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Traditionally, sinking contractors would build a temporary headframe for the sinking set-up, which would then be dismantled to make way for a permanent headframe. With the growth in complexity and duration of shaft sinking projects over time it has become more common to incorporate more of the permanent shaft set-up into the sinking phase.
During the Second World War, the extraction requirements increased so that the sinking work for a central extraction shaft (shaft 7) was started. The above-day expansion of the shaft did not take place until 1949, when the shaft received a double-headed headframe. A breakthrough to the Ewald 3/4 mine followed.
The Magny shaft under construction, with the wooden headframe of the ventilation shaft and a second (temporary) chimney. Between 1856 and 1859, the Société civile des houillères de Ronchamp drilled the Pré de la Cloche borehole to the north of the future Magny shaft, revealing a layer 1.20 meters thick at a depth of 650 meters.
Headframe of the #1 Shaft at Oyuu Tolgoi. A steel headframe is less expensive than a concrete headframe; the tallest steel headframe measures 87 m. [4] Steel headframes are more adaptable to modifications (making any construction errors easier to remedy), and are considerably lighter, requiring less substantial foundations.
The sinking of the shaft began on May 26, 1863. [2] By 1868, the shaft had reached a depth of 447 meters, and the engineers realized that the inclination of the geological strata had changed. While the engineers thought they'd find coal at a depth of 530 meters, they still didn't reach it at 600 meters. [3]
In 1921, two vertical shafts were commenced, a winding shaft 4.3 by 1.8 metres (14.1 by 5.9 ft) to a depth of 11 metres (36 ft) and an upcast shaft 3.7 by 2.1 metres (12.1 by 6.9 ft) to a depth of 109 metres (358 ft). They were secured with a masonry collar and mounted with heavy headframe timbers set on the surface.
The following years of operation the assay was only 3.5% and the mill was spectacularly less successful than the first fifteen years. Controversy arose over management of the three shafts, Froghole, Gully and Great Northern. Heavy water also entered the Gully shaft. Further sinking was postponed pending the erection of a headframe in 1909.
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.