# Petition for Modification of Application of Existing Mandatory Safety Standards
**AGENCY:**
Mine Safety and Health Administration, Labor.
**ACTION:**
Notice.
**SUMMARY:**
This notice is a summary of a petition for modification submitted to the Mine Safety and Health Administration (MSHA) by Mountain Coal Company, LLC.
**DATES:**
All comments on the petition must be received by MSHA's Office of Standards, Regulations, and Variances on or before May 4, 2026.
**ADDRESSES:**
You may submit comments identified by Docket No. MSHA-2026-0199 by any of the following methods:
1. *Federal eRulemaking Portal: https://www.regulations.gov.* Follow the instructions for submitting comments for MSHA-2026-0199.
2. *Fax:* 202-693-9441.
3. *Email: [email protected].*
4. *Regular Mail or Hand Delivery:* MSHA, Office of Standards, Regulations, and Variances, Room C3522, 200 Constitution Ave. NW, Washington, DC 20210.
*Attention:* Jessica D. Senk, Acting Director, Office of Standards, Regulations, and Variances. Individuals may inspect copies of the petition and comments during normal business hours at the address listed above. Before visiting MSHA in person, call 202-693-9440 to make an appointment.
**FOR FURTHER INFORMATION CONTACT:**
Jessica D. Senk, Office of Standards, Regulations, and Variances at 202-693-9440 (voice), *[email protected]* (email), or 202-693-9441 (fax). These are not toll-free numbers.
**SUPPLEMENTARY INFORMATION:**
Section 101(c) of the Federal Mine Safety and Health Act of 1977 and Title 30 of the Code of Federal Regulations (CFR) part 44 govern the application, processing, and disposition of petitions for modification.
**I. Background**
Section 101(c) of the Federal Mine Safety and Health Act of 1977 (Mine Act) allows the mine operator or representative of miners to file a petition to modify the application of any mandatory safety standard to a coal or other mine if the Secretary of Labor determines that:
1. An alternative method of achieving the result of such standard exists which will at all times guarantee no less than the same measure of protection afforded the miners of such mine by such standard; or
2. The application of such standard to such mine will result in a diminution of safety to the miners in such mine.
In addition, sections 44.10 and 44.11 of 30 CFR establish the requirements for filing petitions for modification.
**II. Petition for Modification**
*Docket Number:* M-2026-006-C.
*Petitioner:* Mountain Coal Company, LLC, 5174 Highway 133, Somerset CO 81434.
*Mine:* West Elk Mine, MSHA ID No. 05-03672, located in Gunnison County, Colorado.
*Regulation Affected:* 30 CFR 75.503 (18.35(a)(5)(i), Portable (trailing) cables and cords).
*Modification Request:* The petitioner requests a modification of the existing standard, 30 CFR 75.503 (18.35(a)(5)(i)), to allow the use of up to 1,100 feet of No. 2 AWG G-GC trailing cable supplying 995 volts AC to the Komatsu Shuttle Cars Model 10SC32. The petitioner also requests a modification of the existing standard, 30 CFR 75.503 (18.35(a)(5)(i)), to allow the use of 1,100 feet of No. 2 AWG-SHD-GC trailing cable supplying 995 volts AC to their mobile roof bolter.
The petitioner states that:
(a) Shuttle Cars
(1) On December 10, 1997, a petition under Section 101(c) of the Federal Mine Safety and Health Act of 1977 (Mine Act), 30 U.S.C. 811(c) and 30 Code of Federal Regulations (30 CFR) 44.11, *et seq.,* was issued to Mountain Coal Company, LLC, to modify 30 CFR 75.503. The petition became final on January 14, 1998. The petitioner requested a modification to the existing petition (Docket No. M-96-104-C) to allow the use of 1,100 feet of No. 4/0 AWG trailing cable for continuous miners at the mine. As a result, MSHA issued Docket No. M-2012-096-C, and revoked petition Docket No. M-96-104-C. On May 21, 2013, MSHA issued an Amended Proposed Decision and Order (PDO) granting the referenced petition for modification with sixteen (16) additional stipulations.
(2) On August 28, 2023, Mountain Coal Company, LLC, submitted a new petition to further amend the granted petition for modification. The mine had purchased four (4) Fletcher Mobile Roof Support machines (995 volts), Model MRS17, and was in the process of acquiring Komatsu 10SC32 Shuttle Cars. On March 3, 2025, a PDO was granted for trailing cables supplying three-phase power to 995 VAC trailing cables supplying the Fletcher Mobile Roof Support machines, Model MRS17, (MRS 2 s/n 2018902, MRS 3 s/n 2018903, MRS 5 s/n 2017913 and MRS 6 s/n 2017914) and the Komatsu Shuttle Cars. The petition was granted for the maximum lengths of 1,100 feet of No. 4 trailing cables for Mobile Roof Support Machines and 1,100 feet of No. 2 trailing cable for the shuttle cars used in West Elk Mine, subject to the terms and conditions of the PDO, which included the following provision: The maximum length of No. 4 AWG SHD-GC trailing cables supplying 995 volts AC to the Fletcher Mobile Roof Support Machines Model MRS17 shall be 1,100 feet. The maximum length of No. 2 AWG SHD-GC trailing cables supplying 995 volts AC to the Komatsu Shuttle Cars Model 10SC32 shall be 1,100 feet (Docket No. M-2023-027-C).
