00000nam 2200000za 4500 9.840962 CaOODSP 20221107151955 cr ||||||||||| 170803s1974 oncad ob f000 0 eng d CaOODSP eng n-cn--- M38-8/128E-PDF M38-8/128 Tervo, R. O. Lost a drill hole recently? [electronic resource] / R. Tervo and R. Tirrul, Mining Research Centre. Ottawa : Information Canada, 1974. p. 53-58 : charts, ill. Reprint series ; RS 128 Cover title. "Reprinted from Canadian Mining Journal, vol. 95, no. 3, March 1974, pp. 53, 54 and 58." Historical publication digitized from print 2017 [by Natural Resources Canada]. Includes bibliographical references. “Spotting a drill hole and making the necessary calculations for it to hit target is easily enough done but all too often that hole can go astray in the drilling and many expensive, frustrating and sometimes fruitless hours can be spent looking for it. Until recent years the only way of locating the hole was by listening for the sound of the bit in the target area. At best never a reliable method. Then an inventive team at Inco perfected an electromagnetic hole finder that depending on strength, can locate holes several hundred feet away. Requests from various mines for information on the subject have come into the Mines Branch at Ottawa and a team of research scientists, R. Tervo and L. Tirrul were 'assigned to the case’. The following is a description of their findings on the hole finder and a complete and thorough explanation of its working. A do-it-yourself kind of operation that could prove to be manna from heaven for frustrated drill captains everywhere"--p. 58. gccst Mining industry gccst Drilling Tirrul, L. Canada. Natural Resources Canada. Canada. Department of Energy, Mines and Resources. Canada. Mines Branch. Reprint series - Dept. of Energy, Mines and Resources, Mines Branch ; RS 128 (CaOODSP)9.834843 PDF 2.91 MB https://publications.gc.ca/collections/collection_2017/rncan-nrcan/M38-8/M38-8-128-eng.pdf 300207