Pacific service magazine . time there was developed by oneof the steam shovel companies an airoperated shovel of the full swing or merry-go-round type, mounted on crawlers or «caterpillars. This shovel, with boiler and afuel tank replaced by cast iron counter-weights mounted on the rear of the frame,had the advantage of extreme compactness,its overall length being only eighteen counter-weights act also as armor,which makes it unnecessary for the shovelto move far back from the face during theshooting. The shovel is turned with thisarmored rear end toward the heading andmoved back on
Pacific service magazine . time there was developed by oneof the steam shovel companies an airoperated shovel of the full swing or merry-go-round type, mounted on crawlers or «caterpillars. This shovel, with boiler and afuel tank replaced by cast iron counter-weights mounted on the rear of the frame,had the advantage of extreme compactness,its overall length being only eighteen counter-weights act also as armor,which makes it unnecessary for the shovelto move far back from the face during theshooting. The shovel is turned with thisarmored rear end toward the heading andmoved back only ten to twenty feet fromthe face of the bench. Four of these shovels were purchased,and after modifications quickly made inthe field were put to work in the longerheadings, Nos. 1, 2, 5 and 6. With theirinstallation specially low-built six-yardcapacity side dump cars hauled by seven-ton storage battery locomotives were putinto service, two of these cars making theusual train for a locomotive. Pacific Service Magazine 77. Longitudinal section showing top center heading method. Portion marked1 is top center heading, 2 represents area of enlargement to fullarch, 3 represents the bench. As section 2 is removed, wall platesare laid to true position and grade and on them the top segment each side of the bench is advanced five feet, a post is placed to sup-port the wall plate. The size of this tunnel and the character of theformations made it necessary to timber 98% per cent of the footage. Prior to the use of the shovels muckfrom the top heading was taken in wheel-barrows from the top of the bench out overrunways suspended from the roof of thetunnel. These wheelbarrows, in turn, wereemptied directly into cars. When theshovels were installed these suspended run-ways were eliminated, the wheelbarrowsbeing discharged directly over the edge ofthe bench to the main tunnel floor. Eachshovel with its single operator not only re- placed six hand muckers at the floor of thetunn
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Keywords: ., bookcentury1900, bookdecade1910, bookidpacificservi, bookyear1912