(3) West Elk Mine files this petition for modification to allow the use of up to 1,100 feet (maximum length) of No. 2 AWG G-GC trailing cable supplying 995 volts AC to the Komatsu Shuttle Cars Model 10SC32 in addition to the No. 2 AWG SHD-GC trailing cables. As stated above, West Elk Mine has previously been granted a PDO for the use of up to 1,100 feet (maximum length) of No. 2 AWG SHD-GC trailing cables supplying 995 volts AC to the Komatsu Shuttle Cars Model 10SC32.
(4) As shown in the short circuit analysis (using the minimum amount of current available and having the instantaneous overcurrent protection set at 800 amps), the use of 1,100 feet of non-shielded No. 2 trailing cable does not compromise miner safety nor does it adversely impact electrical protection of the cable. The goal of the fault analysis is to demonstrate that there is enough current available to trip the short circuit protection at the time of a fault. The fault study was prepared using the minimum amount of current available. The study used the maximum distances from the substation according to the current mining plan. The program used (Short-Circuit Version 6.03) for the study was provided by MSHA's Approval & Certification Center. As shown by the study, the 1,100 feet of No. 2 AWG G-GC non-shielded trailing cable with the instantaneous overcurrent protection set at 800 amps does not compromise the protection for the cable or the personnel. The non-shield No. 2 AWG G-GC cable provides a higher fault current than the shielded No. 2 AWG G-GC cable that is currently in the cable length petition.
(b) Mobile Roof Bolters
(1) On August 9, 1996, Mountain Coal Company, LLC, filed a petition under Section 101(c) of the Mine Act, 30 U.S.C. 811(c) and 30 CFR 44.11, et. Seq. seeking to modify 30 CFR 75.503. A PDO granting a modification of the application of the standard was issued on December 17, 1997, and the petition became final on January 14, 1998. The petition was granted modifying the application of 30 CFR 75.503 (18.35(a)(5)(i) of part 18), subject to the terms and conditions of the PDO, which included the following provisions: The maximum length of the trailing cable supplying three-phase, 995-volt, power to the mobile roof bolter shall not exceed 1,000 feet of No. 2 AWG, SHD-GC cable (Docket No. M-96-104-C).
(2) West Elk Mine files this petition for modification to include the use of 1,100 feet of No. 2 AWG-SHD-GC trailing cable for the mobile roof bolters, increasing the distance by an additional 100 feet.
(3) As shown in the short circuit analysis (using the minimum amount of current available and having the instantaneous overcurrent protection set at 800 amps), the use of 1,100 feet of No. 2 AWG SHD-GC trailing cable does not compromise miner safety nor does it adversely impact electrical protection of the cable. The goal of the fault analysis is to demonstrate that there is enough current available to trip the short circuit protection at the time of a fault. The fault study was prepared using the minimum amount of current available. The study used the maximum distances from the substation according to the current mining plan. The program used (Short-Circuit Version 6.03) for the study was provided by MSHA's Approval & Certification Center. As shown by the study, the 1,100 feet of No. 2 AWG SHDGC trailing cable with the instantaneous overcurrent protection set at 800 amps does not compromise the protection for the cable or the personnel.
(c) The alternatives will provide at least an equal measure of protection as the original standard.
The petitioner proposes the following alternative method:
(a) Shuttle Cars
(1) The maximum length of No. 2 AWG G-GC trailing cables supplying 995 volts AC to the Komatsu Shuttle Cars Model 10SC32 shall be 1,100 feet.
(2) All circuit breakers used to protect the No. 2 AWG G-GC trailing cables exceeding 700 feet in length for the 995-volt AC powered Komatsu Shuttle Cars Model 10SC32 shall have instantaneous trip units calibrated to trip at 800 amps. The trip setting of these circuit breakers shall be sealed or locked so that the setting cannot be changed, and these circuit breakers shall have permanent legible labels displaying the maximum short circuit setting. Calibration, sealing and labeling of circuit breakers shall be performed by the circuit breaker manufacturer or an authorized repair facility outfitted with calibrated test equipment. Each label shall identify the circuit breaker as being suitable for protecting No. 2 AWG G-GC cables. The labels shall be maintained legible.
