UNITED STATES BUREAU OF MINES 

INFORMATION CIRCULAR/1995 

Analysis of Underground Coal Mine 

Fire Incidents in the United States 

From 1978 Through 1992 

UNITED STATES DEPARTMENT OF THE INTERIOR 

As the Nation's principal conservation agency, the Department of 

the Interior has responsibility for most of our nationally-owned 

public lands and natural resources. This includes fostering 

sound use of our land and water resources; protecting our fish, 

wildlife, and biological diversity; preserving the environmental 

and cultural values of our national parks and historical places; and 

providing for the enjoyment of life through outdoor recreation. 

The Department assesses our energy and mineral resources and 

works to ensure that their development is in the best interests of 

all our people by encouraging stewardship and citizen participation in their care. The Department also hasa major responsibility 

for American Indian reservation communities and for people who 

live in island territories under U.S.administration. 
Information Circular 9426 

Analysis of Underground Coal Mine 

Fire Incidents in the United States 

From 1978 Through 1992 

By William H. Pomroy and Annie M. Carlgiet 

UNITED STATES DEPARTMENT OF THE INTERIOR 

Bruce Babbitt, Secretary 

BUREAU OF MINES 

Rhea Lydia Graham, Director 
Libray of Congress Cataloging in Publication Data: 

Pomroy, William H. 

Analysis of underground coal mine fire incidents in the United States from 1978 

through 1992 / by William H. Pomrdy and Annie M. Carigiet. 

p. cm. -(Monnation circular / United States Department of the Interior, 

Bureau of W,9426) 

Includes bibliographical nfercnces (p. 24). 

1. Coal mines and mining--Elm and fire prevention-United States-History. 

I. Carigiet, Annie M. 11. Title. 111. Series: Information circular (United States. 

Bumu of Mines); W26. 

TN295.U4TN315 622s--dc;?O [622'.82] 94-49721 CIP 
CONTENTS 

page 

Abstract ........................................................................... 1 


Introduction ........................................................................ 2 


Dataanalysis ....................................................................... 3 


Stateandtimetrends ............................................................... 3 


Coalbedthickness .................................................................. 6 


Minesize ........................................................................ 6 


Miningmethod ................................................................... 8 


Ignitionsource .................................................................... 11 


Burningsubstance ................................................................. 12 


Undergroundlocation ............................................................... l3 


Equipment involved ................................................................ 13 


Detectionmethod .................................................................. 15 


Timeofday ...................................................................... 16 


Tieofyear ..................................................................... 17 


Injuries and fatalities ............................................................... 17 


Method of extinguishment ........................................................... 19 


Mine evacuations .................................................................. 21 


Conclusions ........................................................................ 22 


References ......................................................................... 24 


ILLUSTRATIONS 

1. Number of underground coal mine fires per year. underground coal mine production. and fire incidence rate 6 


2. Number of fires. number of expected fires. fire incidence rate. and underground coal mine production by 


coalbed thickness ................................................................ 7 


3. Number of fires. number of expected fires. fire incidence rate. and underground coal mine production by 


daily tonnage range .............................................................. 10 


4. Number of fires. number of expected fires. fire incidcnce rate. and underground coal mine production by 


undergroundemployees ........................................................... 11 


5. Number of fires by ignition source .................................................... 12 


6. Number of fires by burning substance .................................................. 13 


7. Number of fires by underground location ................................................ 14 


8. Number of fircs by equipment involved ................................................ 14 


9. Number of fires by method of detection ................................................ 16 


10. Number of fires by time of day ...................................................... 17 


11. Numbcr of fires by time of year ...................................................... 18 


12. Number of fires by succcssful method of extinguishment .................................... U) 


13. Numbcr of fircs by degrce of mine evacuation ........................................... 21 


TABLES 

Numbcr of fircs by State and year .................................................... 4 


Undcrground coal mine production by Statc and year ...................................... 4 


Fire incidcncc rate by Statc and year ................................................... 5 


Numbcr of fircs by coalbcd thickness and tirnc pcriod ...................................... 6 


Undcrground coal minc production by coalbcd thickness and year ............................. 7 


Nurnbcr of fircs. firc incidence rate. and numbcr of cxpectcd fircs by coalbcd thickness ............. 8 


Numbcr of fircs by daily undcrground coal minc production tonnagc range and ycar ............... 8 


Undcrground coal minc production by daily production tonnagc range and ycar ................... 9 


Numhcr of fircs. firc incidcncc ratc. and numhcr of expcclcd fircs by daily undcrground coal minc 


production tonnagc rangc ......................................................... 9 

TABLES--Continued 

Page 

10. Number of fires by number of underground employees and year . . . . .. . .... . . . . . . . . . ..... . . . . . 11. Underground coal mine production by number of underground employees and year ..... . ... . ... . . . 12. Number of fires, fue incidence rate, and number of expected fires by number of underground employees 

13. Number of fues by year and mining method .. . ... . . . . . . . . . . .... . . . .. . . . . . ... . . . . . .. . ... . 14. Number of fues by ignition source and time period . . . . . . . . . . . .... . ... . . . . . . . . . . .... . . . . . . . 15. Number of fires by burning substance and time period .... . . .. . . . . . . . . . .. . . . . . . . . .. . . . . . . . . 16. Number of fires by underground location and time period . . . . . . . ... . . . . . . . . .. . . .. . ...... . . . . 17. Number of fues by equipment involved and time period . . . . . . . . . . . . . . . . . ..... . .. . .. . . . .. . . . 18. Number of fires by method of detection and time period .. . . . . . . . ..... . . . . .. . ... . . . . .. . . . . . . 19. Number of fires by time of day and time period .. . . . . . . . . . . . . . . . . . .. .. .. . . .. . . . . . . . . .. . . . 20. Number of fires by time of year and time period .. . . . . . ... . . . . . .... . . . . . . . .. . . . . . . . . . .. .. 21. 	 Injuries and fatal fires by year, number of injuries and/or fatalities, location, equipment involved, and 

ignitionsource .................................................................. 22. 	 Number of fires by method of extinguishment, time period, and number of attempts, number of successful 

attempts, and success rate of extinguishment . . . . . . . . . . . . . . ..... . .... . . . . ... . ... . . . . .. . .. 23. Number of fires by degree of mine evacuation and time period . . . . .. ... . . ... . . . . . . . . . . . . . . . . . 24. Major findings of statistical analysis of underground coal mine fires, 1978-92 .. . . . . . . .. . . . . . . . . ... 25. Major findings of statistical analysis of underground coal mine fires, 1950-77 .... . . . . . . . . . . . . . . . . . 

m. 

UNIT OF MEASURE ABBREVIATIONS USED IN THIS REPORT 

in inch 	 pct percent 

min 	 minute 

Quantities in this report are expressed in U.S. customary units of measure rather than the standard USBM practicc 

of expressing quantities in metric units. U.S. customary units are used because the Federal agcncies that compilc coal 

mine production data used in this report (Energy Information Administration, U.S. Department of Energy; and Minc 

Safety and Health Administration, U.S. Department of Labor) provide this data only in U.S. customary units, and bccausc 

the previous USBM report summarizing coal mine fire incidents in the United States from 1950 to 1977 (Information 

Circular 8830) also uses U.S. customary units. Users of this report are expected to compare, analyze, and cvaluate data 

from this report and the other sources. Use of metric units in this report would therefore have required such uscrs to 

perform extensive unit conversions. 
ANALYSIS OF UNDERGROUND COAL MINE FIRE INCIDENTS 

IN THE UNITED STATES FROM 1978 THROUGH 1992 

By William H. ~omro~' and Annie M. carigie? 

ABSTRACT 

This U.S. Bureau of Mines publication is an analysis of underground coal mine fue incidents 

occurring in the United States during the 15years from 1978 through 1992. The fire data used in this 

analysis were obtained from U.S. Mine Safety and Health Administration mine fire investigation reports. 

Fires were analyzed by year, State, coalbed thickness, mine size, mining method, ignition source, burning 

substance, location, equipment involved, detection method, time of day, time of year, number of injuries 

and fatalities, method of extinguishment, and evacuation measures taken. In all, 164 fues are included 

in this report, or an average of 10.8 fires per year. The most fues occurred in West Virginia, Kentucky, 

and Pennsylvania, respectively. However, the fire incidence rates for these States, expressed as the 

number of fires per million tons of coal mined, were the lowest, second lowest, and fourth lowest of all 

underground coal producing States. The most common ignition source was electricity; the most common 

burning substance was coal; the most frequent fire location was the belt entry; the most common 

equipment involved in fires was the conveyor belt; and the most common extinguishing agent was water. 

'~upenrisor~mining engineer. 

Z~omputerassistant. 

Twin Cities Research Center, U.S. Bureau of Mines, Minneapolis, MN. 
INTRODUCTION 


Underground fires represent a serious and constant 

threat to the safety of mine workers. Miners in the immediate vicinity of a fire must contend with intense heat, 

bliidiig smoke, toxic fumes, roof falls, and the other direct 

effects of a fire. However, the vast majority of victims 

never actually see the fire, succumbing instead to deadly 

fume-laden air or asphyxiation. The mine's ventilation 

system, which normally supplies fresh air to the workings, 

can transport smoke and fire gasses with equal efficiency. 

Additionally, the heat produced by a fire can significantly alter normal airflows and directions. Miners remote 

from a fire may be forced to evacuate through smoke and 

fumes. Sometimes a fire may block the escape route. 

Miners can become confused by unfamiliar ventilation system behavior and usually do not have knowledge of the 

fire's location. No peril is more feared by miners than a 

raging fire in the mine. 

