VOLUME V - COAL MINES
75.1719-2 Lighting Fixtures; Requirements
The required illumination may be provided by light fixtures which
are mounted on board mining equipment and receive power from the
equipment, by stationary light fixtures which are mounted on the
roof or along the rib and receive power through trailing cables,
or by a combination of these two systems. Light fixtures
installed on shearers in longwall systems or continuous miners
in shortwall systems shall be considered machine-mounted light
fixtures. Light fixtures installed on roof support equipment
of longwall or shortwall mining systems shall be considered
stationary light fixtures.
Stationary lighting fixtures which receive power from alternating-current systems which are not resistance grounded as provided in paragraph (c)(2) or from direct-current systems shall be grounded in accordance with the appropriate section of Part 75, Subpart H.
The requirements of paragraph (c)(3) apply to all machine mounted lighting fixtures including headlights that were furnished as original equipment on the machine. The required grounded conductor may be inside the supply cable to the fixture or may be an external grounding shunt. The required grounding conductor shall be in addition to any holes or welds used to fasten the fixture to the machine.
When a grounding conductor inside of the supply cable is used to ground a machine-mounted lighting fixture, the grounding conductor shall connect the frame of the fixture to the grounded explosion-proof enclosure from which the machine-mounted lighting system receives its power.
Paragraph (e) requires that trailing cables conducting power to stationary lighting fixtures be protected against short circuits and overloads. The settings of the circuit breakers providing short circuit protection for such trailing cables shall not exceed the minimum available short circuit current at the end of the cable or the setting specified in Section 75.601-1, whichever is lower. The rating of the device providing overload protection shall not exceed the capacity rating of the cable.
Since the required electrical protection for circuits and trailing cables supplying power to stationary lighting fixtures is specifically contained in paragraphs (c) and (e), a fail-safe ground-check monitor is not required for a three-phase circuit supplying power to stationary lighting fixtures. Likewise, undervoltage protection is not required for a three-phase circuit supplying power to stationary lighting fixtures. The maximum length of trailing cables conducting power to stationary lighting fixtures is not specified; however, the requirement for short circuit protection will limit the length of such cable.
75.1720 Protective Clothing; Requirements
Hard hats or hard caps are required to be worn by miners at
underground coal mines in accordance with paragraph (d) of this
Section. The purpose of the safety standard is to provide
substantial protection for the head from falling objects and to
protect miners against electrical shock or burn. Hard hats are
required to be suitable for these purposes, and if they are
painted, the paint base must be nonmetallic.
Hard hats or caps that meet or exceed the applicable specifications of the American National Standards Institute (ANSI) provide appropriate head protection and comply with these requirements. The applicable standards are ANSI's "Safety Requirement for Industrial Head Protection," Z89.1, and "Safety Requirements for Industrial Protective Helmets for Electrical Workers, Class B," Z89.2.
Hard hats or caps that do not meet or exceed the applicable ANSI or equivalent standards should not be used. Plastic "baseball type" caps and thin plastic hats do not have adequate suspension systems and are not constructed of sufficiently substantial material to afford the necessary protection from impact and penetration of falling objects. Hats or caps constructed of metal materials create an additional hazard of electrical shock or burn because they are conductive.
The phrase "when other hazards to the eyes exist from flying particles" is interpreted to mean that face shields or goggles shall be worn by miners when performing work such as breaking material with a hammer, digging with a pick, tightening a roof support with an axe or hammer, sounding roof, riding in or on haulage equipment (except closed-type equipment such as covered man cars), and any other work considered hazardous to the miners' eyes.
Paragraph (c) of this Section requires that miners wear gloves whenever they troubleshoot or test energized electric power circuits or electric equipment. Work gloves in good condition are acceptable for troubleshooting or testing energized low- and medium-voltage circuits or equipment.
