. Handbook of construction plant, its cost and efficiency. nute. GRADING MACHINES 347 In fitting up the winch for the scraping work, the original cast-iron frame was discarded in favor of a much lighter timberframe, in which skids were made a part of the machine. Fortransmitting power from the transformers to the motor, anarmored three-conductor cable was used. This permitted thewinch to be moved about the field with its own power, and madeunnecessary any moving of transformers. During the executionof the work, the winch was moved twice, that is, had three posi-tions, including the original. T
. Handbook of construction plant, its cost and efficiency. nute. GRADING MACHINES 347 In fitting up the winch for the scraping work, the original cast-iron frame was discarded in favor of a much lighter timberframe, in which skids were made a part of the machine. Fortransmitting power from the transformers to the motor, anarmored three-conductor cable was used. This permitted thewinch to be moved about the field with its own power, and madeunnecessary any moving of transformers. During the executionof the work, the winch was moved twice, that is, had three posi-tions, including the original. The transformers were not disturbed after being originallyconnected, as the nature of the ground permitted the selection ofa location within reach of the several positions of the power company made no extra charge for running the neces-sary pole line—some five or six hundred feet—and connectingthe transformers and motor. The scraper was made of 2-in. planks, the cross-section beingof the shape shown by the accompanying sketch (Fig. 159). The. Fig. 159. Section Through Bucket Used on Electric Drag Scraper. inside measurements were 18x18 in. and it was 12 ft. wide. Alittle experimenting was necessary at the beginning of the workto determine the correct angle at which the bail irons shouldbe set. It was found necessary to make one or two changes ofthis angle during the progress of the work, owing to differentconditions of ground and material. The planks were wellstrapped together with bar steel, and the ends were of steelplate. One, and some of the time two, pieces of rail werefastened to the top of the scraper for added weight. Bothhauling and back lines were second-hand mine hoist ropes, invery good condition, but discarded for mine use in compliancewith state mining laws. With the exception of one or two smallportions of the work, the hauling line ran over only one snatchblock, while the back line ran over three blocks a large^ portionof the time. A fairly liberal
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbuilding, bookyear191
