In the matter of Kedco, Inc.
No. 2 Mine
l.D. No. 46-08019
Petition for Modification
Docket No. M-96-20-C
Date Issued: 0312211997
PROPOSED DECISION AND ORDER
On March 1, 1996 a petition was filed seeking a modification of the application of 30 CFR 75.350 to Petitioner's No. 2 Mine, located in Mingo County, West Virginia. The Petitioner alleges that the alternative method outlined in the petition will at all times guarantee no less than the same measure of protection afforded by the standard.
MSHA personnel conducted an investigation of the petition and filed a report of their findings and recommendations with the Administrator for Coal Mine Safety and Health. After a careful review of the entire record, including the petition, MSHA's investigative report and recommendation, and the Petitioner's subsequent agreement to seven items contained in the investigation report, this Proposed Decision and Order is issued.
Finding of Fact and Conclusion of Law
The alternative method proposed by the Petitioner (as amended by the recommendations of MSHA) will at all times guarantee no less than the same measure of protection afforded the miners under 30 CFR 75.350.
On the basis of the petition and the findings of MSHA's investigation, Kedco Incorporated is granted a modification of the application of 30 CFR 75.350 to its No. 2 Mine.
Wherefore, pursuant to the authority delegated by the Secretary of Labor to the Administrator for Coal Mine Safety and Health, and pursuant to Section lOl(c) of the Federal Mine Safety and Health Act of 1977, 30 U.S.C., sec. 811(c), it is ordered that Kedco Incorporated's Petition for Modification of the application of 30 CFR 75.350 in the No. 2 Mine is hereby:
GRANTED, to allow air coursed through conveyer belt entries to be used to ventilate working places, conditioned upon compliance with the following terms and conditions:
An early warning fire detection system (Carbon monoxide monitoring system) shall be installed as follows:
(a) The carbon monoxide monitoring system shall be installed in all belt entries utilized to course intake air to a working place.
Sensors shall be installed near the center and in the upper third of the belt entry in a location that would not expose personnel working on the system to unsafe situations. Sensors shall not be located in intersections, abnormally high areas or in other areas where airflow patterns do not permit products of combustion to be carried to the sensors.
Sensors shall be installed between 50 and 100 feet downwind of each belt drive, drive/belt take-up combination, and at each tailpiece at a location to prevent damage from mobile equipment, and at intervals not
to exceed 1,000 feet along each conveyor belt entry.
Where a belt drive discharges onto a belt conveyor tailpiece as a continuation of a belt conveyor haulage system, and the belt drive, belt takeup and belt tailpiece are on the same split of air, only one carbon monoxide sensor shall be required at this location. Where the belt haulage system changes direction, if the receiving conveyor belt tailpiece is located outside the rib line of the dumping belt entry, an additional sensor shall be required at the tailpiece.
Sensors shall be installed not more than 100 feet downwind of all electrical installations and any equipment or location in the conveyor belt entry where a potential fire source exists.
The early warning fire detection system shall be designed and maintained as follows:
The carbon monoxide monitoring system shall be capable of providing both visual and audible signals. A visual or audible alert signal shall be activated when the carbon monoxide level at any sensor reaches the level determined in condition 4. An audible and visual alarm signal distinguishable from the alert signal shall be activated when the carbon monoxide level at any sensor reaches the alarm level determined in condition 4.
Audible and visual alarm devices used on the sections shall be of the permissible type if installed in areas where permissible equipment is required. Alarm devices shall give visual and audible signals that can be seen and heard on the working sections and at a location on the surface of the mine where a responsible person(s) is on duty at all times when miners are underground. Alert devices shall give visual or audible signals that can be seen or heard at such surface location.
The carbon monoxide monitoring system shall activate alarm signals at the working section(s) and alert and alarm signals at a location on the surface of the mine where a responsible person(s) is on duty at all times when miners are underground.
