1600 A.D. to the present — a summary
Primitive shaft sinkers used their hands and implements of bone, wood and, later, metal to dig the shafts that were necessary to remove the minerals required in their society. With the arrival of a social system, under the Egyptians and the Phoenicians, shaft sinking and mining became more organized, with slaves, criminals and prisoners of war being utilized. In these early days, fire quenching was utilized along with wedges and hammers to break up the rock, which was then removed in baskets.
With the coming of the Middle Ages, mining and shaft sinking alike became a respected profession; however, mining techniques remained much the same as those used under the Romans. The first major change in shaft sinking practice was the use of black powder rather than fire quenching to break the rock, which occurred in the 17th century.
The Industrial Revolution brought about the next major changes — steam-powered hoists and pumps. In the 19th century, the pneumatic rock drill replaced drilling by hand and in the mid-20th century, mechanical mucking machines replaced hand mucking. All these changes, although slow in coming, drastically increased the speed of shaft sinking.
Summarizing the average sinking speeds from the various periods clearly illustrates the changes in technology over time and the resulting increase in sinking rates.
- Prior to 1600 AD — 1 to 1.2 metres per month
- 1600 to 1800 AD — 3 to 4 metres per month (three-fold increase)
- 1800 to 1900 AD — 10 to 12 metres per month (three-fold increase)
- 1900 to 1940 AD — 30 to 40 metres per month (three-fold increase)
- 1940 to 1970 AD — 90 to 110 metres per month (three-fold increase)
- 1970 to 2007 AD — 90 to 110 metres per month (0 increase)
Prior to 1600 AD
The sinking of shafts had been going on for thousands of years prior to 1600. The Egyptians mined gold extensively in eastern Egypt and Sudan as far back as 2000 BC and sank shallow shafts to access the majority of this gold. It is thought that it was from the Egyptians that the Persians, Greeks and Romans learned their mining and shaft sinking techniques. Besides iron tools, the Romans used fire to fracture the rock. Pliny mentions breaking up the rock by means of fire and vinegar. Other Roman authors, such as Livy and Vitruvius, mention fire setting and vinegar as well.
A summary of the sinking system of 1600:
- Excavation using fire setting and primitive tools
- Hand mucking to small wooden buckets
- Hoisting material with man-powered windlass
- Rectangular or square shafts with wooden shaft linings
- Temporary ground support consisting of platforms in the shaft every few metres
- Crude ventilation or none at all
- Water handling with buckets or other inefficient devices
The big change that occurred in this period was the status of the miners and shaft sinkers. In Egyptian and Roman times, miners and shaft sinkers were generally slaves, criminals or prisoners of war. By the early part of the 12th century, the shaft sinker and the miner were considered to be tradesmen and were much in demand. Personnel involved in the mining trade were freed from paying certain taxes, were allowed to carry arms and did not have to serve as soldiers.
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