Efforts to improve mine fire safety have been a priority 

for mine operators, regulatory authorities, equipment manufacturers, research organizations, and others for many 

years, and signilkant progress toward reducing fire hazards 

has been achieved. Underground fires are now rare 

events, and injuries and fatalities caused by mine fires are 

at an alltime low. However, the threat of fire has not 

been eliminated entirely, and as long as combustible materials and ignition sources are present underground, the 

potential for disastrous fires will remain. Despite the 

recognized seriousness of the mine fire hazard and the 

industry's best efforts toward fire prevention, it is somewhat alarming to note that the number of fires per million 

worker-hours is higher in underground mines than in 

above-ground industrial occupancies 

The U.S. Bureau of Mines (USBM), mining and 

mining-affiliated companies, academic institutions, and 

others have directed considerable research attention to 

reducing fire hazards in mining. A critical prerequisite to 

the development of a sound research strategy is up-to-date 

and accurate data describing and quantifying the industry's 

mine fire experience. Such data would also be useful for 

regulatory decision making, fire safety product marketing, 

development of fire safety training programs, and similar 

purposes. 

In support of the above objectives, the USBM and 

other agencies have completed various analyses of coal 

mine fires (2-4). A comprehensive and detailed statistical 

analysis covering the period from 1950 through 1977 was 

summarized in USBM Information Circular (IC) 8830, "A 

Statistical Analysis of Coal Mine Fire Incidents in the 

United States From 1950 to 1977," which was published in 

'Italic numbers in parentheses refer to items in the list of references 

at the end of this report. 

1980 (5). The most recent data contained in that report 

are now over 15 years old, and significant changes have 

occurred in the U.S. underground coal mining industry 

since then. As a result, the data in IC 8830 are of limited 

usefulness for assessing current mine fire problems. This 

current report was prepared as an update of IC 8830 to 

cover the subsequent 15-year period from 1978 through 

1992. 

The fire data used in the preparation of this report 

were obtained from the files of U.S. Mine Safety and 

Health Administration (MSHA) mine fire Reports of 

Investigation maintained at MSHA's Pittsburgh Safety 

Technology Center. These Reports of Investigation are 

prepared by MSHA Coal Mine Safety and Health staff for 

every fire reported to MSHA authorities. Reporting of 

fires to MSHA is in accordance with mandatory Federal 

regulations requiring coal mine operators to immediately 

notify MSHA in the event of a fire causing an injury or 

any noninjury fire lasting longer than 30 min (6). For each 

such fire (defined as "reportable"), MSHA produces a 

Report of Investigation describing the mine, circumstances 

leading to the fire, cause and detection of the fire, mine 

emergency and fire-fighting operations, post-fire mine 

recovery, and conclusions and recommendations. 

This report differs from IC 8830 (5) in several important respects. The scope of the earlier report included 

both surface and underground mine fires, whereas this report covers only underground fires. This report utilized 

only one source of fire data, the aforementioned MSHA 

Reports of Investigation on file at the Pittsburgh Safety 

Technology Center. In contrast, IC 8830 summarized data 

from three independent sources. In addition to MSHA 

Reports of Investigation, IC 8830 reported data on nonreportable fires and included a section analyzing the expert 

opinions of several mine safety directors. The data on 

nonreportable fires were obtained from cooperating mining companies in an effort to establish similarities and 

differences between the causes and characteristics of 

reportable and nonreportable fires and to estimate the 

percentage of fires that were extinguished before they 

became reportable. 

Another difference between this report (5) and the 

earlier report is the source of the MSHA Reports of 

Investigation. For the earlier report, MSHA's Hcalth and 

Safety Analysis Center and all MSHA Coal Mine Safcty 

and Health district and subdistrict officcs wcrc visitcd. 

Project personnel personally scarchcd the files at thcsc 

offices for fire reports. ' It was notcd at the time that thc 

files at the district and subdistrict officcs containcd informal, internal memoranda concerning short-duration 

fires that wcre lcgally nonrcportablc, but wcrc rcportcd as 

a courtesy. All fire reports, whcthcr rcportahlc or not, 

were included in the analysis for 1C &!30. 
Most of the fire incidents included in this report meet 

MSHA's defrnition of a reportable fire, with only a very 

few being nonreportable. It is likely that more "courtesy 

reports" of short-duration, nonreportable fires would have 

been found had all MSHA district and subdistrict offices 

been visited for this report, as had been the case for the 

earlier report (5). As a result, the reader should be aware 

that when comparing the two reports, the data contained 

in the earlier report may be slightly skewed toward shorter 

duration fires. 

The data tables included in this report present data in 

three 5-year subgroupings covering the 1978-82, 1983-87, 

and 1988-92 periods, as well as for the entire 15-year 

period from 1978 through 1992. Data are presented in this 

fashion to highlight the changes that occur slowly over 

time. 

A small discrepancy in the dates of coverage for IC 

8830 (5) and this report should be noted. Although the 

title of IC 8830 refers to the period from 1950 to 1977, its 

period of coverage did not actually extcnd to the end of 

calendar year 1977. Rather, it extended only to the end of 

September 1977. However, three additional fircs occurred 

during the fourth quarter of 1977. In order for both IC 

8830 and this report to provide continuous coverage of all 

reported underground coal mine fires from 1950 through 

1992, the three late 1977 fires that are not contained in 

IC 8830 are included in this report. Where data are 

grouped by time period in this report, the late 1977 fires 

are included in the 1978-82 grouping. 

Discussion of the data usually covers the entire 15-year 

period from 1978 through 1992. However, certain discussions focus on the most recent period, 1988-92, as these 

data are most relevant to current mining practices. To 

reveal changes that have occurred over a longer time 

period, data from this study are compared to data from 

IC 8830 (5). Normally, these discussions include the entire 

1950 through 1977 period covered by IC 8830. However, 

certain discussions focus on other time periods, such as 

1953 through 1977, corresponding to the beginning of 

Federal mine safety legislation standardizing fire reporting 

requirements, or 1970 through 1977, corresponding to the 

effective date of the 1%9 Mine Safety and Health Act. 

Column summation totals may vary slightly because of 

rounding. 

DATA ANALYSIS 


Data were assembled in two forms: actual numbers of 

fires and fire incidence rates. Fire incidcnce ratcs, for 

purposes of this report, are defined as the number of fires 

per million tons4 of coal mined. Fire incidence rates are 

includcd to enable the readcr to more meaningfully compare data from industry sectors having differing levels of 

coal production and thcrefore differing exposure to fire 

risks. The coal production data requircd for calculating 

incidcnce rates was obtaincd from the U.S. Dcpartmcnt of 

Energy (DOE), Encrgy Information Administration (f), 

and the U.S. Dcpartmcnt of Labor, MSHA (6-22). Production data vary slightly bccause of differing reporting 

requirements from thcsc sourccs. 

Data are prcscntcd in two formats: tablcs and figures. 

Tables arc provided that include thc exact number of fires, 

minc production data, incidcncc ratcs, ctc. Figurcs arc 

includcd to cnablc the rcadcr to bcttcr discern pattcrns in 

the data, such as trcnds over time. The data wcrc not 

statistically analy~cd bccausc of thc oftcn small numbcr of 

fircs occurring in a givcn catcgory and time pcriod. 

Thc minc firc Rcports of Investigation obtaincd from 

thc MSHA Pittsburgh Safcty Tcchnology Ccntcr and uscd 

in this rcport wcrc cntcrcd into'a computcr databasc using 

Paradox databasc software for data reduction and analpis. 

Thosc wishing to obtain a copy of this datahasc arc in\itcd 

to contact thc authors. 

'1n this rcpon. 'tons' rcfcr to 'short tons.' 

STATE AND TIME TRENDS 

A total of 164 fires were reported to MSHA from 1978 

through 1992. Table 1 shows fires by State for each year 

from 1978 through 1992, fires by State for the three major 

time periods, and total number of fires by State. Overall, 

the avcrage number of fires per year was 10.8, compared 

to 32.4 fires per year for the preceding 15-year period 

from 1%3through 1977 (5). The three States having the 

greatest numbcr of fire incidcnts during the 15 years from 

1%3 through 1977 were West Virginia, Pcnnsylvania, and 

Kentucky (23). These same three States recorded the 

greatest number of fires during the 1978 through 1992 

pcriod as well (with Pennsylvania and Kentucky in reversed order). 

Table 2 shows undcrground coal mine production for 

the 1978 through 1992 period. Table 3 shows fuc incidence ratcs for the same time period. The fire incidence 

ratc for all Statcs over the cntirc 15-year period from 1978 

through 1992 was 0.031. From IC 8830 (9,the fire incidcncc ratc for the 1950 through 1977 period was 0.115, 

almost four times higher. Figure 1 shows underground 

coal minc fircs, undcrground coal minc production, and 

firc incidcncc ratcs for the 1978 through 1992 period. An 

upward trend is cvidcnt in coal production, and an overall 

downward trend is evident in both fircs and firc incidcnce 

ratcs. 
Table l.-Number of flres by State and year 

State 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1978-82 

Alabama ..... 1 0 0 2 1 1 0 2 3 0 0 0 0 0 1 4 

Colorado ..... 0 0 1 1 0 1 1 0 2 2 1 0 1 0 0 2 

Illinois ....... 4 4 0 2 0 3 2 1 1 0 1 0 0 1 0 12 

Indiana ...... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

bwa ......... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Kentucky ..... 1 1 1 2 2 0 3 2 3 4 4 2 1 0 1 7 

Maryland ..... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

New Mexico ... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 

Ohio ........ 1 0 1 1 3 0 0 0 1 1 0 0 1 0 0 6 

Pennsylvania . . 1 0 1 1 3 1 2 0 2 3 3 2 3 1 1 6 

Tennessee .... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Utah ........ 0 0 1 1 1 1 1 0 1 1 1 1 0 0 0 3 

