---
kind: "range"
citation: "30 U.S.C. §§ 862–878"
title: "30"
from: "862"
to: "878"
count: 17
release: "119-102"
url: "https://uscodex.org/usc/30/862..878"
---

# §862. Roof support

- (a) **Roof control plan; contents; review; availability—** Each [operator](/usc/30/802.md?p=d) shall undertake to carry out on a continuing basis a program to improve the roof control system of each [coal mine](/usc/30/878.md?p=l) and the means and measures to accomplish such system. The roof and ribs of all active underground roadways, travelways, and [working places](/usc/30/878.md?p=g-2) shall be supported or otherwise controlled adequately to protect [persons](/usc/30/802.md?p=f) from falls of the roof or ribs. A roof control plan and revisions thereof suitable to the roof conditions and mining system of each [coal mine](/usc/30/878.md?p=l) and approved by the [Secretary](/usc/30/802.md?p=a) shall be adopted and set out in printed form within sixty days after the operative date of this subchapter. The plan shall show the type of support and spacing approved by the [Secretary](/usc/30/802.md?p=a). Such plan shall be reviewed periodically, at least every six months by the [Secretary](/usc/30/802.md?p=a), taking into consideration any falls of roof or ribs or inadequacy of support of roof or ribs. No [person](/usc/30/802.md?p=f) shall proceed beyond the last permanent support unless adequate temporary support is provided or unless such temporary support is not required under the approved roof control plan and the absence of such support will not pose a hazard to the [miners](/usc/30/802.md?p=g). A copy of the plan shall be furnished the [Secretary](/usc/30/802.md?p=a) or his authorized representative and shall be available to the [miners](/usc/30/802.md?p=g) and their representatives.
- (b) **Creation of dangers by roof falls—** The method of mining followed in any [coal mine](/usc/30/878.md?p=l) shall not expose the [miner](/usc/30/802.md?p=g) to unusual dangers from roof falls caused by excessive widths of rooms and entries or faulty pillar recovery methods.
- (c) **Location and supply of roof support material; safety devices for roof work—** The [operator](/usc/30/802.md?p=d), in accordance with the approved plan, shall provide at or near each [working face](/usc/30/878.md?p=g-1) and at such other locations in the [coal mine](/usc/30/878.md?p=l) as the [Secretary](/usc/30/802.md?p=a) may prescribe an ample supply of suitable materials of proper size with which to secure the roof of all [working places](/usc/30/878.md?p=g-2) in a safe manner. Safety posts, jacks, or other approved devices shall be used to protect the workmen when roof material is being taken down, crossbars are being installed, roof bolt- holes are being drilled, roof bolts are being installed, and in such other circumstances as may be appropriate. Loose roof and overhanging or loose faces and ribs shall be taken down or supported. Except in the case of recovery work, supports knocked out shall be replaced promptly.
- (d) **Roof bolts—** When installation of roof bolts is permitted, such roof bolts shall be tested in accordance with the approved roof control plan.
- (e) **Recovery of roof bolts—** Roof bolts shall not be recovered where complete extractions of pillars are attempted, where adjacent to clay veins, or at the locations of other irregularities, whether natural or otherwise, that induce abnormal hazards. Where roof bolt recovery is permitted, it shall be conducted only in accordance with methods prescribed in the approved roof control plan, and shall be conducted by experienced [miners](/usc/30/802.md?p=g) and only where adequate temporary support is provided.
- (f) **Safety inspections; correction of dangerous conditions—** Where [miners](/usc/30/802.md?p=g) are exposed to danger from falls of roof, face, and ribs the [operator](/usc/30/802.md?p=d) shall examine and test the roof, face, and ribs before any work or machine is started, and as frequently thereafter as may be necessary to insure safety. When dangerous conditions are found, they shall be corrected immediately.

