DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
Accident Investigation Report
Fatal Haulage Accident
Kellerman Prep Plant, I. D. No. 01-00563
Drummond Company, Incorporated
Kellerman, Tuscaloosa County, Alabama
November 28, 1995
Walter W. Deason
Coal Mine Inspector
Stanley J. Michalek
Pittsburgh Health Technology Center
Terence M. Taylor
Pittsburgh Health Technology Center
Originating Office - Mine Safety and Health Administration
135 Gemini Circle, Suite 213, Birmingham, Alabama 35209-5842
Michael J. Lawless, District Manager
The Kellerman Preparation Plant, Drummond Company, Incorporated, is located in Kellerman, Tuscaloosa County, Alabama on the Warrior River. The plant employs 57 miners and processes daily an average of 4,864 tons of clean coal. The plant operates two production shifts and a maintenance shift five to six days per week.
The plant has a barge loading facility that operates two to three shifts per day, five to seven days per week. The barge loading facility, on the day shift, loads clean coal trucked from the No. 4 Mine, Jim Walter Resources, Incorporated, located in Brookwood, Tuscaloosa County, Alabama. On the evening and owl shifts, the barge loading facility is used to load coal washed at the prep plant hauled in from the Kellerman-Peterson Mine, Drummond Company, Incorporated, located in Brookwood, Tuscaloosa County, Alabama.
The prep plant has three belts that transfer the coal after it has been washed. The No. 15 conveyor is the first clean coal belt out of the washer. The No. 15 conveyor transfers coal to the No. 16 conveyor. If the No. 16 conveyor is out of service, coal can be discharged at the end of the No. 15 conveyor onto the ground. The No. 16 conveyor transfers coal to the No. 17 conveyor.
The No. 17 conveyor belt is located approximately 100 feet above ground level and is 725 feet in length. The No. 17 conveyor belt is supported by four towers. They are located 200 feet apart. The towers are numbered one through four with the number one tower being nearest the river. There are four stalls located in the No. 17 conveyor belt. The stalls are located 200 feet apart. The stalls are numbered one through four with the number one stall being nearest the river. The stall sections are discharge locations where the different grades of coal are discharged and stored on the ground. The No. 17 belt was constructed in 1972. The prep plant had received notice that the plant was closing and was within two weeks of the closing date. The last Mine Safety and Health Administration (MSHA) regular health and safety inspection was conducted September 18-21, 1995.
Officials of Drummond Company, Incorporated are:
Garry N. Drummond................................Chief Executive Officer/Chief Operating Officer
Donald Baxter..........................................President of Mining
Ronald Handley........................................Director of Safety
Description of Accident
On Tuesday, November 28, 1995, at 4:00 p.m., the evening shift prep plant crew met in the eating area located on the first floor of the washer. Jimmy Ray, Outside Plant Foreman and Novey H. Dreher, Inside Plant Foreman, gave job assignments to the sixteen crew members.
The plant was idle due to the refuse slurry line being clogged. They assigned most of the plant crew to work on the slurry line and the remainder of the crew was to operate the belt to run bypass coal through the plant.
Gerald S. Noles, Inside Plant Foreman and Ruel Narramore, Outside Plant Foreman, came on duty of 6:00 p.m. They were informed by Ray and Dreher of the problems with the slurry line. At approximately 7:00 p.m., the crew that was working on the slurry line returned to the plant to eat lunch.
Harold Nelson Hubbard, Central Control Operator, called Noles and informed him that the No. 17 conveyor belt was slipping in the belt conveyor drive and had tripped out and that Jimmy Ray Ellenburg, Electrician, had reset the breaker and the overloads had tripped.
Noles and Gary Isabell, Table Man, went to the No. 17 conveyor belt to see if they could determine the source of the problem. As they examined the No. 17 conveyor belt, they noticed that the belt was loaded heavily. Isabell walked the No. 17 conveyor belt to the No. 1 stall and, while returning, noticed the cat walk leaning in the area of the No. 4 stall. Isabell brought this to Noles attention. Noles examined the area and returned to the first floor of the plant and informed Narramore.
Narramore and Isabell went to the No. 4 stall on the No. 17 conveyor belt to examine the area. Noles called Gene Narramore, Assistant Mine Superintendent, to inform him that the No. 17 conveyor belt was down and that there was a bent angle at the No. 4 stall that probably had the belt in a bind. Noles asked Gene Narramore if he wanted him to pull the men off the pipeline to get the No. 17 conveyor belt running. Gene Narramore told Noles to leave it alone that they could run coal off the end of the No. 15 conveyor belt and he would look at it the next day. When Noles returned to the first floor of the plant, Ruel Narramore had returned from examining the area of the No. 4 stall on the No. 17 conveyor belt. Narramore told Noles that what they looked at was old damage that had already been repaired. Noles told Narramore what Gene Narramore had instructed them to do and Ruel Narramore did not reply. Ruel Narramore told Noles to get six shovels and they could remove some coal off the No. 17 conveyor belt and get it running.