(3) Replacement instantaneous trip units used to protect the No. 2 AWG G-GC trailing cables shall be calibrated to trip at 800 amps and this setting shall be sealed or locked. Calibration, sealing, and labeling of the replacement units shall be conducted by the device manufacturer or an authorized repair facility outfitted with calibrated test equipment.
(4) All components that provide short-circuit protection shall have a sufficient interruption rating in accordance with the maximum calculated fault currents available.
(5) The trailing cables for the Komatsu Shuttle Cars shall be protected by being hung on well-installed insulated hangers from the section transformer to the slack pile of the trailing cable for each machine or to the last open crosscut, whichever is further outby.
(6) Prior to putting the Komatsu Shuttle Cars in service for each shift, examinations by persons designated by the mine operator shall be made to visually examine the trailing cables to ensure that the cables are in a safe operating condition. The instantaneous settings of the specially calibrated circuit breakers shall also be visually examined to ensure that the peals or locks have not been removed and that they do not exceed the settings stipulated in items (2) and (4).
(7) Permanent warning labels shall be installed and maintained on the covers of each circuit breaker and the trailing cable disconnecting device indicating that the cable can only be connected to a circuit breaker that is set to trip at its predetermined instantaneous value. These labels shall warn miners not to change or alter these sealed short-circuit settings and warn them not to connect the trailing cable to an improperly adjusted circuit breaker.
(8) Any trailing cable that is not in a safe operating condition or damaged in any way shall be removed from service immediately and repaired or replaced. Each splice or repair in the trailing cables shall be made in a workmanlike manner and in accordance with the instructions of the manufacturer of the splice or repair materials. The splice or repair shall comply with 30 CFR 75.603 and 75.604.
(9) Excessive cable shall be stored behind the anchors on equipment that use cable reels to prevent cables from overheating. Trailing cable anchoring points located along haulage roads, belt tailpiece or feeder shall be arranged to prevent the shuttle cars from running over their trailing cables, to minimize the need for secondary (temporary) trailing cable anchoring points and minimize back spooling.
(b) Mobile Roof Bolters
(1) The maximum length of No. 2 AWG SHD-GC trailing cables supplying 995 volts AC to mobile roof bolter shall be 1,100 feet.
(2) All circuit breakers used to protect the No. 2 AWG, SHD-GC, trailing cables that exceed 700 feet in length and supply 995-volt, three-phase power to the mobile roof drill shall have instantaneous trip unit(s) calibrated to trip at 800 amps. The trip setting of these circuit breaker(s) shall be sealed, and these circuit breakers shall have permanent, legible labels. The label shall identify the circuit breaker(s) as being specially calibrated circuit breaker(s) and as being suitable for protection of No. 2 AWG, SHD-GC cables. This label shall be maintained legible.
(3) Replacement circuit breakers and/or instantaneous trip units, used to protect the 995-volt, No. 2 AWG, SHD-GC cables, shall be calibrated to trip at 800 amps and this setting shall be sealed.
(4) During each production shift, persons designated by the operator shall visually examine the trailing cables to ensure that the cables are in a safe operating condition and that the instantaneous settings of the specially calibrated circuit breaker settings stipulated in item (2) do not have seals broken or removed. A record of this examination shall be kept by the operator and made available to an authorized representative of the Secretary and to miners in this mine.
(5) Any trailing cable that is not in a safe operating condition shall be removed from service immediately and repaired or replaced.
(6) Each splice or repair in the trailing cables to the mobile roof supports shall be made in a workmanlike manner and in accordance with the instructions of the manufacturer of the splice or repair kit. The outer jacket of each splice or repair shall be vulcanized with flame-resistant material or made with material that has been accepted by MSHA as flame-resistant.
(7) In the event that the mining methods or operating procedures cause or contribute to the damage of any trailing cable, the cable shall be removed from service immediately, repaired or replaced and additional precautions shall be taken to ensure that, in the future, the cable is protected and maintained in a safe operating condition.
(8) Permanent warning labels shall be installed and maintained on the cover(s) of each circuit breaker and the trailing cable disconnecting device(s) indicating that the cable can only be connected to a circuit breaker that is set to trip at its pre-determined instantaneous value. These labels shall warn miners not to change or alter the sealed short-circuit settings and warn them not to connect the trailing cable to an improperly adjusted circuit breaker.
(c) The miners at West Elk Mine are not represented by a labor organization and the petition for modification is posted on the mine bulletin board as of January 21, 2026.
In support of the proposed alternative method, the petitioner has also submitted copies of previously granted PDOs (Docket No. M-2023-027-C and M-96-104-C) and copies of fault analyses.
The petitioner asserts that the alternative method will guarantee no less than the same measure of protection afforded the miners under the mandatory standard.
Jessica D. Senk,
Acting Director, Office of Standards, Regulations, and Variances.