The churn drill is a large

drill A drill is a tool used for making round holes or driving fasteners. It is fitted with a bit, either a drill or driverchuck. Hand-operated types are dramatically decreasing in popularity and cordless battery-powered ones proliferating due to ...

ing machine that bores large diameter holes in the ground. In

mining Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic via ...

, they were used to drill into the soft

carbonate A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonate g ...

rocks of

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...

and

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

hosted regions to extract bulk samples of the ore. Churn drills are also called percussion drills as they function by lifting and dropping a heavy chisel-like bit which breaks the rock as it falls. Churn drills are most effective in soft- to medium-density rock of relative shallow depth (10–50 metres).

History

Churn drills were invented as early as 221 BC in

Qin dynasty The Qin dynasty ( ; zh, c=秦朝, p=Qín cháo, w=), or Ch'in dynasty in Wade–Giles romanization ( zh, c=, p=, w=Ch'in ch'ao), was the first Dynasties in Chinese history, dynasty of Imperial China. Named for its heartland in Qin (state), ...

China, capable of reaching a depth of 1500 m. Churn drills in ancient China were built of wood and labor-intensive, but were able to go through solid rock. The churn drill was transmitted to Europe during the 12th century. A churn drill using

steam power A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be trans ...

, based on "the ancient Chinese method of lifting and dropping a rod tipped with a bit," was first built in 1835 by Isaac Singer in the United States, according to ''The History of Grinding''. In America, they were common in the Tri-State areas during the lead and zinc mining in

Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...

Oklahoma Oklahoma (; Choctaw language, Choctaw: ; chr, ᎣᎧᎳᎰᎹ, ''Okalahoma'' ) is a U.S. state, state in the South Central United States, South Central region of the United States, bordered by Texas on the south and west, Kansas on the nor ...

, and

Kansas Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the ...

. There is an example of one of these machines at the Northern Life Museum in

Fort Smith, Northwest Territories Fort Smith ( chp, Thebacha "beside the rapids") is a town in the South Slave Region of the Northwest Territories (NWT), Canada. It is located in the southeastern portion of the Northwest Territories, on the Slave River and adjacent to the Albert ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

. It was used in 1929–1930 at the Pine Point lead and zinc mine in the

Northwest Territories The Northwest Territories (abbreviated ''NT'' or ''NWT''; french: Territoires du Nord-Ouest, formerly ''North-Western Territory'' and ''North-West Territories'' and namely shortened as ''Northwest Territory'') is a federal territory of Canada. ...

References

External links

*https://web.archive.org/web/20050310013804/http://www.maden.hacettepe.edu.tr/dmmrt/dmmrt217.html Tools Chinese inventions Mining equipment {{tool-stub