| In the matter of McElroy Coal Company McElroy Mine I.D. No. 46-01437 | Petition for Modification Docket No. M-97-101-C |
On September 5, 1997, a petition (M-97-101-C) was filed seeking a modification of the application of 30 CFR 75.312(c)to Petitioner's McElroy Mine located in Marshall County, West Virginia. A petition (M-97-112-C) was also filed seeking a modification of the application of 75.312(d) to the petitioner's McElroy Mine on September 12, 1997. The Petitioner alleges that, for both petitions, the proposed alternative methods will at all times provide the same measure of protection as the standard. On December 16, 1998, the Petitioner filed an amendment to mount a mechanical or magnetic switch such that air reversal door closure operates a relay to activate a light and initiate a signal at a location on the surface when the fan slows or stops. The Administrator has elected to dismiss Docket No. M-97-112-C and has combined petitioner's request to modify 75.312(d) with the request to modify 75.312(c) in Docket No. M-97-101-C.
MSHA personnel conducted investigations of the petitions, including the December 16, 1998, 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 petitions, comments and MSHA's investigative reports and recommendations, this Proposed Decision and Order (PDO) is issued.
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)&(d). These provisions require a fan shutdown to test the automatic fan stoppage signal device and to determine that air-reversal-prevention doors will automatically close when the fan shuts down. 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 main office communication center. Also, the test for automatic closing of the air reversal prevention doors 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 McElroy Mine is a large mine with a complex ventilation system consisting of six (6) main fans with exhaust ventilation. Any delay of a fan restart, after shut down for testing, beyond 15 minutes could result in a lengthy restarting of the mine operating systems.
MSHA's initial investigation of the petitioner's alternate method for compliance with 75.312(c) revealed that the automatic signal activation device for detecting fan stoppage is installed in such a way that 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 as required by 75.312(c), a measurable pressure differential is created by shutting down the fan. However, in the petitioner's alternate method, the measurable pressure differential is created by mechanically operating (closing) a valve, located in the fan recording chart air line. When a reduced air pressure differential is created by closing a valve, activation of the fan stoppage alarm signal device takes place. Both mine fan test records and the fan recording chart on file at the mine will verify that the test was performed. The audible fan signal alarm at the central communication center and dispatchers station will verify the performance of the fan alarm signal system.
On August 26, 1998, ventilation specialists from the Pittsburgh Safety and Health Technology Center (PS&HTC) and from District 3 conducted an evaluation of the fan signal device and the air reversal door at the Big Tribble Fan. PS&HTC's report stated that the proposed means of testing the ability of the air reversal door to function properly without shutting off the fan was demonstrated effectively. However, some concern was expressed regarding the proposed pressure differential system for testing the fan signal device. Since this mine operates with multiple fans (six), the possibility exists that fan shutdown or stoppage alarm signals that detect pressure differentials will not at all times provide notification when a fan slows or stops.
To address this concern, on December 16, 1998, the Petitioner filed an amendment to mount a mechanical or magnetic switch such that air reversal prevention door closure operates a relay to activate a light and initiate a signal at a location on the surface when the fan slows or stops. The relay will also initiate a signal at a location where a person is always on duty.
MSHA's follow-up investigation of the petitioner's amended alternate method for compliance with 75.312(c) revealed that a mechanical switch was mounted on the fan housing and would activate a relay in the fan monitoring panel at the mine site when the air reversal door was in a closed position. The relay also activated a signal at two locations where persons are always on duty.
It is essential that a mine with multiple air fans be equipped with air-reversal-prevention doors on each fan to prevent the air in entries from reversing direction in the event of a fan stoppage. Standard 75.312(d) requires a test at least every 31 days, at mines with multiple fans, to assure that the air-reversal-prevention doors will close automatically in the event of a fan stoppage. The investigation revealed that multiple air fans at the McElroy Mine are equipped with solid metal air-reversal-prevention doors, which are suspended from hinges on the top most vertical location. With the fan operating, the door is held open (nearly horizontal) 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 return air entrance of the mine, thereby eliminating air reversal. The petitioner proposes a alternate method in lieu of a fan shutdown to assure the air-reversal-prevention doors 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-reversal-prevention door and a substantially constructed moveable frame assembly. The frame assembly is hinged using the same bearing location as the solid 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 frame assembly to move to the horizontal position of the door while the fan is in operation. Since the frame and air-reversal-prevention door both use the same horizontal bearing support rod and bearing for their movement, the test will verify that the solid air-reversal-prevention door will, in fact, close in the event of a fan stoppage. If the 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.
On the basis of the petition, the findings of MSHA's investigations, and the recommendations of MSHA, McElroy Coal Company is granted a modification of the application of 30 CFR 75.312(c)&(d) to its McElroy 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 101(c) of the Federal Mine Safety and Health Act of 1977, 30 U.S.C., sec. 811(c), it is ordered that McElroy Coal Company's Petition for Modification of the application of 30 CFR 75.312(c)&(d) in the McElroy Mine is hereby:
- GRANTED, for tests of (1) the automatic fan stoppage signal device and (2) the automatic closing air 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. 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 hinged to a rotatable shaft and latched to the fan housing during normal operation. The 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 flow reversal prevention door shall be held open (nearly horizontal) during normal fan operation. The 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 seven (7) calendar days by rotating the test frame outward from its latched position until it contacts the flow reversal prevention door. Rotation of the test frame shall also rotate the bearings hinging the air flow reversal prevention door.
- 3. The person(s) conducting the test will visually observe the movement of the test frame and the contact between the test frame and the air flow reversal prevention door. Also, the person(s) shall observe the general maintenance of the metal door and frame for good repair.
- 4. Each 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 and shall be designed to activate a relay in the fan monitoring panel when the air reversal prevention door is in the closed position. The relay shall activate a warning light near the door location and shall provide an alarm which is audible and visual at both the dispatcher station and the main office communication center. A responsible person shall always be on duty at each location 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.
- 5. The mechanical automatic fan signal device shall be tested at least once every seven (7) calendar days by actuating the switch mounted to the fan housing to verify that it activates the relay in the fan monitoring panel.
- 6. The activation of the fan signal(s) shall be verified by a responsible person.
- 7. The petitioner shall notify the MSHA District Manager when each fan is equipped with the frame, air flow reversal prevention door and fan alarm signal system such that an inspection may be scheduled prior to conducting the 7 day testing as allowed by this PDO.
- 8. 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.
- 9. By the end of the shift on which the test of the automatic fan signal device and/or the automatic closing of the air reversal prevention door is completed, person(s) performing the tests shall record the result of the tests 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.
- 10. 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.
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.
 _________________________________ Robert A. Elam Administrator for Coal Mine Safety and Health |
