In the matter of PETITION FOR MODIFICATION
Nyrstar Tennessee Mines, Strawberry Plains LLC
Immel Mine
Mine I.D. No. 40-00170 Docket No. M-2025-001-M
PROPOSED DECISION AND ORDER
On January 7, 2025, Nyrstar Tennessee Mines, Strawberry Plains LLC filed a petition seeking modification of the application of 30 Code of Federal Regulations § 57.19073 at its Immel Mine located in Knox County, Tennessee. The petitioner alleges that the alternative method in the petition will at all times guarantee no less than the same measure of protection afforded to the miners by the standard.
The petitioned standard, 30 C.F.R § 57.19073 – Hoisting during shift changes, states,
Rock or supplies shall not be hoisted in the same shaft as persons during shift changes, unless the compartments and dumping bins are partitioned to prevent spillage into the cage compartment.
The petitioner is requesting a modification of the standard to allow use of the currently installed hoisting system at the mine to transport both materials and miners in the same shaft during shift changes.
MSHA personnel investigated the merits of the petition and filed a report of their findings with the Administrator for Mine Safety and Health Enforcement. After careful review of the entire record, including the petition and MSHA's investigative report, the Administrator issues this Proposed Decision and Order.
Findings of Fact and Conclusions of Law
MSHA investigated pertinent details of the Immel Mine on August 4, 5, 12, and 13, 2025. The investigation included an item-by-item review of the proposed petition and an onsite mine visit. During the onsite visit, the MSHA investigator verified that the proposed Petition for Modification (PFM) was posted on the mine’s bulletin board and explained the PFM process and all stipulations to the miners and supervisors.
The Immel Mine employs 133 miners and operates two 12-hour production shifts, 7 days per week. The mine extracts lead-zinc ore by blasting. Miners use front end loaders to load the material into haul trucks and transport the ore to a hopper. The ore is fed from the hopper into a chute. Locomotives are used to move the train cars under the chute where ore is loaded and then transported to the underground dump. From there, the ore is loaded into a skip hoist that transports the ore to the surface.
The hoist in place at the Immel Mine is an Ingersoll-Rand friction hoist and was installed and placed into service in July 1966. The friction hoist relies on balance for safe operation. Currently, the hoist follows the same design that was originally installed in 1966 with the addition of upgraded controls, electrical system, motor frequency drive, and motor. The shaft used to transport the ore to the surface is circular, unlined, 23 feet in diameter, and 1,642 feet deep. The shaft consists of three main lift cages (i.e. compartments) all in one large open shaft: an ore skip, a small personnel cage, and a larger personnel cage that also serves as a service cage. The ore skip and the larger personnel cage counterweight each other in the hoisting system.
The hoisting system in place at the Immel Mine was inspected, and hoisting procedures were observed. The observation of the hoisting procedures included the hoisting of miners in and out of the main shaft, as well as mine supplies, equipment, and ore. The testing of the hoisting operations by mine personnel was also observed.
MSHA’s investigation documented regular occurrence of rock spillage within the shaft requiring cleanup. Photographs of fallen rock at the bottom of the shaft and on top of the personnel cage were taken, and mine procedures were found to be in place for routinely addressing cleanup of spilled material at the bottom of the shaft. MSHA has also documented similar rock spillage and witnessed falling material during previous regular inspections at the mine. It appears the operator cannot stop rock from falling and hitting into the personnel cage during normal operations. This is because during dumping, the skip must open to unload and dump up to 30,000 pounds of varying sized rock at the dump level; and at that time, the personnel cage would be below the loaded skip, when some quantity of rock can and does fall down the shaft.
There was no Representative of Miners at the mine. During the investigation, MSHA interviewed miners involved in the operation and maintenance of the subject hoist, including production crew members, hoist men, hoist bull crew members, and mine management. Some of these miners were concerned about rocks crashing into them under both current operations and the submitted petition.
Title 30 C.F.R. § 44.11(a)(4) requires a mine operator, when a filing a petition, to provide “a concise statement of the modification requested.” Confusingly, Nyrstar does not. Instead of a modification, Nyrstar contends “that it is in compliance with this standard because the compartments and dumping bins are partitioned to prevent spillage into the cage compartment.” This contention makes Nyrstar’s petition unnecessary on its face. It is also wrong. Despite the fact that Nyrstar’s petition does not satisfy 30 C.F.R. § 44.11(a)(4)’s procedural requirement for a concise statement and Nyrstar’s assertion that it is in compliance with the standard, MSHA considered the merits of the petition, nevertheless.
The petitioned standard, 30 C.F.R § 57.19073, prohibits rock or supplies from being hoisted in the same shaft as persons during shift changes, unless the compartments and dumping bins are partitioned to prevent spillage into the cage compartment.
Nyrstar believes it is in compliance with 30 C.F.R § 57.19073 because, even though it wants to hoist rocks in the same shaft as miners during shift changes, there is an adequate partition. At bottom, Nyrstar relies on the notion that “[t]he Main Cage is enclosed in such a manner as to prevent any spillage from the Skip from entering into the Main Cage.” However, this is a narrow reading of the standard that misses the point. The standard’s purpose is not just to protect miners from spillage “entering into” the main personnel cage, but also to protect miners from spillage “into the cage” in the first place.
