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75.1003-1 Other Requirements for Guarding of Trolley Wires and Trolley Feeder Wires
"Equipment" for the purpose of this Section is interpreted to mean track-mounted equipment, off-track mining equipment, component parts of mining equipment, mine supplies, or any item used in the operation or maintenance of a coal mine.

This Section applies to movement of any item that is used in the production or transportation of coal or in performing any duty necessary for the operation and maintenance of the mine. This Section requires mine management to take adequate precautions prior to movement of equipment to prevent the item being moved from contacting the trolley or trolley feeder wire. If the inspector has reason to believe that any equipment, including off-track mining equipment, has been allowed to contact the trolley or trolley feeder wires, creating a short circuit, this Section should be cited.

The following precautions are considered adequate for movement of equipment other than off-track mining equipment in track and trolley entries:

  1. Maintenance of 12 inches vertical clearance between the equipment being moved and energized trolley or trolley feeder wires; or

  2. Deenergization of the trolley and trolley feeder wire while equipment is being moved along track and trolley entries; or

  3. Transportation of the equipment in a mine car or other vehicle having two sides with dimensions not greater than the sides of mine cars normally used in the track haulage system. The equipment being transported shall not extend above the sides of the mine car; or

  4. Transportation of small items of mine equipment, such as small pumps, component parts of mining equipment, and mine supplies, in a vehicle that normally traverses the intended route, provided no part of the equipment being transported extends higher than that part of the frame of the vehicle that is in front of or to the rear of the item being transported.
If items 1 through 4 cannot be met, adequate protection would require compliance with Sections 75.1003-2(a) through 75.1003-2(f)(5) or other equally effective safeguards designed to insure that such equipment will not contact energized trolley wires or trolley feeder wires.
 
75.1003-2 Requirements for Movement of Off-Track Mining Equipment in Areas of Active Workings Where Energized Trolley Wires or Trolley Feeder Wires are Present; Premovement Requirements; Certified and Qualified Persons
"Off-track mining equipment" for the purpose of this Section is interpreted to be a major item of complete or reasonably complete mining equipment, built on its own individual frame, consisting of its own components, performing its own unique function, and not designed to operate on mine track. "Off-track mining equipment" includes all self-propelled equipment including cat-mounted rubber-tired or skid-mounted equipment. "Off-trackmining equipment" includes major items of complete or reasonably complete mobile or stationary mining equipment that is used in the production of coal or to supply electrical, hydraulic, or pneumatic power to mining equipment.

At times, cutting heads, drill booms, conveyor booms, electric motors, etc., are removed from machines to facilitate transportation in the restricted confines of coal mine entries.These machines are still considered to be off-track mining equipment within the meaning of this Section. However, the detached cutting heads, drill booms, conveyor booms, electric motors, etc., are component parts of a machine and cannot be considered to be off-track mining equipment. Neither can roof bolts, oil barrels, steel ties, steel rails, belt structure, or other mine supplies be considered as off-track mining equipment.

When the trolley wire and trolley feeder wire are 12 inches horizontally from the equipment being moved, the equipment almost always passes under turnouts where the trolley wire and trolley feeder wire will be directly over the equipment being moved.Therefore, 12 inches horizontal clearance is not acceptable as compliance with this Section.

The measurement of 12 inches vertical clearance shall be determined by measuring vertically from the trolley wire to a perpendicular line intersecting with the highest projection on the equipment being moved.

Subpart L .... Fire Protection
 
75.1100-1 Type and Quality of Firefighting Equipment [12/11/97 (Release V-29)]
Waterlines, with hoses attached, shall be of sufficient size to deliver 50 gallons of water per minute at a nozzle pressure of 50 psig. With this water flow and nozzle pressure, an effective solid stream can be projected about 60 feet in a 6-foot high entry. Water flow through the nozzle can be measured by a pitot tube instrument if the diameter of the nozzle orifice is known. For adjustable nozzles, the rate of flow decreases as the water flow pattern changes from a solid stream to a spray or fog. The minimum rate of 50 gpm shall be available at the most distant point in the mine. The type and method of installation of waterlines are options of the operator, provided they meet the requirements of Subpart L.

Portable water cars shall be examined during each regular inspection to ensure that the pump, valves and fittings have not corroded excessively.