Virginia ...... 1 0 1 1 3 2 4 1 1 0 2 1 2 0 1 6 

West Virginia .. 1 5 5 2 2 2 1 1 3 4 1 1 0 0 3 15 

Wyoming ..... 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 

Total ...... 10 10 14 13 15 11 14 7 17 15 13 7 8 2 8 62 

Table 2.4nderground coal mine production by State and year. lo6tons 

State 1978' 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1978- 

82 

Alabama ..... 7.8 8.4 9.5 8.6 11.3 10.9 13.2 14.4 13.2 14.3 14.8 16.3 17.5 17.1 15.9 45.6 

Colorado ..... 5.6 6.1 6.2 6.6 6.6 5.6 6.4 6.3 5.5 5.6 6.9 8.5 10.6 9.6 10.2 31.1 

Illinois ....... 32.2 32.7 35.0 29.2 34.7 31.8 38.5 37.3 39.7 37.5 38.5 39.3 41.7 43.1 47.0 163.8 

Indiana ...... 0.7 0.8 0.7 0.6 1.6 1.8 2.2 2.1 1.9 2.4 2.4 2.5 3.1 2.8 2.6 4.4 

Iowa ......... 0.2 0.1 0.2 0 0 0 0.2 0.2 0.1 0 0 0 0 0 0 0.5 

Kentucky ..... 74.9 73.4 75.0 77.2 74.8 64.8 78.2 80.3 87.2 92.1 94.1 98.6 105.3 97.3 95.7 375.3 

Maryland ..... 0.5 0.9 1.6 1.7 1.9 1.6 2.2 1.8 2.5 2.4 2.1 1.8 2.1 2.6 2.4 6.6 

NewMexico ... 0.8 0.8 0.9 0.8 0.7 0.1 0.6 0.8 0.8 0.6 0.2 0 0 0 0.1 4.0 

Ohio ........ 15.5 14.5 12.9 10.7 12.2 10.8 14.1 13.6 14.4 12.6 11.3 10.8 12.9 12.2 12 65.8 

Pennsylvania .. 42.5 43.3 41.5 34.2 35.5 34.5 36.9 35.5 36.8 37.8 38.8 39.1 40.1 40.6 44.7 197.0 

Tennessee .... 5.2 4.3 4.7 5.1 4.5 4.4 5.2 5.1 5.2 4.8. 4.6 4.6 4.5 3.1 2 23.8 

Utah ........ 11.3 12.0 13.3 13.8 17.0 11.8 12.3 12.8 14.3 16.5 18.2 20.1 22.1 21.9 21.3 67.4 

Virginia ...... 27.3 27.4 31.4 32.3 31.0 26.8 32.6 33.3 33.8 36.7 37.6 35.9 39.1 34.1 34.6 149.4 

West Virginia . . 83.6 91.3 95.8 89.1 103.5 91.9 105.8 103.5 103.1 107.2 109.8 113.1 123.3 119.8 115.1 463.3 

Wyoming ..... 0.9 0.7 0.9 1.3 1.3 1.3 1.3 1.1 0.2 0.1 1.1 1.6 1.7 2.4 2.5 5.1 

Total ...... 309.0 316.7 329.6 311.2 336.6 298.1 349.7 348.1 358.7 370.6 380.4 392.2 424.0 406.6 406.1 1,603.1 1

'includes fourth quarter 1977. 

Source: MSHA (4). 
Tabk 3.4lre Incidmw rate by St.1. and yoar 

State 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1978

82 

Alabama ..... 0.128 0 0 0.233 0.088 0.092 0 0.139 0.227 0 0 0 0 0 0.063 0.00

Colorado ..... 0 0 0.161 0.152 0 0.179 0.156 0 0.364 0.357 0.145 0 0.094 0 0 0 

Illinois ....... 0.124 0.122 0.057 0.068 0 0.094 0.052 0.027 0.025 0 0.026 0 0 0.023 0 0.07

Indiana ...... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

kwa ......... 0 0 0 0 0 0 . 0 0 0 0 0 0 0 0 0 0 

Kentucky ..... 0.013 0.014 0.013 0.026 0.027 0 0.038 0.025 0.034 0.043 0.043 0.020 0.009 0 0.010 0.01

Maryimd ..... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Fkw Mxim ... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 10.000 0 

Ohio ........ 0.065 0 0.078 0.093 0.246 0 0 0 0.069 0.079 0 0 0.078 0 0 0.091 

Pennsylvania . . 0.024 0 0.024 0.029 0.085 0.029 0.054 0 0.054 0.079 0.077 0.051 0.075 0.025 0.022 0.030 

Tennessoa .... 0 0 0 0 0 .0 0 0 0 0 0 0 0 0 0 0 

Utah ........ 0 0 0.075 0.072 0.059 0.085 0.081 0 0.070 0.061 0.055 0.050 0 0 0 0.04

Wrginla ...... 0.037 0 0.032 0.031 0.097 0.075 0.123 0.030 0.030 0 0.053 0.028 0.051 0 0.029 0.04

WestWrginla .. 0.012 0.055 0.052 0.022 0.019 0.022 0.009 0.010 0.029 0.037 0.009 0.008 0 0 0.026 0.03

Wyoming ..... 0 0 1.111 0 0 0 0 0 0 0 0 0 0 0 0 0.19

ToW ...... 0.033 0.032 0.043 0.043 0.046 0.038 0.041 0.021 0.049 0.042 0.035 0.018 0.019 0.005 0.020 0.04
COALBED THICKNESS 

Table 4 shows the number of fires that occurred during 

the three major time periods and the total number of fires 

by various ranges of coalbed thickness. Table 5 shows 

underground coal mine production by year for the same 

coalbed thickness ranges. Table 6 shows the number of 

reported fires, number of fires per million tons of production, and expected number of fires if fires occurred in 

linear proportion to production. Over three-quarters of all 

fires for which coalbed thickness was reported occurred in 

mines having coalbed thicknesses from 49 to % in. The 

range from 73 to 96 in had the highest number of fires per 

million tons of production. Figure 2 shows reported fires, 

expected fires, fire incidence rates, and underground coal 

mine production by coalbed thickness. An upward trend 

is evident in the fire incidence rate from thinner to thicker 

coalbeds. 

Table 4.--Number of fires by coalbed thickness and time perlod 

Coalbed thickness, in 197& 1983- 1988- Total 

82 87 92 

36 or less ............. 3 2 4 9 

37t048 .............. 5 2 4 11 

49 to 60 .............. 14 20 8 42 

61 to 72 .............. 7 11 8 26 

73 to 96 .............. 18 15 8 41 

More than 96 .......... 3 7 2 12 

Not reported .......... 12 7 4 23 

Total .............. 62 64 38 164 

0.05 Key 

Coal 

production 

Number of 

fires per 

year 

Incidence 

rate 

MINE SIZE 

Fire data were analyzed with respect to mine size using 

two independent measures of mine size: mine production 

tonnage and number of underground employees. However, the reader is cautioned that previous research by the 

USBM and others has caused the reliability of selfreported accident data by small mines to be questioned 

(24). For a variety of reasons, small mines have been 

shown to underreport accidents that do not result in a 

serious injury or fatality. Since most fires do not cause an 

injury or fatality, it is probable that small mincs are 

underrepresented in the fire data. The analysis in this 

section (and throughout the report) is based almost entirely on fires that were self-reported by mining companies 

without attempting to correct for the probable reporting 

bias. 

Table 7 shows fires by mine size as defined by daily 

production tonnage. The most fires occurred at mines 

having production greater than 2,000 tons pcr day. However, as shown in table 8, mines producing more than 

2,000 tons per day account for the grcatcst perccntage of 

overall production. Therefore, it is logical that thcsc 

mines should also account for the most fires. 

A more meaningful representation of the data rcquircs 

the number of fires within each mine size category to bc 

compared to that category's proportion of total production. 

Table 9 shows the numbcr of rcportcd fircs by daily 

production tonnage, incidcncc ratcs, and cxpcctcd numbcr 

of fires if fires wcrc in lincar proportion to production 
0.04 Key 

Number of 

fires 

0.03
 -1 Number of 

expected fires 

--f-	Incidence 

rate 

0.02 --l--.Coal 

production 

. . 

COALBED THICKNESS, in 	 Ib 

Table 5.4nderground coal mine production by coalbad lhlcknesr and year, 10'tons 

Coalbed 1978' 1979 1980 1981 1982 1983 1984 1985 1986 1987 

thickness. in 

36 or less . . . . . . 20.9 25.0 25.5 26.7 27.0 23.0 29.7 26.5 31.0 28.0 

37 to 48 . . . . . . . 82.6 79.2 79.5 78.8 . 78.2 65.1 75.9 78.1 77.9 83.0 

49 to 60 . . . . . . . 78.0 84.0 87.3 78.7 85.2 71.4 82.9 97.5 90.7 94.5 

61 to 72 . . . . . . . 46.6 44.4 52.5 47.8 51.6 54.3 63.3 47.4 53.9 65.6 

73 to 96 . . . . . . . 56.3 65.5 64.8 59.8 72.7 . 67.0 78.4 83.3 85.6 78.1 

More than 96 .. . 19.8 18.3 19.7 19.4 21.9 17.6 19.8 16.1 19.4 22.0 

Total . . . . . . . 304.2 316.4 329.3 311.2 336.6 298.4 350.0 348.9 359.0 371.2 

1988 1989 1990 1991 1992 1978-82 1983-87 1-92 Total 

37 to 48 .. . . . . . 80.5 87.8 77.6 77.2 71.9 398.3 380.0 395.0 1,173.0 

49 to 60 . . . . . . . 93.2 93.7 85.8 81.5 78.8 41 3.2 437.0 433.0 1.283.0 

61 to 72 . . . . .. . 68.5 72.4 81 .O 85.0 86.3 242.9 284.5 393.2 920.6 

73 to 96 . . . . . . . 76.0 72.8 83.6 78.4 75.9 319.1 392.4 386.7 1,098.0 

More than 96 . . . 29.0 34.8 37.8 36.0 39.2 99.1 95.4 176.8 371.3 

Total . . . . . . . 380.4 392.6 423.7 406.3 406.3 1.597.0 1,727.0 2.009.3 5.333.3 

'includes fourth quarter 1977. 