Sensors located from the mouth of the section to the section loading point shall activate section alarms if the alarm level is reached. During the initial development of a section, all sensors for a distance of 4,000 feet outby the section loading point shall activate the section alarm if carbon monoxide reaches the established alarm levels. The distance outby the mouth of the panel may be decreased proportionately as the section advances to a total of 4,000 or more feet; at such time, the sensors outby the mouth of the panel shall not be required to activate the section alarm.
The carbon monoxide monitoring system shall be capable of monitoring electrical continuity and detecting electrical malfunctions such as open-circuits, short-circuits, ground-faults and, where appropriate, pneumatic malfunctions in the system.
The carbon monoxide monitoring system shall be capable of identifying any activated sensor(s).
The carbon monoxide monitoring system shall be capable of giving warning of a fire for a minimum of 4 hours after the source of power to the belt is removed as required by 30 CFR 75.1103-4(e). When power is removed due to fan(s) stoppage, the carbon monoxide monitoring system shall be deenergized if not intrinsically safe as required by 30 CFR 75.313(e).
The carbon monoxide monitoring system shall limit time delay periods to not more than a total of 180 seconds for the alert and alarm. Ifused, time delays shall be specified in the mine ventilation plan. Time delays shall only be used in mines using diesel equipment.
Velocity in the belt conveyor entry.
(a) The air in the belt conveyor entry shall have a velocity of at least 50 feet a minute and have a definite and distinct movement in the designated direction.
https://arlweb.msha.gov/PETI TIONS/M96020C. htm 216
(b) Velocity measurements shall be determined at locations in the entry which are representative of the cross sectional areas found throughout the entry and not at locations where the entry is abnormally high (e.g. belt drives) or low (e.g. under overcasts).
Determination of the carbon monoxide alert, alarm, and ambient levels in the conveyor belt entry.
The alert and alarm settings for the mine shall be determined by adding the ambient level to the levels established from Tables 1 - 6 which are attached and incorporated into this Proposed Decision and Order.
The carbon monoxide alert and alarm level can be different for various areas in the mine. For example, settings in the main conveyor belt entries could be lower than settings in mechanized mining sections due to larger air quantities. The number of carbon monoxide alert and alarm settings used shall be minimized and may be limited by the District Manager to maintain system effectiveness.
Alert and alarm settings can also be different development, retreat, longwall set-up and longwall removal.
Ambient levels can be different for various areas of the mine. When different ambient levels are determined for distinct portions of the mine, either the lowest ambient level can be utilized throughout the mine or the carbon monoxide monitoring system can be divided into distinct areas that utilize the ambient level determined for each area. The ambient level shall be determined under normal mining conditions as follows:
A properly calibrated carbon monoxide sensor(s) shall be used for an ambient determination. Measurements from one sensor can be used to determine the level in the conveyor belt entry for each separate conveyor belt airsplit not exceeding 10,000 feet in length. For airsplits longer than 10,000 feet in length, additional sensors shall be used so that at least one sensor is used for each additional 10,000 feet or part thereof. Hourly readings shall be taken and recorded for a total of five (5) production shifts to establish a mine history of carbon monoxide levels. The average of the data collected for each separate conveyor airsplit will determine its ambient level.
Ambient levels shall be representative of normal operating conditions. Diesel equipment shall not be unnecessarily idled in the air split where the ambient level is being determined.
The cross-sectional areas used for alert and alarm level determination from the Tables shall be measured at locations in the entry representative of the cross-sectional areas found throughout the entry and not at locations where the entry is abnormally high (i.e. belt drives) or low (i.e. under overcasts). For belt entries that are common with other entries, the sum of cross-sectional areas for belt entries and the common entries shall be used.
Where the representative total cross sectional area of the belt entry and the common entry exceeds the 240 square feet, the alert and alarm levels shall be determined from Table 6 for air quantities up to 202,000 cubic feet per minute (cfm). Air quantities greater than 202,000 cfm cannot be used.
Iftwo or more entries are common with the belt entry, a study of the effects of diffusion and/or dilution of carbon monoxide shall be conducted to establish appropriate alert and alarm levels.
