VERTICAL V. INCLINED SUAFTS.

Inangahua Times, Volume II, Issue II, 3 December 1880, Page 2

VERTICAL V. INCLINED SUAFTS.

Our correspondent, Mr Frederick M. Amelung, in a recent letter, when Speaking of a certain mine, made use of tbe following expresion : ' A new inclined shaft, , following the dip of the vein, has been started. ... It is my opinion that this is false manage** ment, since the vertical shaft would answer the purpose far better, be free from «*ater, and enable the mine to be worked in a systematic manner".' Whereupon a correspondent in the Silver Worjd of July* lOfch becomes indignant, and writes to that paper, saying that inclined are better in al! respeets than verticrl shafts, and summarizes their advantages as fowows :. ' Anv miner of Capt. Cruse's experience knows full well the superior ' value of inclined shafts for operating on fissure»veinß which have a dip, both < for economy and systematic working, for tbe following rerecm . I First — An inclined shaft follow the i course of the lode and proves its value as depth is gained, and not infrequpnty mineral ia found in such quan* lities as to pny the whole cost; of sinking, as in all probability the Uie shaft will 03 found to do t thus saying great expense to the owners. Second— AH tbe cost of driving crosscuts to intersect the lode as in the case of vertical shafts is saved. Third — An inclined shaft being on the vein, as sorn a3 deep enough, stations can be cut, levels can be extended, and thus the mine can be systematically aud expeditiously developed. Four! h — The cage or bucket, as the casa xaiy be, for hoisting, conies down directly to the stations, plants or levels where the mineral ia broken, thus obviating the necessity of taking tbe mineral in cars through long cross* cuts to a vertical shaft. Fifth — It gives far better ventilation and air to the mine. v Sixth — There is no more water than in a vertical shaft. Seventh— The inclined tmaft can be sunk to a great depth and ye f - be in proxiuvty to the lode; whereas, in a vertical shaft, as depth is gained, it departs from the vein until further operations provj impracticable ' Where the object of work is to ex* plore a vein, especially in a new district, and where lime is limited, there can be no question but that the incline followi r g the lode is the most advantageous. As the vein ia u>.a.illy wetter, than the country-rock, the incline on the vein is general more troubled with water than the vertical shaft ; but when it com^s to permanent work (not exploration), the greater speed with which hoisting can beMone in a vertical shaft, the less length required to attain a given depth, and consequently the less amount of columopipes, pump-rods, guides, rope, ets.. required, are all in favour of vertical shaft s. The great variations in the dip of a vein at d fferenls point is but one of the diffi" culties met with in^making an incline on the vein a convenient shaft for permanent work. But a simple reference to Comstock practice — unquestionably the best in metal milling in this countrv — and the more and general adoption of vertical shafts in the place of indiues iu the anthracite coal mines, where a single shaft will turn out 1500 to 2,oo ■".) tons in 10 hours* w>rk, shows the pract'cii recognition tf advantnges of tho vertical shaft over inclined one for reguUr work. Thle, however, doei not aiteet Ihe claim for superior economy arid speed in exploring a vein by adopting an incline instead'of a vertical shaft. So that each haa ita appropriate place, and neither is the best unier all circumstances — Engineering and Mining Journal.