Diamantbohrungen für Schürf-und Aufschlußarbeiten über und unter Tage

SUBJECT AREA: Mining and extraction technology

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Having completed his studies at the Technological Institute in Stockholm and the Mining School at Falun, Crælius was awarded a grant by the Swedish Jernkontoret and in 1879 he travelled to Germany, France and Belgium in order to study technological aspects of the mining, iron and steel industries. In the same year he went to the United States, where he worked with an iron works in Colorado and a mining company in Nevada. In 1884, having returned to Sweden, he obtained an appointment in the Norberg mines; two years later, he took up employment at the Ängelsberg oilmill.

His mining experience had shown him the demand for a reliable, handy and cheap method of drilling, particularly for prospecting purposes. He had become acquainted with modern drilling methods in America, possibly including Albert Fauck's drilling jar. In 1886, Crælius designed his first small-diameter drill, which was assembled in one unit. Its rotating boring rod, smooth on the outside, was fixed inside a hollow mandrel which could be turned in any direction. This first drill was hand-driven, but the hydraulic version of it became the prototype for all near-surface prospecting drills in use worldwide in the late twentieth century.

Between 1890 and 1900 Crælius was managing director of the Morgårdshammar mechanical workshops, where he was able to continue the development of his drilling apparatus. He successfully applied diesel engines in the 1890s, and in 1895 he added diamond crowns to the drill. The commercial exploitation of the invention was carried out by Svenska Diamantbergborrings AB, of which Crælius was a director from its establishment in 1886.

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See also: Fauvelle, Pierre-Pascal