Source: MSHA (4) 

Mincs producing 401 to 800 tons pcr day cxpcricnccd the The other independent measure of mine six is the 

fcwcst fircs rclativc to production; mincs producing grcatcr numbcr of underground employccs. Table 10 shows the 

than 2,000 tons pcr day cxpcricnccd thc grcatcst numbcr numbcr of reported fires by minc size as defined by numof fircs rclativc to production. bcr of underground employees. The greatest number of 
fires was reported at mines having more than 250 under- experienced the greatest number of fires relative to 

ground employees. However, as shown in table 11,mines production. 

employing more than 250 underground workers also ac- Figures 3 and 4 show reported fires, expected fires, fire 

count for the greatest percentage of overall production; incidence rates, and underground coal mine production by 

therefore, the higher number of fires does not necessarily mine size, defined by daily production tonnage and numindicate a greater hazard. Just as was true in the earlier ber of underground employees, respectively. Increasing 

analysis, it is logical that these larger mines should also trends in both number of fires and fire incidence rates are 

account for the most fues. evident for both measures of mine size. However, as 

noted above, these results are valid only if reporting of 

Table 6.-Number of fires, fire incidence rate, and number fires is consistent between all size groups. 

of expected fires by coalbed thickness 

MINING METHOD Coalbed Number Fire inci- Number of 


thickness, in of fires dence rate expected fires 


Underground coal mines in the United States are cate- 36 or less ..... 9 0.01 8 12.9 

37to42 ...... 11 0.009 31.O gorized as either longwall or room and pillar, depending 

43to60 ...... 42 0.033 33.9 on the extraction system used. The layout of longwall 

61 to72 ...... 26 0.028 24.3 mine workinas - is considerablv different than the room73to96 ...... 4 1 0.037 29.0 and-pillar arrangements employed in continuous and conMore than 96 . . 12 0.032 9.8 ventional mining. In turn, these differences profoundly Total known ... 141 NA NA 

Not reported . . 23 N A 141.o affect ventilation, haulage, emergency escape routes, and 

other mine characteristics that impact fire safety. There- Total ...... 164 NA NA 

fore, an analysis of reported fires and fire incidence rates NA Not available. by mining method (longwall or room and pillar) is of considerable interest. 

Table 12 shows the number of reported fues by number The MSHA Accident Investigation Reports used as the 

of underground employees, incidence rates, and expected primary source of fire incident data for this report 

number of fues if fires were in linear proportion to pro- provided mining method information in about 50 pct of 

duction. Mines employing 35 to 99 underground workers cases. For the cases where the mining method was 

experienced the fewest fires relative to production, where- omitted from these reports, information on the mining 

as mines employing 250 or more underground workers method was obtained from the "Longwall Census" reports 

Table 7.--Number of fires by daily underground coal mine production tonnage range and year 

Production, tons 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 

per day 

otom ......... 
 201 to 400 ....... 
 401 to 800 ....... 
 801 to 2,000 ...... 
 More than 2,000 ... 
 Not reported ..... 
 Not producing .... 
 Total ......... 


1988 1989 1990 1991 1992 1978-82 1983-87 1988-92 Total 


otom ......... 2 0 1 0 0 2 0 3 5 


201 to 400 ....... 0 2 0 0 0 3 3 2 8 


401 to 800 ....... 0 0 0 0 0 2 5 0 7 


801 to 2,000 ...... 2 0 0 0 2 4 11 4 19 


More than 2,000 ... 8 5 6 2 4 35 35 25 95 


Not reported ..... 1 0 1 0 2 16 7 4 27 


Not producing .... 0 0 0 0 0 0 3 0 3-
 Total ......... 13 7 8 2 8 62 64 38 164 

Table 8.--Underground coal mlne production by dally production tonnage range and year 

Production, tons 1978~ 1979 1980 1981 1982 1983 1 984 1985 1 986 1987 

per day 

0 to 200 ........ 38.6 22.6 20.5 22.8 23.5 19.0 18.0 16.7 17.4 15.7 

201to400 ...... 31.8 29.5 32.0 34.3 33.2 27.9 29.3 28.0 25.3 24.5 

401 to800 ...... 39.9 35.7 39.2 40.9 41.1 36.0 43.0 38.7 37.6 36.8 

801 to 2,000..... 69.5 62.8 70.4 71 .O 65.0 48.6 59.0 61.5 62.9 61.2 

More than 2,000. . 128.9 165.7 167.3 142.4 174.2 166.9 200.7 203.8 215.7 232.9 

Total ........ 308.7 316.3 329.4 311.4 337.0 298.4 350.0 348.7 358.9 371.1 


1988 1989 1990 1991 1992 1978-82 198387 198892 Total 

0 to 200 ........ 14.0 12.2 11.8 9.6 8.1 128.0 86.8 55.7 270.5 

201to400 ...... 21.3 21.9 21.1 19.3 16.5 160.8 135.0 100.1 396.0 

401t0800 ...... 39.8 38.4 40.0 32.1 30.3 196.8 192.1 160.6 569.5 

801 to 2,000..... 64.0 64.7 75.4 73.3 72.1 338.7 293.2 349.5 981.4 

More than 2,000.. 241.5 255.4 275.3 272.1 279.3 778.5 1,020.0 1,323.0 3.122.0 

Total ........ 380.6 392.6 423.6 406.4 406.3 1.602.0 1,727.1 2,009.0 5.338.1 


'includes fourth quarter 1977. 

Source: MSHA (4). 

Table 9.--Number of fires, fire incidence rate, and number conducted by "Coal Mining & Processing" magazine (name 

of expected flres by dally underground coal changed to "Coal Mining" in 1984 and then changed to mlne production tonnage range "Coal" in 1988) for the years 1982 and 1984 through 1992 

Production, tons Number Fire inci- Number of (25-35). A summary of fire incidents in longwall and 

per day of fires dence rate expected fires room-and-pillar mines from 1982 through 1992 is shown in 

Otom ......... 5 0.018 6.8 table 13. The reader is cautioned that these data -- are

MIto 400 ....... 8 0.020 9.9 classified by mine type and not by location within a mine. 


401 to 800 ....... 7 0.012 14.3 Fires in a longwall mine could have occurred at a longwall 
 801 to 2,000...... 19 0.019 24.6 

More than 2.000 ... 95 0.030 78.4 face or somewhere else in a longwall mining section. 

Total known ...... 134 NAp 134.0 However, they might also have occurred in another uart of . - -

Unknown or not the mine and involve equipment and procedures that are reported ........ 30 NAp NAp 
 common to both longwall and room-and-pillar mines. Total ......... 1 64 NAD NAo
 7 

NAp Not applicable. 

Table 10.4umber of fires by number of underground employees and year 

Number of 1978 1979 1980 1981 1982 1983 1 984 1 985 1986 1987 

employees 

11034.......... 0 0 1 2 3 1 1 1 1 2 

35 to 99 ......... 0 1 0 1 0 0 3 0 1 2 

100to 249 ....... 0 0 2 2 1 3 6 1 5 4 

250 or more ...... 8 5 5 7 9 3 4 5 7 3 

Not reported ..... 2 4 6 1 2 '4 0 0 3 4 

Total ......... 10 10 14 13 15 11 14 7 17 15 


1988 1989 1990 1991 1992 197842 1983-87 198892 Total 

1 to 34 .......... 2 2' 1 0 0 6 6 5 17 

35 to 99 ......... 2 0 1 0 1 2 6 4 12 

100 to 249 ....... 4 1 1 0 2 5 19 8 32 


250 or more ...... 5 4 4 2 3 34 22 18 74 

Not reported ..... 0 0 1 0 2 15 11 3 29 

Total ......... 13 7 8 2 8 62 64 38 164 


'includes three fires that ocurred in temporarily inactive mines. 
- - -- 

Table 11.4nderground coal mlne production by number of underground employees and year, 106tons 

Number of 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 


employees 


1 to34 ......... 35.9 46.0 53.4 55.5 61.2 57.4 69.6 67.7 71.O 72.1 

351099.. ...... 34.7 40.4 45.0 48.3 50.0 43.0 53.1 52.9 57.6 58.6 

loot0249 ...... 56.8 69.3 78.3 75.6 75.5 69.6 79.0 83.6 91.1 100.2 

250 or more ..... 101.3 144.2 143.8 120.0 141.6 121.7 140.3 137.8 132.6 133.1 

Total .....:.. 228.7 299.9 320.5 299.4 328.3 291.7 342.0 342.0 352.3 364.0 

1988 1989 1990 1991 1992 197882 1983-87 1988-92 Total 


1 to 34 ......... 75.1 77.7 83.4 74.0 78.6 252.0 337.8 388.8 978.6 

35 to 99 ........ 68.6 73.6 80.6 82.0 81.1 218.4 265.2 385.9 869.5 

100to249 ...... 90.1 95.3 102.4 101.2 99.9 355.5 423.5 488.9 1,267.9 

250 or more ..... 142.7 139.9 152.7 146.3 143.8 650.9 665.5 725.4 2,041.8 

Total ........ 376.5 386.5 419.1 403.5 403.4 1,476.8 1,692.0 1,989.0 5,157.8 

Source: MSHA (8-22). 

