In the matter of Petition for Modification
Consolidation Coal Company
Shoemaker Mine
I.D. No. 46-01436 Docket No. M-1999-119-C
PROPOSED DECISION AND ORDER
On October 28, 1999, a petition was filed seeking a modification of the application of 30 CFR 75.312(c) and (d) to Petitioner's Shoemaker Mine located in Marshall County, West Virginia. On April 18, 2000, the Petitioner filed an amendment to include the petitioner's Dupont blowing fan within the scope of the request. The Petitioner alleges that the proposed alternative method will at all times provide the same measure of protection as the standard.
MSHA personnel conducted an investigation of the petition, including the amendment, and filed reports 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, comments and MSHA's investigative reports and recommendations, this Proposed Decision and Order (PDO) 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 75.312(c) and (d). These provisions require a fan shutdown to test the automatic fan stoppage signal device [75.312(c)] and to determine that air-reversal-prevention doors will automatically close when the fan shuts down [75.312(d)]. These tests are required to take place at least every 31 days. Only persons necessary to evaluate the effect of the fan stoppage or restart, or to perform maintenance or other repair work that cannot otherwise be made while the fan is operating, are permitted in the mine.
The petitioner proposes an alternate method of performing the tests without shutting down the fan(s) and without removing the miners from the mine. The petitioner's alternate method will result in the fan alarm signal being verified by a responsible person at the mine dispatcher’s station. Also, the test for automatic closing of the air flow reversal prevention door will be visually observed by the mine personnel performing the test. A report of all tests will be recorded.
According to the MSHA report of investigation for the petition for modification, Shoemaker Mine is a large mine with a complex ventilation system consisting of eight (8) main fans, seven with exhaust and one operating with blowing ventilation. Each fan is equipped with a pressure recording gage and an automatic signal device designed to give an alarm should the fan slow. All exhaust fans are equipped with automatic closing doors to prevent the reversal of air into the mine upon shutdown of the fan. The blowing fan is not equipped with air reversal prevention doors. The petitioner alleges that any delay of a fan restart, after shut down for testing, beyond 15 minutes could result in a lengthy restarting of the mine operating system.
MSHA's investigation of the petitioner's alternate method for compliance with 75.312(c) revealed that the automatic signal activation device for detecting fan stoppage for each exhaust fan is provided with a fan alarm signal system consisting of a mechanical switch. The switch is mounted to the fan housing and designed to activate a relay in the fan monitoring panel when the air reversal prevention door is in the closed position.
The Dupont blowing fan, which is not provided with a automatic closing door, is provided with a fan alarm signal system consisting of a pressure recorder designed to activate a relay in the fan monitoring panel when the operating pressure decreases below a set value. When the fan is operating, the mine air pressure differential, as measured between the inby side of the fan and the atmosphere, prohibits the activation of the signal device.
When a measurable change in the air pressure differential takes place, the fan alarm signal activates.During testing of the fan stoppage signal device, by shutting down the fan as required by 75.312(c), a measurable pressure differential is created. However, in the petitioner's alternate method, the measurable pressure differential is artificially created by mechanically operating (opening) a valve, located in the fan recording chart air line. When a reduced air pressure differential is created by opening the valve, activation of the fan stoppage alarm signal device takes place.
For both the blowing and exhaust fans, when the fan stoppage signal system is tested, a warning light, located near the pressure recorder or the mechanical switch, is visible to personnel performing the fan signal test. In addition, a audible fan signal alarm, sounding at the dispatcher station, verifies the performance of the fan alarm signal system at a location where a responsible person is on duty whenever miners are in the mine and provided with two way communication to working sections and work stations.
It is essential that a mine with multiple ventilation fans be equipped with air flow reversal prevention doors on each fan to prevent the air in entries from reversing direction in the event of a fan stoppage. 75.312(d) requires a fan shutdown at least every 31 days, at mines with multiple fans, to ensure that the air flow reversal prevention doors will close automatically in the event of a fan stoppage. The investigation revealed that multiple exhaust air fans at the Shoemaker Mine are equipped with solid metal air flow reversal prevention doors, which are suspended from hinges on the top most vertical location. With the fan operating, the door is held open by the air velocity (force) blowing from the mine fan. In the event of a fan stoppage, the force of gravity causes the door to close to a vertical position, which blocks the air entrance of the mine, thereby eliminating air flow reversal.