75.1722 Mechanical Equipment Guards
Guards installed to prevent contact with moving parts of
machinery shall:
- Be of substantial construction;
- Be of such construction that openings in the guard are too small to admit a person's hand;
- Be firmly bolted or otherwise installed in a stationary position; and
- Be of sufficient size to enclose the moving parts and exclude the possibility of any part of a person's body from contacting the moving parts while such equipment is in motion.
Guards, such as substantial chains, cables, or the equivalent,installed to protect persons from contact with the inby side of ventilating fans shall:
- Be located at least 6 feet on the inby side of the fan blade;
- Be installed to a height of at least one-half the height of the air passageway; and
- Extend the width of the air passageway. Inspectors should carefully examine each belt conveyor drive to determine whether all rollers are sufficiently guarded to prevent persons from becoming entangled between the rollers and the conveyor belt.
Face shields or goggles shall be worn when operating any type of grinding wheel regardless of how the wheel is guarded.
75.1724 Hand-Held Power Tools; Safety Devices
If a hand-held power tool is equipped with a friction device in lieu of a switch which requires constant pressure to keep the tool operating, the friction device shall be adjusted to readily slip in case of emergency.
75.1725 Machinery and Equipment; Operation and Maintenance
The presence of defects, such as worn tires, defective steering or brakes, malfunctioning hydraulic controls, worn lagging on belt conveyor drive rollers, or frozen or damaged idler rollers could indicate that such machinery and equipment is not maintained in safe operating condition. Therefore, a violation of this section would exist if such defects render the equipment or machinery unsafe to operate.
When an inspector finds a violation as described above, he shall issue a citation requiring the condition to be corrected in reasonable time. Since this Section also requires that unsafe equipment or machinery be removed from service immediately, the operator should be advised of the requirement. If the operator removes such unsafe equipment or machinery from service immediately it should be noted on the citation. If the operator does not remove such equipment or machinery from service immediately, another citation for such failure should be issued giving the operator reasonable time to comply.
This Section in no way affects enforcement of other mandatory safety standards and should be used only where such condition is not covered by any other regulation. Lack of frame grounding,improper protection, etc., are to be cited under the appropriate sections in accordance with Section 104 of the Act allowing reasonable time for compliance.
Loading machines and continuous-mining machines shipped from the manufacturer after January 1, 1981, are required to be equipped with load-locking valves in the boom and head lift cylinders.Where it is determined that a unit of equipment was shipped after January 1, 1981, and the load-locking valves are not maintained,enforcement action should be taken under Section 75.503, for failure to maintain the electric face equipment in permissible condition. Load-locking valves provided on equipment shipped from the manufacturer prior to January 1, 1981, also have to be maintained. Appropriate enforcement action under this Section should be taken if these load-locking valves are not being maintained.
The tramming of solid-state controlled battery powered equipment in the high-tram mode immediately upon energization of the tram motors indicates that an electrical fault is present on the equipment. When this occurs, the equipment is not in safe operating condition and must be removed from service and properly repaired.
Faulty equipment responds in two ways. First, the tram motors may start in high tram and then immediately stop, which cayuses machine to "lurch" a short distance. This response indicates that the protective circuits in the solid-state logic unit are sensing a fault and are functioning properly. Second, the tram motors immediately start in high-tram and continue to run in this mode. This response indicates that an electrical fault is present on the machine and that the protective circuits in the solid-state logic unit are inoperative.
Proper functioning of temperature-sensitive switches or other devices which shut down air compressor motors when overheating occurs is essential to the safe operation of this equipment.Examinations and testing performed on air compressors must include attention to over temperature devices, and whenever these safety features are not functioning properly the equipment must be immediately removed from service.
Management shall have the responsibility of designating only properly trained personnel to operate equipment and machinery.
The trailing cable shall be disconnected from the source of power before repairs are made on portable or mobile equipment, except when the equipment must be operated for making adjustments.