# §863. Ventilation

- (a) **Equipment; approval; daily examinations—** All [coal mines](/usc/30/878.md?p=l) shall be ventilated by mechanical ventilation equipment installed and operated in a manner approved by an authorized representative of the [Secretary](/usc/30/802.md?p=a) and such equipment shall be examined daily and a record shall be kept of such examination.
- (b) **Standards for air in work areas—** All [active workings](/usc/30/878.md?p=g-4) shall be ventilated by a current of air containing not less than 19.5 volume per centum of oxygen, not more than 0.5 volume per centum of carbon dioxide, and no harmful quantities of other noxious or poisonous gases; and the volume and velocity of the current of air shall be sufficient to dilute, render harmless, and to carry away, flammable, explosive, noxious, and harmful gases, and dust, and smoke and explosive fumes. The minimum quantity of air reaching the last open crosscut in any pair or set of developing entries and the last open crosscut in any pair or set of rooms shall be nine thousand cubic feet a minute, and the minimum quantity of air reaching the intake end of a pillar line shall be nine thousand cubic feet a minute. The minimum quantity of air in any [coal mine](/usc/30/878.md?p=l) reaching each [working face](/usc/30/878.md?p=g-1) shall be three thousand cubic feet a minute. Within three months after the operative date of this subchapter, the [Secretary](/usc/30/802.md?p=a) shall prescribe the minimum velocity and quantity of air reaching each [working face](/usc/30/878.md?p=g-1) of each [coal mine](/usc/30/878.md?p=l) in order to render harmless and carry away methane and other explosive gases and to reduce the level of respirable dust to the lowest attainable level. The authorized representative of the [Secretary](/usc/30/802.md?p=a) may require in any [coal mine](/usc/30/878.md?p=l) a greater quantity and velocity of air when he finds it necessary to protect the health or safety of [miners](/usc/30/802.md?p=g). Within one year after the operative date of this subchapter, the [Secretary](/usc/30/802.md?p=a) or his authorized representative shall prescribe the maximum respirable dust level in the intake aircourses in each [coal mine](/usc/30/878.md?p=l) in order to reduce such level to the lowest attainable level. In robbing areas of [anthracite](/usc/30/878.md?p=e) mines, where the air currents cannot be controlled and measurements of the air cannot be obtained, the air shall have perceptible movement.
- (c) **Line brattice; functions; exceptions; repairs; flame resistant material—**
  - (1) Properly installed and adequately maintained line brattice or other approved devices shall be continuously used from the last open crosscut of an entry or room of each [working section](/usc/30/878.md?p=g-3) to provide adequate ventilation to the [working faces](/usc/30/878.md?p=g-1) for the [miners](/usc/30/802.md?p=g) and to remove flammable, explosive, and noxious gases, dust, and explosive fumes, unless the [Secretary](/usc/30/802.md?p=a) or his authorized representative permits an exception to this requirement, where such exception will not pose a hazard to the [miners](/usc/30/802.md?p=g). When damaged by falls or otherwise, such line brattice or other devices shall be repaired immediately.
  - (2) The space between the line brattice or other approved device and the rib shall be large enough to permit the flow of a sufficient volume and velocity of air to keep the [working face](/usc/30/878.md?p=g-1) clear of flammable, explosive, and noxious gases, dust, and explosive fumes.
  - (3) Brattice cloth used underground shall be of flame-resistant material.
- (d) **Pre-shift examinations and tests; scope; violations of mandatory standards; notification; posting of “DANGER” signs; restriction of entry; records; re-entry—**
  - (1) Within three hours immediately preceding the beginning of any shift, and before any [miner](/usc/30/802.md?p=g) in such shift enters the [active workings](/usc/30/878.md?p=g-4) of a [coal mine](/usc/30/878.md?p=l), certified [persons](/usc/30/802.md?p=f) designated by the [operator](/usc/30/802.md?p=d) of the mine shall examine such workings and any other underground area of the mine designated by the [Secretary](/usc/30/802.md?p=a) or his authorized representative. Each such examiner shall examine every [working section](/usc/30/878.md?p=g-3) in such workings and shall make tests in each such [working section](/usc/30/878.md?p=g-3) for accumulations of methane with means approved by the [Secretary](/usc/30/802.md?p=a) for detecting methane and shall make tests for oxygen deficiency with a permissible flame safety lamp or other means approved by the [Secretary](/usc/30/802.md?p=a); examine seals and doors to determine whether they are functioning properly; examine and test the roof, face, and rib conditions in such [working section](/usc/30/878.md?p=g-3); examine active roadways, travelways, and belt conveyors on which men are carried, approaches to [abandoned areas](/usc/30/878.md?p=h), and accessible falls in such section for hazards; test by means of an anemometer or other device approved by the [Secretary](/usc/30/802.md?p=a) to determine whether the air in each split is traveling in its proper course and in normal volume and velocity; and examine for such other hazards and violations of the [mandatory health or safety standards](/usc/30/802.md?p=l), as an authorized representative of the [Secretary](/usc/30/802.md?p=a) may from time to time require. Belt conveyors on which coal is carried shall be examined after each coal-producing shift has begun. Such mine examiner shall place his initials and the date and time at all places he examines. If such mine examiner finds a condition which constitutes a violation of a [mandatory health or safety standard](/usc/30/802.md?p=l) or any condition which is hazardous to [persons](/usc/30/802.md?p=f) who may enter or be in such area, he shall indicate such hazardous place by posting a “DANGER” sign conspiciously[^1] at all points which [persons](/usc/30/802.md?p=f) entering such hazardous place would be required to pass, and shall notify the [operator](/usc/30/802.md?p=d) of the mine. No [person](/usc/30/802.md?p=f), other than an authorized representative of the [Secretary](/usc/30/802.md?p=a) or a [State](/usc/30/802.md?p=c) mine inspector or [persons](/usc/30/802.md?p=f) authorized by the [operator](/usc/30/802.md?p=d) to enter such place for the purpose of eliminating the hazardous condition therein, shall enter such place while such sign is so posted. Upon completing his examination, such mine examiner shall report the results of his examination to a [person](/usc/30/802.md?p=f), designated by the [operator](/usc/30/802.md?p=d) to receive such reports at a designated station on the surface of the mine, before other [persons](/usc/30/802.md?p=f) enter the underground areas of such mine to work in such shift. Each such mine examiner shall also record the results of his examination with ink or indelible pencil in a book approved by the [Secretary](/usc/30/802.md?p=a) kept for such purpose in an area on the surface of the mine chosen by the [operator](/usc/30/802.md?p=d) to minimize the danger of destruction by fire or other hazard, and the record shall be open for inspection by interested [persons](/usc/30/802.md?p=f).
  - (2) No [person](/usc/30/802.md?p=f) (other than certified [persons](/usc/30/802.md?p=f) designated under this subsection) shall enter any underground area, except during any shift, unless an examination of such area as prescribed in this subsection has been made within eight hours immediately preceding his entrance into such area.
- (e) **Daily examinations and tests; scope; imminent danger; withdrawal of persons; abatement of danger—** At least once during each coal-producing shift, or more often if necessary for safety, each [working section](/usc/30/878.md?p=g-3) shall be examined for hazardous conditions by certified [persons](/usc/30/802.md?p=f) designated by the [operator](/usc/30/802.md?p=d) to do so. Any such condition shall be corrected immediately. If such condition creates an [imminent danger](/usc/30/802.md?p=j), the [operator](/usc/30/802.md?p=d) shall withdraw all [persons](/usc/30/802.md?p=f) from the area affected by such condition to a safe area, except those [persons](/usc/30/802.md?p=f) referred to in [section 814(d) of this title](/usc/30/814.md?p=d), until the danger is abated. Such examination shall include tests for methane with a means approved by the [Secretary](/usc/30/802.md?p=a) for detecting methane and for oxygen deficiency with a permissible flame safety lamp or other means approved by the [Secretary](/usc/30/802.md?p=a).
- (f) **Weekly examination for hazardous conditions; scope; notification; repairs; imminent danger; withdrawal of persons; abatement; records—** In addition to the pre-shift and daily examinations required by this section, examinations for hazardous conditions, including tests for methane, and for compliance with the [mandatory health or safety standards](/usc/30/802.md?p=l), shall be made at least once each week by a certified [person](/usc/30/802.md?p=f) designated by the [operator](/usc/30/802.md?p=d) in the return of each split of air where it enters the main return, on pillar falls, at seals, in the main return, at least one entry of each intake and return aircourse in its entirety, idle workings, and, insofar as safety considerations permit, [abandoned areas](/usc/30/878.md?p=h). Such weekly examination need not be made during any week in which the mine is idle for the entire week, except that such examination shall be made before any other [miner](/usc/30/802.md?p=g) returns to the mine. The [person](/usc/30/802.md?p=f) making such examinations and tests shall place his initials and the date and time at the places examined, and if any hazardous condition is found, such condition shall be reported to the [operator](/usc/30/802.md?p=d) promptly. Any hazardous condition shall be corrected immediately. If such condition creates an [imminent danger](/usc/30/802.md?p=j), the [operator](/usc/30/802.md?p=d) shall withdraw all [persons](/usc/30/802.md?p=f) from the area affected by such condition to a safe area, except those [persons](/usc/30/802.md?p=f) referred to in [section 814(d) of this title](/usc/30/814.md?p=d), until such danger is abated. A record of these examinations, tests, and actions taken shall be recorded in ink or indelible pencil in a book approved by the [Secretary](/usc/30/802.md?p=a) kept for such purpose in an area on the surface of the mine chosen by the mine [operator](/usc/30/802.md?p=d) to minimize the danger of destruction by fire or other hazard, and the record shall be open for inspection by interested [persons](/usc/30/802.md?p=f).
- (g) **Weekly ventilation examinations; scope; records—** At least once each week, a [qualified person](/usc/30/878.md?p=b) shall measure the volume of air entering the main intakes and leaving the main returns, the volume passing through the last open crosscut in any pair or set of developing entries and the last open crosscut in any pair or set of rooms, the volume and, when the [Secretary](/usc/30/802.md?p=a) so prescribes, the velocity reaching each [working face](/usc/30/878.md?p=g-1), the volume being delivered to the intake end of each pillar line, and the volume at the intake and return of each split of air. A record of such measurements shall be recorded in ink or indelible pencil in a book approved by the [Secretary](/usc/30/802.md?p=a) kept for such purpose in an area on the surface of the [coal mine](/usc/30/878.md?p=l) chosen by the [operator](/usc/30/802.md?p=d) to minimize the danger of destruction by fire or other hazard, and the record shall be open for inspection by interested [persons](/usc/30/802.md?p=f).
- (h) **Methane examinations at working place; periodic intervals; standards; procedures for different air contents of methane—**
  - (1) At the start of each shift, tests for methane shall be made at each [working place](/usc/30/878.md?p=g-2) immediately before electrically operated equipment is energized. Such tests shall be made by [qualified persons](/usc/30/878.md?p=b). If 1.0 volume per centum or more of methane is detected, electrical equipment shall not be energized, taken into, or operated in, such [working place](/usc/30/878.md?p=g-2) until the air therein contains less than 1.0 volume per centum of methane. Examinations for methane shall be made during the operation of such equipment at intervals of not more than twenty minutes during each shift, unless more frequent examinations are required by an authorized representative of the [Secretary](/usc/30/802.md?p=a). In conducting such tests, such [person](/usc/30/802.md?p=f) shall use means approved by the [Secretary](/usc/30/802.md?p=a) for detecting methane.
  - (2) If at any time the air at any [working place](/usc/30/878.md?p=g-2), when tested at a point not less than twelve inches from the roof, face, or rib, contains 1.0 volume per centum or more of methane, changes or adjustments shall be made at once in the ventilation in such mine so that such air shall contain less than 1.0 volume per centum of methane. While such changes or adjustments are underway and until they have been achieved, power to electric face equipment located in such place shall be cut off, no other work shall be permitted in such place, and due precautions shall be carried out under the direction of the [operator](/usc/30/802.md?p=d) or his [agent](/usc/30/802.md?p=e) so as not to endanger other areas of the mine. If at any time such air contains 1.5 volume per centum or more of methane, all [persons](/usc/30/802.md?p=f), except those referred to in [section 814(d) of this title](/usc/30/814.md?p=d), shall be withdrawn from the area of the mine endangered thereby to a safe area, and all electric power shall be cut off from the endangered area of the mine, until the air in such [working place](/usc/30/878.md?p=g-2) shall contain less than 1.0 volume per centum of methane.
- (i) **Methane examination of air returning from working section; periodic intervals; standards; procedures for different air contents; virgin territory—**
  - (1) If, when tested, a split of air returning from any [working section](/usc/30/878.md?p=g-3) contains 1.0 volume per centum or more of methane, changes or adjustments shall be made at once in the ventilation in the mine so that such returning air shall contain less than 1.0 volume per centum of methane. Tests under this paragraph and paragraph (2) of this subsection shall be made at four-hour intervals during each shift by a [qualified person](/usc/30/878.md?p=b) designated by the [operator](/usc/30/802.md?p=d) of the mine. In making such tests, such [person](/usc/30/802.md?p=f) shall use means approved by the [Secretary](/usc/30/802.md?p=a) for detecting methane.
  - (2) If, when tested, a split of air returning from any [working section](/usc/30/878.md?p=g-3) contains 1.5 volume per centum or more of methane, all [persons](/usc/30/802.md?p=f), except those [persons](/usc/30/802.md?p=f) referred to in [section 814(d) of this title](/usc/30/814.md?p=d), shall be withdrawn from the area of the mine endangered thereby to a safe area and all electric power shall be cut off from the endangered area of the mine, until the air in such split shall contain less than 1.0 volume per centum of methane.
  - (3) In virgin territory, if the quantity of air in a split ventilating the [active workings](/usc/30/878.md?p=g-4) in such territory equals or exceeds twice the minimum volume of air prescribed in [subsection (b)](#b) of this section for the last open crosscut, if the air in the split returning from such workings does not pass over trolley wires or trolley feeder wires, and if a certified [person](/usc/30/802.md?p=f) designated by the [operator](/usc/30/802.md?p=d) is continually testing the methane content of the air in such split during mining operations in such workings, it shall be necessary to withdraw all [persons](/usc/30/802.md?p=f), except those referred to in [section 814(d) of this title](/usc/30/814.md?p=d), from the area of the mine endangered thereby to a safe area and all electric power shall be cut off from the endangered area only when the air returning from such workings contains 2.0 volume per centum or more of methane.
- (j) **Abandoned area air; pre-shift examination—** Air which has passed by an opening of any abandoned area shall not be used to ventilate any [working place](/usc/30/878.md?p=g-2) in the [coal mine](/usc/30/878.md?p=l) if such air contains 0.25 volume per centum or more of methane. Examinations of such air shall be made during the pre-shift examination required by [subsection (d)](#d) of this section. In making such tests, a certified [person](/usc/30/802.md?p=f) designated by the [operator](/usc/30/802.md?p=d) shall use means approved by the [Secretary](/usc/30/802.md?p=a) for detecting methane. For the purposes of this subsection, an area within a [panel](/usc/30/802.md?p=m) shall not be deemed to be abandoned until such [panel](/usc/30/802.md?p=m) is abandoned.
- (k) **Abandoned area air; inaccessible or unsafe for inspection; air from where pillars have been removed—** Air that has passed through an abandoned area or an area which is inaccessible or unsafe for inspection shall not be used to ventilate any [working place](/usc/30/878.md?p=g-2) in any mine. No air which has been used to ventilate an area from which the pillars have been removed shall be used to ventilate any [working place](/usc/30/878.md?p=g-2) in a mine, except that such air, if it does not contain 0.25 volume per centum or more of methane, may be used to ventilate enough advancing [working places](/usc/30/878.md?p=g-2) immediately adjacent to the line of retreat to maintain an orderly sequence of pillar recovery on a set of entries.
- (l) **Methane monitors; required equipment; maintenance; warnings; deenergizing of equipment—** The [Secretary](/usc/30/802.md?p=a) or his authorized representative shall require, as an additional device for detecting concentrations of methane, that a methane monitor, approved as reliable by the [Secretary](/usc/30/802.md?p=a) after the operative date of this subchapter, be installed, when available, on any electric face cutting equipment, continuous [miner](/usc/30/802.md?p=g), longwall face equipment, and loading machine, except that no monitor shall be required to be installed on any such equipment prior to the date on which such equipment is required to be permissible under [section 865(a) of this title](/usc/30/865.md?p=a). When installed on any such equipment, such monitor shall be kept operative and properly maintained and frequently tested as prescribed by the [Secretary](/usc/30/802.md?p=a). The sensing device of such monitor shall be installed as close to the [working face](/usc/30/878.md?p=g-1) as practicable. Such monitor shall be set to deenergize automatically such equipment when such monitor is not operating properly and to give a warning automatically when the concentration of methane reaches a maximum percentage determined by an authorized representative of the [Secretary](/usc/30/802.md?p=a) which shall not be more than 1.0 volume per centum of methane. An authorized representative of the [Secretary](/usc/30/802.md?p=a) shall require such monitor to deenergize automatically equipment on which it is installed when the concentration of methane reaches a maximum percentage determined by such representative which shall not be more than 2.0 volume per centum of methane.
- (m) **Idle area inspections; authorized inspectors—** Idle and [abandoned areas](/usc/30/878.md?p=h) shall be inspected for methane and for oxygen deficiency and other dangerous conditions by a certified [person](/usc/30/802.md?p=f) with means approved by the [Secretary](/usc/30/802.md?p=a) as soon as possible but not more than three hours before other [persons](/usc/30/802.md?p=f) are permitted to enter or work in such areas. [Persons](/usc/30/802.md?p=f), such as pumpmen, who are required regularly to enter such areas in the performance of their duties, and who are trained and qualified in the use of means approved by the [Secretary](/usc/30/802.md?p=a) for detecting methane and in the use of a permissible flame safety lamp or other means approved by the [Secretary](/usc/30/802.md?p=a) for detecting oxygen deficiency are authorized to make such examinations for themselves, and each such [person](/usc/30/802.md?p=f) shall be properly equipped and shall make such examinations upon entering any such area.
- (n) **Intentional roof falls; prior inspections; safeguards—** Immediately before an intentional roof fall is made, pillar workings shall be examined by a [qualified person](/usc/30/878.md?p=b) designated by the [operator](/usc/30/802.md?p=d) to ascertain whether methane is present. Such [person](/usc/30/802.md?p=f) shall use means approved by the [Secretary](/usc/30/802.md?p=a) for detecting methane. If in such examination methane is found in amounts of 1.0 volume per centum or more, such roof fall shall not be made until changes or adjustments are made in the ventilation so that the air shall contain less than 1.0 volume per centum of methane.
- (o) **Methane and dust control plans; contents—** A ventilation system and methane and dust control plan and revisions thereof suitable to the conditions and the mining system of the [coal mine](/usc/30/878.md?p=l) and approved by the [Secretary](/usc/30/802.md?p=a) shall be adopted by the [operator](/usc/30/802.md?p=d) and set out in printed form within ninety days after the operative date of this subchapter. The plan shall show the type and location of mechanical ventilation equipment installed and operated in the mine, such additional or improved equipment as the [Secretary](/usc/30/802.md?p=a) may require, the quantity and velocity of air reaching each [working face](/usc/30/878.md?p=g-1), and such other information as the [Secretary](/usc/30/802.md?p=a) may require. Such plan shall be reviewed by the [operator](/usc/30/802.md?p=d) and the [Secretary](/usc/30/802.md?p=a) at least every six months.
- (p) **Devices for detection of methane and oxygen deficiency; maintenance—** Each [operator](/usc/30/802.md?p=d) shall provide for the proper maintenance and care of the permissible flame safety lamp or any other approved device for detecting methane and oxygen deficiency by a [person](/usc/30/802.md?p=f) trained in such maintenance, and, before each shift, care shall be taken to insure that such lamp or other device is in a permissible condition.
- (q) **Pillar recovery; areas without bleeder systems—** Where areas are being pillared on the operative date of this subchapter without bleeder entries, or without bleeder systems or an equivalent means, pillar recovery may be completed in the area, to the extent approved by an authorized representative of the [Secretary](/usc/30/802.md?p=a), if the edges of pillar lines adjacent to [active workings](/usc/30/878.md?p=g-4) are ventilated with sufficient air to keep the air in open areas along the pillar lines below 1.0 volume per centum of methane.
- (r) **Overcast and undercast intake air split requirements; time extension—** Each mechanized mining section shall be ventilated with a separate split of intake air directed by overcasts, undercasts, or the equivalent, except an extension of time, not in excess of nine months, may be permitted by the [Secretary](/usc/30/802.md?p=a), under such conditions as he may prescribe, whenever he determines that this subsection cannot be complied with on the operative date of this subchapter.
- (s) **Blasting; prior and subsequent examinations for methane—** In all underground areas of a [coal mine](/usc/30/878.md?p=l), immediately before firing each shot or group of multiple shots and after blasting is completed, examinations for methane shall be made by a [qualified person](/usc/30/878.md?p=b) with means approved by the [Secretary](/usc/30/802.md?p=a) for detecting methane. If methane is found in amounts of 1.0 volume per centum or more, changes or adjustments shall be made at once in the ventilation so that the air shall contain less than 1.0 volume per centum of methane. No shots shall be fired until the air contains less than 1.0 volume per centum of methane.
- (t) **Mine fan stop plans; requisites—** Each [operator](/usc/30/802.md?p=d) shall adopt a plan within sixty days after the operative date of this subchapter which shall provide that when any mine fan stops, immediate action shall be taken by the [operator](/usc/30/802.md?p=d) or his [agent](/usc/30/802.md?p=e) (1) to withdraw all [persons](/usc/30/802.md?p=f) from the [working sections](/usc/30/878.md?p=g-3), (2) to cut off the power in the mine in a timely manner, (3) to provide for restoration of power and resumption of work if ventilation is restored within a reasonable period as set forth in the plan after the [working places](/usc/30/878.md?p=g-2) and other [active workings](/usc/30/878.md?p=g-4) where methane is likely to accumulate are reexamined by a certified [person](/usc/30/802.md?p=f) to determine if methane in amounts of 1.0 volume per centum or more exists therein, and (4) to provide for withdrawal of all [persons](/usc/30/802.md?p=f) from the mine if ventilation cannot be restored within such reasonable time. The plan and revisions thereof approved by the [Secretary](/usc/30/802.md?p=a) shall be set out in printed form and a copy shall be furnished to the [Secretary](/usc/30/802.md?p=a) or his authorized representative.
- (u) **Modifications affecting main air current or any split; withdrawal of personnel; removal of power—** Changes in ventilation which materially affect the main air current or any split thereof and which may affect the safety of [persons](/usc/30/802.md?p=f) in the [coal mine](/usc/30/878.md?p=l) shall be made only when the mine is idle. Only those [persons](/usc/30/802.md?p=f) engaged in making such changes shall be permitted in the mine during the change. Power shall be removed from the areas affected by the change before work starts to make the change and shall not be restored until the effect of the change has been ascertained and the affected areas determined to be safe by a certified [person](/usc/30/802.md?p=f).
- (v) **Reading and countersigning of daily and weekly reports; foreman; superintendent—** The mine foreman shall read and countersign promptly the daily reports of the pre-shift examiner and assistant mine foremen, and he shall read and countersign promptly the weekly report covering the examinations for hazardous conditions. Where such reports disclose hazardous conditions, they shall be corrected promptly. If such conditions create an [imminent danger](/usc/30/802.md?p=j), the [operator](/usc/30/802.md?p=d) shall withdraw all [persons](/usc/30/802.md?p=f) from, or prevent any [person](/usc/30/802.md?p=f) from entering, as the case may be, the area affected by such conditions, except those [persons](/usc/30/802.md?p=f) referred to in [section 814(d) of this title](/usc/30/814.md?p=d), until such danger is abated. The mine superintendent or assistant superintendent of the mine shall also read and countersign the daily and weekly reports of such [persons](/usc/30/802.md?p=f).
- (w) **Daily mine condition reports; requisites; signatures—** Each day, the mine foreman and each of his assistants shall enter plainly and sign with ink or indelible pencil in a book approved by the [Secretary](/usc/30/802.md?p=a) provided for that purpose a report of the condition of the mine or portion thereof under his supervision, which report shall [state](/usc/30/802.md?p=c) clearly the location and nature of any hazardous condition observed by him or reported to him during the day and what action was taken to remedy such condition. Such book shall be kept in an area on the surface of the mine chosen by the [operator](/usc/30/802.md?p=d) to minimize the danger of destruction by fire or other hazard, and shall be open for inspection by interested [persons](/usc/30/802.md?p=f).
- (x) **Reopening of abandoned or declared inactive mine; notification; inspection—** Before a [coal mine](/usc/30/878.md?p=l) is reopened after having been abandoned or declared inactive by the [operator](/usc/30/802.md?p=d), the [Secretary](/usc/30/802.md?p=a) shall be notified, and an inspection shall be made of the entire mine by an authorized representative of the [Secretary](/usc/30/802.md?p=a) before mining operations commence.
- (y) **Separation of intake and return aircourses from belt haulage entries; standards—**
  - (1) In any [coal mine](/usc/30/878.md?p=l) opened after the operative date of this subchapter, the entries used as intake and return aircourses shall be separated from belt haulage entries, and each [operator](/usc/30/802.md?p=d) of such mine shall limit the velocity of the air coursed through belt haulage entries to the amount necessary to provide an adequate supply of oxygen in such entries, and to insure that the air therein shall contain less than 1.0 volume per centum of methane, and such air shall not be used to ventilate active [working places](/usc/30/878.md?p=g-2). Whenever an authorized representative of the [Secretary](/usc/30/802.md?p=a) finds, in the case of any [coal mine](/usc/30/878.md?p=l) opened on or prior to the operative date of this subchapter which has been developed with more than two entries, that the conditions in the entries, other than belt haulage entries, are such as to permit adequately the coursing of intake or return air through such entries, (1) the belt haulage entries shall not be used to ventilate, unless such entries are necessary to ventilate, active [working places](/usc/30/878.md?p=g-2), and (2) when the belt haulage entries are not necessary to ventilate the active [working places](/usc/30/878.md?p=g-2), the [operator](/usc/30/802.md?p=d) of such mine shall limit the velocity of the air coursed through the belt haulage entries to the amount necessary to provide an adequate supply of oxygen in such entries, and to insure that the air therein shall contain less than 1.0 volume per centum of methane.
  - (2) In any [coal mine](/usc/30/878.md?p=l) opened on or after the operative date of this subchapter, or, in the case of a [coal mine](/usc/30/878.md?p=l) opened prior to such date, in any new [working section](/usc/30/878.md?p=g-3) of such mine, where trolley haulage systems are maintained and where trolley wires or trolley feeder wires are installed, an authorized representative of the [Secretary](/usc/30/802.md?p=a) shall require a sufficient number of entries or rooms as intake aircourses in order to limit, as prescribed by the [Secretary](/usc/30/802.md?p=a), the velocity of air currents on such haulageways for the purpose of minimizing the hazards associated with fires and dust explosions in such haulageways.
- (z) **Pillar extractions; bleeder systems and sealing requirements; standards—**
  - (1) While pillars are being extracted in any area of a [coal mine](/usc/30/878.md?p=l), such area shall be ventilated in the manner prescribed by this section.
  - (2) Within nine months after the operative date of this subchapter, all areas from which pillars have been wholly or partially extracted and [abandoned areas](/usc/30/878.md?p=h), as determined by the [Secretary](/usc/30/802.md?p=a) or his authorized representative, shall be ventilated by bleeder entries or by bleeder systems or equivalent means, or be sealed, as determined by the [Secretary](/usc/30/802.md?p=a) or his authorized representative. When ventilation of such areas is required, such ventilation shall be maintained so as continuously to dilute, render harmless, and carry away methane and other explosive gases within such areas and to protect the [active workings](/usc/30/878.md?p=g-4) of the mine from the hazards of such methane and other explosive gases. Air coursed through underground areas from which pillars have been wholly or partially extracted which enters another split of air shall not contain more than 2.0 volume per centum of methane, when tested at the point it enters such other split. When sealing is required, such seals shall be made in an approved manner so as to isolate with explosion-proof bulkheads such areas from the [active workings](/usc/30/878.md?p=g-4) of the mine.
  - (3) In the case of mines opened on or after the operative date of this subchapter, or in the case of [working sections](/usc/30/878.md?p=g-3) opened on or after such date in mines opened prior to such date, the mining system shall be designed in accordance with a plan and revisions thereof approved by the [Secretary](/usc/30/802.md?p=a) and adopted by such [operator](/usc/30/802.md?p=d) so that, as each [working section](/usc/30/878.md?p=g-3) of the mine is abandoned, it can be isolated from the [active workings](/usc/30/878.md?p=g-4) of the mine with explosion-proof seals or bulkheads.

