Pretoria Chert Mine
| Pretoria Chert Mine | |
|---|---|
| Route length: | 1.6 km |
| Gauge : | 457 mm |
The Pretoria Chert Mine was a Chert -Bergwerk in Bakewell in Derbyshire , in the Hornstein using six driven winches 1.6-kilometer narrow-gauge - funicular railways with a track width of 1 foot 6 inches (457 mm) was promoted.
history
The Pretoria Mine opened in 1902 and, along with the Holme Bank Mine, was one of the last operating Chert mines in Derbyshire. In 1905 it still had 38 employees, but after the First World War the number of employees fell to about twelve. During the Cold War , the mine was equipped as an underground living space. In 1964 the number of employees fell to four, of which only two worked underground. The mine was closed in the winter of 1968/69.
In addition, there used to be Holme Hall at Bakewell and other chert mines west of Great Longstone, as well as Ashford , Masson Hill , Bonsall and Over Haddon .
Narrow-gauge railways
In the period from 1900 to 1918 there were three narrow-gauge railways underground and up to 1964 there were even six, one of which has not been preserved because the tunnels were backfilled. There was also a vertical elevator shaft .
geology
The Chert layer averaged 2.7 meters (9 feet) and up to 5.5 meters (18 feet) thick in places with a slope of 1 in 3.7 (270 ‰). It was obtained by removing the underlying limestone layer so that the chert fell under its own weight. He was with a compressed air-operated lift truck loaded onto flat cars with one driven by compressed air funicular were drawn on a line extending in the mountain Schmalspurbahnrtrecke to the surface. The limestone, considered to be waste, was built into mighty buttresses.
Industrial use of chert
Chert has been used for grinding calcined flint, which is used as a bleach in the manufacture of ceramics, since the late 18th century. The potter Josiah Wedgwood recognized in 1772 that the white Chert from Derbyshire is much better than granite for millstones, as the granite abrasion left annoying black spots in white ceramic. Porcelain factories have since used Chert as millstones for their grinders, with the large blocks rotating on a floor paved with smaller blocks.
literature
- John Barnatt and Terry Worthington: Quarrying Chert at Bakewell: A Detailed Archaeological Survey of Pretoria Mine and Observations on Holme Bank, Holme Hall and Endcliffe Mines. In: Mining History. Spring 2017, Volume 19, Issue 6, pp. 1–119.
- Trevor D. Ford: An unusual bit of the hard stuff - Derbyshire chert. July 7, 2008
Web links
Individual evidence
- ↑ a b c d e f Julie Bunting: Bygone industries of the Peak, Derbyshire. In: The Peak Advertiser, October 16, 1995, update March 11, 2005, p. 7. Published in Illustrated Paperback in 2006, Wildtrack Publishing, Sheffield, ISBN 1-904098-01-0
- ^ John Barnatt and Terry Worthington: Going Underground. Archeology and Conservation in Derbyshire. Edition January 13, 2016.
- ^ A b John Barnatt: Pretoria Mine: A Sixth Tramway. In: Peak District Mines Historical Society Ltd. Newsletter No. 163, July 2017.
- ^ Underground accommodation: Pretoria Chert Mine, Bakewell, Derbyshire. The National Archives, Ref. WORK 28/251, March 27, 1952 - September 26, 1953.
Coordinates: 53 ° 12 ′ 37.8 " N , 1 ° 41 ′ 10.5" W.