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Shaft mining or shaft sinking is the action of excavating a mine shaft from the top down, where there is initially no access to the bottom. [1] Shallow shafts , typically sunk for civil engineering projects, differ greatly in execution method from deep shafts, typically sunk for mining projects.
When wet sinking a shaft the shaft is allowed to flood and the muck is excavated out of the base of the shaft underwater using a grab on the end of a crane or similar excavation method. Because the shaft is flooded, the lining can not be constructed at the excavation level of the shaft so this method only suits methods where the lining is ...
The vertical line test, shown graphically. The abscissa shows the domain of the (to be tested) function. In mathematics, the vertical line test is a visual way to determine if a curve is a graph of a function or not. A function can only have one output, y, for each unique input, x.
The Saint-Charles shaft (or No. 8 shaft) is one of the main collieries of the Ronchamp coal mine. It is located in Ronchamp , Haute-Saône , in eastern France. In the second half of the nineteenth century, this shaft made it possible to mine large coal seams, contributing to the company's golden age.
The dynamometer measures the thrust and torque of the propeller. The propeller shaft extends a sufficient length forward from the boat to ensure that the flow around the propeller is not disturbed by the boat. The test is conducted by towing the open water boat at a steady speed while running the propeller at a constant revolution rate.
Schematic cross section of a pressurized caisson. In geotechnical engineering, a caisson (/ ˈ k eɪ s ən,-s ɒ n /; borrowed from French caisson 'box', from Italian cassone 'large box', an augmentative of cassa) is a watertight retaining structure [1] used, for example, to work on the foundations of a bridge pier, for the construction of a concrete dam, [2] or for the repair of ships.
The sinking of a 4.3 meter ("m") diameter exploration shaft (known as "J53") began in June 1970 and was completed to a depth of 630 m in June 1973. [15] Sinking the "P49" service and hoisting shaft (8 m in diameter) began in 1971, and this shaft was completed to a depth of 1040 m in December 1975.
The shafts of the three concessions established in the mid-19th century. The Ronchamp colliery shafts (French, Les puits des houillères de Ronchamp) are a series of collieries undertaken by the various mining companies in the Ronchamp coalfield between the early 19th and mid-20th centuries at Ronchamp, Champagney, and Magny-Danigon, in the Haute-Saône département of France.