APR 30 2020
In the matter of Petition for Modification
Wilson Creek Energy, LLC
Acosta Deep Mine
I.D. No. 36-09893 Docket No. M-2018-018-C
PROPOSED DECISION AND ORDER
On August 30, 2018 a petition was filed seeking a modification of the application of 30 CFR § 75.503 to Petitioner's Acosta Deep Mine located in Somerset County, Pennsylvania. The petitioner requested the modification to allow the use of trailing cables exceeding the length specified in 30 CFR § 18.35(a)(5)(i). The petitioner alleges that the alternative method proposed in the petition will at all times guarantee no less than the same measure of protection afforded by the standard.
30 CFR § 75.503 provides in part:
The operator of each coal mine shall maintain in permissible condition all electric face equipment required by §§75.500, 75.501, and 75.504 to be permissible which is taken into or used inby the last open crosscut of any such mine.
30 CFR § 18.35(a)(5)(i) provides in part:
(5) Ordinarily the length of a portable (trailing) cable shall not exceed 500 feet. Where the method of mining requires the length of a portable (trailing) cable to be more than 500 feet, such length of cable shall be permitted only under the following prescribed conditions:
(i) The lengths of portable (trailing) cables shall not exceed those specified in Table 9, Appendix 1, titled "Specifications for Portable Cables Longer than 500 Feet."
MSHA personnel conducted an investigation for the petition and filed a report of their findings with the Administrator for Mine Safety and Health Enforcement on May 15, 2019. After a careful review of the entire record, including the petition and MSHA's investigative report, this Proposed Decision and Order is issued.
Findings of Fact and Conclusions of Law
MSHA's investigation found that the mine is opened into the Middle Kittanning coal seam through four drift openings. The mine produces coal on two working sections using continuous mining machines and continuous haulage systems. The mine also has one non-producing section. The mine operates six days per week with two production shifts and one maintenance shift each day. The mine produces an average of 2,928 tons of raw coal daily and employs 91 persons underground. Coal is transported from the working sections to the surface by conveyor belts. A miners' representative is not appointed at the mine and the miners are not represented by a union.
In the normal course of mining, rooms are developed off of the mains or submains a distance of approximately 600 feet. The petitioner maintains that roof bolters do not have enough cable to reach the working faces in these areas of the mine under the current limit imposed by 30 CFR 18.35(a)(5)(i), and that this necessitates the installation of additional electrical distribution boxes. The mine utilizes the installation of additional distribution boxes (D-box) so that the roof bolting machines have enough cable to reach the faces. The mine currently complies with the maximum trailing cable lengths established by the provision.
The petitioner alleges that the alternate method will reduce the amount of cable handling associated with the installation of these additional distribution boxes, and that sprains and strains from cable handling are the most frequent injuries at the mine. The petitioner did not submit any accident and injury data to support this claim.
The alternate method proposed by the petitioner indicates that #2 AWG trailing cables with a maximum length of 1,100 feet will be used to provide 480-volt power to Fletcher Roof Ranger II roof bolters at the mine. The alternate method does not limit the use of extended length trailing cables to only those areas of the mine where rooms are developed off of the mains or submains. No information was provided to justify the need for extended length trailing cables in other areas of the mine.
The safety purpose of 30 C.F.R. § § 75.503 and 18.35(a)(5)(i) is to ensure that electric equipment will not cause a mine ignition, fire, or explosion which is taken into or used inby the last open crosscut of any such mine. Similarly, the petitioner's alternative proposal seeks to ensure that the extended trailing cables when used will not introduce an ignition, fire, or explosion hazard by limiting such use to situations in which a maximum trailing cable length is established, sealed instantaneous trip units are provided and calibrated within a plus or minus 10 percent trip tolerance, providing short circuit protection having sufficient interruption rating in accordance with the calculated fault currents available, more frequent examinations, removing unsafe conditions, making repairs and splices is a workman like manner, storing excess trailing cable, and training.
The alternate method states that circuit breakers protecting #2 AWG cables exceeding 700 feet in length will have instantaneous trip units calibrated to trip at 700 amperes. The petitioner attached a letter from Global Mine Services Inc., of Fayette City, Pennsylvania, indicating that the affected circuit breakers would be calibrated to trip at 700 amperes, with a+ /-10% tolerance. With the specified tolerance, the circuit breaker could be expected to trip at 630 to 770 amperes.
The petitioner provided a short circuit analysis which reported a minimum fault current of 784 amperes at the end of an extended length #2 AWG trailing connected to the mine power system. MSHA investigators also conducted a short circuit analysis (based on the projected workings of the mine provided by the petitioner), which showed a minimum fault current of only 764 amperes. The available fault current reported by the MSHA analysis was less than the maximum expected trip value (770 amperes) based on the specified tolerance.
MSHA investigators analyzed the power system at the affected mine using the short circuit program developed by the MSHA Approval and Certification. This program assigns a default trip tolerance of 30% to circuit breakers. This value has been used consistently by MSHA in short circuit calculations through the years to account for the uncertainty associated with the calibration and operation of circuit breaker trip units.
Maximum trailing cable lengths and circuit breaker settings are limited by 30 CFR Part 18 in order to ensure that fault current will not be limited to the extent that the circuit breaker will not trip when a short circuit occurs. If circuit breakers fail to trip when short circuits occur, cable damage and mine fires can be the result. Petitions proposing cable lengths or circuit breaker settings that exceed the maximums given in 30 CFR Part 18 must provide detailed information which clearly demonstrates that the available fault current is sufficient to trip the circuit breaker under all short circuit conditions.
Based on the information submitted by the petitioner and the investigation conducted by MSHA, it cannot determined with a reasonable degree of confidence that the affected circuit breakers will trip under all short circuit conditions with the proposed settings and cable lengths. The petition does not provide the same measure of protection for miners as required by the standard.
The petition does not provide an alternative method of compliance that will at all times guarantee no less than the same measure of protection to the miners. Since the proposed alternative method achieves neither the specific safety goal of the standard nor promotes other safety benefits associated with the standard, it must be rejected.
Therefore, on the basis of the petition and a review of the entire record, Wilson Creek Energy is not granted a modification of the application of 30 C.F.R. § 75.503, 18.35(a)(5)(i) to its Acosta Deep 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, § 811(c), it is ordered that Wilson Creek Energy's Petition for Modification of the application of § 75.503 in the Acosta Deep Mine is hereby:
Denied, for the use of #2 AWG extended length trailing cables supplying power to 480-volt roof bolters at the mine.
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, 201 12th Street South - Suite 401, Arlington, Virginia 22202-5450.
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 may 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.
/s/
Timothy R. Watkins
Administrator for
Mine Safety and Health Enforcement
Certificate of Service
I hereby certify that a copy of this proposed decision was served personally or mailed, postage prepaid, or provided by other electronic means this 30th day of April 2020, to:
R. Henry Moore
Attorney for Wilson Creek Energy, LLC
Fisher & Phillips LLP
Six PPG Place
Suite 830
Pittsburgh, PA 15222
hmoore@fisherphillips.com
Robert Bodenschatz Director of Safety
1576 Stoystown Rd.
Friedens, PA 15541
bbodenschatz@corsacoal.com
/s/
Rodney Adamson
Mine Safety and Health Specialist
cc: Mr. Richard A. Wagner, P.E., Acting Director, Bureau of Mine Safety, PA Dept. of Environmental Protection, 131 Broadview Road, New Stanton, PA 15672; rwagner@pa.gov