The operator shall cooperate and participate with MSHA in conducting a systematic evaluation of the effects of multiple common entries upon the diffusion of carbon monoxide and the appropriate alert and alarm levels for an early warning fire detection system. The operator will provide a controlled environment for the study by establishing and maintaining air quantities, controlling equipment activity, and maintaining ventilation controls of the test area. Significant ventilation changes in the test area shall not be made without prior agreement with MSHA personnel involved in the evaluation.
Until the study is completed and the report is finalized, interim alert and alarm levels in the area(s) affected
by the tests shall be taken from Table 6 for the appropriate air quantity. During such time, the air quantity in the belt and common entries shall not exceed 202,000 cubic feet per minute.
Upon completion of the test(s) and final report, the mine ventilation plan shall be revised to show the appropriate sensors spacing, alert levels, and alarm levels which have been determined in the test. Sensor spacing may be less than 1,000 feet and the alert and alarm levels may be less than the interim levels taken from Table 6, as shown to be appropriate by the test.
Should the test results show that a carbon monoxide monitoring system cannot provide early warning fire detection, within the belt and common entries, this Proposed Decision and Order shall be amended or revoked as applicable.
The air quantity used for the sensor level determination from the Tables shall be the sum of the air quantity measured or planned to be used in the belt conveyor entry and any common entry(s). The determination shall be made at locations representing the greatest volume of air in the entry(s).
The carbon monoxide alert and alarm levels and the ambient level(s) determined in condition 4 shall be submitted to the District Manager for verification and shall be included in the mine ventilation plan. The District Manager is authorized to require reevaluation of alert, alarm, and ambient levels if conditions change. Ifchanges in conditions affect the alert, alarm or ambient level, the mine ventilation plan shall be revised to reflect such changes.
When the carbon monoxide monitoring system gives a visual or audible alert signal, all miners in the working sections on the same split of air shall be notified immediately and an investigation shall be conducted to determine the cause of the actuation. When the carbon monoxide system gives an audible and visual alarm signal, all miners in the same split(s) of air shall be withdrawn immediately to a safe location at least one sensor outby the sensor(s) activating the alarm, unless the cause is known not to be a hazard to the miners. When the carbon monoxide warning system gives an audible and visual alarm signal at shift change, no one shall be permitted to enter the mine except qualified persons designated to investigate the source of the alarm. Ifminers are enroute underground, they shall be held at, or be withdrawn to, a safe location, at least one sensor outby the sensor(s) activating the alarm. When a determination is made as to the source of the alarm, and that the mine is safe to enter, the miners shall be permitted underground. The mine evacuation plan required by 30 CFR 75.110123(a) shall be revised to specify the actions to be taken for alert and alarm signals. Such revisions shall be approved by the District Manager. A record of each alert and alarm signal given, and the action taken shall be maintained at the mine for a period of one year.
Personnel stationed at the surface location described in condition 2 shall have two-way communications with all working sections. When the established alert and alarm levels are reached, such persons shall notify all working sections and other locations where personnel are normally assigned to work (e.g. belt transfers). Personnel stationed at the surface location shall also be trained in the operation of the carbon monoxide monitoring system and in the proper procedures to follow in the event of an emergency or malfunction and, in that event, shall take appropriate action immediately.
The carbon monoxide monitoring system shall be examined visually at least once each shift. The monitoring system shall be inspected at intervals no exceeding seven (7) days to ensure that the system is operating properly. The monitoring sensors shall be calibrated with known concentrations of carbon monoxide and air
mixtures at intervals not to exceed 31 calendar days. An inspection record shall be maintained on the surface and made available to all interested persons. The inspection record shall show the date and time of each weekly inspection and monthly calibration and all maintenance performed, whether at the time of the weekly inspection or otherwise.