Table 12--Number of fires, fire Incidence rate, and number Table 13.--Number of flres by year and mining method 


of expected flres by number of underground employees 


Year Longwall Room and pillar 


Number of Number Fire inci- Number of 1982 .............. 5 10 


employees of fires dence rate expected fires 1983 .............. 
 1984 ..............
 1 to34 .......... 17 0.017 25.6 
 1985 ..............
 351099 ......... 12 0.014 22.8 
 1986 ..............
 100to 249 ....... 32 0.025 33.2 
 1987 .............. 
 250 or more ...... 74 0.036 53.5 1988 .............. 
 Total (known) ..... 135 N& 135.1 1989 .............. 
 Unknown or not 1990 .............. 
 reported ........ 29 NAP NAP 1991 .............. 
 Total ......... 164 NAI, NAI, 1992 .............. 


NAp Not applicable. Total ............ 


0.04 Key 

BNumber of 

0

fires 

Number of 

0.03 expected fires 

+Incidence 

rate 

&Coal 

0.02 production 

b 


.PRODUCTION, tons per day 

~qf~nwnbaqfeqxcted~~~emte,and~cwlmitu

'by


tmmqp me 1978-92 

0.04 K ey 

Number of 

fires 

Number of 

0.03 expected fires 

+Incidence 

rate 

I	Coal 

production 

0.02 

1 to 34 35 to 99 100 to 249 250 or more 

NUMBER OF UNDERGROUND EMPLOYEES 

1-1 

For fire incidence rate calculations, coal production 

data from longwall operations are required. However, 

until quite recently, such industry-wide data were not 

routinely collected and published. DOE'S Energy Information Administration collccts coal mine production data 

from mining companies on its EIA-7A form. This form 

was modified to include questions on production method 

(longwall or room and pillar) in 1989, and production 

method data were first published in 1990. 

For the years 1990 through 1992, DOE reports that 

longwall mining accounted for 29, 29, and 31 pct, respcctivcly, of total underground coal production. Evcn these 

figures are suspect, however. In 1991, mining equipment 

manufacturers and suppliers estimated longwall faccs 

accounted for 37 pct of production from U.S. underground 

coal mincs (36). Using the DOE longwall production 

data for the 1990-1992 period, the incidence rate for fires 

in longwall operations was 0.022. The incidcnce rate for 

fires in room-and-pillar operations during the same time 

period was 0.012. Based on the equipment manufacturers' 

and suppliers' estimate of longwall production, the incidence ratcs would be 0.017 and 0.013, rcspcctivcly. These 

results suggest a somcwhat higher halard may exist in 

longwall mines. 

IGNITION SOURCE 

Reported fires by ignition source for the three major 

time periods are listed in table 14 and illustrated in 

figure 5. Of the 164 fires reported to MSHA, the ignition 

source was known and reported in 140 cases. The leading 

underground coal mine fie ignition source for the 1978 

through 1992 period is electrical, accounting for over 

41 pct qf all fues for which the ignition source was known 

and 35 pct of all fires. Electrical fires include fues that 

resulted directly from an electrical fault or failure, such as 

a short circuit or insulation failure. Not all fires on 

electrically powered equipment were necessarily classified 

as electrical fires. Such fires were classified as electrical 

only if the fire originated from an electrical fault or 

failure. 

The second leading cause of fires was friction, accounting for about one-quarter of all fires for which the 

ignition source was reported. Frictional fires include 

conveyor belts rubbing on pulleys or stationary objects, 

ovcrheatcd brakes, overheated compressors, etc. The frcquency of electrical fires declined over time, whereas fires 

caused by frictional sources increased. For the most rccent time period, friction was the leading caw of fires. 
I 

Welding and flame cutting 

Spontaneous combustion 

Electrical 

Friction 

1978-82 

1983-87 

Other I= 

Unknown or not reported 

0 10 20 30 

NUMBER OF FIRES 

Table 14.--Number of flrer by ignition source and lime period 

Ignition source 1970- 1983- 1988- Total 

82 87 92 

Welding and flame cutting ... 10 10 6 26 

Electrical ................ 27 20 10 57 

Spontaneous combustion .... 8 9 4 21 

Friction ................. 8 13 11 32 

Other ................... '3 21 0 4 

Unknown or not reported .... 6 11 7 24 

Total ................. 62 64 38 164 

'overheated brakes, two roof falls. 

2~ooffall. 

164 fires that occurred during the period. Coal-coal dust 

was the most common burning substance, followed by 

electrical insulation, oil-grease, conveyor belt-rollers, and 

rubber hose-tires. Data from IC 8830 (5) for the 1953-77 

period show the same five lea- burning substances. As 

shown in figure 6, all burning substances experienced a 

drop in the number of fires over time, except for conveyor 

belt and rollers, which showed an increase for each time 

period. 

Tablo 15.-dumber of flros by burning rubstance 

@ndlime period 

Referring to IC 8830 (9,the leading ignition sources Substance 1970- 1983- 1988- Total 

82 87 92 during the 1970 through 1977 period were (in descending wood ................... 7 11 1 order) electrical, spontaneous combustion, welding and Rubber hose end tires . . , , . . 19 

12 7 6 25 

cutting, and friction. These same four ignition sources ma,and ......... ,,I dust 29 32 14 75 

accounted for the greatest number of fues in the 1978 Electrical insulation ........ 22 17 11 50 

through 1992 period, however in different rank order. Conveyor belt and rollers .... 7 8 12 27 

Oil and grease ............ 15 10 5 30 

.................. BURNING SUBSTANCE other1 5 8 4 17 

Not reported ............. 1 1 2 4 

Total(known) ............ 92 Table 15identifies the substances that were involved in 85 49 226 

the fires. These data are illustrated in figure 6. More l~-fylene, methane, branice, clothing, polyurethane foam, 

than one substance was involved in most fires, so the and 

column totals add to considerably more than the total of 
Key 

Wood 1978-82 

Rubber hose and tires 

Coal and coal dust 

Oil and grease 

Other 

Not reported 

NUMBER OF FIRES 

Number offins by bsuning sub- 1978-92 

UNDERGROUND LOCATION 	 is consistent with the 1950-77 data from IC 8830 (5).but 

in reverse rank order. Beghhg with the 198387 period 

The underground locations where coal mine fues and continuing through the 1988-92 period, the belt entry 

originated are listed in table 16 and illustrated in figure 7. becomes the leading fire location, hereas fires occurring 

In most cases, mine personnel were able to determine pre- in the track-haulage entry drop dramatically. The inaease 

cisely where the fire originated. In a few cases, mine in the number of fires in belt entries is probably related to 

personnel inferred the point of origin from their knowl- the increased utilization of belt haulage over the past 

edge of the location of specific fue hazards and the ' decade rather than an increased level of fue b d in belt 

behavior of the fue. entries. 

An haeasing trend is also evident for power centers or 

electrical equipment. However, the actual number of fires 

in this category is relatively low for all three time periods 

Location 1970- 1983- 1- TOW (1978-82,1983-87, and 1988-92). 

Shaft, elope, bottom, or station . . Track haulage .............. Beltentry .................. Working face ............... Intake entry ................ Power center or electrical 

equipment ................ Mined out, caved, or gob ...... Unknown or not reported ...... 

Other' .................... 

Total ................... 


'bturn entry, shop, and stockpile recovery tunnel. 

The most frequent fire locations before 1982 were the 

track-haulage entry and working face areas. This finding 

EQUIPMENT INVOLVED 

The equipment involved in underground coal mine 

fues is Listed in table 17 and illustrated in figure 8. The 

equipment category accounting for the grcatcsl number of 

fues during the 1978 through 1992 period was conveyorconveyor drive, followed by arc weldmg-oxyfuel cutting 

equipment, trolley vehicle-redirier, and power centertransformer-eledrical equipment. Increasing trends arc 

observed for roof bolters, power unters-transfonnerselectrical equipment, and conveyor-conveyor drives. However, the high number of fues associated with conveyors 

and conveyor drives makes that inaeasing trend the moat 

important. 
Figure 7 

Shaft, slope, 


bottom, or station 


Track haulage 


Belt entry 


Working face 


Intake entry 


Power center or 


electrical equipment 


Mined out, caved, or gob 

Unknown or not reported 

Other 

0 5 10 15 20 

NUMBER OF FIRES 

Arc welding or oxyfuel torch 

Air compressor 

Trolley vehicle or rectifier 

Shuttle car or scoop 

Cutting 

Roof 

machine- 


bolter e, 


Conveyor or conveyor drive 


Battery vehicle or charger-


Power center, transformer 


or electrical equipmen{ 


Continuous miner 


None 


Not reported 


.Other 


Unknown 


0 5 10 15 

NUMBER OF FIRES 
Table 17.--Number of fires by equipment involved and time period 

Equipment 1-72 1973-77 1978-62 198347 1986-92 197892 

Arc welding or oxyiuel torch ...................... 4 2 8 10 5 23 

Air compressor ................................ 3 4 7 5 0 12 

Trolley vehicle or rectifier ........................ 11 6 8 3 4 15 

Shuttle car or scoop ............................ 17 2 5 0 1 6 

Roofbolter ................................... 6 4 2 1 3 6 

Cutting machine .............................. 27 4 2 2 0 4 

Conveyor or conveyor drive ...................... 24 9 7 13 13 33 

Battery vehicle or charger ........................ N A NA 3 4 1 8 

Power center, transformer or electrical equipment ...... 4 9 3 7 4 14 

Continuousminer .............................. 8 1 4 1 1 6 

None ....................................... 49 21 12 13 4 29 

Notreported ................................. 0 0 0 0 1 1 

Other ....................................... 12 0 1 4 0 '5 

Unknown .................................... 2 0 0 1 1 2 

Total ..................................... 167 62 62 64 38 164 

NA Not available. 


'car spotter, two diesel trucks, and two water pumps. 


