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Chapter 6

Coal dust and rock dust

Nathaniel Jeter described himself as a dust man, the senior member of a two-man crew responsible for spreading rock dust throughout the Upper Big Branch mine during the hoot owl, or overnight, shift.1 On nights when he wasn’t pulled off his dusting duties to do other jobs,2 Jeter drove a motor that pulled or pushed a big orange track duster. The duster had two pods3 that held about a ton and a half of rock dust.4 When properly functioning, the duster spread a wide swath of rock dust through the track entries.

Rock dust, or crushed limestone, has long been regarded as a vital safety component in underground mines because it dilutes the explosive nature of coal dust. Yet this geographically expansive mine had but one crew spreading dust – and even then dusting wasn’t a fulltime job. Jeter estimated that he generally spent only about three days a week rock dusting because he also was called upon to help with construction projects – building stoppings, setting timbers and delivering supplies to sections.5

Mines the size of Upper Big Branch typically use track-mounted tank or pod dusters – like the one Jeter operated – to rock dust the track haulage, belt lines, airways, working sections and construction sites. Efficient use of a track duster in a mine the size of Upper Big Branch would have required drilling a borehole midway in the mine and not far from the working sections. This would have allowed a speedy delivery of bulk rock dust to refill the tank dusters. There was no such borehole at UBB. As a result, the rock dust crew had to take a loaded duster from the outside to their point of destination and disperse the dust. When the duster was empty, the crew had to travel back outside to refill. The nearly two-hour round trip travel time suggests it is unlikely that more than one tank of dust per shift or per day was applied using the orange duster.

In addition to the tank or pod dusters, UBB miners testified that scoops or roof bolt machines equipped with small machine dusters were used to spread dust. Miners also stated that they spread rock dust by hand on the floor and walls of working sections, using 40-pound bags of dust that were transported to the sections on flat cars. A flaw with this method was that the roof was not dusted, as required by law, because it was difficult for the miners to spread it on the top. Also, as some of them testified, trying to dust the top made it extremely hard for the workers to breathe.

The dusting, difficult to begin with because the small crew had to cover an extremely large area and contend with mine traffic,6 was further complicated by the fact that the big orange duster at UBB didn’t work properly much of the time.

“Sometimes it would clog up, so we would have to spend 30 minutes trying to unclog the hoses to get dusted,” Jeter said. “Then it would clog up again.” The crew carried dust to spread by hand “just in case, to play it safe,” he said.7

Cody Irwin also complained about what he referred to as the pod duster used at UBB, saying, “it would break a lot.”8

“You just had to twist all the knobs right,” he said. “And sometimes you could turn the air up too high or have your dust up too high, and it’d clog the hose up and you’d have to beat on it… You have to have it just right.”9

It’s not surprising the two-man hoot owl dust crew had trouble with the orange duster, which was prone to failure because of its age and because it had not been adequately maintained. The lack of maintenance was immediately evident to investigators. Following the explosion, the very first time Massey employees attempted to use the duster to perform MSHA-required dusting, the motor burned up.

Documents obtained from and communications with the manufacturer, the A. L. Lee Corporation of Lester, West Virginia, indicate that the duster likely came with Massey’s purchase of the property from Peabody in 1994. An official for A. L. Lee estimated that it originally was sold in the 1980s, although the company’s sales records do not go back that far. The company was able to locate a 1996 record of rebuilding a rail-mounted, twin-tank machine rock duster from Upper Big Branch, Performance Coal Company. Lee converted the duster from 250V to 128V and returned it to Performance. By early 2010, the duster was in excess of 25 years old and had not been rebuilt for at least seven years.

During the course of the investigation, investigators located a white duster, which workers said was used when the orange duster was down. The white duster, parked near the UBB Truck Shop, was locked and tagged “out of service.” Investigators later found it had been stripped down to its frame for parts.

In order for the Upper Big Branch mine to have been rock dusted well enough to have been in compliance with minimum state and federal regulations, management should have assigned crews to rock dust designated areas of the mine each shift. A mine the size of UBB could justify a two-man crew assigned solely to rock dusting on at least two shifts each day, and preferably on all three shifts. Yet a two-man crew was responsible for dusting the entire mine on a part-time basis with no set schedule and with faulty equipment.

The age and poorly maintained condition of the dusting equipment, coupled with the fact that UBB did not have an established rock dust crew that adhered to a schedule like that of a production crew, indicate that rock dusting was not a priority at Upper Big Branch in the early days of 2010.