A portable chemical car shall contain 125 pounds of all-purpose dry powder for each 500 gallons of water capacity required of a water car. The car shall contain provisions for expelling dry chemical through a hose and attached nozzle. The hose shall be a minimum of 100 feet long and a maximum of 150 feet long. The dry chemical is expelled rapidly; therefore, firefighting operations using a portable chemical car should be conducted by personnel trained in its use.

The portable foam-generating machine or device shall be equipped with all hardware necessary to install the machine or device in a mine passageway. Generally, plastic brattice (or equivalent) material is needed to seal the entry at the installation location. The foaming agent tends to be corrosive to metal parts and, unless the machine or device is carefully cleaned after use, the valves, pump and fittings may become inoperative.

Only foam-producing and multi-purpose dry chemical portable fire extinguishers are acceptable. The older type sodium bicarbonate extinguisher can be converted for use with all-purpose dry chemicals; however, such conversion can be hazardous and voids the approval of Underwriters' Laboratories, Inc., and Factory Mutual Research Corp. Therefore, such converted extinguishers are not acceptable as complying with paragraph (e) of this Section.

Portable fire extinguishers purchased after March 30, 1971, shall have a 2A 10 BC minimum rating. The letters "A," "B," "C" refer to the class of fire for which the dry chemical is effective, and the numerals "2" and "10" refer to the size of the standard fire for which the extinguisher is effective.

Class A fires are those occurring in solids such as coal, wood, rubbish, textiles and rubber. Class B fires are those occurring in flammable and combustible liquids such as fuel oils, lubricating oils, grease, paint, varnish and lacquer. Class C fires are those which involve energized electrical equipment where the electrical nonconductivity of the extinguishing medium is of importance. Where electricity is involved in a fire, the electric circuit should be broken or deenergized as soon as possible.

Fire hose suitable for use in coal mines must meet specific requirements. The lining material shall pass MSHA's test outlined in Schedule 2G to limit the flammability. Generally, the lining will be a synthetic rubber. The jacket shall be polyester or its equivalent. When subject to flame, the polyester jacket will melt and burn somewhat; however, the polyester is more vermin-resistant than other jacket materials. The flammability characteristics of the polyester jacket can be reduced by chemical treatment or by an impregnation of synthetic rubber of the type used for the liner. Such hose is highly recommended but is not necessary to meet the minimum specifications. The bursting pressure of the hose shall be at least four times the static pressure at the hose inlet. The hose coupling should also be designed to withstand the required bursting pressure. Couplings approved for fire hoses by the Underwriters' Laboratories, Inc., or Factory Mutual Research Corp. are recommended. Short shank couplings (of the type ordinarily used on water or air hose) will blow off at pressures ranging from 300 to 600 psig even if fastened with two hose clamps. Short shank couplings are not recommended for fire hoses; however, in a few instances, where the static pressure is less than 120 psig, they might meet the minimum requirements of the regulations, provided the water flow rate of 50 gpm through the nozzle is obtained. Short shank couplings cause excessive pressure loss; therefore, it is important to ensure that the minimum quantity of 50 gpm is met.

Fire hose purchased prior to December 30, 1970, may be used if it meets all requirements except those for flammability. An inspector having reason to doubt the acceptability of a specific fire hose should obtain all available manufacturer's specifications and refer such information to his supervisor. The supervisor should request clarification from the MSHA Approval and Certification Center, Technical Support. Manufacturers of fire hose accepted by MSHA for flame resistance are required to place the acceptance numbers at intervals not to exceed 3 feet along the length of the fire hose.

Where waterlines are installed on a section, sufficient fire hose shall be provided to reach from the water outlet to each working face for fire-control operations. Water hose, ordinarily provided in a section and connected to machines for dust-suppression purposes shall be considered inadequate as fire hose if the rate of water flow through the hose and nozzle is less than the required 50 gallons per minute.

Average daily production figures shall be obtained from information submitted in accordance with procedures, as required by the respirable dust information reporting system.

Rock dust shall be dry and usable to comply with this section. If containers other than bags are used, a means of transporting the rock dust, such as shovels, pails, etc., to any location on the section shall be provided.
 