The petitioner proposes a alternate method in lieu of a fan shutdown to ensure the air flow reversal prevention doors on exhaust fans will close in the event of a fan stoppage. A series of engineering drawings has been submitted by the petitioner which explains the physical and mechanical construction of the fan doors used in the alternative method test procedure. The alternate method uses an air flow reversal prevention door and a substantially constructed moveable test frame assembly. The test frame assembly is hinged using the same bearing and shaft assembly as the solid metal air flow reversal prevention door. The normal location of the frame assembly is fastened against the end of the fan housing. Petitioner's alternative test method consists of manually causing the test frame assembly to move to the horizontal position (operation position) of the door while the fan is in operation. Since the test frame and air flow reversal prevention door both use the same horizontal bearing support shaft for bearing attachment, the test will verify that the solid air reversal prevention door will, in fact, close in the event of a fan stoppage. If the test frame will move to the door and form a tight fit, then the door will close against the fan housing during an actual fan stoppage and form a tight fit since the air velocity (force) which holds the door open will be eliminated.
Personnel from the Mine Safety and Health Administration, Technical Support Division, participated in the investigation and filed a report for the Dupont fan. This is a blowing fan and is not equipped with a air flow reversal prevention door. Technical support reported that should a stoppage of the Dupont fan occur, mechanical ventilation pressures created by any remaining operating exhausting fan(s) would not reverse the direction of the airflow through the stopped Dupont fan. It was also concluded by Technical Support personnel, that should another blowing ventilation fan be connected to this multiple fan ventilation system, air flow reversal doors may be needed to ensure airflow would not reverse through the stopped blowing fan due to mechanical ventilation pressures created by the remaining operating blowing fan.
MSHA's Technical Support personnel also evaluated the Dupont fan automatic fan shutdown signal system. They concluded that the difference between the fan operating pressure and the pressure recorded during the fan stoppage should be large enough in magnitude that the accuracy of the pressure detecting instruments or the normal fluctuations in the fan's operating pressure is insignificant. The closer the activation pressure is to the operating pressure, the greater the degree of assurance the alarm would be activated upon fan stoppage. However, the difference should not be so small that normal fluctuations in the fan's operating pressure would result in nuisance alarms. In addition, the use of the evaluated method of testing the fan signal device would be unacceptable in situations in which the accuracy of the pressure detecting instruments or normal fluctuations in the fan's operating pressure were significant compared with the difference between the fan operating pressure and the pressure recorded during the fan stoppage. The report concluded that the preset activation pressure for the fan signal device appeared to be adequate for detection of a fan stoppage, however an actual fan stoppage of the Dupont fan should be conducted following any significant change in the operating pressure of the Dupont fan. This stoppage will continue to ensure the appropriateness of the preset activation pressure for the fan signal device.
On the basis of the petition, the findings of MSHA's investigations, and the recommendations of MSHA, Consolidation Coal Company is granted a modification of the application of 30 CFR 75.312(c) & (d) to its Shoemaker 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, 30 U.S.C., sec. 811(c), it is ordered that Consolidation Coal Company's Petition for Modification of the application of 30 CFR 75.312(c) & (d) in the Shoemaker Mine is hereby:
GRANTED, for tests of (1) the automatic fan stoppage signal device and (2) the automatic closing air flow reversal prevention doors to be performed without shutting down the mine fan, without removing the miners from the mine, and conditioned upon compliance with the following terms and conditions:
1. Exhaust fans subject to this PDO shall be equipped with a specially equipped fan door assembly consisting of an open test frame and a solid air flow reversal prevention door. The test frame shall be attached to a rotatable shaft and latched to the fan housing during normal operation.The air flow reversal prevention door shall be attached by bearing sets to the shaft supporting the test frame and shall be rotatable around the shaft. The air flow reversal prevention door shall be held open during normal fan operation. The test frame shall be latched against the fan housing when not being used for testing.
2. The air flow reversal prevention door(s) shall be tested at least every 7 calendar days for one year from the date inspected by MSHA under Paragraph 10 of the PDO by rotating the test frame outward from its latched position until it contacts the air flow reversal prevention door (Initial Test Period). Rotation of the test frame shall also rotate the shaft and bearings hinging the air flow reversal prevention door.
3. The person(s) conducting the test must be able to visually observe the movement of the test frame and to visually observe the rotation of the attached shaft. After the Initial Test Period, all parties shall evaluate the door and frame test system, and unless a major problem with the system is determined by MSHA, the test frequency shall change, to at least every 31 days. The person(s) conducting the testing shall observe the contact between the test frame and the air flow reversal prevention door to determine that a proper fit exists. Also, the person(s) shall observe the general maintenance of the metal door and frame for good repair.