Jeter said he took his job very seriously and “did it to the best of my abilities,”10 but he became increasingly frustrated. “You give me a duster that’s supposed to work properly,” he said. “If you want me to do my job properly, I need equipment that works properly. If I come to you and say, look, my duster is not working, we need to get it fixed, please don’t blow me off. Because if something happens, they’re going to be looking at me, well, why this didn’t get done.”11

Jeter said he complained often and loudly to Gary May, mine superintendent for the South Side of UBB, and Everett Hager, superintendent for the headgate and tailgate sections.12 He even mentioned the faulty equipment to Performance Coal President Chris Blanchard during a meeting in 2008.13

“I said to him, ‘Well, when are they going to get the track duster fixed?’ He said, ‘What track duster?’ I said, ‘That orange thing that I use with two pods on it.’ He said, ‘Track duster? I didn’t know we had a track duster.’ I said, “Well, yeah. We need to get that fixed.’ He said, “Well, I’ll look into it.’ So they had the write-up for it, all the parts and everything, but it never left the mines.”14

It should be noted that Jeter was fired on February 5, 2010,15 for allegedly sleeping on the job.16 He maintains that he was not asleep and that he was unfairly dismissed.17 Regardless of which story is true, the events of April 5 strongly support Jeter’s assertion that the amount of rock dust applied in UBB was insufficient to stop the propagation of an explosion. Following Jeter’s departure, UBB records indicate that Gary Young and Dustin Richardson were assigned to the rock dust job. A short time later, Richardson was given another assignment and Clifton Stover was assigned to work as a rock duster with Young. Beginning on February 9, 2010, Young and Stover recorded their rock dusting efforts in a spiral-bound notebook. In all, the two men made 25 entries, including one on the day of the explosion.

The handwritten notes tell a frustrating story of days in which rock dust couldn’t be applied because the miners ran out of dust, because the men had no motor to run the duster and, most often, because the equipment failed.

On February 10, the entry reads: “Everything broke/malfunction, worked on hoses and duster.” On Thursday, February 11: “got duster mostly empty, breaks, track from 25-34, 35.” There is a gap in the entries until Thursday, February 18: “Took duster to 1 North, got 2 breaks & belt dusted. Duster went down AGAIN, got cleaned off and ready to install new seal on back pod. Need (2) 2” brass ball valves, (2) crescent wrenches, (2) pipe wrenches, and some pen. oil. Should be able to get running from there, til the rest can be repaired. Also cleaned all the filters for the ocmp. (wouldn’t hurt to change them as well.)”

After another gap of six days, the record notes on Wednesday, February 24: “Dusted from 1-2 breaks up from power center down to track. Hand dusted,” followed by another gap until Monday, March 1, when the note explains: “Dusted 2N & 3N, track & breaks from 52. Helped drag some cable, switched out several times. Had to unclog hose (discharge) and change fill hose before standing.” A Thursday, March 4 notation reads, “Dust from Ellis to 25 break, from 3-4 brk to around 18 (Ellis 5).” On March 9: “Had no motor to run duster.” Again on March 11: “Had no motor again, no ride either.” On March 23: “NO RIDE, NO help. NO spotter. I’ll call you today. I’m set up to fail here.”

During his testimony, Clifton Stover confirmed that the track duster was frequently inoperative because of malfunctions and equipment failure; on some shifts he had no helper and thus could not dust beyond the track; he was frequently taken away from rock dusting to perform other chores; on some days, when the duster was down, he piled bags of rock dust on a mantrip and applied it by hand; on several days no rock dusting was done at all.

Stover also said the neutral, intake and return airways were not rock dusted. Stover testified that no one had explained to him how much rock dust to apply. About a week prior to the explosion a boss told him the rock dusting he and Young had been doing was inadequate suggesting that they were not applying enough dust which may well have been a result of the difficulty of getting enough dust into the mine.

Furthermore, the rock dust effort was also hampered because Young, who was employed as a contractor, was laid off shortly before the explosion.18 Young testified that the crew would be directed to rock dust in areas where the company had received citations for inadequate rock dusting.19

Jeter’s testimony, Stover’s testimony and the Young and Stover log also is backed up by the testimony of other miners. Rodney Osborne, a roof bolter on the hoot owl shift, spoke of “low, low dusting.”