The word “into” in 30 C.F.R § 57.19073 is used to mean “to a position of contact with: against” as in “running into a wall”, or as in “rocks falling 1600 feet down a mine shaft before crashing into a miner.” This reading, consistent with past Agency practice, offers miners protection from two distinct hazards from falling rock: direct impact to the miners riding inside the personnel cage; and impact damage to the cage while occupied. Both hazards create serious safety risks to the miners inside the personnel cage and could lead to miners being injured or killed on the job. These hazards are especially concerning here given the documented regular occurrence of rock spillage within the shaft requiring cleanup and photographs of fallen rock at the bottom of the shaft and on top of the personnel cage.
Further, even under Nyrstar’s narrower reading of the standard, the operator has not provided engineering calculations or validation demonstrating that the proposed steel enclosure is adequate to protect miners against the hazards of rock spillage. Nyrstar only remarks that the cage is “fully covered.” However, there are no analyses showing that the largest credible piece of material hoisted in the skip, falling from the greatest expected height of the skip above the cage, would not penetrate or deform the enclosure. In short, they have not shown that rock spillage cannot enter into the main cage. Without such evidence, MSHA cannot determine that the enclosure would withstand worst-case impact loads, leaving miners exposed to the hazards described above. In sum, Nyrstar failed procedurally to provide a proposed modification of the standard and failed substantively to provide evidence to support its interpretation of the standard. Accordingly, MSHA cannot determine that Nyrstar’s proposed alternative method meets the statutory and regulatory requirement that the proposed method will at all times guarantee no less than the same measure of protection afforded by the standard.” 30 U.S.C. § 811(c); § 44.4(a)(1).
Nonetheless, during the investigation and observation of the hoisting procedures, MSHA determined that the request to hoist miners in the cage at the same time ore is being skipped is not operationally necessary. Information in the hoist manual and other reports indicates the separate four-man personnel hoist can transport all miners in a timely manner. Thus, with different crew scheduling and dispatch, all personnel could be moved in approximately 60 minutes using the four-man personnel hoist, whereas current procedures result in shift-change transport taking 2½ to 3 hours. These findings suggest that operational improvements, rather than modifying hoisting methods to carry personnel in the cage, can improve transportation efficiency while maintaining the safety afforded to miners required by the standard.
During the investigation, additional hazards were identified related to the balance of the friction hoist. Proper balance is fundamental to safe operation and depends on an accurate determination of the skip payload. MSHA found that Nyrstar’s current method for measuring the skip payload is inaccurate, which prevents reliable verification that the hoist is balanced and that the required safety factor is maintained. Mismeasurement of the skip payload can lead to slippage or unintended movement that would elevate risk to miners. The hoist must be used within the design capacity intended by the manufacturer to maintain proper tension and prevent slippage.
To provide an equal or greater level of protection than the standard, the alternative method must prevent spillage into the personnel cage, i.e., a position of contact with the cage. Such protection cannot be achieved unless falling rock is prevented from contacting the occupied personnel cage altogether. There are two primary ways to accomplish this:
• Operational separation, such that ore/rock is not hoisted or dumped while personnel are located anywhere in the shaft; or
• Physical partitioning of the shaft to prevent any falling material from the ore skip from reaching the personnel cage. Partitioning may be constructed using various methods such as concrete bulkheads or wire mesh panels or sheets.
Based on the findings discussed above, MSHA has made a substantive determination, even in the absence of a proposed alternative method of compliance or sufficient evidence provided by the petitioner, that the petition does not at all times guarantee no less than the same level of protection to the miners. Equivalent protection requires either ensuring that ore hoisting and dumping does not occur while personnel are present anywhere in the shaft, or installing a physical partition that prevents falling material from contacting the personnel conveyance.
On the basis of the submitted petition, MSHA’s investigation findings, and the foregoing reasons, Nyrstar Tennessee Mines is denied a modification of the application of 30 C.F.R. § 57.19073 at its Immel Mine.
ORDER
Wherefore, pursuant to the authority delegated by the Secretary of Labor to the Administrator for Mine Safety and Health Enforcement and pursuant to Section 101(c) of the Federal Mine Safety and Health Act of 1977, 30 U.S.C. § 811(c), it is ordered that Nyrstar Tennessee Mines, Strawberry Plains LLC’s Petition for Modification M-2025-001-M of 30 CFR § 57.19073 is hereby:
DENIED
Any party to this action desiring a hearing on this matter must file in accordance with 30 C.F.R. § 44.14 within 30 days. The request for hearing must be filed with the Administrator for Mine Safety and Health Enforcement, 200 Constitution Ave NW, Suite C3522, Washington, DC, 20210.
Any hearing request must contain a concise summary of position on the issues of fact or law to be raised by the party requesting the hearing, including specific objections to the proposed decision. A party other than the Petitioner who has requested a hearing may also comment on 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 of this Proposed Decision and Order, the Decision and Order will become final and must be posted by the operator on the bulletin board at the mine.
__________________________________
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 paid, or provided by other electronic means this day of to:
Donna V. Pryor
Attorney
Husch Blackwell LLP
1801 Wewatta Street, Suite 1000
Denver, CO 80203
Donna.pryor@huschblackwell.com
_____________________________________
Alexander Bullinger
General Engineer