Ifat any time the carbon monoxide monitoring system or any portion of the system required by this Proposed Decision and Order has been deenergized for reasons such as routine maintenance or failure of a sensor unit, the belt conveyor may continue to operate provided the miners in the affected working section are notified and the
affected portion of the belt conveyor entry is continuously patrolled and monitored for carbon monoxide in the following manner until the affected monitoring system is returned to normal operation:
The patrolling and monitoring must be conducted by a person or persons trained in the mine evacuation plan, the operation of a handheld carbon monoxide detection device, use of the two-way communication device provided, and the following procedures:
The trained person(s) performing monitoring shall be provided with a two-way communication device enabling the person(s) to communicate with the surface;
Each of these trained persons shall be provided with a handheld carbon monoxide detection device. A carbon monoxide detection device shall also be available for use on each working section.
Ifone sensor becomes inoperative, the trained person shall monitor at that sensor location;
Iftwo or more adjacent sensors become inoperative, a trained person shall patrol and monitor the area affected; and
Ifthe complete system becomes inoperative, a sufficient number of trained person(s) shall patrol and monitor the affected entries of the mine so that the affected entries will be traveled once each hour in their entirety.
The procedure outlined above is applicable only for a short period of time that is to be determined by the reasonable amount of time required to repair or replace the equipment causing the malfunction. The mine operator shall begin corrective action immediately and continue until the defective equipment causing the malfunction is replaced or repaired. The responsible person on the surface shall immediately establish two-way communication with the working section(s) and notify them of the particular malfunction(s) or problem.
The details for the early warning fire detection system including, but not necessarily limited to, type of monitor, specific sensor location on the mine map, and the alert and alarm levels shall be included as a part of the mine ventilation plan required by 30 CFR 75.370. The District Manager may require additional carbon monoxide sensors to be installed as part of said plan to ensure the safety of the miners.
The concentration of respirable dust in the intake air coursed through a belt conveyor haulageway shall not exceed 1.0 mg/m3. Compliance with this requirement will be determined by establishing a designated area (DA) sampling location within 15 feet outby the working section belt tailpiece and sampled in accordance with 30 CFR 70.208. The specific DA sampling location shall be identified in the mine ventilation plan with a four-digit number beginning with 8, followed by the middle two digits of the MMU number, and ending with 9 (i.e., 8119 for MMU OllO).
A new conveyor-belt flammability test has been developed by MSHA. When compatible belting identified by MSHA as having passed the new flame-resistant test becomes commercially available, all subsequent belt purchases shall be of this improved type belting.
Intake escapeways shall be maintained free of potential fire sources, such as diesel-powered, battery powered, and electrical equipment, unless such sources are equipped with a fire suppression system installed and maintained in accordance with the applicable provisions of 30 CFR 75.ll07-3 through 75.ll07-16.
The integrity of the atmosphere in the primary escapeway shall be protected during mine layout and design. Factors such as location of the primary escapeway with respect to the belt and return aircourses, the number of entries within each aircourse, and the projected ventilating air quantities and pressures shall be considered. In areas of the mine developed after the effective date of this Proposed Decision and Order, the system shall be designed such that aircourse containing the conveyor belt carries less than half of the air for section ventilation and, to the extent practical, the pressure differential shall be maintained from the primary escapeway to the belt entry aircourse. Air measurements shall be made at the locations specified in 30 CFR 75.364 (c)(l). Wherever the pressure differential is from the belt entry aircourse to the primary escapeway, special care shall be taken to miniized leakage. This shall include the repair and sealing of ventilation controls as needed. The design of the system shall be specified in the mine ventilation plan.
15. Before belt haulage entries are used to ventilage working places, miners shall be trained in proper evacuation procedures, including instruction and drills in evacuation and instruction precautions to be taken for esacape through smoke.
16. Prior to implementing the alternative method, the early warning fire detection system shall be inspected by MSHA and be fully operational and in compliance with the terms and conditions of this Proposed Decision and Order.
17. Within 60 days after this Proposed Decision and order becomes final, the Petitioner shall submit proposed revisions for its approved 30 CFR Part 48 training plan to the District Manager. These proposed revisions shall specify initial and refresher training regarding compliance with the conditions specified by the Proposed Decision and Order.