# §864. Combustible materials and rock dusting

- (a) **Accumulations; maintenance—** Coal dust, including float coal dust deposited on rock-dusted surfaces, loose coal, and other combustible materials, shall be cleaned up and not be permitted to accumulate in [active workings](/usc/30/878.md?p=g-4), or on electric equipment therein.
- (b) **Abatement of hazards in active working areas—** Where underground mining operations in [active workings](/usc/30/878.md?p=g-4) create or raise excessive amounts of dust, water or water with a wetting [agent](/usc/30/802.md?p=e) added to it, or other no less effective methods approved by the [Secretary](/usc/30/802.md?p=a) or his authorized representative, shall be used to abate such dust. In [working places](/usc/30/878.md?p=g-2), particularly in distances less than forty feet from the face, water, with or without a wetting [agent](/usc/30/802.md?p=e), or other no less effective methods approved by the [Secretary](/usc/30/802.md?p=a) or his authorized representative, shall be applied to coal dust on the ribs, roof, and floor to reduce dispersibility and to minimize the explosion hazard.
- (c) **Rock dusting of all areas of underground mines; exceptions—** All underground areas of a [coal mine](/usc/30/878.md?p=l), except those areas in which the dust is too wet or too high in incombustible content to propagate an explosion, shall be rock dusted to within forty feet of all [working faces](/usc/30/878.md?p=g-1), unless such areas are inaccessible or unsafe to enter or unless the [Secretary](/usc/30/802.md?p=a) or his authorized representative permits an exception upon his finding that such exception will not pose a hazard to the [miners](/usc/30/802.md?p=g). All crosscuts that are less than forty feet from a [working face](/usc/30/878.md?p=g-1) shall also be rock dusted.
- (d) **Distribution of rock dust; places, quantities—** Where [rock dust](/usc/30/878.md?p=d) is required to be applied, it shall be distributed upon the top, floor, and sides of all underground areas of a [coal mine](/usc/30/878.md?p=l) and maintained in such quantities that the incombustible content of the combined coal dust, [rock dust](/usc/30/878.md?p=d), and other dust shall be not less than 65 per centum, but the incombustible content in the return aircourses shall be no less than 80 per centum. Where methane is present in any ventilating current, the per centum of incombustible content of such combined dusts shall be increased 1.0 and 0.4 per centum for each 0.1 per centum of methane where 65 and 80 per centum, respectively, of incombustibles are required.
- (e) **Limitation of applicability—** [Subsections (b) through (d)](#b..d) of this section shall not apply to underground [anthracite](/usc/30/878.md?p=e) mines.

