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Lead Mining Methods of Mendip and Derbyshire

For a minority of Mendip Folk, mineral mining conjures up visions of great vaults and vast networks of passages having teams and teams of miners hewing their existence out of the living rock.  This is, of course, not an accurate picture and the miners endured, in their efforts to eke out a living, many dangers including those of gas, collapse and inundation.

Of the three, collapse was perhaps the easiest to deal with as almost all of the passages were in solid limestone or toadstone, so it was when the "old man" was driving through shale that he was troubled by collapse problems.  These were mainly overcome by the construction of lined shafts and arched adits or levels.  However, the shale also presented the problem of Gas.

Fire Damp (CH4) only found in mineral mines when shale or the like is exposed and the gas, when able to collect in rock crevices to mix with four to twelve times its volume of air, is potentially lethal.  The effect of its ignition could be to produce a sheet of flame which would seal the upper part of the mine passages and in the wake of the explosion would come the Choke Damp (carbonic ash residue) which being heavier than air would soon overcome and suffocate any survivors of the explosion.  Another gas hazard could arise from the imperfect combustion of the Fire Damp, Carbon Monoxide (White Damp) was equally deadly and even if it did not kill on the spot it had a more or less permanent effect on the inhaler as it was most difficult to expel from the body. Explosions were not confined to being caused by gas though, the occurrence of 'Slickensides' or 'Cracking Holes' or 'Looking Glass' (limestone or sometimes lead ore with a ribbed and polished surface) sometimes caused explosions of incredible violence due to stress and strain forces building up in them.  These occurrences were particularly common in the Eyam district of Derbyshire where there are records of many miners being killed in such explosions.

The main problem countrywide encountered by the Miner was how to drain the workings.  In Derbyshire there was usually a simple solution by driving an adit through to the nearest valley and so empty the water from the workings there.  Sometimes, where two or more mines were working in close proximity a joint effort was made to effect drainage.

Passages below this level were pumped out and several methods used are worthy of note.  The Mendip miners hampered by the absence of deep valleys, hauled out the water in nine gallon leather buckets and the miners would make use of local swallow holes both for drainage purposes and also for spoil dumps.

One of the early pump methods in use was the Archimedes screw which was generally produced by the use of a hollow log containing a wooden corkscrew inside which when turned would raise a small amount of water.  However, if it was inclined at too steep an angle the water would drain out so the more efficient Rag and Chain type pump was used.

The Rag and Chain was used extensively in the early 17th Century and through to the mid 19th Century. It consisted of an endless chain passed through a hollow log which was looped and turned by a spiked wheel of 2 to 3 feet diameter.  At intervals on the chain were mounted leather bags filled with horse hair or rags and these fitted closely inside the log pipe.  When the log was immersed in the water pumping was effected by turning the wheel and trapping water in the pipe and transferring it to the top.  This was the first pump capable of moving large volumes of water and sludge but its operation was exhausting to those driving it. The next generation of pumps were those of the steam age such as the Newcomen 'atmospheric' engine and the Bolton and Watt beam engines.

But thatÂ’s another story