Although all other equipment types show downward 

trends, two categories are particularly noteworthy. The 

number of fires on cutting machines showed a marked 

downward trend, especially for the 1%8 to 1972 period 

versus the post-1972 period. This finding is consistent with 

the downward trend in conventional mining, which is the 

only mining method to utilize the cutting machine. The 

other noteworthy downward trend was in the "none" category, which also dropped dramatically, meaning that more 

and more fires in recent years have involved mining 

equipment. 

One of the more significant trends in underground coal 

mining equipment utilization in recent years is the increasing application of diesel-powered mobile equipment. 

This trend has been accompanied by increasing safety 

concerns related to the storage, handling, and use of large 

quantities of diesel fuel underground, and the potential 

fire risks associated with the mobile equipment itself. 

However, these data do not indicate a serious problem. 

Only, two diesel equipment fires are included in table 17, 

and referring to table 15, reported fires involving rubber 

hose and tires and oil and grease are declining. 

DETECTION METHOD 

The methods by which underground coal mine fires 

were detected are listed in table 18 and illustrated in 

figure 9. The leading methods were miners who were 

present when the fire started, and miners who saw or 

smelled smoke at some time after the fire started. These 

two methods accounted for 112 of the 164 fires, or 68 pct 

during the 1978 through 1992 period. This compares to 

693 out of 987 fires, or 70 pct for the 1953 through 1977 

period. Two other findings from the detection data are 

noteworthy. Despite the high number of fires occurring on 

conveyors (the most frequent equipment involved in fires), 

and MSHA regulations which, until recently, required 

thermal detection systems on belt lines and at belt drives 

(carbon monoxide gas or smoke detection systems may 

now be used in place of thermal detection systems), only 

two fires, or 1.2 pct, were detected by belt fire detedion 

systems. In several instances where belts were involved in 

fues, the belt fire detection system did alarm; however, it 

was after the fire had been detected by other means. This 

finding is consistent with a large body of conveyor belt 

entry fue detection research, which indicates the relative 

insensitivity of spot-thermal belt fire detection systems. 

Table 18.--Numkr of fires by method of d.1.ctlocr 

and time period 

Method of detection 1978-

Miner saw fire start ............ 18 

Miner saw fire or smoke ........ 27 

Preshifter sew or smelled smoke . . 3 

Surface personnel aaw smoke ... 7 

Air samples contained gases .... 4 

Electric power lost ............ 1 

Belt detection system .......... 1 

Mine-wide monitoring system .... 0 4 2 6 

Not reported ................ 1 4 2 7 

Total .................... 62 64 38 164 

Finally, it is noteworthy that mine atmosphere analysis 

accounted for 13 fires or 7.9 pct. Six of these fires were 

detected by a mine-wide monitoring system. With increased usage of mine-wide monitoring systems, mine 

atmosphere analysis can be expected to become a more 

common means of fire detection in the future. However, 

even more importantly, the reader is reminded that the 

source of data for this analysis consisted almost entirely of 

reportable fires, meaning that they caused an injury or 
Miner saw fire stort 

Miner saw fire or smoke 

Preshifter saw 

or smelled smoke 

Surface personnel saw smoke k 

Air samples contained gases P 

Electric power lost b 

Belt detection system t 

Mine-wide monitoring system b 

Not reported b 

0 5 10 

NUMBER OF FIRES 

were noninjury fires lasting longer that 30 min. Since 

mine-wide monitoring systems are capable of detecting 

fires in their early stages, it is quite possible, and indeed 

probable, that a much larger number of fires were actually 

detected by mine-wide monitoring systems than the data 

in table 17indicate. However, the fires would likely have 

been discovered while they were still very small and easily 

extinguished, hence not causing injury or lasting longer 

than 30 min and, therefore, not having to be reported to 

MSHA. Although the low number of fires detected by 

conveyor belt thermal fire detection systems might be 

attributed to this same reasoning, such an explanation is 

unlikely because of the well-documented slow response 

time of these systems. 

TIME OF DAY 

The time of day (expressed as an interval corresponding 

to day, evening, or night shift) when underground coal 

mine fires were first discovered is listed in table 19 and 

illustrated in figure 10. These times are not intended to 

represent the time when the fues actually started. However, in many cases, personnel were present at the time, or 

very close to the time when the fires started. In a few 

cases, particularly for spontaneous combustion fires, discovery lagged initiation by a considerable amount, and a 

definitive determination of the time when initiation occurred was impossible. For consistency in data reporting, 

1.
 1978-82 


the times indicated in table 19 are the time of day when 

the fires were first discovered and reported. 

Table 19.--Number of firer by lime of day and lime perlod 

Time of day 1978-82 1983-87 198892 197892 -- 

07:OO to 14:- . . . . . 25 20 19 64 

15:OOto22:59 . . . . . 24 16 9 49 

23:OOto 0659 . . . . . 12 21 9 42 

Not repofled . . . . . . 1 7 1 9 

Total . . . . . . . . . . 62 64 38 164 

The greatest number of fires was discovered on the day 

shift, followed by the evening shift and night shift. However, these findings are not particularly useful. Since the 

mining activity that correlates with both the occurrence 

and discovery of fires is generally greater during the day 

shift, one would expect more fires to occur and be discovered during the day shift. A more meaningful and revealing insight would be provided by determining whether 

the discovery of fires during a particular shift was in 

proportion, or not in proportion to the level of mining 

activity occurring during that shift. 

It was not possible to precisely determine whether the 

discovery of fires was in proportion to the level of mining 

activity on a given shift because data quantifying the level 

of underground coal mining activity occurring during each 

shift were not available. However, an indication of the 
Not reported 

0 5 10 

NUMBER OF FIRES 

level of mining activity was obtained from a U.S. Bureau 

of Labor Statistics (BLS) survey of shiftwork practices in 

various U.S. industries (37). These data show that about 

81.7 pct of the mining work force is employed on the day 

shift, 7.5 pct on the evening shift, and 10.8 pct on the night 

shift. 

These data are not necessarily representative of shiftwork practices specific to the underground coal minirig 

industry ("mining" as defined in the BLS survey includes all 

sectors of the mining industry, including surface and 

underground metal, nonmetal, and coal mining, as well as 

oil and gas production). However, using the BLS factors 

to estimate the expected number of fues discovered on 

each shift, the discovery of fires on the day shift was 

considerably lower than expected, and the discovery of 

fues on the evening and night shifts was considerably 

higher than expected. 

TIME OF YEAR 

Reported fires by time of ye'ar are listed in table 20 and 

illustrated in figure 11. Data are shown grouped by 

season, with fall including September through November, 

winter including December through February, spring including March through May, and summer including June 

through August. No dramatic trends are evident in the 

15 20 25 

data; however, a slight decrease was noted for the winter 

months during the most recent time period. 

Time of war 1978-82 1983-87 1-92 1970-92 

Fall . . . . . . . . . . . . . 18 16 10 44 

Wnter . . . . . . . . .. . 16 12 6 34 

Spring ........... 16 18 12 46 

Summer.. . . . . . . . . . 12 18 10 40 

Total . . . . . . . . . . 62 64 38 164 

INJURIES AND FATALITIES 

Table 21 shows injuries and fatalities caused by underground coal mine fires from 1978 through 1992, and the 

location, equipment involved, and ignition source for each 

fire that caused an injury or fatality. Over thii 15-year 

period, a total of 17 fires caused 43 injuries and 30 fatalities. The injury incidence ratc (injuries per 100 million 

tons of coal mined) over this period was 0.82 and the 

fatality incidence rate (fatalities per 100 million tons of 

coal mined) was 0.57. The injury incidence rate during thc 

1950 through 1977 period was 235, or 2.86 times the 1978 

through 1992 ratc. The fatal incidence rate over the 1950 

through 1977 period was 0.79, or 138 times the 1978 

through 1992 rate. 
Key Fall 

1978-82 

Spring 

Summer 

0 5 10 

NUMBER OF FIRES 

Table 2l.lnjurles and fatal fires by year, number of injuries and/or fatalities, location, equipment Involved, and ignition source 

Year Number of Number of Location Equipment involved Ignition source 

injuries fatalities 

1978 .......... 0 1 Shaft bottom .............. Oxyacetylene torch ..... flame cutting. 

6 0 Track entry ................ Trolley line ............ Electrical. 

1979 .......... 1 0 ..do. .................... .do. ................ Electrical. 

1980 .......... 2 0 Working face ............... Shuttle car ............ Electrical. 

1981 .......... 1 0 Track entry ................ Trolley line ............ Electrical. 

1982 .......... 1 0 Not reported .............. Oxyacetylene torch ..... Flame cutting. 

2 0 Track entry ................ Air compressor ......... Friction. 

1984 .......... 10 0 Longwall headgate .......... Power cable ........... Electrical. 

0 27 Main intake ............... Air compressor ......... Friction. 

1986 .......... 3 0 Longwall face .............. Oxyacetylene torch ..... flame cutting. 

2 1 Belt entry ................. Conveyor belt ......... Friction. 

1987 .......... 0 1 Working face .............. Continuous miner ....... Friction. 

3 0 Longwall headgate .......... Air compressor ......... Friction. 

1 0 Belt entry ................. Conveyor belt ......... Unknown. 

1988 .......... 5 0 ..do. .................... .do. ................ Friction. 

1992 .......... 1 0 Working face .............. Power center .......... Electrical. 

5 0 ..do. .................... Not re~orted .......... Not re~orted. 9 ~ 

Total ........ 43 30 NAp NAp NAp. 

NAp Not applicable. 