# §865. Electrical equipment

- (a) **Allowable equipment; replacements; maintenance; permits for noncompliance; renewals; limitations; list of electric face equipment; survey of new and rebuilt equipment; publication of results—**
  - (1) Effective one year after the operative date of this subchapter—
    - (A) all junction or distribution boxes used for making multiple power connections inby the last open crosscut shall be permissible;
    - (B) all handheld electric drills, blower and exhaust fans, electric pumps, and such other low horsepower electric face equipment as the [Secretary](/usc/30/802.md?p=a) may designate within two months after the operative date of this subchapter which are taken into or used inby the last open crosscut of any [coal mine](/usc/30/878.md?p=l) shall be permissible;
    - (C) all electric face equipment which is taken into or used inby the last open crosscut of any [coal mine](/usc/30/878.md?p=l) classified under any provision of law as gassy prior to the operative date of this subchapter shall be permissible; and
    - (D) all other electric face equipment which is taken into or used inby the last crosscut of any [coal mine](/usc/30/878.md?p=l), except a [coal mine](/usc/30/878.md?p=l) referred to in paragraph (2) of this subsection, which has not been classified under any provision of law as a gassy mine prior to the operative date of this subchapter shall be permissible.
  - (2) Effective four years after the operative date of this subchapter, all electric face equipment, other than equipment referred to in paragraph (1)(B) of this subsection, which is taken into or used inby the last open crosscut of any [coal mine](/usc/30/878.md?p=l) which is operated entirely in coal seams located above the watertable and which has not been classified under any provision of law as a gassy mine prior to the operative date of this subchapter and in which one or more openings were made prior to December 30, 1969, shall be permissible, except that any [operator](/usc/30/802.md?p=d) of such mine who is unable to comply with the provisions of this paragraph on such effective date may file with the [Panel](/usc/30/802.md?p=m) an application for a permit for noncompliance ninety days prior to such date. If the [Panel](/usc/30/802.md?p=m) determines, after notice to all interested [persons](/usc/30/802.md?p=f) and an opportunity for a public hearing under [section 804 of this title](/usc/30/804.md), that such application satisfies the provisions of paragraph (10) of this subsection and that such [operator](/usc/30/802.md?p=d), despite his diligent efforts, will be unable to comply with such provisions, the [Panel](/usc/30/802.md?p=m) may issue to such [operator](/usc/30/802.md?p=d) such a permit. Such permit shall entitle the permittee to an additional extension of time to comply with the provisions of this paragraph of not to exceed twenty-four months, as determined by the [Panel](/usc/30/802.md?p=m), from such effective date.
  - (3) The [operator](/usc/30/802.md?p=d) of each [coal mine](/usc/30/878.md?p=l) shall maintain in permissible condition all electric face equipment required by this subsection to be permissible which is taken into or used inby the last open crosscut of any such mine.
  - (4) Each [operator](/usc/30/802.md?p=d) of a [coal mine](/usc/30/878.md?p=l) shall, within two months after the operative date of this subchapter, file with the [Secretary](/usc/30/802.md?p=a) a statement listing all electric face equipment by type and manufacturer being used by such [operator](/usc/30/802.md?p=d) in connection with mining operations in such mine as of the date of such filing, and stating whether such equipment is permissible and maintained in permissible condition or is nonpermissible on such date of filing, and, if nonpermissible, whether such nonpermissible equipment has ever been rated as permissible, and such other information as the [Secretary](/usc/30/802.md?p=a) may require.
  - (5) The [Secretary](/usc/30/802.md?p=a) shall promptly conduct a survey as to the total availability of new or rebuilt permissible electric face equipment and replacement parts for such equipment and, within six months after the operative date of this subchapter, publish the results of such survey.
  - (6) Any [operator](/usc/30/802.md?p=d) of a [coal mine](/usc/30/878.md?p=l) who is unable to comply with the provisions of paragraph (1)(D) of this subsection within one year after the operative date of this subchapter may file with the [Panel](/usc/30/802.md?p=m) an application for a permit for noncompliance. If the [Panel](/usc/30/802.md?p=m) determines that such application satisfies the provisions of paragraph (10) of this subsection, the [Panel](/usc/30/802.md?p=m) shall issue to such [operator](/usc/30/802.md?p=d) a permit for noncompliance. Such permit shall entitle the permittee to an extension of time to comply with such provisions of [paragraph (1)(D)](#a-1-D) of not to exceed twelve months, as determined by the [Panel](/usc/30/802.md?p=m), from the date that compliance with the provisions of paragraph (1)(D) of this subsection is required.
  - (7) Any [operator](/usc/30/802.md?p=d) of a [coal mine](/usc/30/878.md?p=l) issued a permit under paragraph (6) of this subsection who, ninety days prior to the termination of such permit, or renewal thereof, determines that he will be unable to comply with the provisions of paragraph (1)(D) of this subsection upon the expiration of such permit may file with the [Panel](/usc/30/802.md?p=m) an application for renewal thereof. Upon receipt of such application, the [Panel](/usc/30/802.md?p=m), if it determines, after notice to all interested [persons](/usc/30/802.md?p=f) and an opportunity for a public hearing under [section 804 of this title](/usc/30/804.md), that such application satisfies the provisions of paragraph (10) of this subsection and that such [operator](/usc/30/802.md?p=d), despite his diligent efforts, will be unable to comply with the provisions of [paragraph (1)(D)](#a-1-D), may renew the permit for a period not exceeding twelve months.
  - (8) Any permit or renewal thereof issued pursuant to this subsection shall entitle the permittee to use such nonpermissible electric face equipment specified in the permit during the term of such permit.
  - (9) Permits for noncompliance issued under paragraphs (6) or (7) of this subsection shall, in the aggregate, not extend the period of noncompliance more than forty-eight months after December 30, 1969.
  - (10) Any application for a permit of noncompliance filed under this subsection shall contain a statement by the [operator](/usc/30/802.md?p=d)—
    - (A) that he is unable to comply with [paragraph (1)(D)](#a-1-D) or paragraph (2) of this subsection, as appropriate, within the time prescribed;
    - (B) listing the nonpermissible electric face equipment being used by such [operator](/usc/30/802.md?p=d) in connection with mining operations in such mine on the operative date of this subchapter and the date of the application by type and manufacturer for which a noncompliance permit is requested and whether such equipment had ever been rated as permissible;
    - (C) setting forth the actions taken from and after the operative date of this subchapter to comply with [paragraph (1)(D)](#a-1-D) or paragraph (2) of this subsection, as appropriate, together with a plan setting forth a schedule of compliance with said paragraphs for each such equipment referred to in such paragraphs and being used by the [operator](/usc/30/802.md?p=d) in connection with mining operations in such mine with respect to which such permit is requested and the means and measures to be employed to achieve compliance; and
    - (D) including such other information as the [Panel](/usc/30/802.md?p=m) may require.
  - (11) No permit for noncompliance shall be issued under this subsection for any nonpermissible electric face equipment, unless such equipment was being used by an [operator](/usc/30/802.md?p=d) in connection with the mining operations in a [coal mine](/usc/30/878.md?p=l) on the operative date of this subchapter.
  - (12) Effective one year after the operative date of this subchapter, all replacement equipment acquired for use in any mine referred to in this subsection shall be permissible and shall be maintained in a permissible condition, and in the event of any major overhaul of any item of equipment in use one year from the operative date of this subchapter such equipment shall be put in, and thereafter maintained in, a permissible condition, unless, in the opinion of the [Secretary](/usc/30/802.md?p=a), such equipment or necessary replacement parts are not available.
- (b) **Notification of permits—** A copy of any permit granted under this section shall be mailed immediately to a representative of the [miners](/usc/30/802.md?p=g) of the mine to which it pertains, and to the public official or agency of the [State](/usc/30/802.md?p=c) charged with administering [State](/usc/30/802.md?p=c) laws relating to [coal mine](/usc/30/878.md?p=l) health and safety in such mine.
- (c) **Gassy mines; maintenance of equipment—** Any [coal mine](/usc/30/878.md?p=l) which, prior to the operative date of this subchapter, was classed gassy under any provision of law and was required to use permissible electric face equipment and to maintain such equipment in a permissible condition shall continue to use such equipment and to maintain such equipment in such condition.
- (d) **Location of nonpermissible power connection units—** All power-connection points, except where permissible power connection units are used, outby the last open crosscut shall be in intake air.
- (e) **Mine map; contents; modifications—** The location and the electrical rating of all stationary electric apparatus in connection with the mine electric system, including permanent cables, switchgear, rectifying substations, transformers, permanent pumps and trolley wires and trolley feeder wires, and settings of all direct-current circuit breakers protecting underground trolley circuits, shall be shown on a mine map. Any changes made in a location, electric rating, or setting shall be promptly shown on the map when the change is made. Such map shall be available to an authorized representative of the [Secretary](/usc/30/802.md?p=a) and to the [miners](/usc/30/802.md?p=g) in such mine.
- (f) **Repairs; deenergizing of equipment; authorized personnel; locking out of disconnection devices—** All power circuits and electric equipment shall be deenergized before work is done on such circuits and equipment, except when necessary for trouble shooting or testing. In addition, energized trolley wires may be repaired only by a [person](/usc/30/802.md?p=f) trained to perform electrical work and to maintain electrical equipment and the [operator](/usc/30/802.md?p=d) of such mine shall require that such [person](/usc/30/802.md?p=f) wear approved and tested insulated shoes and wireman’s gloves. No electrical work shall be performed on low-, medium-, or high-voltage distribution circuits or equipment, except by a [qualified person](/usc/30/878.md?p=b) or by a [person](/usc/30/802.md?p=f) trained to perform electrical work and to maintain electrical equipment under the direct supervision of a [qualified person](/usc/30/878.md?p=b). Disconnecting devices shall be locked out and suitably tagged by the [persons](/usc/30/802.md?p=f) who performed such work, except that, in cases where locking out is not possible, such devices shall be opened and suitably tagged by such [persons](/usc/30/802.md?p=f). Locks or tags shall be removed only by the [persons](/usc/30/802.md?p=f) who installed them or, if such [persons](/usc/30/802.md?p=f) are unavailable, by [persons](/usc/30/802.md?p=f) authorized by the [operator](/usc/30/802.md?p=d) or his [agent](/usc/30/802.md?p=e).
- (g) **Periodic examinations; maintenance; records; accessibility—** All electric equipment shall be frequently examined, tested, and properly maintained by a [qualified person](/usc/30/878.md?p=b) to assure safe operating conditions. When a potentially dangerous condition is found on electric equipment, such equipment shall be removed from service until such condition is corrected. A record of such examinations shall be kept and made available to an authorized representative of the [Secretary](/usc/30/802.md?p=a) and to the [miners](/usc/30/802.md?p=g) in such mine.
- (h) **Electrical conductors—** All electric conductors shall be sufficient in size and have adequate current-carrying capacity and be of such construction that a rise in temperature resulting from normal operation will not damage the insulating materials.
- (i) **Electrical connections—** All electrical connections or splices in conductors shall be mechanically and electrically efficient, and suitable connectors shall be used. All electrical connections or splices in insulated wire shall be reinsulated at least to the same degree of protection as the remainder of the wire.
- (j) **Cables and wires; entry through metal frames—** Cables shall enter metal frames of motors, splice boxes, and electric compartments only through proper fittings. When insulated wires other than cables pass through metal frames the holes shall be substantially bushed with insulated bushings.
- (k) **Support of power wires—** All power wires (except trailing cables on mobile equipment, specially designed cables conducting high-voltage power to underground rectifying equipment or transformers, or bare or insulated ground and return wires) shall be supported on well-insulated insulators and shall not contact combustible material, roof, or ribs.
- (l) **Insulation of power wires; exceptions—** Power wires and cables, except trolley wires, trolley feeder wires, and bare signal wires, shall be insulated adequately and fully protected.
- (m) **Circuit breakers; overload protection for three-phase motors—** Automatic circuit-breaking devices or fuses of the correct type and capacity shall be installed so as to protect all electric equipment and circuits against short circuit and overloads. Three-phase motors on all electric equipment shall be provided with overload protection that will deenergize all three phases in the event that any phase is overloaded.
- (n) **Disconnecting switches for main power circuits; location and installation—** In all main power circuits, disconnecting switches shall be installed underground within five hundred feet of the bottoms of shafts and boreholes through which main power circuits enter the underground area of the mine and within five hundred feet of all other places where main power circuits enter the underground area of the mine.
- (o) **Switches—** All electric equipment shall be provided with switches or other controls that are safely designed, constructed, and installed.
- (p) **Lightning arresters—** Each ungrounded, exposed power conductor that leads underground shall be equipped with suitable lightning arresters of approved type within one hundred feet of the point where the circuit enters the mine. Lightning arresters shall be connected to a low resistance grounding medium on the surface which shall be separated from neutral grounds by a distance of not less than twenty-five feet.
- (q) **Nonapproved devices—** No device for the purpose of lighting any [coal mine](/usc/30/878.md?p=l) which has not been approved by the [Secretary](/usc/30/802.md?p=a) or his authorized representative shall be permitted in such mine.
- (r) **Deenergizing of electric face equipment—** An authorized representative of the [Secretary](/usc/30/802.md?p=a) may require in any mine that electric face equipment be provided with devices that will permit the equipment to be deenergized quickly in the event of an emergency.

# §866. Trailing cables

- (a) **Requirements established for flame resistant cables—** Trailing cables used in [coal mines](/usc/30/878.md?p=l) shall meet the requirements established by the [Secretary](/usc/30/802.md?p=a) for flame-resistant cables.
- (b) **Circuit breakers; markings and visual observation of position of disconnection devices—** Short-circuit protection for trailing cables shall be provided by an automatic circuit breaker or other no less effective device approved by the [Secretary](/usc/30/802.md?p=a) of adequate current-interrupting capacity in each ungrounded conductor. Disconnecting devices used to disconnect power from trailing cables shall be plainly marked and identified and such devices shall be equipped or designed in such a manner that it can be determined by visual observation that the power is disconnected.
- (c) **Distribution center junctions; safety connections—** When two or more trailing cables junction to the same distribution center, means shall be provided to assure against connecting a trailing cable to the wrong size circuit breaker.
- (d) **Temporary splices; usable period; exceptions; quality—** One temporary splice may be made in any trailing cable. Such trailing cable may only be used for the next twenty-four hour period. No temporary splice shall be made in a trailing cable within twenty-five feet of the machine, except cable reel equipment. Temporary splices in trailing cables shall be made in a workmanlike manner and shall be mechanically strong and well insulated. Trailing cables or hand cables which have exposed wires or which have splices that heat or spark under load shall not be used. As used in this subsection, the term “splice” means the mechanical joining of one or more conductors that have been severed.
- (e) **Permanent splices; quality—** When permanent splices in trailing cables are made, they shall be—
  - (1) mechanically strong with adequate electrical conductivity and flexibility;
  - (2) effectively insulated and sealed so as to exclude moisture; and
  - (3) vulcanized or otherwise treated with suitable materials to provide flame-resistant qualities and good bonding to the outer jacket.
- (f) **Clamping of cables—** Trailing cables shall be clamped to machines in a manner to protect the cables from damage and to prevent strain on the electrical connections. Trailing cables shall be adequately protected to prevent damage by mobile equipment.
- (g) **Making and breaking of connections to junction boxes—** Trailing cable and power cable connections to junction boxes shall not be made or broken under load.

# §867. Grounding of equipment

- (a) **Metallic enclosed power conductors; metallic frames and other equipment; methods—** All metallic sheaths, armors, and conduits enclosing power conductors shall be electrically continuous throughout and shall be grounded by methods approved by an authorized representative of the [Secretary](/usc/30/802.md?p=a). Metallic frames, casings, and other enclosures of electric equipment that can become “alive” through failure of insulation or by contact with energized parts shall be grounded by methods approved by an authorized representative of the [Secretary](/usc/30/802.md?p=a). Methods other than grounding which provide no less effective protection may be permitted by the [Secretary](/usc/30/802.md?p=a) or his authorized representative.
- (b) **Frames of offtrack direct current machines; enclosures of related detached components—** The frames of all offtrack direct current machines and the enclosures of related detached components shall be effectively grounded, or otherwise maintained at no less safe voltages, by methods approved by an authorized representative of the [Secretary](/usc/30/802.md?p=a).
- (c) **Stationary high-voltage equipment powered by underground delta systems—** The frames of all stationary high-voltage equipment receiving power from ungrounded delta systems shall be grounded by methods approved by an authorized representative of the [Secretary](/usc/30/802.md?p=a).
- (d) **Repairs of high-voltage lines; exceptions—** High-voltage lines, both on the surface and underground, shall be deenergized and grounded before work is performed on them, except that repairs may be permitted, in the case of energized surface high-voltage lines, if such repairs are made by a [qualified person](/usc/30/878.md?p=b) in accordance with procedures and safeguards, including, but not limited to a requirement that the [operator](/usc/30/802.md?p=d) of such mine provide, test, and maintain protective devices in making such repairs, to be prescribed by the [Secretary](/usc/30/802.md?p=a) prior to the operative date of this subchapter.
- (e) **Deenergizing of underground power circuits on idle days; exceptions—** When not in use, power circuits underground shall be deenergized on idle days and idle shifts, except that rectifiers and transformers may remain energized.