At approximately 8:45 p.m., Ruel Narramore, Noles, Isabell, Jack Pittman, Filter Operator, Jerry Taylor, Mag Man and Richard Benny Lowe (victim), Dozer Operator, left the plant going to the No. 17 conveyor belt. When they arrived on the No. 17 conveyor belt, Lowe started removing coal from the belt at the tailpiece and was working toward the No. 4 stall area. The other five men went down the belt to the area of the No. 3 tower and started removing coal from the belt. They were approximately 75 to 100 feet from the No. 4 stall.
At approximately 9:30 p.m., the No. 4 stall collapsed, starting a toppling effect. When the No. 4 stall fell, it pulled and twisted the No. 4 tower. The No. 4 tower was supporting approximately 100 feet of the No. 17 conveyor belt and the No. 16 conveyor belt and conveyor belt drive.
Approximately 100 feet of the No. 17 conveyor belt fell straight down and the No. 16 conveyor belt fell across the No. 17 conveyor belt. Five of the miners were trapped on the remaining structure of the No. 17 conveyor belt. Three men climbed down the No. 3 tower and the other two men were removed by the use of a crane and work platform, approximately two hours later.
Isabell and Tommy Styron, Truck Operator, located Lowe approximately twenty minutes after the collapse of the structure on the catwalk of the No. 16 conveyor belt that had fallen. There were no vital signs detected. The rescue squad located in Brookwood, Alabama, arrived in approximately twenty-five minutes. Lowe was pronounced dead by the medical examiner at the scene.
Physical Factors Involved
- The entire stacker belt structure, including the No. 16 and No. 17 conveyor belts
was designed and constructed in 1972. These belts were used to handle the washed
coal product leaving the preparation plant facility. Cleaned coal from the plant was
transported up the inclined No. 16 belt. At its upper end, the No. 16 belt would
discharge the coal onto the elevated No. 17 belt. The No. 17 belt was the coal
stacker belt. Both belts were 36 inches wide. Based on the quality and properties
of the washed coal product, the coal would be dumped from one of four deposition
locations along the stacker belt.
- The No. 17 stacker belt structure was 725 feet long and was elevated approximately
100 feet above the ground. The belt rested on a truss structure. The No. 17 belt was
supported by four steel frame towers and spanned 190 feet between towers. The No.
16 belt was supported at its upper end by the No. 4 tower. This tower was common
to the Nos. 16 and 17 belt lines. The four columns common to the No. 16 belt truss
were approximately 18 feet taller than the two outer columns supporting the No. 17 belt
truss. The top level of the tower supporting No. 16 belt consisted of four horizontal
beams tying the columns together. Once material was dropped onto the No. 17
belt, it could be deposited off three chutes, located midspan of the trusses between
the four towers. The end of the trusses cantilevered out beyond the No. 1 tower.
The No. 17 belt could also discharge off this final location at the end roller. The chute
described as the No. 4 chute was located between towers 3 and 4. Similarly, the
No. 3 chute was located between towers 2 and 3, and the No. 2 chute was
between towers 1 and 2.
- The No. 17 belt truss consisted of three 5 feet deep, 50 feet long sections called
suspended galleries. They were suspended from 50 feet long tapered
trusses that extended from each of the towers. These are referred to as the
intermediate galleries. The intermediate galleries were 15 feet deep at the tower
locations and tapered to 5 feet deep, where they were bolted to the suspended
galleries. Near the tower location the intermediate galleries were connected to the
corbel galleries. The corbel galleries were 50 feet long and approximately 15
feet deep trusses. They straddled over each of the four towers. Each of the three
chutes were located midspan of the suspended galleries. The suspended galleries
consisted of single angle sections, while other galleries were composed of channels
as well as angle sections. Most connections were welded.
- Two days prior to the failure under the No. 4 chute, it is believed a
fracture occurred under the No. 3 chute. The failure occurred at approximately
5:00 p.m. on Sunday, November 26, 1995. The two bottom truss chords under
the chute fractured at midspan. Both members were corroded from the constant
exposure to moisture and built-up coal, and had experienced a loss of cross-
sectional area. According to plant personnel, the bottom chords separated
approximately 5 inches. The fracture occurred when the tension in the bottom
chord exceeded the capacity of the angle section. Five sections over from the
No. 3 chute, the bottom chord buckled when the compression load in the angle
section exceeded the critical buckling load of the member. The buckle of this
bottom chord member most likely occurred immediately prior to the bottom
chord separation under the No. 3 chute.
