In the matter of Petition for Modification
Arch of Illinois
Conant Mine
I.D. No. 11-02886 Docket No.M-97-029-C
Date Issued: 05/29/1998
PROPOSED DECISION AND ORDER
On March 3, 1997, a petition was filed seeking a modification of the application of 30 CFR 75.323(b)(1) and (b)(2) to Petitioner's Conant Mine, located in Perry County, Illinois. The petition is specific to a unique mining system developed by the petitioner and referred to as the Archveyor system. The Archveyor system includes, as a unit, the stageloader, the continuous haulage conveyor, the continuous mining machine, and when used, a bolter car.
An on-site investigation was conducted by MSHA and a report of the investigation results was received on May 28, 1997. Comments were received from the miner’s representative on various aspects of the Archveyor system. Studies of various aspects of the Archveyor system have been conducted by NIOSH both in the mine and under laboratory conditions.
The Agency has reviewed and considered all pertinent information available in developing this Proposed Decision and Order.
Finding of Fact and Conclusion of Law
The petitioner alleges that an alternative method of achieving the result of the standard exists that will at all times guarantee no less than the same measure of protection afforded by the standard.
The petition would permit use of the Archveyor system in a retreat mining mode referred to as “winging.” In this application, a panel of coal is developed similar to the development of a panel for a retreating longwall. Once developed, however, retreat would be conducted using the remotely controlled Archveyor system wherein successive diagonal cuts would be made completely across the panel. The Archveyor system would have three methane detection devices near the face and a blowing ventilation tube carried on the Archveyor system, discharging near the face. A web, or rib, of coal several feet in width is left between each wing cut. As successive wing cuts are developed, the webs are designed to crush, resulting in a panel gob area similar to a longwall gob.
The investigation report discusses the application of the standard to the Archveyor system. The investigation report for this petition indicated that the mine liberates approximately 132,000 cubic feet of methane per 24 hour period.
Section 75.323(b)(1) and (b)(2) require that actions be undertaken when methane levels of 1.0% and 1.5% are reached in working places or face areas. Accumulations of methane in face areas can present an extreme hazard to miners particularly with potential ignition sources such as electrical equipment and the cutting of coal and rock. When methane has increased above the specified threshold levels, the standard provides that ignition sources be removed by deenergizing electrical power and requires changes or adjustments in ventilation to dilute and remove the accumulation of methane. The standard also provides for withdrawal of personnel and prohibits work other than corrective action, at the specified methane levels. The alternative method, as stipulated, provides protection equivalent to the standard during winging through: two additional methane detection devices, powered independently from the Archveyor system; a lower methane action level of 0.7%; and, other monitoring instrumentation and frequent checks of safety systems.
The alternative method proposed by the Petitioner together with the following terms and conditions will at all times guarantee no less than the same measure of protection afforded the miners under 30 CFR 75.323(b)(1) and (b)(2).
On the basis of the petition, the findings of MSHA's investigation, comments from the miners' representative, analyses conducted by NIOSH, and other available information, Arch of Illinois is granted a modification of the application of 30 CFR 75.323(b)(1) and (b)(2) to its Conant Mine.