# §868. Underground high-voltage distribution

- (a) **Circuits entering underground areas of mines; circuit breakers—** High-voltage circuits entering the underground area of any [coal mine](/usc/30/878.md?p=l) shall be protected by suitable circuit breakers of adequate interrupting capacity which are properly tested and maintained as prescribed by the [Secretary](/usc/30/802.md?p=a). Such breakers shall be equipped with devices to provide protection against under-voltage, grounded phase, short circuit, and overcurrent.
- (b) **Circuits extending underground and supplying equipment; direct neutral grounds; ground conductors for frames, exceptions; location of disconnection devices, exceptions—** High-voltage circuits extending underground and supplying portable, mobile, or stationary high-voltage equipment shall contain either a direct or derived neutral which shall be grounded through a suitable resistor at the source transformers, and a grounding circuit, originating at the grounded side of the grounding resistor, shall extend along with the power conductors and serve as a grounding conductor for the frames of all high-voltage equipment supplied power from that circuit, except that the [Secretary](/usc/30/802.md?p=a) or his authorized representative may permit ungrounded high-voltage circuits to be extended underground to feed stationary electrical equipment if such circuits are either steel armored or installed in grounded, rigid steel conduit throughout their entire length, and upon his finding that such exception does not pose a hazard to the [miners](/usc/30/802.md?p=g). Within one hundred feet of the point on the surface where high-voltage circuits enter the underground portion of the mine, disconnecting devices shall be installed and so equipped or designed in such a manner that it can be determined by visual observation that the power is disconnected, except that the [Secretary](/usc/30/802.md?p=a) or his authorized representative may permit such devices to be installed at a greater distance from such area of the mine if he determines, based on existing physical conditions, that such installation will be more accessible at a greater distance and will not pose any hazard to the [miners](/usc/30/802.md?p=g).
- (c) **Grounding resistors—** The grounding resistor, where required, shall be of the proper ohmic value to limit the voltage drop in the grounding circuit external to the resistor to not more than 100 volts under fault conditions. The grounding resistor shall be rated for maximum fault current continuously and insulated from ground for a voltage equal to the phase-to-phase voltage of the system.
- (d) **Inclusion of fail safe ground check circuits in resistance grounded systems; operative functions; time extension—** Six months after the operative date of this subchapter, high-voltage, resistance grounded systems shall include a fail safe ground check circuit to monitor continuously the grounding circuit to assure continuity and the fail safe ground check circuit shall cause the circuit breaker to open when either the ground or pilot check wire is broken, or other no less effective device approved by the [Secretary](/usc/30/802.md?p=a) or his authorized representative to assure such continuity, except that an extension of time, not in excess of twelve months, may be permitted by the [Secretary](/usc/30/802.md?p=a) on a mine-by-mine basis if he determines that such equipment is not available.
- (e) **Underground cables used in resistance grounded systems; metallic shields for power conductors; standards; splices—**
  - (1) Underground high-voltage cables used in resistance grounded systems shall be equipped with metallic shields around each power conductor, with one or more ground conductors having a total cross-sectional area of not less than one-half the power conductor, and with an insulated internal or external conductor not smaller than No. 8 (AWG) for the ground continuity check circuit.
  - (2) All such cables shall be adequate for the intended current and voltage. Splices made in such cables shall provide continuity of all components.
- (f) **Couplers for power circuits; guidelines for construction—** Couplers that are used with medium-voltage or high-voltage power circuits shall be of the three-phase type with a full metallic shell, except that the [Secretary](/usc/30/802.md?p=a) may permit, under such guidelines as he may prescribe, no less effective couplers constructed of materials other than metal. Couplers shall be adequate for the voltage and current expected. All exposed metal on the metallic couplers shall be grounded to the ground conductor in the cable. The coupler shall be constructed so that the ground check continuity conductor shall be broken first and the ground conductors shall be broken last when the coupler is being uncoupled.
- (g) **Connections of single-phase loads—** Single-phase loads, such as transformer primaries, shall be connected phase to phase.
- (h) **Installation of underground transmission cables—** All underground high-voltage transmission cables shall be installed only in regularly inspected air courses and haulageways, and shall be covered, buried, or placed so as to afford protection against damage, guarded where men regularly work or pass under them unless they are six and one-half feet or more above the floor or rail, securely anchored, properly insulated, and guarded at ends, and covered, insulated, or placed to prevent contact with trolley wires and other low-voltage circuits.
- (i) **Disconnection devices; location; visual observation of position of switch—** Disconnecting devices shall be installed at the beginning of branch lines in high-voltage circuits and equipped or designed in such a manner that it can be determined by visual observation that the circuit is deenergized when the switches are open.
- (j) **Circuit breakers and disconnection devices; markings—** Circuit breakers and disconnecting switches underground shall be marked for identification.
- (k) **Splices in cables used as trailing cables; terminations and splices in other cables—** In the case of high-voltage cables used as trailing cables, temporary splices shall not be used and all permanent splices shall be made in accordance with [section 866(e) of this title](/usc/30/866.md?p=e). Terminations and splices in all other high-voltage cables shall be made in accordance with the manufacturer’s specifications.
- (l) **Grounding of frames of underground equipment—** Frames, supporting structures, and enclosures of stationary, portable, or mobile underground high-voltage equipment and all high-voltage equipment supplying power to such equipment receiving power from resistance grounded systems shall be effectively grounded to the high-voltage ground.
- (m) **Moving of power centers, transformers, and cables; deenergizing; exceptions; safety guidelines; record of examinations—** Power centers and portable transformers shall be deenergized before they are moved from one location to another, except that, when equipment powered by sources other than such centers or transformers is not available, the [Secretary](/usc/30/802.md?p=a) may permit such centers and transformers to be moved while energized, if he determines that another equivalent or greater hazard may otherwise be created, and if they are moved under the supervision of a [qualified person](/usc/30/878.md?p=b), and if such centers and transformers are examined prior to such movement by such [person](/usc/30/802.md?p=f) and found to be grounded by methods approved by an authorized representative of the [Secretary](/usc/30/802.md?p=a) and otherwise protected from hazards to the [miner](/usc/30/802.md?p=g). A record shall be kept of such examinations. High-voltage cables, other than trailing cables, shall not be moved or handled at any time while energized, except that, when such centers and transformers are moved while energized as permitted under this subsection, energized high-voltage cables attached to such centers and transformers may be moved only by a [qualified person](/usc/30/878.md?p=b) and the [operator](/usc/30/802.md?p=d) of such mine shall require that such [person](/usc/30/802.md?p=f) wear approved and tested insulated wireman’s gloves.

# §869. Underground low- and medium-voltage alternating current circuits

- (a) **Circuits providing power for three-phase equipment; circuit breakers—** Low- and medium-voltage power circuits serving three-phase alternating current equipment shall be protected by suitable circuit breakers of adequate interrupting capacity which are properly tested and maintained as prescribed by the [Secretary](/usc/30/802.md?p=a). Such breakers shall be equipped with devices to provide protection against under-voltage, grounded phase, short circuit, and over-current.
- (b) **Circuits used underground; direct neutral grounds; ground conductors for frames; exceptions; grounding resistors—** Low- and medium-voltage three-phase alternating-current circuits used underground shall contain either a direct or derived neutral which shall be grounded through a suitable resistor at the power center, and a grounding circuit, originating at the grounded side of the grounding resistor, shall extend along with the power conductors and serve as a grounding conductor for the frames of all the electrical equipment supplied power from that circuit, except that the [Secretary](/usc/30/802.md?p=a) or his authorized representative may permit ungrounded low- and medium-voltage circuits to be used underground to feed such stationary electrical equipment if such circuits are either steel armored or installed in grounded rigid steel conduit throughout their entire length. The grounding resistor, where required, shall be of the proper ohmic value to limit the ground fault current to 25 amperes. The grounding resistor shall be rated for maximum fault current continuously and insulated from ground for a voltage equal to the phase-to-phase voltage of the system.
- (c) **Inclusion of fail safe ground check circuits in resistance ground systems; operative functions; time extension; couplers for power circuits; guidelines for construction—** Six months after the operative date of this subchapter, low- and medium-voltage resistance grounded systems shall include a fail safe ground check circuit to monitor continuously the grounding circuit to assure continuity which ground check circuit shall cause the circuit breaker to open when either the ground or pilot check wire is broken, or other no less effective device approved by the [Secretary](/usc/30/802.md?p=a) or his authorized representative to assure such continuity, except that an extension of time, not in excess of twelve months, may be permitted by the [Secretary](/usc/30/802.md?p=a) on a mine-by-mine basis if he determines that such equipment is not available. Cable couplers shall be constructed so that the ground check continuity conductor shall be broken first and the ground conductors shall be broken last when the coupler is being uncoupled.
- (d) **Disconnecting devices installed in conjunction with circuit breakers; purpose; trailing cables for mobile equipment; guidelines for construction; time extension; splices—** Disconnecting devices shall be installed in conjunction with the circuit breaker to provide visual evidence that the power is disconnected. Trailing cables for mobile equipment shall contain one or more ground conductors having a cross sectional area of not less than one-half the power conductor, and, six months after the operative date of this subchapter, an insulated conductor for the ground continuity check circuit or other no less effective device approved by the [Secretary](/usc/30/802.md?p=a) or his authorized representative to assure such continuity, except that an extension of time, not in excess of twelve months may be permitted by the [Secretary](/usc/30/802.md?p=a) on a mine-by-mine basis if he determines that such equipment is not available. Splices made in the cables shall provide continuity of all components.
- (e) **Connections of single phase loads—** Single phase loads shall be connected phase to phase.
- (f) **Circuit breakers; markings—** Circuit breakers shall be marked for identification.
- (g) **Trailing cables for medium voltage circuits; guidelines for construction—** Trailing cables for medium voltage circuits shall include grounding conductors, a ground check conductor, and ground metallic shields around each power conductor or a grounded metallic shield over the assembly, except that on equipment employing cable reels, cables without shields may be used if the insulation is rated 2,000 volts or more.

# §870. Trolley wires and trolley feeder wires

- (a) **Intervals for cutoff switches—** Trolley wires and trolley feeder wires shall be provided with cutout switches at intervals of not more than 2,000 feet and near the beginning of all branch lines.
- (b) **Overcurrent protection devices—** Trolley wires and trolley feeder wires shall be provided with overcurrent protection.
- (c) **Location of wires—** Trolley wires and trolley feeder wires, high-voltage cables and transformers shall not be located inby the last open crosscut and shall be kept at least 150 feet from pillar workings.
- (d) **Adequate insulation and guard devices; promulgation of safety guidelines—** Trolley wires, trolley feeder wires, and bare signal wires shall be insulated adequately where they pass through doors and stoppings, and where they cross other power wires and cables. Trolley wires and trolley feeder wires shall be guarded adequately (1) at all points where men are required to work or pass regularly under the wires; (2) on both sides of all doors and stoppings; and (3) at man-trip stations. The [Secretary](/usc/30/802.md?p=a) or his authorized representatives shall specify other conditions where trolley wires and trolley feeder wires shall be adequately protected to prevent contact by any [person](/usc/30/802.md?p=f), or shall require the use of improved methods to prevent such contact. Temporary guards shall be provided where trackmen and other [persons](/usc/30/802.md?p=f) work in proximity to trolley wires and trolley feeder wires.

# §871. Fire protection

- (a) **Firefighting equipment; promulgation of minimum requirements for equipment; existing requirements; examinations after blasting—** Each [coal mine](/usc/30/878.md?p=l) shall be provided with suitable firefighting equipment adapted for the size and conditions of the mine. The [Secretary](/usc/30/802.md?p=a) shall establish minimum requirements for the type, quality, and quantity of such equipment, and the interpretations of the [Secretary](/usc/30/802.md?p=a) or the Director of the United States Bureau of Mines relating to such equipment in effect on the operative date of this subchapter shall continue in effect until modified or superseded by the [Secretary](/usc/30/802.md?p=a). After every blasting operation, an examination shall be made to determine whether fires have been started.
- (b) **Underground storage areas for lubricating oils and greases; construction; exceptions—** Underground storage places for lubricating oil and grease shall be of fireproof construction. Except for specially prepared materials approved by the [Secretary](/usc/30/802.md?p=a), lubricating oil and grease kept in all underground areas in a [coal mine](/usc/30/878.md?p=l) shall be in fireproof, closed metal containers or other no less effective containers approved by the [Secretary](/usc/30/802.md?p=a).
- (c) **Housing of underground structures, stations, shops, and pumps; construction; ventilation—** Underground transformer stations, battery-charging stations, substations, compressor stations, shops, and permanent pumps shall be housed in fireproof structures or areas. Air currents used to ventilate structures or areas enclosing electrical installations shall be coursed directly into the return. Other underground structures installed in a [coal mine](/usc/30/878.md?p=l) as the [Secretary](/usc/30/802.md?p=a) may prescribe shall be of fireproof construction.
- (d) **Use of arc or flame in underground mines; fireproof enclosures; operations outside fireproof enclosures; procedures; standards—** All welding, cutting, or soldering with arc or flame in all underground areas of a [coal mine](/usc/30/878.md?p=l) shall, whenever practicable, be conducted in fireproof enclosures. Welding, cutting or soldering with arc or flame in other than a fireproof enclosure shall be done under the supervision of a [qualified person](/usc/30/878.md?p=b) who shall make a diligent search for fire during and after such operations and shall, immediately before and during such operations, continuously test for methane with means approved by the [Secretary](/usc/30/802.md?p=a) for detecting methane. Welding, cutting, or soldering shall not be conducted in air that contains 1.0 volume per centum or more of methane. [Rock dust](/usc/30/878.md?p=d) or suitable fire extinguishers shall be immediately available during such welding, cutting, or soldering.
- (e) **Installation of fire suppression devices on un­attended underground equipment; flame-resistant hydraulic fluids—** Within one year after the operative date of this subchapter, fire suppression devices meeting specifications prescribed by the [Secretary](/usc/30/802.md?p=a) shall be installed on unattended underground equipment and suitable fire-resistant hydraulic fluids approved by the [Secretary](/usc/30/802.md?p=a) shall be used in the hydraulic systems of such equipment. Such fluids shall be used in the hydraulic systems of other underground equipment unless fire suppression devices meeting specifications prescribed by the [Secretary](/usc/30/802.md?p=a) are installed on such equipment.
- (f) **Deluge-type water sprays at main and secondary drives—** Deluge-type water sprays or foam generators automatically actuated by rise in temperature, or other no less effective means approved by the [Secretary](/usc/30/802.md?p=a) of controlling fire, shall be installed at main and secondary belt-conveyor drives. Where sprays or foam generators are used they shall supply a sufficient quantity of water or foam to control fires.
- (g) **Installation of slippage and sequence switches on belt conveyors; fire suppression devices on belt haulageways—** Underground belt conveyors shall be equipped with slippage and sequence switches. The [Secretary](/usc/30/802.md?p=a) shall, within sixty days after the operative date of this subchapter, require that devices be installed on all such belts which will give a warning automatically when a fire occurs on or near such belt. The [Secretary](/usc/30/802.md?p=a) shall prescribe a schedule for installing fire suppression devices on belt haulageways.
- (h) **Flame-resistant conveyor belt—** On and after the operative date of this subchapter, all conveyor belts acquired for use underground shall meet the requirements to be established by the [Secretary](/usc/30/802.md?p=a) for flame-resistant conveyor belts.