Raised, elevated, and unsecured equipment must be securely blocked to prevent movement before miners position themselves under or between movable components of the equipment.
Occasionally more than one component location on a machine must be blocked. Blocking material must be capable of supporting the weight of the equipment or component. Wood used for blocking material must be solid and should be flat sided. Most equipment can be safely blocked with a wooden crib. The crib should be installed on a solid footing and wedged tightly to the machine to prevent any initial movement that could dislodge the blocking.
Machinery shall not be lubricated manually while in motion or while energized unless facilities are provided to assure against equipment accidentally starting while being lubricated. Section 75.509 prohibits equipment from being lubricated while energized.This would prohibit the use of machine-powered, hand-operated lubricators on the same machine that is being lubricated.
When it is necessary to position certain mechanical parts of equipment for repairs, maintenance, or lubrication, or when hydraulic fluid must be power-pumped, the machine may be energized for that portion of work. However, when hydraulic fluid is power-pumped, no other repair, maintenance, or lubrication work shall be done. Repair, maintenance, or lubrication work shall not be done until the power is removed from the machine. This would prohibit the use of machine-powered, hand-operated lubricators on the same machine that is being lubricated, unless all incoming power connectors are broken by a circuit breaker. A small circuit breaker, connected to the line side of the power circuit breaker, could supply power to a machine-mounted lubricating system if the power circuit breakers are opened before the machine is lubricated. Opening a circuit breaker which is installed on the machine, and which opens all power conductors entering the machine, shall be acceptable as compliance with this Section for lubrication or changing bits.Opening a double-pole control switch which will open both the negative and positive control circuits, shall be acceptable on direct-current-powered cutting machines and continuous miners for the purpose of deenergizing the machine for changing cutting bits.
When machines are mechanically connected to each other but trammed independently, and are sufficiently different in size,weight, and power, an emergency stop switch shall be installed on the smaller machine to deenergize the larger machine. Without an emergency stop switch the equipment is not considered to be in a safe operating condition and must be removed from service.
75.1729 Welding Operations
Welding operations shall be shielded to the extent that the other persons working in the adjacent area will not be able to view the welding area directly. Areas in which welding operations are being performed shall be ventilated sufficiently to prevent accumulation of smoke and other contaminants.
75.1730 Compressed Air; General; Compressed Air Systems
All pressure vessels shall be plainly marked with the manufacturer's name and maximum allowable working pressure.Safety relief valves shall be adjusted to flow at a pressure not exceeding the maximum allowable working pressure of the vessel,except that if the vessel is exposed to fire or other sources of external heat the relief valve may be adjusted to a value not exceeding 110 percent of maximum allowable working pressure.
PART 77 .... MANDATORY SAFETY STANDARDS - SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES
Subpart C .... Surface Installations
77.100 Demonstration of Ability to Test for Methane and for Oxygen Deficiency
The demonstration of ability requirement of 30 CFR 77.100 applies when an applicant works at a surface area of an underground mine or a surface mine where there is a need for competence in testing for methane and/or oxygen deficiency. Locations where such tests are required include:
Tests for Methane
| 77.201-1 | structures, enclosures, or other facilities where coal is handled or stored; |
| 77.211(b) | tunnels located below stockpiles, surge piles, and coal storage silos; |
| 77.1112(b) | areas where welding, cutting, or soldering will take place and that are likely to contain methane; |
| 77.1916(c) | any slope or shaft designed to penetrate into any coal bed below the surface and where welding, cutting, or soldering is to be performed; |
Tests for Oxygen Deficiency and Methane
| 77.1501(c) | the collar of auger holes when the auger hole penetrates an abandoned or mined out area of an underground mine; and |
| 77.1901(a) | slope and shaft areas. |
Applicants for temporary certification who work at mines where one or more of the above standards has application are required to demonstrate their ability to competently perform the prescribed test to an MSHA inspector or training specialist.Where none of the circumstances or conditions described by the above standards are present, persons working at such mines and applying for temporary certification are not required to demonstrate their ability to perform methane or oxygen deficiency tests. MSHA inspectors will determine whether a demonstration of ability is necessary on a mine-by-mine basis. A temporary certification under 30 CFR 77.100 applies only to the mine where the miner is employed at the time the temporary certification is granted.