4. The air flow reversal prevention door(s) shall be tested every five to seven months by stopping the fan motor(s) to ensure the door(s) automatically close when the fan shuts down.
5. Each exhaust mine fan subject to this PDO shall be provided with a fan alarm signal system consisting of a mechanical switch. The switch shall be mounted to the fan housing. Testing of the mechanical switch shall be performed by actuating the switch to verify that it activates a relay in the fan monitoring panel. This switch actuation shall occur by moving the test frame assembly so that it contacts the fan signal switch. The relay shall activate a warning light near the door location, which is visible to person(s) performing the testing, and shall provide an alarm which is audible and visual at the dispatcher station. A responsible person shall always be on duty at the dispatchers station when miner(s) are underground and have two way communication with working sections and work stations. A magnetic switch may be used if tested and approved in advance by MSHA's District Manager.
6. The Dupont blowing fan which is not equipped with an automatic closing door, shall be provided with a fan alarm signal system consisting of a pressure recorder designed to activate a relay in the fan monitoring panel when the operating pressure decreases. The preset value for activation of the signal shall be such that the alarm is activated before the operating pressure decreases below 50 percent of the difference between the normal operating pressure and the pressure at which the recorder measures when the fan is stopped. An actual test by stopping the fan shall be conducted to determine the continued appropriateness of the preset activation pressure following any change to the pressure recorder or a change which exceeds 20 percent of the normal fan operating pressure.
The automatic fan signal system shall be tested by opening a valve located in the air pressure line to the pressure recorder and observing the movement of the pressure recorder tracing arm. The relay shall activate a warning light near the recorder location, be visible to the person(s) performing the testing, and provide an alarm which is audible and visual at the dispatcher station. A responsible person shall always be on duty at the dispatcher’s station when miner(s) are underground and have two way communication with working sections and work stations.
7. After an Initial Test Period of testing once every 7 days and tests being performed for one year, all parties shall evaluate the mechanical fan signal device setup and the blowing fan pressure recording fan signal device setup, and unless a major problem with the system(s) is determined by MSHA, the test frequency shall change to at least every 31 days.
8. The activation of the fan signal(s) shall be verified by a responsible person.
9. The automatic fan signal device and signal alarm shall be tested every five to seven months, by stopping the fan motor(s), to ensure that the automatic signal alarm device(s) causes the signal alarm to activate, when the fan shuts down.
10. The petitioner shall notify the MSHA District Manager when each exhausting fan is equipped with the test frame and air flow reversal prevention door for the exhaust fan(s) and the appropriate fan alarm signal system for the blowing fan and exhaust fan(s) so that an inspection will be scheduled prior to conducting the 7 day testing as allowed by this PDO. The test procedure(s) shall be demonstrated and the fan(s) shall be shut down during this MSHA inspection to verify that the air flow reversal prevention door(s) close and the appropriate automatic fan signal alarm systems activate at the dispatchers station. Upon completion of the above inspection and with the approval of MSHA, the Initial Test Period shall commence for each installation.
11. Until all the mine fans are equipped in compliance with the PDO, the miners must be removed from the mine for the testing of any fan not yet equipped as per the PDO.
12. By the end of the shift on which the test of the automatic fan signal devices and/or the automatic closing of the air flow reversal prevention door is completed, person(s) performing the test(s) shall record the result of the test(s) in a secure book. The record book shall be retained at a surface location at the mine for at least one year and shall be made available for inspection by an authorized representative of the Secretary and the representative of the miners. Such recording shall also indicate the general repair of the system.
13. Prior to the installation of another blowing fan added to the ventilating system for the Shoemaker Mine, MSHA shall be notified. The alternative method will be re-investigated at that time by MSHA to determine whether the PDO needs to be amended to require air reversal prevention doors on the blowing fan(s), or revocation proceedings initiated. Another blowing fan could cause airflow to reverse through the stopped blowing fan due to mechanical ventilating pressures created by the remaining operating blowing fan.
14. Within 60 days of the PDO being granted, the Petitioner shall submit proposed revisions for its approved 30 CFR 48 training plan to the MSHA's District Manager. These proposed revisions shall include initial and refresher training regarding compliance with the PDO. Also, miners who are to perform the tests under the PDO must be specifically trained on the proper method of testing upon his or her initial assignment to these responsibilities and at least annually thereafter.
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.
Michael J. Lawless
Deputy Administrator
for Coal Mine Safety and Health