# §872. Maps

- (a) **Fireproof repository; contents; certification—** The [operator](/usc/30/802.md?p=d) of a [coal mine](/usc/30/878.md?p=l) shall have in a fireproof repository located in an area on the surface of the mine chosen by the mine [operator](/usc/30/802.md?p=d) to minimize the danger of destruction by fire or other hazard, an accurate and up-to-date map of such mine drawn on scale. Such map shall show the [active workings](/usc/30/878.md?p=g-4), all pillared, worked out, and [abandoned areas](/usc/30/878.md?p=h), except as provided in this section, entries and aircourses with the direction of airflow indicated by arrows, contour lines of all elevations, elevations of all main and cross or side entries, dip of the coalbed, escapeways, adjacent mine workings within one thousand feet, mines above or below, water pools above, and either producing or abandoned oil and gas wells located within five hundred feet of such mine and any underground area of such mine, and such other information as the [Secretary](/usc/30/802.md?p=a) may require. Such map shall identify those areas of the mine which have been pillared, worked out, or abandoned which are inaccessible or cannot be entered safely and on which no information is available. Such map shall be made or certified by a registered engineer or a registered surveyor of the [State](/usc/30/802.md?p=c) in which the mine is located. Such map shall be kept up to date by temporary notations and such map shall be revised and supplemented at intervals prescribed by the [Secretary](/usc/30/802.md?p=a) on the basis of a survey made or certified by such engineer or surveyor.
- (b) **Availability for inspection; confidential copies—** The [coal mine](/usc/30/878.md?p=l) map and any revision and supplement thereof shall be available for inspection by the [Secretary](/usc/30/802.md?p=a) or his authorized representative, by [coal mine](/usc/30/878.md?p=l) inspectors of the [State](/usc/30/802.md?p=c) in which the mine is located, by [miners](/usc/30/802.md?p=g) in the mine and their representatives and by [operators](/usc/30/802.md?p=d) of adjacent [coal mines](/usc/30/878.md?p=l) and by [persons](/usc/30/802.md?p=f) owning, leasing, or residing on surface areas of such mines or areas adjacent to such mines. The [operator](/usc/30/802.md?p=d) shall furnish to the [Secretary](/usc/30/802.md?p=a) or his authorized representative and to the [Secretary](/usc/30/802.md?p=a) of Housing and Urban Development, upon request, one or more copies of such map and any revision and supplement thereof. Such map or revision and supplement thereof shall be kept confidential and its contents shall not be divulged to any other [person](/usc/30/802.md?p=f), except to the extent necessary to carry out the provisions of this chapter and in connection with the functions and responsibilities of the [Secretary](/usc/30/802.md?p=a) of Housing and Urban Development.
- (c) **Notification of mine closures; filing of revised and supplemental map; certification—** Whenever an [operator](/usc/30/802.md?p=d) permanently closes or abandons a [coal mine](/usc/30/878.md?p=l), or temporarily closes a [coal mine](/usc/30/878.md?p=l) for a period of more than ninety days, he shall promptly notify the [Secretary](/usc/30/802.md?p=a) of such closure. Within sixty days of the permanent closure or abandonment of the mine, or, when the mine is temporarily closed, upon the expiration of a period of ninety days from the date of closure, the [operator](/usc/30/802.md?p=d) shall file with the [Secretary](/usc/30/802.md?p=a) a copy of the mine map revised and supplemented to the date of the closure. Such copy of the mine map shall be certified by a registered surveyor or registered engineer of the [State](/usc/30/802.md?p=c) in which the mine is located and shall be available for public inspection.

# §873. Blasting and explosives

- (a) **Limitations on storage and use of black powder and mudcaps—** Black blasting powder shall not be stored or used underground. Mudcaps (adobes) or other unconfined shots shall not be fired underground.
- (b) **Storage of explosives and detonators; mudcaps in anthracite mines; restrictions; tests—** Explosives and detonators shall be kept in separate containers until immediately before blasting. In underground [anthracite](/usc/30/878.md?p=e) mines, (1) mudcaps or other open, unconfined shake shots may be fired, if restricted to battery starting when methane or a fire hazard is not present, and if it is otherwise impracticable to start the battery; (2) open, unconfined shake shots in pitching veins may be fired, when no methane or fire hazard is present, if the taking down of loose hanging coal by other means is too hazardous; and (3) tests for methane shall be made immediately before such shots are fired and if 1.0 volume per centum or more of methane is present, when tested, such shot shall not be made until the methane content is reduced below 1.0 volume per centum.
- (c) **Permissible explosives, detonators, and devices; firing; stem boreholes; nonpermissible explosives; compressed air blasting—** Except as provided in this subsection, in all underground areas of a [coal mine](/usc/30/878.md?p=l) only permissible explosives, electric detonators of proper strength, and permissible blasting devices shall be used and all explosives and blasting devices shall be used in a permissible manner. Permissible explosives shall be fired only with permissible shot firing units. Only incombustible materials shall be used for stemming boreholes. The [Secretary](/usc/30/802.md?p=a) may, under such safeguards as he may prescribe, permit the firing of more than twenty shots and allow the use of nonpermissible explosives in sinking shafts and slopes from the surface in rock. Nothing in this section shall prohibit the use of compressed air blasting.
- (d) **Container construction for carrying explosives or detonators in underground mines—** Explosives or detonators carried anywhere underground in a [coal mine](/usc/30/878.md?p=l) by any [person](/usc/30/802.md?p=f) shall be in containers constructed of nonconductive material, maintained in good condition, and kept closed.
- (e) **Transportation of explosives or detonators in underground mines—** Explosives or detonators shall be transported in special closed containers (1) in cars moved by means of a locomotive or rope, (2) on belts, (3) in shuttle cars, or (4) in equipment designed especially to transport such explosives or detonators.
- (f) **Storage of explosives and detonators in working sections of underground mines; containers; locations—** When supplies of explosives and detonators for use in one or more [working sections](/usc/30/878.md?p=g-3) are stored underground, they shall be kept in section boxes or magazines of substantial construction with no metal exposed on the inside, located at least twenty-five feet from roadways and power wires, and in a dry, well rock-dusted location protected from falls of roof, except in pitching beds, where it is not possible to comply with the location requirement, such boxes shall be placed in niches cut into the solid coal or rock.
- (g) **Location of explosive and detonator containers in working places of underground mines—** Explosives and detonators stored in the [working places](/usc/30/878.md?p=g-2) shall be kept in separate closed containers which shall be located out of the line of blast and not less than fifty feet from the [working face](/usc/30/878.md?p=g-1) and fifteen feet from any pipeline, powerline, rail, or conveyor, except that, if kept in niches in the rib, the distance from any pipeline, powerline, rail, or conveyor shall be at least five feet. Such explosives and detonators, when stored, shall be separated by a distance of at least five feet.

# §874. Hoisting and mantrips

- (a) **Transporting of persons; required equipment and capabilities; safety catches; daily examinations; operators—** Every hoist used to transport [persons](/usc/30/802.md?p=f) at a [coal mine](/usc/30/878.md?p=l) shall be equipped with overspeed, overwind, and automatic stop controls. Every hoist handling platforms, cages, or other devices used to transport [persons](/usc/30/802.md?p=f) shall be equipped with brakes capable of stopping the fully loaded platform, cage, or other device; with hoisting cable adequately strong to sustain the fully loaded platform, cage, or other device; and have a proper margin of safety. Cages, platforms, or other devices which are used to transport [persons](/usc/30/802.md?p=f) in shafts and slopes shall be equipped with safety catches or other no less effective devices approved by the [Secretary](/usc/30/802.md?p=a) that act quickly and effectively in an emergency, and such catches shall be tested at least once every two months. Hoisting equipment, including automatic elevators, that is used to transport [persons](/usc/30/802.md?p=f) shall be examined daily. Where [persons](/usc/30/802.md?p=f) are transported into, or out of, a [coal mine](/usc/30/878.md?p=l) by hoists, a qualified hoisting engineer shall be on duty while any [person](/usc/30/802.md?p=f) is underground, except that no such engineer shall be required for automatically operated cages, platforms, or elevators.
- (b) **Promulgation of other safeguards—** Other safeguards adequate, in the judgment of an authorized representative of the [Secretary](/usc/30/802.md?p=a), to minimize hazards with respect to transportation of men and materials shall be provided.
- (c) **Rated capacities; indicator for position of cage—** Hoists shall have rated capacities consistent with the loads handled and the recommended safety factors of the ropes used. An accurate and reliable indicator of the position of the cage, platform, skip, bucket, or cars shall be provided.
- (d) **Methods for signaling between shaft stations and hoist rooms—** There shall be at least two effective methods approved by the [Secretary](/usc/30/802.md?p=a) of signaling between each of the shaft stations and the hoist room, one of which shall be a telephone or speaking tube.
- (e) **Braking equipment for haulage cars used in underground mines—** Each locomotive and haulage car used in an underground [coal mine](/usc/30/878.md?p=l) shall be equipped with automatic brakes, where space permits. Where space does not permit automatic brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other similar devices approved by the [Secretary](/usc/30/802.md?p=a) which are designed to stop the locomotives and haulage cars with the proper margin of safety.
- (f) **Automatic couplers for haulage equipment—** All haulage equipment acquired by an [operator](/usc/30/802.md?p=d) of a [coal mine](/usc/30/878.md?p=l) on or after one year after the operative date of this subchapter shall be equipped with automatic couplers which couple by impact and uncouple without the necessity of [persons](/usc/30/802.md?p=f) going between the ends of such equipment. All haulage equipment without automatic couplers in use in a mine on the operative date of this subchapter shall also be so equipped within four years after the operative date of this subchapter.

# §875. Emergency shelters; construction; contents; implementation plans


The [Secretary](/usc/30/802.md?p=a) or an authorized representative of the [Secretary](/usc/30/802.md?p=a) may prescribe in any [coal mine](/usc/30/878.md?p=l) that rescue chambers, properly sealed and ventilated, be erected at suitable locations in the mine to which [persons](/usc/30/802.md?p=f) may go in case of an emergency for protection against hazards. Such chambers shall be properly equipped with first aid materials, an adequate supply of air and self-contained breathing equipment, an independent communication system to the surface, and proper accommodations for the [persons](/usc/30/802.md?p=f) while awaiting rescue, and such other equipment as the [Secretary](/usc/30/802.md?p=a) may require. A plan for the erection, maintenance, and revisions of such chambers and the training of the [miners](/usc/30/802.md?p=g) in their proper use shall be submitted by the [operator](/usc/30/802.md?p=d) to the [Secretary](/usc/30/802.md?p=a) for his approval.