75.1100-2 Quantity and Location of Firefighting Equipment
Paragraph (a)(1) requires that each working section in the coal mine, where the production is 300 tons per shift or more, shall be provided with one of the combinations of firefighting equipment listed below:

  Combination Options
and Number Required
Fire Suppression Equipment a b c d e f g
Portable fire extinguisher 2 2 2 2 2 2 2
240 pounds of rock dust 1 1 1 1 1 1 1
Waterline with fire hose 1            
Portable water car     1 1     2
Portable chemical car   2     1 1  
Portable foam-generating machine     1   1    
Portable high-pressure rock-dusting machine       1   1  

Paragraph (a)(2) requires that each working section in the mine, where the mine production is less than 300 tons per shift, shall be provided with one of the combinations of firefighting equipment listed below:

  Combination Options
and Number Required
Fire Suppression Equipment a b c d
Portable fire extinguisher 2 2 2 2
240 pounds of rock dust 1 1 1 1
500 gallons of water with three 10-quart pails 1      
Waterline with fire hose   1    
Portable water car (500 gallon) with hose     1  
Portable all-purpose chemical car (125 pounds)       1

If 500 gallons of water and three 10-quart pails are provided, the water supply shall be available for transportation to any location on the section. Where water cars are used as section fire protection equipment, the water cars shall contain no less than the minimum amount of water required at all times. If the water cars provide water for dust abatement, etc., additional cars or water capacity shall be provided to ensure the availability of the minimum amount of required water at all times.

Firefighting equipment provided for working sections in all coal mines shall be stored in an accessible location at or inby the loading point.

The waterline required by paragraph (b) of this Section can be located in an adjacent entry, but outlets with valves must project into the belt entry every 300 feet. Fire hose connected to a waterline and projected into the belt entry will not be considered adequate since the valve must be located in the belt entry. "Entire length of belt conveyors," as used in this Section, includes that portion of underground belt conveyors that extend onto the surface of a mine, unless the surface located drive unit for the belt is 100 feet or more from any intake airway.

Five-hundred feet of fire hose, at strategic locations, shall be provided for each belt conveyor which is independently driven. However, where the length of the belt conveyor is less than 500 feet, only a length of fire hose sufficient to reach the length of such belt conveyor need be provided.If 500 gallons of water and three 10-quart pails are provided, the water supply shall be available for transportation to any location on the section. Where water cars are used as section fire protection equipment, the water cars shall contain no less than the minimum amount of water required at all times. If the water cars provide water for dust abatement, etc., additional cars or water capacity shall be provided to ensure the availability of the minimum amount of required water at all times.

Firefighting equipment provided for working sections in all coal mines shall be stored in an accessible location at or inby the loading point.

The waterline required by paragraph (b) of this Section can be located in an adjacent entry, but outlets with valves must project into the belt entry every 300 feet. Fire hose connected to a waterline and projected into the belt entry will not be considered adequate since the valve must be located in the belt entry. "Entire length of belt conveyors," as used in this Section, includes that portion of underground belt conveyors that extend onto the surface of a mine, unless the surface located drive unit for the belt is 100 feet or more from any intake airway.

Five-hundred feet of fire hose, at strategic locations, shall be provided for each belt conveyor which is independently driven. However, where the length of the belt conveyor is less than 500 feet, only a length of fire hose sufficient to reach the length of such belt conveyor need be provided.

Direction of the air current along the belt, amount of fire hose,height of coal seam, and availability of transportation for men and materials must be considered to determine strategic locations for storing fire hose along belt conveyors. Ideally, the fire hose should be stored on intake air near the belt conveyor drive,but conditions may dictate that another location is suitable, or that a separation of the hose into two or more sections is necessary. Any tools or accessories required to join hose pieces or connect fire hose to the waterline shall be stored with the fire hose and shall be easily accessible. Waterlines are not required to parallel extensible and Lo-Lo conveyor belts serving mining machines if the length of such belt is less than 600 feet and sufficient fire hose is available to extend to the working face. Fire suppression devices and signal and alarm systems are not required to be installed along such conveyor belts. However,the belts considered as face equipment must have fire protection at the belt drive as specified in paragraph (e) of this Section for permanent electrical installations and, if hydraulically operated, must have fire suppression devices as provided in Section 75.1107.