The most frequent locations for injury fires were the occurring at the shaft bottom, main intakc, bclt cntry, and 

track entry (4 fires, 10 injuries), working face (3 fires, workingface. From Id8830 (9,thc most frcqucn; loca8 injuries), and belt entry (3 fires, 8 injuries). The four tion for injury fires during thc 1970 through 1977 pcriod 

track entry fires all occurred before 1983, while the three was the working face (five fircs) and haulagcway (two 

belt entry fues all occurred after 1985. For fatal fires, no fires). For fatal fires, two wcrc locatcd at thc facc and 

single location accounted for more than one fire, with fires three were outby during thc 1970-77 pcriod. 
The equipment most frequently involved in injury fires agent, followed by dry chemicals. Use of rock dust was 

was the trolley line (three fires, eight injuries) and con- more common than sealing (including both sealing with 

veyor belt (three fues, eight injuries). Oxyacetylene and without carbon dioxide or nitrogen injection). Howcutting torches and air compressors were each involved in ever, sealing was successhd in extinguishing more fires 

two injury fires. No single type of equipment was involved than rock dust. Fire-fighting usually involved the use of 

in more than one fatal fire, with fues involving an oxy- more than one extinguishing agent, and, often, more than 

acetylene torch, air compressor, conveyor belt, and con- one extinguishing agent was required for successful extinuous miner. From IC 8830 (3,the equipment most fre- tinguishment. Thus, the totals in both attempted extinquently involved in injury fues during the 1970 through guishment and successful extinguishment add to more than 

1977 period was oxyacetylene cutting torches, with three the total number of fires that occurred during the period. 

fires. For fatal fues, no type of equipment was involved in The success rate for the various extinguishing agents is 

more than one fire during the 1970-77 period. also shown in table 22 for all time periods. The success 

The most common ignition sources for injury fires were rate is the ratio of the number of fires that were sucelectrical (6 fires, 20 injuries), friction (4 fues, 10 injuries), cessfully extinguished with a given agent to the number of 

and flame cutting (2 fires, 4 injuries). The ignition source fires in which an attempt was made to extinguish the fire 

for three of the four fatal fires was friction; however, the with that agent. 

source of the friction was different in all three cases This analysis is not intended to suggest that one agent 

(overheated air compressor, stuck idlers on conveyor belt, is inherently more effective in fighting coal mine fires than 

frictional ignition of methane at a working face). From IC another agent based solely on the difference in the number 

8830 (9,the most common ignition source for injury fires of successful attempts or success rate. Other factors were 

during the 1970 through 1977 period was electrical (six often significant, such as the quantity of agent immediately 

fires), with no other ignition source accounting for more available to fire fighters and the size of the fue. 

than one fire. During that time period, all five fatal fires In the case of water versus rock dust or dry chemical 

were electrical in origin. extinguishers, for example, fire fighters might use rock 

dust or dry chemicals to suppress a fire while a hose line 

METHOD OF EXTINGUISHMENT is connected and extended to the fire area. Total extinguishment could be achieved with water, and table 22 inThe attempted and successful extinguishing agents for dicates water as the successful extinguishing agent. Howunderground coal mine fires from 1978 through 1992 are ever, successful extinguishment might not have been 

listed in table 22. Figure 12 shows successful extinguishing possible without the temporary control of the fire using 

agents only. For all three time periods, water was the rock dust or dry chemical efiinguishers. 

most common attempted and successful extinguishing 

Table 22.--Number of fires by method of extinguishment, time period, and number of attempts, numbw 

of successful attempts, and success rate of extmgulrhm.nt 

1978-62 1983-87 

Method of extinguishment Number of Number of suc- Success Number of Number of urc- Succrss 

attempts cessful attempts rate attempts cbrsful attempts rate 

Rockdust .................. 21 11 0.52 13 11 0.85 

Dry chemicals ............... 32 13 0.41 17 12 0.71 

Sealing with CO2or N2 injection . . 10 10 1 .OO 7 5 0.71 

Water ...................... 39 34 0.87 35 28 0.80 

Sealing only ................. 3 3 1.00 9 6 0.67 

Other ...................... 6 8 NA 7 4 NA 

Not reported ................ 3 3 NA 1 1 NA 

1-92 1970-92 

Number of Number of suc- Success Number of Numbor of urcattempts cessful attempts rate attempts cessf~lattempts rate 

Rockdust .................. Dry chemicals ............... 10 

25 

3 

9 

0.30 

0.36 

44 

74 

25 

34 

0.U 

0.46 

Sealing with C02or N, injection . . 2 2 1.00 19 17 0.89 

Water ...................... 40 24 0.60 114 86 0.75 

baling only ................. 7 6 0.86 19 15 0.79 

Other ...................... 9 2 NA 22 14 NA 

Not reported ................ 4 4 NA 8 8 NA 

NA Not available. 
Rock dust 

Dry chemical 

Sealing with C02 

or N2 injection 

Sealing only 


Other P88889 


Not reported P7 


0 5 10 15 20 25 30 35 

NUMBER OF FIRES 

Niunberofjhs by SUCC~metJuni of tztinguishrnent, 1978-92 

More importantly, it must be remembered that the data 

utilized in this analysis are limited, almost entirely, to 

reportable fires. However, it is believed that most fires 

are successfully extinguished before they become reportable (less than 30 min and without injury). For example, in IC 8830 (3,it is estimated that three times 

more fires are extinguished at the nonreportable stage 

than those that cause an injury or last longer than 30 min, 

thus becoming reportable. In order for a fue to be extinguished while still nonreportable, firefighting would 

almost certainly have to be initiated immediately, or within 

a very few minutes after those fires start. Dry chemicals, 

rock dust, and manually operated or automatic fue sup 

pression systems would be the most likely methods to be 

used immediately on a fire, thereby achieving extinguishment while the fire is still nonreportable. The relatively 

small number of cases of successful extinguishment for dry 

chemical, rock dust, and manually operated or automatic 

fire suppression systems is believed to relate more to their 

effectiveness in extinguishing fires than to their lack of use 

or lack of effectiveness. 

If it were possible to determine the success rate for 

extinguishing agents based on the total number of fires 

occurring rather than the number of reportable fues, the 

results would almost certainly be quite different than those 

shown in table 22. Again, referring to IC 8830 (5)where 

such data are included, the most common successful 

extinguishing agent for reportable fues from 1953 through 

1977 was water, but the most common successful extinguishing agent for nonreportable fues during that period 

was dry chemicals. 

Sealing a mine or portion of a mine is the fire extinguishing method of last resort and is implemented only 

when all other methods have been tried and failed, or 

eliminated from consideration. Sealing a mine or portion 

of a mine is laborious and dangerous work, extremely 

costly, risks the loss of considerable coal resources, and 

often prevents mine production activities for months or 

years. Carbon dioxide or nitrogen injection can add considerable expense to the already high costs of sealing a 

mine. Every attempt is made to extinguish a mine fire 

by means other than sealing. Thus, the number of fires 
where extinguishment was attempted by sealing is a measure of the failure of other fire-fighting methods. During 

the 1978 through 1992 period, 23 pct of mine fires required all or part of the mine to be sealed. The proportion of mine fires that were required to be sealed during the 1953 through 1977 period was exactly the same: 

23 pct. 

MINE EVACUATIONS 

The number and extent of mine evacuations implemented at mines experiencing reportable fires during the 

1978 through 1992 period are listed in table 23 and illustrated in figure 13. During this period, total mine 

evacuations were implemented in 74 out of 164 fires, or 

45 pct. During the 1978 through 1982 period, total mine 

evacuations were implemented in 23 out of 62 fires, or 

37 pct. During the 1988 through 1992 period, this proportion had increased to 20 out of 38 fires, or 53 pct. 

When considering both total evacuations and partial evacuations (evacuating inby personnel only), the proportion 

Mine successfully evacuated 

lnby personnel evacuated 

No wacuation 

Other 

Not reported Fr= 

1 1 I 

0 5 10 

NUMBER OF FIRES 

increased from 48 pct in the earlier time period to 68 pct 

in the later time period. The downward trend in the "no 

evacuation" category is clearly evident in figure 13. 

The fire report data do not support a definitive explanation for this increase in the percentage of fires 

resulting in total or partial evacuations. It may result from 

a generally increased level of knowledge of, and caution 

by, management regarding the risks to underground personnel from fire. 

Table 23.--Number of firer by degree of mine 

evacuation and time perlod 

Degree of evacuation 1978- 1983- 1988- 197% 

82 87 92 92 

Mine successfully evacuated . . 23 3 1 20 74 

lnby personnel evacuated ..... 7 11 6 24 

No evacuation ............. 21 17 6 44 

Other .................... 0 3 0 3 

Not reported .............. 11 2 6 19 

Total .................. 62 64 38 164 

I I I 1 1 

15 20 25 30 35 
CONCLUSIONS 


The major findings of this statistical analysis of un- than the rate for the 1978 through 1992 period. The 

derground coal mine fires are shown in table 24. For fatality incidence rate (fatalities caused by underground 

comparison purposes, table 25 contains the major findings coal mine fires per 100 million tons of coal mined) for the 

from IC 8830 (5). 1978 through 1992 period was 0.57. The fatality incidence 

During the 1978 through 1992 period, the overall fire rate for the 1950 through 1977 period was 0.79, about oneincidence rate (fires per million tons of coal mined) was thud higher than the rate for the 1978 through 1992 

0.031. The fire incidence rate for the 1950 through 1977 period. 

period was 0.115, over three times higher than the rate In comparing the 1950 through 1977 period to the 1978 

for the 1978 through 1992 period. The injury incidence through 1992 period, significant reductions in the incidence 

rate (injuries caused by underground coal mine fires per rates for total fues, injuries, and fatalities are clearly 

100 million tons of coal mined) for the 1978 through 1992 evident. However, since 1968, no downward trend is 

period was 0.82. The injury incidence rate for the 1950 evident in incidence rates for total fires, injuries, or 

through 1977 period was 2.35, over 2% times higher fatalities. 

Table 24.-Major findings of statistical analysis of underground coal mine fires, 1978-92 

Cateaow All fires lniuw fires Fatal fires 

Ignition source . . . . . . . . . . .. . . . . Electrical, friction, welding or Electrical, friction, welding or Friction, welding or cutting. 

cutting. cutting. 