77.200 Surface Installations; General
This Section does not apply to housekeeping. It is to be used for keeping surface facilities in good repair relative to safety.
Inspections of surface facilities, structures, and enclosures should include an examination of all load-carrying members and related bracing. When such members or bracing are substantially warped, bent, deteriorated due to corrosion or weathering, or otherwise damaged or missing, the structure may be unstable or have a reduced load-carrying capacity. These conditions can cause or contribute to serious accidents and injuries, and appropriate enforcement action must be taken pursuant to this Section to require the structure, enclosure, or other facility to be maintained in good repair.
The district engineering staff should be consulted to evaluate the condition of a surface structure where assistance is needed in determining whether the condition causes instability or reduces the load-carrying capacity of the structure.
77.201 Methane Content in Surface Installations
Methane tests are not required where there are no surface structures, enclosures, or other facilities where methane could accumulate; where auger mining is not being conducted; or where tunnels are not located below stockpiles. There may be other conditions that do not require methane tests, in which case the inspector should use good judgment in requiring compliance with this regulation.
77.201-1 Tests for Methane; Qualified Person; Use of Approved Device
These tests are required regardless of any other gas detecting methods used.
77.201-2 Methane Accumulations; Change in Ventilation
This Section may be used to determine if a ventilation fan is needed for various surface facilities. However, it does not provide the authority to require a fan if other satisfactory adjustments in ventilation can be made.
77.202 Dust Accumulations in Surface Installations
This section is not meant to control dust from a health standpoint. It is meant to control dangerous quantities of coal dust that would create a fire or explosion hazard.
77.206 Ladders; Construction; Installation and Maintenance
The phrase "wooden members" in Paragraph (b) includes the sidemembers and rungs of ladders.
The words "used regularly" in Paragraph (c) mean, if the ladder is used for any regularly scheduled purpose regardless of the time interval. Paragraph (c) also states that backguards are required on all steep or vertical ladders that are more than 7 feet in height. This requirement in Paragraph (c) cannot be used to cite ladders on mobile equipment or for step ladders and vertical ladders that are not secured at a fixed location.
77.207 Illumination
The inspector should also consider the quality of light in providing a safe working environment. Attention should be given to glare, diffusion, and direction of the light. In areas where moving equipment is present, it is necessary to have the general working area lighted in order to provide sufficient illumination.An area may be illuminated by fixed lighting, machine-mounted lights, or portable lights.
77.208 Storage of Materials
It is not the intent of Paragraph (b) of this section to require valve covers on well secured intermittently used compressed gas cylinders in occupied shops and designated repair areas.However, the valve should be closed promptly after each period of use. Paragraph (e) permits the transportation and storage of compressed gas cylinders with recessed valves without additional protection.
77.211 Draw-off Tunnels; Stockpiling and Reclaiming Operations; General
The requirements of Paragraph (a) of this section may be used as a factor in making a determination as to the need for a ventilation fan. However, it does not provide the authority to require a fan if satisfactory ventilation can be achieved by other means. Paragraph (b) does not require installation of a methane monitor.
77.212 Draw-off Tunnel Ventilation Fans; Installation
This section does not require the installation of a fan to ventilate a draw-off tunnel; however, it does regulate the installation if used.
77.213 Draw-off Tunnel Escapeways
This section applies to any tunnel of sufficient length in which a miner could be entrapped. The escapeway shall be provided from the enclosed end to the surface by an exit other than the existing tunnel. "Equivalent size" means that the smallest dimension in the escapeway from draw-off tunnels shall be no less than 30 inches.