Paragraphs (c)(1) and (c)(2) require that in mines producing 300tons of coal or more per shift, all track entries in which mechanized equipment is used shall be protected by suitable fire fighting equipment. Where waterlines are used, a minimum of 500 feet of fire hose shall be located at a readily accessible location which is plainly marked. Crosscuts, runarounds,sidetracks, etc. may be provided protection with one waterline if the outlet valves are located in a manner which allows 500 feet of fire hose, connected to one of the valves, to reach any such track location. Where two portable water cars are used in lieu of waterlines prescribed in this section, each water car shall operate individually and not be dependent on another water car for pump, hose, nozzle, or water. Where two or more adjacent mines are connected by track, one of the water cars required for each mine may be considered to be a common unit. All water cars shall be located on intake air as near the entrances to the mine as conditions permit and shall be properly filled, equipped, and ready for use at all times.

If rock dust is used as fire protection along such haulage tracks, the rock dust shall be in a dry, usable condition at all times.

One portable fire extinguisher is also required on each battery-powered tractor by paragraph (d).

A permanent electrical installation as addressed by paragraph (e)is electric equipment that is expected to remain in place for a relatively long or indefinite period of time.

Consequently, the following electric equipment should be considered permanently installed:

The following electric equipment should not be considered permanently installed:

Paragraph (f) does not apply to synthetic ester types of fire-resistant hydraulic fluids. Storage underground of more oil than is normally delivered to the working sections shall be considered a permanent oil storage station.

When welding, cutting, soldering or other operations using open flame are conducted on a working section, the fire fighting equipment provided under paragraph (a) of this Section may be used at the welding, cutting, or soldering site to fulfill the requirement of paragraph (g).

As addressed in paragraph (i), if 5 tons of rock dust is readily available, within 2 miles of each working section, loaded in or on a wheeled vehicle, it does not have to be located with the other emergency materials. All other emergency materials shall be stored together and shall be readily accessible at all times.

When emergency material is stored at a central warehouse or building supply company, the inspector should determine whether the material will be available for shipment to the mine at all times.
 
75.1100-3 Condition and Examination of Firefighting Equipment
All firefighting equipment shall be maintained in a usable and operative condition. Rock dust shall be dry, water cars shall be kept filled and operative, water containers and pails shall be in usable condition, and chemical extinguishers shall be examined every 6 months. The inspection of chemical extinguishers should determine that:

  1. The extinguisher is in its designated place.

  2. Access and visibility to the extinguisher are not obstructed.

  3. Seals should not be broken. This is an indication that the extinguisher may not be full. Some extinguishers have to be lifted slightly to determine if they are full.

  4. The extinguisher has not been physically damaged or have any obvious defects (clogged nozzle, corrosion, leakage, damaged hose, etc.).

  5. The examination record on the tag is up-to-date. This section is interpreted to mean that water shall be kept constantly in the waterlines in sufficient amounts to meet the requirements of Section 75.1100-1(a). The phrase "50 gallons of water per minute," as used in Section 75.1100-1(a), does not mean for only 1 minute.
In those instances where there is danger of freezing and bursting the waterlines if water is kept in the lines, the mine operator should consider a pressurized system, or should file a petition for modification under the provisions of Section 101(c) of the Act.
 
75.1101 Deluge-Type Water Sprays, Foam Generators;Main and Secondary Belt-Conveyor Drives
In requiring fire suppression systems for belt conveyor drives,apply the same rule used in Section 75.603 and in Section 75.1103, which permit the use of belt conveyor drives without a fire suppression system for 24 production shift hours after they have been installed before a citation is issued.

The figures "50 feet" and "150 feet" referred to in Sections 75.1101, 75.1101-5(b)(1) and (2), 75.1101-7(b) and 75.1101-14(a)mean lineal feet of belt entry.

Guidelines for Fire Protection at Surface Located Drive Units for Underground Belt Conveyors:

  1. All belt drive units located within 25 feet of any intake airway should be equipped with an automatically actuated fire suppression system as described in this Section.

  2. Belt drive units located more than 25 feet but less than 50 feet from any intake airway should be equipped with an automatically actuated fire suppression system, unless fire doors or air lock doors are provided in the belt entry and in all intake entries within 50 feet of the drive unit.