Detection . . . . . . . . . . . . . . . . . . . . Miner saw or smelled smoke, Miner saw fire start, miner Miner saw fire start, miner saw 

miner saw fire start, examiner saw or smelled smoke. or smelled smoke. 

saw or smelled smoke. 

Burning substance . . . . . . . . . . . . . Coal, electrical insulation, Coal, electrical insulation, Coal, conveyor belt or rollers, 

conveyor belt or rollers. conveyor belt or rollers. electrical insulation. 

Equipment involved . . . . . . . . . . . . Conveyor belt, welding or cut- Trolley line, conveyor belt, Conveyor belt, air compressor, 

ting, trolley line, electrical welding or cutting, air welding or cutting, continequipment. compressor. uous miner. 

Location . . ... . . . .. .. . . . . . . . . . Belt entry, working face, intake Track entry, working face, Shaft bottom, intake aircourse, 

aircourse, track entry. belt entry, longwall. belt entry, working face. 

Successful extinguishing agent . . . . Water, dry chemicals, rock dust Water, dry chemicals, rock Water, dry chemicals. 

dust. 

Table 25.-Major findings of statistical analysis of underground coal mines fires, 1950-77 

Category AIl fires Injury fires Fatal fires 

ignition source . . . . . . . . . .. . .. . . Electrical, spontaneous com- Electrical, welding or cutting Electrical. 

bustion, friction. 

Detection . . .. . . . . . . . . . .. . . . . . Miner saw fire start, miner saw Miner saw fire start, miner Miner saw fire start, miner saw 

or smelled smoke. saw or smelled smoke. or smelled smoke. 

Burning substance . . . . . . . . . . . . . Electrical insulation, coal, con- Electrical insulation, coal, Electrical insulation, coal, conveyor belt or rollers. conveyor belt or rollers. veyor belt or rollers. 

Equipment involved . . . . . . . . . . . . Conveyor belt, cutting ma- Welding or cutting . . . . . . . Conveyor belt, cutting 

chine, track locomotive. machine, track locomotive. 

Location ... . ...... . . . . . . . . . . . Outby working face, working Outby face, haulageway . . . Outby face, working face. 

face, haulageway. 

Successful extinguishing agent . . . . Water, dry chemicals, rock dust Water, dry chemicals, rock Water, dry chemicals, rock 

dust. dust. 
Following the pattern established during the 1950 

through 1977 period, electricity was the most frequent 

ignition source for underground coal mine fires during 

1978 through 1992, followed by friction and weldingcutting. However, for the most recent time period, friction 

became the leading ignition source. The most frequent 

ignition sources for injury fires were also electricity, 

friction, and welding-cutting. For fatal fires, friction was 

the most frequent ignition source. The most notable differences between the 1950-77 and the 1978-92 ignition 

source data a? the decline in the incidence of electrical 

fires and the emergence of friction as an ignition source of 

increasing significance. Electricity is still the most frequent source of fires, but during the 1950-77 period, 62 pct 

of all fires were electrical in origin, compared to 35 pct 

during the 1978-92 period. In contrast, friction was the 

ignition source in 21 pct of all fues during the 1978-92 

period, but only 9.6 pct during the 1950-77 period. It is 

likely that the increased usage of conveyor belts for both 

section haulage and main haulage underground and the 

increased use of mobile equipment and air compressors 

have all contributed to the increase in fires caused by 

friction. 

The most frequent method of fire detection during the 

1978-92 period was nearby miners who saw or smelled 

smoke and investigated until they discovered a fue. The 

next most frequent fire detection methods were miners 

who were present when the fire actually started and preshift examiners or supervisors who saw or smelled smoke 

as they fue bossed the mine. For injury and fatal fires, the 

most frequent method of fire detection was miners who 

saw the fire start, followed by nearby miners who saw or 

smelled smoke. During the 1950-?7 period, the most frequent method of fire detection for all fues, injury fues,, 

and fatal fues were miners who saw the fie start, followed 

by nearby miners who saw or smelled smoke. 

Coal, electrical insulation, and rubber were the most 

frequent burning substances involved in underground coal 

mine fires during both the 1950-77 and 1978-92 periods. 

These three materials were also the most frequent burning 

substances for injury fires and fatal fires during both time 

periods. Coal was involved in about 45 pct of all fires. 

Electrical insulation was involved in 43 pct of fires prior to 

1978, but only 30 pct after 1978. Rubber was involved in 

about 30 pct of fues during both time periods. During the 

1978 through 1992 period, fires involving rubber were 

equally divided between rubber hoses-tires and conveyor 

bclts. 

During the 1978-92 period, conveyor belts, welding and 

cutting equipment, and trolley lines were the equipment 

most frequently involved in underground coal mine fires. 

The equipment most frequently involved in injury fires 

during that period was the trolley line, followed by conveyor belts, welding and cutting equipment, and air compressors. Only four fatal fires occurred during the period, 

with one each involving a conveyor belt, air compressor, 

welding and cutting equipment, and continuous miner. 

During the 1950-77 period, conveyor belts were the equip 

ment most frequently involved in fires, followed by cutting 

machines and trolley locomotives. During that time 

period, the equipment most frequently involved in injury 

fues was welding and cutting equipment. For fatal fires, 

it was conveyor belts, cutting machines, and trolley locomotives. Conveyor belts, trolley-powered equipment, and 

welding and cutting equipment have been the leading 

equipment involved in underground coal mine fires for 

over 40 years, from 1950 through 1992. The only new 

equipment type to become an important fador in recent 

years is the air compressor. 

During the 1978-92 period, the most fues occurred in 

the belt entry, followed by the working face area, the 

intake entry, and the track entry. The most injury fues 

occurred in the track entry, followed by the working face 

area and the belt entry. Fatal fires occurred in the shaft 

bottom area, belt entry, intake entry, and workmg face 

area. During the 1950-7 period, most fues occurred immediately outby the working face. This area was also the 

frequent location for injury fires and fatal fues during that 

time period. Other frequent fue locations included the 

working face and haulageway (both track and belt). 

The agent that was most frequently successful in extinguishing underground coal mine fues was water, followed by dry chemicals and rock dust. This was true for 

all fires.from 1950 through 1992, as well as for injury fues 

over that period and for fatal fires during the 1950-n 

period. 

Two sigxuficant conclusions can be drawn from this 

analysis. First and most important, the fue incidence rate, 

injury incidence rate, and fatality incidence rate haw all 

declined between the 1950 through 1977 period and the 

1978 through 1992 period. Liely causes of this decline 

are safer mining equipment and practices and strider enforcement of mine fue safety regulations. 

The other significant conclusion is the similarity bctween the 1950 through 1977 and the 1978 through 1992 

data sets regarding ignition sources, fue detection, burning 
- - 

- - 

substances, equipment involved, location, and successful 

extinguishing agent. These sets were almost identical for 

both time periods (though sometimes in differing rank 

order), which together span over 40 years. This observation is in apparent conflict with the obvious and fundamental changes in mining technology, methods, and equipment that have occurred over the past four decades. 

One possible explanation for the decline in fire incidence rates but lack of change in fire characteristics is 

that the newer technology and equipment may, in relative 

terms, present less fire risk, while the older technology and 

methods may present an inherently greater fire risk, even 

when improved fire protection technology and stricter regulations are applied. As older, more fire-prone equipment 

is mothballed or scrapped, or "old technology" mines are 

shut down, the fire risks they represent are mothballed, 

scrapped, and shut down along with them, resulting in a 

lower overall fire incidence rate. For example, in the 

earlier time periods, a large number of fires were reported 

on trolley equipment and cutting machines. These represent older mining technologies. However, for the most 

recent time period, very few fires were reported on longwall faces, which represent a newer technology. As new 

and safer materials, fire protection technologies, electrical 

systems, hydraulic systems, etc. are developed and made 

available, they may be more readily incorporated into 

new equipment designs and newer mines than retrofitted 

to older equipment or installed in older mines. Fires 

involving the newer generation of equipment may be occurring, but might be of shorter duration and therefore not 

reportable. 

Future implications of these findings are not obvious. 

Although a continuation of the decline in the number or 

fires and fire incidence rates might be expected, such a 

decline would not be automatic. The observed decline in 

reported fires and incidence rates is probably the result of 

a combination of many factors, though improvements in 

mining and safety technology coupled with stricter regulations and enforcement activities must certainly be the 

predominate factors responsible. It must therefore be 

concluded that further reductions in the number of fires 

and the fire incidence rate will be possible only through 

continued efforts in all of these areas. 

It must also be recognized that although newer mining 

technology may be inherently less fire prone than older 

technology, it is not without risk. Conveyor belt haulage, 

for example, may be an improvement over track haulage 

in terms of fire risk, but conveyors are, nonetheless, a 

significant source of fires in underground coal mines. As 

new technologies are introduced, their effect on mine fire 

protection must continually be assessed and deficiencies 

corrected on an ongoing basis. 

Clearly, improvements in mine fire protection technology are necessary and achievable, and use of data such as 

that contained in this report can assist in these efforts. 

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bottom, or station 

Track haulage 

Belt entry 

Working face 

Intake entry 

Power center or 

electrical equipment 

Mined out, caved, or gob 

Unknown or not reported 

Other 

0 5 10 15 20 

NUMBER OF FIRES 

Arc welding or oxyfuel torch 

Air compressor 

Trolley vehicle or rectifier 

Shuttle car or scoop 

Roof bolter 

Cutting mochine 

Conveyor or conveyor drive 

Battery vehicle or charger 

Power center, transformer 

or electrical equipment 

Continuous miner 

Not reported 

Other 

Unknown 

I 1 

0 5 10 15 

NUMBER OF FIRES