“I mean, you know, like low rock dusting, they didn’t do a lot of it,” he said. “They had one rock dust crew for the whole mines, and they worked the hoot owl. And we hardly ever seen them because they were always doing other things instead of rock dusting like they should have been.”

James Fleming, who was on the third shift belt move crew, cited “not enough rock dusting” as one way in which things changed at UBB during his four years at the mine.20 “As far as I can remember, they only had two men on one shift trying to rock dust this whole coal mines,” Fleming said. “And then when they do rock dust, the only place they rock dust is the track and belt entries. That’s it.”21

Ray Ara, longwall utility man on the midnight shift, said the rock dust “wasn’t too great on the tail side,” that it was “grayish” rather than white. “I don’t know how often they got over in there and dusted … it ain’t like being on the main line or being on the other side you know.”22

Michael Ferrell, who worked as a belt construction foreman at UBB until the second week in February, said rock dusting was insufficient on the tailgate side of the longwall,23 and Tim Blake noted that as he walked down the intake on April 5, it “was pretty bad, lack of rock dust.”24

Morris Hulgan, who worked evening shift on Headgate 22, said management relied on scoop operators to rock dust the section, a less than ideal situation because the scoop man had so much to do. Hulgan said for the most part rock dusting was done by hand.

Michael Smith, an evening shift roof bolt operator on the Tailgate 22 section, also said most of the dusting on his section was done by hand. “We really didn’t have a scoop man, so we didn’t really have many people to dust,” he said.

“When we’d hand dust, we’d only hand dust the ribs,” he said. “We wouldn’t hand dust the top. Most of the time the top was … dusted with a scoop duster and a bucket duster. Like I say, that was done basically once a week by us.”25

When asked why the crew didn’t hand dust the roof, Smith replied, “Well, we really had no air. If we … it would just leave a cloud of dust and choke us up.”26

Note 1: The information used in determining when rock dusting was performed consisted of UBB’s own Pre-Shift Examination of Belt Conveyors reports for the hoot owl, day and afternoon shifts. The symbols noting “dusting performed” were based on notes made by firebosses or belt examiners, such as “ran duster”, “dusted”, etc., but not when the examiner simply wrote “cleaned.”

Note 2: Due to the difficulty in reading the handwritten examiners’ notes on the reports and the possibility of error by investigators in interpreting them, some variation may be found by others interpreting these same reports.


In addition to witness testimony, strong evidence from company pre-shift records indicates that rock dusting was a haphazard and poorly managed operation at UBB. Although the GIIP has found the pre-shift examination recordkeeping to be problematic at times, a review of the pre-shift examinations of the belt conveyors for the period between March 10, 2010, and April 4, 2010, revealed 561 notations (or requests by the examiners) that the belts needed dusting. Under pre-shift requirements, a notation is also to be made when the dusting is performed.

During the same March-April time period, preshift reports indicate that of the 561 dustings requested, only 65 dustings were subsequently noted. Thus, rock dusting was carried out just 11.6 percent of the time it was requested. (See graphic above)

In addition to the 30 days prior to the explosion, reports prepared by UBB firebosses and foremen, as required by both federal and state regulations, were available for the January through March 2010 period. Using the available pre-shift examination data for the working sections for the period January through April 2010, investigators identified 1,834 instances when rock dusting was needed, and only 302 times (16.47 percent) when rock dusting was performed.

Extensive tests conducted by MSHA after the disaster support miners’ testimony that the Upper Big Branch mine was poorly dusted. In analyses of 1,803 dust samples taken from UBB after the explosion, MSHA found that 78.92 percent were out of compliance with the federal standard.27

State and federal citation records likewise offer dramatic evidence of inadequate dusting. During 2009, mining inspectors with the WVMHST issued 26 citations at the Upper Big Branch Mine for coal dust accumulation and for failure to adequately apply rock dust. Federal inspectors also cited the mine for the same conditions. In the 15 months preceding the disaster, UBB received citations from federal or state inspectors every month but one for rock dust issues. Violations were observed in all four miner sections, on the longwall and along several of the belts. Nearly half the 40 citations issued by MSHA were classified as “significant and substantial.”28

On a violation in April 2009, a federal inspector wrote of the “failure to keep combustible materials from accumulating in the area where #2 section is punching through into the #1 section. At the #1, 2, 3 punch through, coal has been left in each intersection in piles as wide as the intersection and up to 2 ft. in depth.”