  3. Belt drive units located more than 50 feet but less than 100 feet from any intake airway should be equipped with a sensor system which will automatically sound an alarm and stop the conveyor drive motor when a fire occurs on or near such belt drive.

    The alarm shall be at a location where it can be heard by a responsible person who is always on duty while men are underground.

    If a responsible person is not stationed where he can hear the alarm and/or is not always on duty while the belt is running and miners are underground, a fire door or air lock should be installed in the belt entry and all intake entries within 100 feet of the belt drive. If the conditions are not met, a fire suppression system should be required.

  4. Belt drive units located 100 feet or more from any intake airway should be protected with one or two portable fire extinguishers as applicable under Sections 75.1100-2(e)(1) or (e)(2) (electrical installations).

    Measurements made to determine the distance between the drive unit and the mine opening should be made between the belt drive roller and the nearest mine opening or intake airway, as applicable. The fire suppression system, fire door/air lock doors, and sensor controlled stop and alarm described in paragraphs 1, 2, 3 and 4 are in addition to portable fire extinguishers and waterlines equipped with fire hose outlets and valves required by Sections 75.1100-2(b) and 75.1100-2(e).

 
75.1101-3 Water Requirements
The following additional features are to be considered and,unless deemed not necessary by the District Manager, shall be included in the installation:
  1. When activated, the sensor system (or water flow) should stop the belt;

  2. Sensors and nozzles should be located at or near the electrical controls, belt takeup and gear reducing units;

  3. A manually-operated by-pass valve, located away from the belt drive, should be installed to furnish water to the suppression system in the event the automatically activated valve fails to open;

  4. The sensor system required by Section 75.1103 must be provided with a standby power source maintaining an operative system for a minimum of 4 hours, unless the belt haulageway is examined in accordance with Section 75.1103-4(e);

  5. When activated, the sensor (or water flow) shall operate an effective alarm signal, preferably both audible and visual. The warning sign must be located at a site where someone is in constant attendance, such as an attended belt loading point, section loading point, dispatcher's office, shop, mine office, lamp house, etc.;

  6. The sensor system shall include a warning indicator (or test circuit) which shows it is in operative condition; and

  7. The system shall require manual shut-off.
The installation of a water deluge system generally requires two branch lines to provide adequate water on the top of the top belt and to the surfaces between the two belts. A single branch line located at the top belt ordinarily does not offer an equivalent flow pattern. However, the single branch line system can be considered equivalent when the following conditions are met:
  1. The entry width does not exceed 16 feet, and the entry height is not less than 6 feet;

  2. The static water pressure is not less than 250 psig and the quantity of water delivered with all nozzles operating is not less than 1.0 gallon per square foot of top belt surface area per minute; and

  3. The nozzles are mounted above the top conveyor belt near the roof, and reasonable water coverage of the belt surfaces is achieved by splashing action.
The maximum distance between nozzles shall not be more than 8 feet to achieve a reasonable water spray pattern. In general,the nozzles need not be closer than 6 feet apart.

The regulations require that 50 feet of fire-resistant belt and 150 feet of nonfire-resistant belt adjacent to the drive be protected. Depending on ventilation, design, and belt arrangement, this 50 (or 150) feet of protected belt should begin at the discharge roller if the discharge roller and drive roller are not more than 25 (or 75) feet apart. Where the discharge roller and drive rollers are more than 25 (or 75) feet apart, the protected area should include 25 (or 75) feet of adjacent belt in each direction from the drive roller. Where air velocity is a factor, the greater part of the protected area should be downwind from the drive roller.

The type, number, and location of the sensors are critical features of a water deluge system. There are about a dozen basic types of sensors which can be used, i.e., fixed temperature(heat), rate of temperature rise, rate compensation, radiation,ionization, combustion gases, smoke, heat detecting wire,pneumatic tube type, and resistance bridge type.

The location of the sensors should, in general, be in accord with the recommendation of the manufacturer. Sensors responding to heat should be located near the roof, preferably above the belt,drive rollers, powered takeup unit, transmission, and motor.Often, one sensor can be situated strategically to serve two of the possibly hazardous units.