# §876. Communication facilities; locations and emergency response plans

- (a) **In general—** Telephone service or equivalent two-way communication facilities, approved by the [Secretary](/usc/30/802.md?p=a) or his authorized representative, shall be provided between the surface and each landing of main shafts and slopes and between the surface and each [working section](/usc/30/878.md?p=g-3) of any [coal mine](/usc/30/878.md?p=l) that is more than one hundred feet from a portal.
- (b) **Accident preparedness and response—**
  - (1) **In general—** Each underground [coal mine](/usc/30/878.md?p=l) [operator](/usc/30/802.md?p=d) shall carry out on a continuing basis a program to improve [accident](/usc/30/802.md?p=k) preparedness and response at each mine.
  - (2) **Response and preparedness plan—**
    - (A) **In general—** Not later than 60 days after June 15, 2006, each underground [coal mine](/usc/30/878.md?p=l) [operator](/usc/30/802.md?p=d) shall develop and adopt a written [accident](/usc/30/802.md?p=k) response plan that complies with this subsection with respect to each mine of the [operator](/usc/30/802.md?p=d), and periodically update such plans to reflect changes in operations in the mine, advances in technology, or other relevant considerations. Each such [operator](/usc/30/802.md?p=d) shall make the [accident](/usc/30/802.md?p=k) response plan available to the [miners](/usc/30/802.md?p=g) and the [miners](/usc/30/802.md?p=g)’ representatives.
    - (B) **Plan requirements—** An [accident](/usc/30/802.md?p=k) response plan under [subparagraph (A)](#b-2-A) shall—
      - (i) provide for the evacuation of all individuals endangered by an emergency; and
      - (ii) provide for the maintenance of individuals trapped underground in the event that [miners](/usc/30/802.md?p=g) are not able to evacuate the mine.
    - (C) **Plan approval—** The [accident](/usc/30/802.md?p=k) response plan under [subparagraph (A)](#b-2-A) shall be subject to review and approval by the [Secretary](/usc/30/802.md?p=a). In determining whether to approve a particular plan the [Secretary](/usc/30/802.md?p=a) shall take into consideration all comments submitted by [miners](/usc/30/802.md?p=g) or their representatives. Approved plans shall—
      - (i) afford [miners](/usc/30/802.md?p=g) a level of safety protection at least consistent with the existing standards, including standards mandated by law and regulation;
      - (ii) reflect the most recent credible scientific research;
      - (iii) be technologically feasible, make use of current commercially available technology, and account for the specific physical characteristics of the mine; and
      - (iv) reflect the improvements in mine safety gained from experience under this chapter and other worker safety and health laws.
    - (D) **Plan review—** The [accident](/usc/30/802.md?p=k) response plan under [subparagraph (A)](#b-2-A) shall be reviewed periodically, but at least every 6 months, by the [Secretary](/usc/30/802.md?p=a). In such periodic reviews, the [Secretary](/usc/30/802.md?p=a) shall consider all comments submitted by [miners](/usc/30/802.md?p=g) or [miners](/usc/30/802.md?p=g)’ representatives and intervening advancements in science and technology that could be implemented to enhance [miners](/usc/30/802.md?p=g)’ ability to evacuate or otherwise survive in an emergency.
    - (E) **Plan content-general requirements—** To be approved under [subparagraph (C)](#b-2-C), an [accident](/usc/30/802.md?p=k) response plan shall include the following:
      - (i) **Post-accident communications—** The plan shall provide for a redundant means of communication with the surface for [persons](/usc/30/802.md?p=f) underground, such as secondary telephone or equivalent two-way communication.
      - (ii) **Post-accident tracking—** Consistent with commercially available technology and with the physical constraints, if any, of the mine, the plan shall provide for above ground personnel to determine the current, or immediately pre-[accident](/usc/30/802.md?p=k), location of all underground personnel. Any system so utilized shall be functional, reliable, and calculated to remain serviceable in a post-[accident](/usc/30/802.md?p=k) setting.
      - (iii) **Post-accident breathable air—** The plan shall provide for—
        - (I) emergency supplies of breathable air for individuals trapped underground sufficient to maintain such individuals for a sustained period of time;
        - (II) in addition to the 2 hours of breathable air per [miner](/usc/30/802.md?p=g) required by law under the emergency temporary standard as of the day before June 15, 2006, caches of self-rescuers providing in the aggregate not less than 2 hours per [miner](/usc/30/802.md?p=g) to be kept in escapeways from the deepest work area to the surface at a distance of no further than an average [miner](/usc/30/802.md?p=g) could walk in 30 minutes;
        - (III) a maintenance schedule for checking the reliability of self rescuers, retiring older self-rescuers first, and introducing new self-rescuer technology, such as units with interchangeable air or oxygen cylinders not requiring doffing to replenish airflow and units with supplies of greater than 60 minutes, as they are approved by the [Administration](/usc/30/802.md?p=n) and become available on the market; and
        - (IV) training for each [miner](/usc/30/802.md?p=g) in proper procedures for donning self-rescuers, switching from one unit to another, and ensuring a proper fit.
      - (iv) **Post-accident lifelines—** The plan shall provide for the use of flame-resistant directional lifelines or equivalent systems in escapeways to enable evacuation. The flame-resistance requirement of this clause shall apply upon the replacement of existing lifelines, or, in the case of lifelines in [working sections](/usc/30/878.md?p=g-3), upon the earlier of the replacement of such lifelines or 3 years after June 15, 2006.
      - (v) **Training—** The plan shall provide a training program for emergency procedures described in the plan which will not diminish the requirements for mandatory health and safety training currently required under [section 825 of this title](/usc/30/825.md).
      - (vi) **Local coordination—** The plan shall set out procedures for coordination and communication between the [operator](/usc/30/802.md?p=d), mine rescue teams, and local emergency response personnel and make provisions for familiarizing local rescue personnel with surface functions that may be required in the course of mine rescue work.
    - (F) **Plan content-specific requirements—**
      - (i) **In general—** In addition to the content requirements contained in [subparagraph (E)](#b-2-E), and subject to the considerations contained in [subparagraph (C)](#b-2-C), the [Secretary](/usc/30/802.md?p=a) may make additional plan requirements with respect to any of the content matters.
      - (ii) **Post accident communications—** Not later than 3 years after June 15, 2006, a plan shall, to be approved, provide for post [accident](/usc/30/802.md?p=k) communication between underground and surface personnel via a wireless two-way medium, and provide for an electronic tracking system permitting surface personnel to determine the location of any [persons](/usc/30/802.md?p=f) trapped underground or set forth within the plan the reasons such provisions can not be adopted. Where such plan sets forth the reasons such provisions can not be adopted, the plan shall also set forth the [operator](/usc/30/802.md?p=d)’s alternative means of compliance. Such alternative shall approximate, as closely as possible, the degree of functional utility and safety protection provided by the wireless two-way medium and tracking system referred to in this subpart.[^1]
    - (G) **Plan dispute resolution—**
      - (i) **In general—** Any dispute between the [Secretary](/usc/30/802.md?p=a) and an [operator](/usc/30/802.md?p=d) with respect to the content of the [operator](/usc/30/802.md?p=d)’s plan or any refusal by the [Secretary](/usc/30/802.md?p=a) to approve such a plan shall be resolved on an expedited basis.
      - (ii) **Disputes—** In the event of a dispute or refusal described in [clause (i)](#b-2-G-i), the [Secretary](/usc/30/802.md?p=a) shall issue a citation which shall be immediately referred to a [Commission](/usc/30/802.md?p=o) Administrative Law Judge. The [Secretary](/usc/30/802.md?p=a) and the [operator](/usc/30/802.md?p=d) shall submit all relevant material regarding the dispute to the Administrative Law Judge within 15 days of the date of the referral. The Administrative Law Judge shall render his or her decision with respect to the plan content dispute within 15 days of the receipt of the submission.
      - (iii) **Further appeals—** A party adversely affected by a decision under [clause (ii)](#b-2-G-ii) may pursue all further available appeal rights with respect to the citation involved, except that inclusion of the disputed provision in the plan will not be limited by such appeal unless such relief is requested by the [operator](/usc/30/802.md?p=d) and permitted by the Administrative Law Judge.
    - (H) **Maintaining protections for miners—** Notwithstanding any other provision of this chapter, nothing in this section, and no response and preparedness plan developed under this section, shall be approved if it reduces the protection afforded [miners](/usc/30/802.md?p=g) by an existing [mandatory health or safety standard](/usc/30/802.md?p=l).