Problems with accumulation of coal dust and inadequate rock dust persisted in 2010. State and federal inspectors wrote 14 citations in the three months preceding the disaster.

A violation written by a state inspector on March 23, 2010 – just ten days before the explosion – found that:

“The Head Gate 22 conveyor belt which is close to 1 mile in length is not being maintained properly due to [three words illegible] cleaning under the belt as well as the spillage in the walkway and rock and coal from the ribs in the walkway as well. In addition, float dust is present from the belt head to the belt tail.”29

Just weeks earlier the same inspector wrote a similar violation:

“The track entry and breakthrough connected [illegible] from the longwall track switch to the #1/HG22 working section needs rock-dusted due to float dust in this area.”30

And on several occasions in 2009, state inspectors wrote violations noting:

“Management is aware of the condition of the conveyor belt [with float dust] as the conditions have been recorded since 5/21/09 in the pre-shift record book for conveyor belts.”31

West Virginia code governing the WVMHST states that “dangerous accumulations of fine, dry coal and coal dust shall be removed from the mine, and all dry and dusty operating sections and haulageways and conveyors and back entries shall be rock dusted or dust allayed.” It specifies that rock dust be “applied and maintained in such quantity that the incombustible content in the return entries shall not be less than 80 percent.”32

The federal mine act also states very specifically that “coal dust, including float coal dust deposited on rock-dusted surfaces, loose coal, and other combustible materials shall be cleaned up and not be permitted to accumulate in active workings or on electric equipment therein.”

Federal law in place on April 5, 2010, also was specific about the application of rock dust.33

Despite the detailed requirements outlined in the law, evidence suggests that Massey did not have adequate procedures in place to ensure that the company complied with rock dust requirements. When asked by MSHA for records of analyses used to determine the adequacy of the company’s rock-dusting system, a law firm representing the company wrote, “Performance Coal Company has not independently had rock dust analyzed.”34 The company was not making an active effort to determine if it was adequately rock dusting and making the coal dust inert so as to make their miners safe, but rather simply relying on federal or state inspectors to catch them if the rock dusting was not adequate.

Likewise, section bosses and foremen appeared to lack a protocol by which they could determine whether the dusting was adequate. They, too, appeared to depend on having an inspector write a citation to let them know the dusting was inadequate, or they relied on their own “eyeball test” – whether it looked like enough dust had been applied.35

“It must’ve been up to standard,” longwall foreman Harold Lilly said, “because I can’t remember getting a violation on --- it didn’t bother me, wasn’t real black.”36

Massey Energy officials have stated that coal dust played no part in the explosion at the Upper Big Branch Mine. The company’s general counsel, Shane Harvey, told the Associated Press that the mine “appears to have been very well rock-dusted with rock dust still in place.”37

The combined evidence from a number of sources strongly suggests otherwise: the witnesses who testified that the mine was not well dusted; the series of citations issued by state and federal officials in the year leading up to the disaster; the preshift examination records of the conveyor belts, which indicate that only 11.6 percent of the rock dustings requested were completed; the absence of a systematic rock dust procedure; the frequent changes in rock dust personnel; the fact that rock dust crews were given other assignments; the physical distance the explosion traveled; and the findings from the rock dust samples taken after the explosion. Had coal dust not been a factor in the explosion, the damage at Upper Big Branch might well have been contained to the longwall area. The victims on Headgate 22 were located about 0.75 miles from the longwall. The victims on the mantrip at 66 break were found approximately 1.15 miles from the longwall face.

The fact that the explosion killed men working so far away from the initial impact, offers strong evidence that coal dust played a significant role in propagating the blast throughout the mine, and, in George Samuel Rice’s prescient 1913 words, “leaving a trail of wreckage and death.”38 Ultimately, all of the historic lessons so painfully learned as result of the terrible loss of life during the first decade of the 20th century apparently were forgotten or ignored by the management of UBB.

