author: clarence watson owings

Some Information on Timbering Bituminous-coal Mines

... earthing system . All the conductors of an earthing system shall have a ... earth . Provided that no conductor of an earthing system shall have a cross ... truck was usually found to be satisfactory in grounding that machine to the ...

Methods of Sampling and Analyzing Coal-mine Dusts for Incombustable Content

... - spout gate 7 ball and socket bearing Overflow spout Overflow - spout adjustable gate Overflow - spout adjustable gate guide Overflow - spout adjustable gate handwheel Overflow - spout adjustable gate bracket Overflow - spout adjustable ...

Comparison of Storage-battery and Cable-reel Gathering Locomotives in a West Virginia Coal Mine

... voltage drop ( the voltage at the sections ranges from about 450 to 565 ) ... comparison , the storage - battery locomotives re- quire about 0.49 kilowatt ... comparison of the power demands for the two types of haulage locomotives is ...

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