Underground machinery

Fire-resistant hydraulic fluids shall be used in hydraulically-actuated underground machinery and equipment unless such equipment is protected by a fire suppression system or by multipurpose fire extinguisher(s) rated at of sufficient capacity for the type and size of hydraulic equipment involved, but rated at least 4A 40B C. 

The commercial value of a clay deposit depends on market trends, competitive materials, transportation faciflties, new machinery and processes, and labor and fuel costs. Naturally exposed outcrops, geological area and stmcture maps, aerial photographs, hand and power auger drills, core drills, earth resistivity, and shallow seismic methods are used ia exploration for clays (32). Clays are mined primarily by open-pit operation, including hydraulic extraction however, underground mining is also practiced. 

Installations underground in mines and self-propelled mobile surface mining machinery and its attendant electrical trailing cable. 

From May to October the refrigeration machinery was operated according to the moisture removal requirement in the underground workings. Air in the quarry was recirculated in a closed system, the only... 

In underground mining methods, it is difficult if not impossible to separate the shale, clay, and other non-coal partings from the coal seam as the mining machinery removes the entire coal seam— partings included—to maintain a workable height for miners and sometimes to achieve maximum roof stability. The raw coal must be cleaned on the surface at the coal-processing plant. 

To reach deeper coal beds, miners typically dig underground mines. Two or more shafts are tunneled down into a coal seam—typically, different shafts are used for the passage of miners and machinery and for the passage of mined coal. 

Economic losses are divided into (1) direct losses and (2) indirect losses. Direct losses include the costs of replacing corroded structures and machinery or their components, such as condenser tubes, mufflers, pipelines, and metal roofing, including necessary labor. Other examples are (a) repainting structures where prevention of rusting is the prime objective and (b) the capital costs plus maintenance of cathodic protection systems for underground pipelines. Sizable direct losses are illustrated by the necessity to replace several million domestic hot-water tanks each year because of failure by corrosion and the need for replacement of millions of corroded automobile mufflers. Direct losses include the extra cost of using corrosion-resistant metals and alloys instead of carbon... 

The figures used by the commentators cited earlier refer to all mines, both underground and open cut. Open cut mines use larger machinery and are thus more productive than underground mines. 

This covers a number of possibilities. For example, motor-powered machinery operating underground fork-lifts carrying containers in a RORO (roll on roll off) vessel and fork-lifts operating in cool or freezer storage. It could also include ozone emissions from electric motors, cars in a multilevel car park, and stack emissions from coal, gas, or oil fired electricity generation. 

Controls on underground diesel machinery generally involve correct tuning of the motors with frequent checks and adequate mine airflows in the operational areas. 

The Directives define the types of machines that are regarded as hazardous. This list includes, for example, sawing machines, certain wood-working machines, presses, and machinery for underground working. For non-hazardous machinery, i.e. machinery not included in this list, internal... 

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