1 Nathaniel Jeter testimony, p. 14
2 Steve Campbell, who left UBB to work for MSHA, described Jeter as a “motorman” who had assignments other than dusting, Steve Campbell testimony, p 51.
3 Nathaniel Jeter testimony, p. 17
4 Nathaniel Jeter testimony, p. 18
5 Nathaniel Jeter testimony, p. 16
6 Nathaniel Jeter testimony, p. 20
7 Nathaniel Jeter testimony, p. 18
8 Cody Irwin testimony, p. 23
9 Cody Irwin testimony, p. 23
10 Nathaniel Jeter testimony, p. 47
11 Nathaniel Jeter testimony, p. 54
12 Nathaniel Jeter testimony, p. 65
13 Titles from letter from Allen, Guthrie & Thomas, PLLC, to Norman Page, MSHA, April 23, 2010
14 Nathaniel Jeter testimony, p. 65
15 Termination date obtained from Massey personnel list.
16 Nathaniel Jeter testimony, p. 60
17 Nathaniel Jeter testimony p. 47
18 Clifton Stover testimony, February 27, 2011
19 Gary Young testimony, p. 73
20 James Fleming testimony, p. 20
21 James Fleming testimony, p. 21
22 Ray Ara testimony, p. 34
23 Michael Ferrell testimony, p. 89
24 Timothy Blake testimony, p. 23
25 Michael Smith testimony, p. 62
26 Michael Smith testimony, p. 75
27 Soot and Coking map
28 Lincoln Selfe testimony, p. 41. During his interview, Selfe MSHA District 4 Assistant District Manager testified that “every time I was in the mine it was very well rock dusted.” Given the fact that during the months running up to the explosion the mine was cited monthly and the dusting crews were hampered by equipment failures, etc., it suggests that there was a disconnect between MSHA’s District 4 management view and the MSHA inspectors’ experience.
29 WVMHST, Violation No. 31091, March 23, 2010, at 11:30 a.m.
30 WVMHST Violation No. 31080, March 2, 2010, at 1:00 p.m.
31 WVMHST Violation No. 10784, June 16, 2009, at 12:10 p.m.
32 WVMHST “Control of coal dust rock dusting” 22A-2-24
33 Mine Act, Section 304; CFR 75.403. “…All underground areas of a coal mine, except those areas in which the dust is too wet or too high in incombustible content to propagate an explosion, shall be rock dusted to within forty feet of all working faces, unless such areas are inaccessible or unsafe to enter or unless the Secretary or his authorized representative permits an exception upon his finding that such exception will not pose a hazard to the miners. All crosscuts that are less than forty feet from a working face shall also be rock dusted. Where rock dust is required to be applied, it shall be distributed upon the top, floor, and sides of all underground areas of a coal mine and maintained in such quantities that the incombustible content of the combined coal dust, rock dust, and other dust shall be not less than 65 per centum, but the incombustible content in the return aircourses shall be no less than 80 per centum. Where methane is present in any ventilating current, the per centum of incombustible content of such combined dusts shall be increased 1.0 and 0.4 per centum for each 0.1 per centum of methane where 65 and 80 per centum, respectively, of incombustibles are required,” On September 23, 2010, MSHA used its emergency rulemaking authority to improve the rock dust requirements for underground coal mines. (75 Federal Register 57849) The new standard (75.403) requires the incombustible content of coal dust, rock dust and other dust to be not less than 80 percent
34 Letter from Allen, Guthrie & Thomas, PLLC, to MSHA, June 2, 2010, p. 19
35 Longtime UBB weekly examiner Charles Semenske testified that he couldn’t be sure that rock dusting meets regulatory requirements unless a physical sample is taken and sent to a laboratory for analysis. Semenske, who had worked in coal mines for 39 years, depends on the color of “everything” to tell him whether rock dusting is good, but conceded that “you can’t really tell unless you see how much they have put on it, you know, more or less just dig down, you know, and see how much dust you have on it,”
36 Harold Lilly testimony, p. 66
37 Ward, Ken, Jr., Coal Tattoo, The Charleston Gazette, September 17, 2010.
38 U.S. Department of the Interior. Bureau of Mines. Notes on the Prevention of Dust and Gas Explosions in Coal Mines, by George S. Rice, Washington, DC: Government Printing Office, 1913.

ROCK DUST:

‘Keeping an explosion from leaving a trail of wreckage and death’

There are sound historic reasons for the strongly worded provisions regarding control of coal dust in both state and federal law. Although commercial mining began in the United States in 1730 in Virginia,1 it was widely believed that coal dust was not explosive until well into the first decade of the 20th century. A series of disasters in 1906 and 1907 spurred pioneering work of mining engineers J. Taffanel in France and George Samuel Rice in the U.S. Taffanel’s and Rice’s research provided convincing evidence – which became accepted fact – that coal dust was and is highly volatile.