ORDER
Wherefore, pursuant to the authority delegated by the Secretary of Labor to the Administrator for Coal Mine Safety and Health, and pursuant to Section 101(c) of the Federal Mine Safety and Health Act of 1977 (the Act), 30 U.S.C., sec. 811(c), it is ordered that Arch of Illinois's Petition for Modification of the application of 30 CFR 75.323(b)(1) and (b)(2) in the Conant Mine is hereby:
GRANTED, for application only during the second mining process known as “winging” using the Archveyor system, conditioned upon compliance with the following terms and conditions:
1. The continuous mining machine, as part of the Archveyor system, shall be equipped with three methane monitoring devices, described below, all of which shall be operational and in proper working order prior to beginning any wing cut. Methane monitoring devices shall be maintained and calibrated according to the manufacturers’ recommendations. A copy of the manufacturers’ recommendations shall be maintained at the mine and shall be made available to representatives of the miners and MSHA. The MSHA District Manager may increase calibration frequency through the mine ventilation plan if warranted. The three methane monitoring devices shall consist of:
(a) One methane monitor (a CSE 140 BLD or equivalent) for compliance with 30 CFR 75.342 ; and
(b) Two atmospheric detection system (ADS) type methane detection devices (Trolex Model TX 3266 or equivalent) which shall:
(i) Be located as near to the face as practicable, at a maximum of nine feet from the inby end and on the return side (the side opposite the ventilation tubing) of the continuous mining machine. This location is analogous to location no. 7 in NIOSH simulations of the Archveyor system;
(ii) Provide a readout at the control cab whenever the continuous mining machine is operating in a wing cut; and
(iii) Be operated independently from the methane monitor used to comply with 30 CFR 75.342. The Trolex ADS-type methane detection devices shall be powered separately from the Archveyor system and shall be provided with an uninterruptable power supply (UPS) capable of powering the system for 4 hours after a mine power loss. Should the power loss exceed 4 hours, the Trolex-type ADS shall be capable of reenergizing itself, without reenergizing either the continuous mining machine or any other part of the Archveyor system.
2. If one of the Trolex ADS-type methane detection devices fails during mining of a wing cut, mining may continue if the 30 CFR 75.342 monitor is operational. If both of the Trolex ADS-type methane detection devices fail, or one of the TrolexADS-type devices and the 30 CFR 75.342 monitor fail, mining shall cease and the Archveyor system shall be withdrawn for repairs.
3. The continuous mining machine of the Archveyor system shall be equipped with a wet-bed scrubber. The screens of the scrubber shall be serviced prior to beginning each wing cut. The scrubber ductwork shall be maintained so as to ensure proper operation of the system.
4. The water spray system on the continuous mining machine of the Archveyor system shall be checked for compliance with the mine ventilation plan prior to each wing cut.
5. An air velocity monitor (Airflow Sensor Model TX1322 or equivalent) shall be maintained in the ventilation tubing near the inby end of the Archveyor system. The velocity monitor shall be visually checked prior to beginning each wing cut. The velocity monitor shall provide a readout at the control cab to indicate whether the minimum air quantity, specified in the mine ventilation plan, is being provided. The air velocity monitor shall be calibrated in accordance with the manufacturer's recommendations.
6. If a methane concentration of 0.7% or more is detected by any one of the three methane monitoring devices in the working place (wing cut) the Archveyor system shall be deenergized. In addition, the following actions shall be taken:
(a) A qualified person shall immediately test and continue to monitor for methane at the auxiliary fan:
(i) If methane at this location is less than 1.0%, the auxiliary fan may continue to operate to provide face ventilation. A qualified person shall monitor the undiluted air from the active wing cut at the mouth of the wing cut. A probe shall be available for use when conditions necessitate such use.
(ii) If, at any time, the methane concentration at the auxiliary fan reaches 1.0% or more methane, the auxiliary fan shall be deenergized. Changes or adjustments to the ventilation system shall be made at once to reduce the concentration of methane to less than 1.0%. Once the methane concentration is reduced to less than 1.0%, the auxiliary fan may be reenergized.
(b) A qualified person shall immediately test and continue to monitor for methane at the transformer/control cab area. If, at any time, the methane concentration at the transformer/control cab area reaches 1.0% or more methane, the transformer/control cab shall be deenergized. Changes or adjustments to the ventilation system shall be made at once to reduce the concentration of methane to less than 1.0%. Once the methane concentration is reduced to less than 1.0%, the transformer/control cab may be reenergized.
7. If, at any time, the methane concentration in the working place (wing cut), determined by any one of the three methane monitoring devices, reaches or exceeds 1.5%, the section transformer, control cab and auxiliary fan shall be deenergized. Everyone, except those persons referred to in Section 104(c) of the Act, shall be withdrawn from the affected area. In addition, the following actions shall be taken promptly:
(a) Power cables to the Archveyor system shall be disconnected and locked out at the section transformer;
(b) Qualified persons shall test and monitor for methane at the section transformer/control cab area, and near the auxiliary fan; and
(c) Changes or adjustments to the ventilation system shall be made at once to reduce the concentration of methane to less than 1.0%. If an increase in section ventilation of more than 9,000 cfm is necessary to abate the condition, 30 CFR 75.324 shall be followed. The Archveyor system shall be reenergized as described in item 9.
