network of tunnels from which the coal had been got, separated by pillars of coal left to support the roof. This stall (or bord) and pillar system was once universal, and a few examples are still found in Northumberland and Durham today.

In this system the bord was usually worked by one man on his own. First, he undercut the coal to a depth of several feet; then he cut nicks up each side of the bord, so enabling him to break the coal down by driving wedges into it with a hammer. The large lumps were then broken up with a pick.

         The alternative system, which developed first in Shropshire in the seventeenth century, and of which there have been many variants, enabled a number of men to work co-operatively on one long coal face. From the middle of the nineteenth until well into the twentieth century the chief variant was the system known as " long wall tub-stall", and this is still practised today at a few small privately owned mines. First, a main roadway was driven out from the pit bottom some distance into the seam, leaving an  unworked pillar of coal around the shaft to give it support. 

On each side of this roadway, subsidiary main roads were driven at intervals, and working coalfaces were opened out on either side of these. Whereas with early coal mines (say pre-1850) all roadways were commonly driven entirely in coal, so that the height of a roadway was the same as the thickness of the seam (which could be 3 feet, 0.9 m, or less). In later practice most roadways were made high enough to allow men and ponies to travel along them comfortably. However, the actual coal faces were (and are) still as high as the seam is thick, typically between 1 and 2 metres (40-80 inches). The roadways were supported by substantial puncheons of wood set vertically, usually with horizontal wooden bars over them pressed up to the roof.  

With all variants of longwall the first process at the coal face was to undercut the coal using a sharp-pointed pick. This work (called holing or carving) was arduous. Having cut along the floor of the seam for 8 or 10 inches (200-250 mm), the holer set catch props under the cut to prevent the coal falling whilst he was cutting. He would then extend his cut to 4 feet (1.2 m) or so under the seam, necessitating putting his head and trunk at risk. On a coal face 100 metres (328 feet) long, two men would do all the cutting.                            

The cut completed, " the getters " knocked out the catch props with a hammer, allowing the weight of the coal to bear down. Then the coal was got by hammering wedges into the face and levering lumps down with the pick or (in later practice) a long iron crowbar called a "ringer". Before the industrial revolution, iron was so expensive that hammers, wedges and shovels were made -from wood. Iron tools (other than pick heads) only became common from about 1780. From about 1830, gun- powder came into use at the coal face , to help to break the coal down. Holes were made in the coal by a chisel-pointed round iron bar called a jumper (later by drills) and into each hole a quantity of gunpowder was poured. Some kind of fuse (often a straw filled with gunpowder) was put into the hole, and the mouth of the hole stemmed with clay. Then the shotfirer lit the fuse and moved away as quickly as possible.

For the house-coal market, large coal was wanted, so the use of gunpowder was restricted and in many cases forbidden. Having broken the coal into lumps of suitable size, the men loaded it into baskets (before about 1845) or into small wagons called tabs or trams, to be transported out of the mine.                                                                                                                                     

                      INTRODUCTION  OF COAL- CUTTING  MACHINES 

     The first coal face operation to be mechanised was the undercutting of the coal. The earliest coal-cutting machines, dating from the 1850s, were unsuccessful because of the lack of a suitable power source. In the 1870s compressed air became available, followed in the 1890s by electricity, but there were few cutting machines in use before the twentieth century. Indeed, even in 1913 only 8.5 per cent of British coal was mechanically cut; this rose to 31 per cent in 1930 and 73.9 per cent in  1946.                                                      

     These machines were of three types. One had a disc with picks slotted around its periphery, which was made to rotate like a circular saw along the floor of the seam whilst the machine travelled along the face. Another had a rotating round iron bar set with picks; and the third had a chain laced with picks travelling around an iron jib. All three took a cut of about 4 inches (100 mm) from, the floor of the seam thus producing much less small coal than the hand holer, who necessarily took a much bigger cut because he had to get his body into it to reach far enough back. 

        These machines still left the getting and filling operations to be done by hand. However, during the Second World War a new breed of power loading machines began to evolve. These machines cut the whole section of coal to be worked and loaded it mechanically on to a moving iron conveyor belt (the armoured face conveyor or panzer) running along the face. By the 1970's some 97 or 98 per cent of all coal produced in Britain was power loaded.