On March 10, 1906, an explosion that ripped through the Courrières mine in northern France took the lives of 1,099 men in Europe’s most deadly mine accident. Soon after, a number of countries began examining the possible explosiveness of coal dust. Taffanel suggested that since the Courrières mines had been free from methane, the disaster “demonstrated in an indisputable manner the reality of the coal-dust danger.”2 He began conducting experiments in Lievin, France, in 1907, focusing on the chemistry of dust explosions. This work formed the foundation for continued research into mine explosions.3

In the U.S., there appeared to be little urgency about addressing the issue of coal dust explosions until the terrible month of December 1907, which began with a December 1 explosion at the Naomi Mine in Fayette City, Pennsylvania, that killed 34 miners.

Less than a week later the most deadly mining disaster in U.S. history took place in Monongah, West Virginia, when a massive explosion ripped through the Monongah No. 6 and 8 mines. The final death toll was more than 500 boys and men.4

The Monongah disaster was followed on December 16 by an explosion in Yolande, Alabama, that killed 57 miners, then by a blast on December 19 at the Darr Mine in Van Meter, Pennsylvania, which claimed 239 more lives. Finally, as the year came to a close, the Bernal mine in Carthage, New Mexico, exploded on December 31, killing 11 more miners.5

With the blood of 703 dead men spilled in the nation’s mines in one short month, the U.S. Congress took action in 1908, appropriating funds for an investiga- tion into the causes of the explosions.6 A testing station was established in Pittsburgh, Pennsylvania, which operated under the auspices of the United States Geological Survey until it was transferred to the newly formed Bureau of Mines (BOM) in July 1910.7

George Samuel Rice, the chief mining engineer for the BOM, compiled a collection of materials, papers and research studies, all of which pointed to the need to render coal dust inert. In 1913, Rice stated “coal dust is the agency that causes an explosion to sweep through a mine, leaving a trail of wreckage and death.”8

By then, Rice also had made recommendations as to how to prevent dust explosions. Most impressive was his suggestion to render the dust inert by applying rock dust to it.9 Sir William Garforth of England had suggested the use of rock dust to prevent or limit coal dust explosions as early as 1891. However, it was Rice who made the case in the U.S., based on test results that confirmed that when coal dust and rock dust had an incombustible content of 64 percent, ignitions could be prevented.10

Although Rice and the BOM advocated use of rock dust as early as 1910, most coal mines in the U.S., with the exception of a mine operated by the federal government in Colorado, did not start using it until the 1920s.11 Even then, there was no federal law mandating its use, and only the most progressive, safety-oriented coal operators opted to follow BOM guidelines and recommendations.

Through the years operators tried other methods to address the coal dust situation, but, in the end, rock dust proved to be the most successful method to address the explosiveness of coal, and its use became an industry standard.

Rock dust works because it causes a decrease in the temperature of coal dust. During an explosion, the rock dust disperses and mixes with coal dust,12 acting as a thermal inhibitor and reducing the flame temperature to the point that an explosion of coal particles can no longer occur.13 The amount of rock dust required to prevent an explosion depends on the size of the coal particles as well as the size of the rock dust. As the coal particle size is reduced, a more severe explosion hazard is present.14

On April 7, 1927, the BOM issued a safety decision recommending that all coal mines be rock dusted and emphasizing the importance of thoroughly cleaning up the coal dust prior to the rock-dusting.15

An information circular produced by the Bureau of Mines similarly offered a conclusion that emphasized the importance of rock-dusting:

… the only safe procedure in the preventing of disastrous explosions is to rock dust thoroughly in every accessible part of a mine. Re-rockdust immediately when the content of either floor dust or rib and timber dust falls to 55 per cent in any zone in the mine and maintain at all times the average noncombustible content of the mine dust above 65 per cent.17

Although the recommended standard was thorough and complete, containing much of what since has been written into federal laws governing coal mine safety, Congress did not grant the Bureau the authority to inspect mines or formulate a regulatory code.18 As a result, dusting was haphazard – performed to the recommended standard in some progressive mines, not performed at all in others.