8. Following a loss or removal of power to the section transformer, the transformer shall be reenergized after an examination and tests for methane show that methane is less than 1.0% in outby areas, including the section transformer/control cab area, and auxiliary fan.
9. Once deenergized, the Archveyor system shall be reenergized only in accordance with the procedures and sequence specified below:
(a) If the Trolex ADS-type methane detection devices have remained operational under UPS power, the Archveyor system shall be reenergized only:
(i) after the auxiliary fan operates for the time necessary for one complete air exchange within the wing cut;
(ii) if the Trolex ADS-type methane detection devices show less than 0.7% methane; and
(iii) if methane tests at the mouth of the wing cut show that methane is less than 1.0%.
(b) If the Trolex ADS-type methane detection devices have not remained energized by the UPS, such as by a power interruption exceeding 4 hours, the Archveyor system shall be reenergized only after the specified steps are taken in the following order:
(i) tests for methane are conducted at the auxiliary fan show that methane is under 1.0%;
(ii) the auxiliary fan is energized and restores blowing ventilation to the wing cut;
(iii) the Trolex-type ADS methane detection devices are energized;
(iv) the wing cut has been ventilated for at least the time necessary for one complete air exchange within the wing cut;
(v) the Trolex-type ADS methane detection devices show less than 0.7% methane; and
(vi) methane tests at the mouth of the wing cut show that methane is less than 1.0%.
10. Once the Archveyor system is reenergized, the head of the continuous mining machine shall be raised to the roof to permit a reading through the ADS. If methane is less than 0.7%, the cutting drum of the continuous mining machine may be started and mining may resume.
11. A record shall be maintained in the mine pre-shift/on-shift record book of any concentration of methane over 1.5% occurring in an active wing cut along with the actions and time needed to clear the methane. The record shall be made available to representatives of the miners and MSHA.
12. A two-way communication system shall be maintained at all times between the section transformer/control cab area and a manned surface location. No wing cut shall be started unless such a communication system is operating properly.
13. The section transformer/control cab area shall be maintained in intake air and located at least 300 feet outby the wing cut.
14. Any incident involving a breakdown or hangup of the Archveyor system in a wing cut which is not resolved within 30 minutes shall be immediately reported to MSHA. The mine ventilation plan and roof control plan shall included general procedures for recovery of the Archveyor system should a breakdown or entrapment occur. The plans shall be supplemented as deemed necessary by the District Manager to address specific occurrences.
15. Prior to implementation, personnel assigned to the section where the Archveyor system operates shall be instructed in the requirements of this modification, specifically including the methane action levels of 0.7% and 1.5%, whether detected by the Trolex ADS-type methane detection devices or the 75.342 methane monitor. Within 60 days after this modification becomes final, the Petitioner shall submit any necessary proposed revisions for its approved 30 CFR 48 training plan to the District Manager. These revisions shall specify initial and refresher training regarding compliance with the conditions specified by this modification.
16. Prior to implementing this modification and beginning the initial wing cut, the Archveyor system shall be inspected by MSHA and determined to be in compliance with the terms and conditions of this modification. MSHA shall be given at least 5 working days notice to conduct the initial compliance inspection of the Archveyor system.
Any party to this action desiring a hearing on this matter must file in accordance with 30 CFR 44.14, within 30 days. The request for hearing must be filed with the Administrator for Coal Mine Safety and Health, 4015 Wilson Boulevard, Arlington, Virginia 22203.
If a hearing is requested, the request shall contain a concise summary of position on the issues of fact or law desired to be raised by the party requesting the hearing, including specific objections to the proposed decision. A party other than Petitioner who has requested a hearing shall also comment upon all issues of fact or law presented in the petition, and any party to this action requesting a hearing may indicate a desired hearing site. If no request for a hearing is filed within 30 days after service thereof, the Decision and Order will become final and must be posted by the operator on the mine bulletin board at the mine.
Robert A. Elam
Deputy Administrator
for Coal Mine Safety and Health