登入選單
返回Google圖書搜尋
Experimental Longwall Mining in a Pennsylvania Anthracite Mine (in Two Parts).
Wilbert T. MalenkaRobert J. Brennan
其他書名
Use of a shearer loader
出版U.S. Department of the Interior, Bureau of Mines, 1966
URLhttp://books.google.com.hk/books?id=BGS2UMVYlpYC&hl=&source=gbs_api
EBookFULL_PUBLIC_DOMAIN
註釋In its search for a highly productive mining system for anthracite beads pitching from 10° to 20°, where conventional mobile equipment cannot be used, the Bureau initiated a longwall project by introducting [sic] a shearer drum cutter loader of European origin. Because of the undulating nature of the roof and floor and changing bed thicknesses, the machine proved inflexible and extra work was required in lifting bottom coal and blasting top coal.