In a 1939 report, the BOM concluded that rock-dusting practices in the U.S. fell far short of providing absolute protection against coal dust explosions; that state mine safety laws were inadequate with respect to rock dusting requirements; that limestone or gypsum is accessible to all coal fields in the country; and that the average cost of rockdusting amounted to $.0089 per ton of coal mined.19 (As of October 2010, the cost per net ton of bulk mine safety dust was $28, according to Greer Industries, still a great bargain for the safety it provides.20)

In addition, BOM records for a nine-year span leading up to the 1939 report, revealed that in 60 rock-dusted mines where explosions had taken place, rock dust was credited with stopping or limiting the explosions in 26 of them.21

Still, it wasn’t until 1969 that the Bureau was granted the authority to regulate the mining industry with the passage of the Federal Coal Mine Health and Safety Act (Coal Act), passed by the Congress in the aftermath of the catastrophic explosion that killed 78 miners at Consolidation Coal Company’s Farmington No. 9 Mine on November 20, 1968. The Coal Act provided for monetary penalties for all violations and criminal penalties for knowing and willful violations. In 1973, the Mining Enforcement and Safety Administration was formed; in 1977, it became the Mine Safety and Health Administration (MSHA).

The rock-dusting standard in place when the Upper Big Branch Mine exploded on April 5, 2010, was the same standard that was established in 1927, unchanged through the years despite the increased use of machinery in the mines, which has resulted in a finer, more explosive coal dust. In September 2010, five months after the UBB explosion, MSHA issued an emergency temporary standard22 raising the percentage of incombustible content for intake airways from 65 to 80 percent.23 The Mine Act requires the agency to replace an emergency temporary standard with a permanent, final standard within nine months.24

1 McCartney, Martha W., “Historical Overview of the Midlothian Coal Mining Company Tract, Chesterfield County, Virginia”
2 Transactions of the American Institute of Mining Engineers, Vol. 50, Investigations of Coal Dust Explosion, Vol. 50, 1915, p 589
3 Sapko, Michael J., Eric S. Weiss, Marcia L. Harris, Chi-Keung Man, Samuel P. Harteis, National Institute for Occupational Safety and Health, A Centennial of Mine Explosion Prevention Research, p. 2.
4 McAteer, J. Davitt, Monongah, West Virginia University Press, 2007, p. 241
5 National Institute for Occupational Safety and Health, Mining Disasters
6 U.S. Department of the Interior. Bureau of Mines. The Explosibility of Coal Dust, by George S. Rice. Washington, DC: Government Printing Office, 1911.
7 U.S. Department of the Interior. Bureau of Mines. The Explosibility of Coal Dust, 33
8 U.S. Department of the Interior. Bureau of Mines. Notes on the Prevention of Dust and Gas Explosions in Coal Mines, by George S. Rice, Washington, DC: Government Printing Office, 1913.
9 Rice, The Explosibility of Coal Dust, 84-6 and Ibid, 16-7.
10 U.S. Department of the Interior, Bureau of Mines, Report of Investigations: Methods of Rock-Dusting American Coal Mines, by J.J. Forbes, September 1939.
11 Ibid.
12 NIOSH, How does limestone rock dust prevent coal dust explosions in coal mines?, by C.K. Man
and K.A. Teacoach, Pittsburgh, PA.
13 Ibid.
14 U.S. Department of the Interior. Bureau of Mines, Coal-dust Explosibility Factors Indicated by Experimental Mine Investigations (1911-1929), Rice, G.S. and Greenwald, H.P., Technical Paper 464, 2919
15 U.S. Department of Commerce. Bureau of Mines. Information Circular: Effective Rock-Dusting of Coal Mines, by George S. Rice, Washington, DC: 1927.
16 Ibid.
17 Ibid.
18 MSHA website, History of Mine Safety and Health Legislation.
19 U.S. Department of the Interior, Bureau of Mines, Report of Investigations: Methods of Rock-Dusting American Coal Mines, by J.J. Forbes, September 1939, p. 20
20 Correspondence with J. Davitt McAteer
21 U.S. Department of the Interior, Bureau of Mines, Report of Investigations: Methods of Rock-Dusting American Coal Mines, by J.J. Forbes, September 1939, p. 21
22 MSHA, Maintenance of Incombustible content of rock dust in underground coal mines, 75 Federal Register 57849, September 23, 2010, which became fully effective on November 22, 2010.
23 U.S. Department of Health and Human Services. NIOSH. Report of Investigations 9679: Recommendations for a New Rock Dusting Standard to Prevent Coal Dust Explosions in Intake Airways, Pittsburgh, PA, May 2010
24 Section 101(b), Federal Mine Safety and Health Act of 1977


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