# §877. General safety provisions

- (a) **Location of oil and gas wells; establishment and maintenance of barriers; minimum requisites; exceptions—** Each [operator](/usc/30/802.md?p=d) of a [coal mine](/usc/30/878.md?p=l) shall take reasonable measures to locate oil and gas wells penetrating coalbeds or any underground area of a [coal mine](/usc/30/878.md?p=l). When located, such [operator](/usc/30/802.md?p=d) shall establish and maintain barriers around such oil and gas wells in accordance with [State](/usc/30/802.md?p=c) laws and regulations, except that such barriers shall not be less than three hundred feet in diameter, unless the [Secretary](/usc/30/802.md?p=a) or his authorized representative permits a lesser barrier consistent with the applicable [State](/usc/30/802.md?p=c) laws and regulations where such lesser barrier will be adequate to protect against hazards from such wells to the [miners](/usc/30/802.md?p=g) in such mine, or unless the [Secretary](/usc/30/802.md?p=a) or his authorized representative requires a greater barrier where the depth of the mine, other geologic conditions, or other factors warrant such a greater barrier.
- (b) **Boreholes in advance of work face; distance in advance of work face; distance between boreholes—** Whenever any [working place](/usc/30/878.md?p=g-2) approaches within fifty feet of [abandoned areas](/usc/30/878.md?p=h) in the mine as shown by surveys made and certified by a registered engineer or surveyor, or within two hundred feet of any other [abandoned areas](/usc/30/878.md?p=h) of the mine which cannot be inspected and which may contain dangerous accumulations of water or gas, or within two hundred feet of any workings of an adjacent mine, a borehole or boreholes shall be drilled to a distance of at least twenty feet in advance of the [working face](/usc/30/878.md?p=g-1) of such [working place](/usc/30/878.md?p=g-2) and shall be continually maintained to a distance of at least ten feet in advance of the advancing [working face](/usc/30/878.md?p=g-1). When there is more than one borehole, they shall be drilled sufficiently close to each other to insure that the advancing [working face](/usc/30/878.md?p=g-1) will not accidentally hole through into [abandoned areas](/usc/30/878.md?p=h) or adjacent mines. Boreholes shall also be drilled not more than eight feet apart in the rib of such [working place](/usc/30/878.md?p=g-2) to a distance of at least twenty feet and at an angle of forty-five degrees. Such rib holes shall be drilled in one or both ribs of such [working place](/usc/30/878.md?p=g-2) as may be necessary for adequate protection of [miners](/usc/30/802.md?p=g) in such place.
- (c) **Prohibition against smoking; implementation programs—** No [person](/usc/30/802.md?p=f) shall smoke, carry smoking materials, matches, or lighters underground, or smoke in or around oil houses, explosives magazines, or other surface areas where such practice may cause a fire or explosion. The [operator](/usc/30/802.md?p=d) shall institute a program, approved by the [Secretary](/usc/30/802.md?p=a), to insure that any [person](/usc/30/802.md?p=f) entering the underground area of the mine does not carry smoking materials, matches, or lighters.
- (d) **Portable electric lamps; exceptions—** [Persons](/usc/30/802.md?p=f) underground shall use only permissible electric lamps approved by the [Secretary](/usc/30/802.md?p=a) for portable illumination. No open flame shall be permitted in the underground area of any [coal mine](/usc/30/878.md?p=l), except as permitted under [section 871(d) of this title](/usc/30/871.md?p=d).
- (e) **Promulgation of lighting standards—** Within nine months after the operative date of this subchapter, the [Secretary](/usc/30/802.md?p=a) shall propose the standards under which all [working places](/usc/30/878.md?p=g-2) in a mine shall be illuminated by permissible lighting, within eighteen months after the promulgation of such standards, while [persons](/usc/30/802.md?p=f) are working in such places.
- (f) **Escapeways; ventilation; maintenance; tests of passageways; protection of entrance; connection between mine openings—**
  - (1) Except as provided in paragraphs (2) and (3) of this subsection, at least two separate and distinct travelable passageways which are maintained to insure passage at all times of any [person](/usc/30/802.md?p=f), including disabled [persons](/usc/30/802.md?p=f), and which are to be designated as escapeways, at least one of which is ventilated with intake air, shall be provided from each [working section](/usc/30/878.md?p=g-3) continuous to the surface escape drift opening, or continuous to the escape shaft or slope facilities to the surface, as appropriate, and shall be maintained in safe condition and properly marked. Mine openings shall be adequately protected to prevent the entrance into the underground area of the mine of surface fires, fumes, smoke, and flood water. Escape facilities approved by the [Secretary](/usc/30/802.md?p=a) or his authorized representative, properly maintained and frequently tested, shall be present at or in each escape shaft or slope to allow all [persons](/usc/30/802.md?p=f), including disabled [persons](/usc/30/802.md?p=f), to escape quickly to the surface in the event of an emergency.
  - (2) When new [coal mines](/usc/30/878.md?p=l) are opened, not more than twenty [miners](/usc/30/802.md?p=g) shall be allowed at any one time in any mine until a connection has been made between the two mine openings, and such connections shall be made as soon as possible.
  - (3) When only one mine opening is available, owing to final mining of pillars, not more than twenty [miners](/usc/30/802.md?p=g) shall be allowed in such mine at any one time, and the distance between the mine opening and [working face](/usc/30/878.md?p=g-1) shall not exceed five hundred feet.
  - (4) In the case of all [coal mines](/usc/30/878.md?p=l) opened on or after the operative date of this subchapter, and in the case of all new [working sections](/usc/30/878.md?p=g-3) opened on or after such date in mines opened prior to such date, the escapeway required by this section to be ventilated with intake air shall be separated from the belt and trolley haulage entries of the mine for the entire length of such entries to the beginning of each [working section](/usc/30/878.md?p=g-3), except that the [Secretary](/usc/30/802.md?p=a) or his authorized representative may permit such separation to be extended for a greater or lesser distance so long as such extension does not pose a hazard to the [miners](/usc/30/802.md?p=g).
- (g) **Erection of fireproof structures; prior existing structures; fire doors; monthly tests; records; availability—** After the operative date of this subchapter, all structures erected on the surface within one hundred feet of any mine opening shall be of fireproof construction. Unless structures existing on or prior to such date which are located within one hundred feet of any mine opening are of such construction, fire doors shall be erected at effective points in mine openings to prevent smoke or fire from outside sources endangering [miners](/usc/30/802.md?p=g) underground. These doors shall be tested at least monthly to insure effective operation. A record of such tests shall be kept in an area on the surface of the mine chosen by the [operator](/usc/30/802.md?p=d) to minimize the danger of destruction by fire or other hazard and shall be available for inspection by interested [persons](/usc/30/802.md?p=f).
- (h) **Prevention of accumulations of coal dust and methane gas; surface coal-handling facilities; air-intake openings—** Adequate measures shall be taken to prevent methane and coal dust from accumulating in excessive concentrations in or on surface coal-handling facilities, but in no event shall methane be permitted to accumulate in concentrations in or on surface coal-handling facilities in excess of limits established for methane by the [Secretary](/usc/30/802.md?p=a) within one year after the operative date of this subchapter. Where coal is dumped at or near air-intake openings, provisions shall be made to avoid dust from entering the mine.
- (i) **Training programs—** Every [operator](/usc/30/802.md?p=d) of a [coal mine](/usc/30/878.md?p=l) shall provide a program, approved by the [Secretary](/usc/30/802.md?p=a), of training and retraining of both qualified and certified [persons](/usc/30/802.md?p=f) needed to carry out functions prescribed in this chapter.
- (j) **Electric face equipment; installation of canopies—** An authorized representative of the [Secretary](/usc/30/802.md?p=a) may require in any [coal mine](/usc/30/878.md?p=l) where the height of the coalbed permits that electric face equipment, including shuttle cars, be provided with substantially constructed canopies or cabs to protect the [miners](/usc/30/802.md?p=g) operating such equipment from roof falls and from rib and face rolls.
- (k) **Mine entrances; sealing; prevention of entry by unauthorized personnel—** On and after the operative date of this subchapter, the opening of any [coal mine](/usc/30/878.md?p=l) that is declared inactive by its [operator](/usc/30/802.md?p=d) or is permanently closed or abandoned for more than ninety days, shall be sealed by the [operator](/usc/30/802.md?p=d) in a manner prescribed by the [Secretary](/usc/30/802.md?p=a). Openings of all other mines shall be adequately protected in a manner prescribed by the [Secretary](/usc/30/802.md?p=a) to prevent entrance by unauthorized [persons](/usc/30/802.md?p=f).
- (l) **Facilities for changing and storing clothes; toilet and bathing facilities—** The [Secretary](/usc/30/802.md?p=a) may require any [operator](/usc/30/802.md?p=d) to provide adequate facilities for the [miners](/usc/30/802.md?p=g) to change from the clothes worn underground, to provide for the storing of such clothes from shift to shift, and to provide sanitary and bathing facilities. Sanitary toilet facilities shall be provided in the [active workings](/usc/30/878.md?p=g-4) of the mine when such surface facilities are not readily accessible to the [active workings](/usc/30/878.md?p=g-4).
- (m) **Emergency medical assistance preparations; locations for medical equipment; filing of implementation plans—** Each [operator](/usc/30/802.md?p=d) shall make arrangements in advance for obtaining emergency medical assistance and transportation for injured [persons](/usc/30/802.md?p=f). Emergency communications shall be provided to the nearest point of assistance. Selected [agents](/usc/30/802.md?p=e) of the [operator](/usc/30/802.md?p=d) shall be trained in first aid and first aid training shall be made available to all [miners](/usc/30/802.md?p=g). Each [coal mine](/usc/30/878.md?p=l) shall have an adequate supply of first aid equipment located on the surface, at the bottom of shafts and slopes, and at other strategic locations near the [working faces](/usc/30/878.md?p=g-1). In fulfilling each of the requirements of this subsection, the [operator](/usc/30/802.md?p=d) shall meet at least minimum requirements prescribed by the [Secretary](/usc/30/802.md?p=a) of Health and Human Services. Within two months after the operative date of this subchapter, each [operator](/usc/30/802.md?p=d) shall file with the [Secretary](/usc/30/802.md?p=a) a plan setting forth in such detail as the [Secretary](/usc/30/802.md?p=a) may require the manner in which such [operator](/usc/30/802.md?p=d) has fulfilled the requirements in this subsection.
- (n) **Self-rescue device; training of personnel—** A self-rescue device approved by the [Secretary](/usc/30/802.md?p=a) shall be made available to each [miner](/usc/30/802.md?p=g) by the [operator](/usc/30/802.md?p=d) which shall be adequate to protect such [miner](/usc/30/802.md?p=g) for one hour or longer. Each [operator](/usc/30/802.md?p=d) shall train each [miner](/usc/30/802.md?p=g) in the use of such device.
- (o) **Methods of eliminating oxygen deficiencies—** The [Secretary](/usc/30/802.md?p=a) shall prescribe improved methods of assuring that [miners](/usc/30/802.md?p=g) are not exposed to atmospheres that are deficient in oxygen.
- (p) **Identification check system; records—** Each [operator](/usc/30/802.md?p=d) of a [coal mine](/usc/30/878.md?p=l) shall establish a check-in and check-out system which will provide positive identification of every [person](/usc/30/802.md?p=f) underground, and will provide an accurate record of the [persons](/usc/30/802.md?p=f) in the mine kept on the surface in a place chosen to minimize the danger of destruction by fire or other hazard. Such record shall bear a number identical to an identification check that is securely fastened to the lamp belt worn by the [person](/usc/30/802.md?p=f) underground. The identification check shall be made of a rust resistant metal of not less than sixteen gauge.
- (q) **Installation of devices to prevent and suppress ignition on electric cutting face equipment—** The [Secretary](/usc/30/802.md?p=a) shall require, when technologically feasible, that devices to prevent and suppress ignitions be installed on electric face cutting equipment.
- (r) **Tunnelling under water; permits; contents; necessity; safety zones; restrictions—** Whenever an [operator](/usc/30/802.md?p=d) mines coal from a [coal mine](/usc/30/878.md?p=l) opened after the operative date of this subchapter, or from any new [working section](/usc/30/878.md?p=g-3) of a mine opened prior to such date, in a manner that requires the construction, operation, and maintenance of tunnels under any river, stream, lake, or other body of water, that is, in the judgment of the [Secretary](/usc/30/802.md?p=a), sufficiently large to constitute a hazard to [miners](/usc/30/802.md?p=g), such [operator](/usc/30/802.md?p=d) shall obtain a permit from the [Secretary](/usc/30/802.md?p=a) which shall include such terms and conditions as he deems appropriate to protect the safety of [miners](/usc/30/802.md?p=g) working or passing through such tunnels from cave-ins and other hazards. Such permits shall require, in accordance with a plan to be approved by the [Secretary](/usc/30/802.md?p=a), that a safety zone be established beneath and adjacent to such body of water. No plan shall be approved unless there is a minimum of cover to be determined by the [Secretary](/usc/30/802.md?p=a), based on test holes drilled by the [operator](/usc/30/802.md?p=d) in a manner to be prescribed by the [Secretary](/usc/30/802.md?p=a). No such permit shall be required in the case of any new [working section](/usc/30/878.md?p=g-3) of a mine which is located under any water resource reservoir being constructed by a Federal agency on December 30, 1969, the [operator](/usc/30/802.md?p=d) of which is required by such agency to operate in a manner that adequately protects the safety of [miners](/usc/30/802.md?p=g) working in such section from cave-ins and other hazards.
- (s) **Drinking water—** An adequate supply of potable water shall be provided for drinking purposes in the [active workings](/usc/30/878.md?p=g-4) of the mine, and such water shall be carried, stored, and otherwise protected in sanitary containers.
- (t) **Standards for prevention of explosions from nonmethane gases and for testing for accumulations—** Within one year after the operative date of this subchapter, the [Secretary](/usc/30/802.md?p=a) shall propose standards for preventing explosions from explosive gases other than methane and for testing for accumulations of such gases.

# §878. Definitions


For the purpose of this subchapter and subchapter II of this chapter, the term—

- (a) “certified” or “registered” as applied to any [person](/usc/30/802.md?p=f) means a [person](/usc/30/802.md?p=f) certified or registered by the [State](/usc/30/802.md?p=c) in which the [coal mine](#l) is located to perform duties prescribed by such subchapters, except that, in a [State](/usc/30/802.md?p=c) where no program of certification or registration is provided or where the program does not meet at least minimum Federal standards established by the [Secretary](/usc/30/802.md?p=a), such certification or registration shall be by the [Secretary](/usc/30/802.md?p=a);
- (b) “qualified person” means, as the context requires,
  - (1) an individual deemed qualified by the [Secretary](/usc/30/802.md?p=a) and designated by the [operator](/usc/30/802.md?p=d) to make tests and examinations required by this chapter; and
  - (2) an individual deemed, in accordance with minimum requirements to be established by the [Secretary](/usc/30/802.md?p=a), qualified by training, education, and experience, to perform electrical work, to maintain electrical equipment, and to conduct examinations and tests of all electrical equipment;
- (c) “permissible” as applied to—
  - (1) equipment used in the operation of a [coal mine](#l), means equipment, other than permissible electric face equipment, to which an approval plate, label, or other device is attached as authorized by the [Secretary](/usc/30/802.md?p=a) and which meets specifications which are prescribed by the [Secretary](/usc/30/802.md?p=a) for the construction and maintenance of such equipment and are designed to assure that such equipment will not cause a mine explosion or a mine fire,
  - (2) explosives, shot firing units, or blasting devices used in such mine, means explosives, shot firing units, or blasting devices which meet specifications which are prescribed by the [Secretary](/usc/30/802.md?p=a), and
  - (3) the manner of use of equipment or explosives, shot firing units, and blasting devices, means the manner of use prescribed by the [Secretary](/usc/30/802.md?p=a);
- (d) “rock dust” means pulverized limestone, dolomite, gypsum, anhydrite, shale, adobe, or other inert material, preferably light colored, 100 per centum of which will pass through a sieve having twenty meshes per linear inch and 70 per centum or more of which will pass through a sieve having two hundred meshes per linear inch; the particles of which when wetted and dried will not cohere to form a cake which will not be dispersed into separate particles by a light blast of air; and which does not contain more than 5 per centum of combustible matter or more than a total of 4 per centum of free and combined silica (SiO<sub>2</sub>), or, where the [Secretary](/usc/30/802.md?p=a) finds that such silica concentrations are not available, which does not contain more than 5 per centum of free and combined silica;
- (e) “anthracite” means coals with a [volatile ratio](#f) equal to 0.12 or less;
- (f) “volatile ratio” means volatile matter content divided by the volatile matter plus the fixed carbon;
- (g)
  - (1) “working face” means any place in a [coal mine](#l) in which work of extracting coal from its natural deposit in the earth is performed during the mining cycle,
  - (2) “working place” means the area of a [coal mine](#l) inby the last open crosscut,
  - (3) “working section” means all areas of the [coal mine](#l) from the loading point of the section to and including the [working faces](#g-1),
  - (4) “active workings” means any place in a [coal mine](#l) where [miners](/usc/30/802.md?p=g) are normally required to work or travel;
- (h) “abandoned areas” means sections, [panels](/usc/30/802.md?p=m), and other areas that are not ventilated and examined in the manner required for [working places](#g-2) under [section 863 of this title](/usc/30/863.md);
- (i) “permissible” as applied to electric face equipment means all electrically operated equipment taken into or used inby the last open crosscut of an entry or a room of any [coal mine](#l) the electrical parts of which, including, but not limited to, associated electrical equipment, components, and accessories, are designed, constructed, and installed, in accordance with the specifications of the [Secretary](/usc/30/802.md?p=a), to assure that such equipment will not cause a mine explosion or mine fire, and the other features of which are designed and constructed, in accordance with the specifications of the [Secretary](/usc/30/802.md?p=a), to prevent, to the greatest extent possible, other [accidents](/usc/30/802.md?p=k) in the use of such equipment; and the regulations of the [Secretary](/usc/30/802.md?p=a) or the Director of the United States Bureau of Mines in effect on the operative date of this subchapter relating to the requirements for investigation, testing, approval, certification, and acceptance of such equipment as permissible shall continue in effect until modified or superseded by the [Secretary](/usc/30/802.md?p=a), except that the [Secretary](/usc/30/802.md?p=a) shall provide procedures, including, where feasible, testing, approval, certification, and acceptance in the field by an authorized representative of the [Secretary](/usc/30/802.md?p=a), to facilitate compliance by an [operator](/usc/30/802.md?p=d) with the requirements of [section 865(a) of this title](/usc/30/865.md?p=a) within the periods prescribed therein;
- (j) “low voltage” means up to and including 660 volts; “medium voltage” means voltages from 661 to 1,000 volts; and “high voltage” means more than 1,000 volts;
- (k) Repealed. Pub. L. 95–164, title II, § 202(b), Nov. 9, 1977, 91 Stat. 1317.
- (l) “coal mine” includes areas of adjoining mines connected underground.