- The No. 3 chute is located near the geometrical center of the entire No. 17 belt
structure. It is centrally located between the No. 2 and No. 3 towers. Both of
these towers are symmetrically loaded by the belt truss frame. When the bottom
chord under the No. 3 chute broke, the entire truss did not fall to the ground.
The top chord remained intact. The suspended truss structure under the No. 3
chute was held in place by the cantilevered support being provided by the
tapered intermediate truss sections, extending from both the No. 2 and No. 3
towers. Both of the cantilevered trusses remained stable, because they were
symmetrically balanced over their respective towers.
- The truss size and shape under chute No. 4 were identical to that under chute No. 3 with two angles 3" x 3" x 3/8" used for the top chord and two angles of identical size composing the bottom chord. These truss members were also severely corroded, as there was coal built-up on the bottom chords of the truss. Measurements taken of the fractured truss members under chute No. 4 were as follows:
MEASURED MEASURED REDUCT. ORIGINAL ORIGINAL THICKNESS* LEG LENGTH IN LENGTH OF THICKNESS (in) (in) CROSS- EACH OF EACH -------------- --------------- SECTION LEG LEG VERT. HORIZ. VERT. HORIZ. AREA CHORD SIDE (in) (in) LEG LEG LEG LEG (%) Top Woods 3 .375 .271 .250 3.000 3.000 29 Top Plant 3 .375 .325 .257 2.500 2.627 33 Bottom Woods 3 .375 .179 .174 2.500 2.375 61 Bottom Plant 3 .375 .115 .162 2.313 2.375 70
* thicknesses were measured approximately 1.5" in from the fracture
The two bottom chord members under chute No. 4 experienced a reduction of up to 70% in cross-sectional area. Due to the potential instability of the remaining portion of the No. 17 belt truss still standing after the collapse, the investigating team was unable to take caliper measurements of the chord thickness under chute No. 3. Therefore, a dimensional comparison could not be made.
- Chute No. 4 was located between towers 3 and 4. Tower No. 3 was an interior tower, whereas tower No. 4 was an exterior
tower (meaning it is located at the end of the No. 17 belt superstructure).
In general the interior towers were loaded symmetrically by the truss, while
the loading on the exterior towers was unsymmetrical. In comparison, chute
No. 3 was located between towers 2 and 3, both of which were symmetrically
loaded towers. It is believed that the reason the structure did not collapse when
the chord under the No. 3 chute fractured was because the superstructure was
still symmetrically balanced over Towers 2 and 3, which minimized any
overturning effects of these towers.
- Perhaps the reason the fracture occurred at chute No. 3 two days earlier was due
to a more advanced stage of corrosive deterioration under chute No. 3, although
no measurements could be taken. Eyewitness reports from workers who repaired
the break indicated the bottom chord members of the truss were severely
- In conducting the failure investigation, there was evidence indicating that the belt
was fully loaded beyond chute No. 2. There was also eyewitness testimony that
the belt was overloaded. At the time of failure, men were on the structure
shoveling off excess coal to restart the No. 17 belt that had stopped possibly
from an overload. There was also a considerable amount of coal heaped around the
No. 3 chute.
- There were other signs of prior structural distress as well. At the location of the
No. 4 chute, the top chord had previously buckled approximately three feet over
from the section that failed. This suggests that, in the past, the capacity
of the top chord member had been exceeded, probably due to a loss of cross-
sectional area from corrosion. None of the individuals interviewed were
knowledgeable of when this prior buckle had occurred. In the suspended gallery
section of truss, the bending moments were largest under the No. 4 chute. Therefore,
the angle section top chord was experiencing its highest compressive load at this
location and it followed that this area would be the first area to experience a
compressive buckle. The company had repaired the buckled top chords by adding
a new angle section and bolting it to the bent member.
- Reportedly, some "dirty" coal had been run through the plant in the weeks prior to
the collapse. This coal had a considerable fraction of fine-grained, cohesive particles
combined with the coal. During the investigation, it was observed that material with
this characteristic had accumulated unevenly on one of the rollers under the No. 4
chute. This build-up of material would have caused the belt to track unevenly and
could have accelerated the fracture by causing additional dynamic forces. In addition,
in the hours leading up to the collapse, witnesses had reported that it had been
raining. The belt canopy was missing over many areas of the belt. The wet
conditions would have added weight to material on the No. 17 belt. All the above
factors could have caused the belt to slip on its drive rollers, which would have slowed
it down, allowing the belt to accept coal from Belt No. 16 at a faster rate than it could
- The culvert beneath the No. 4 tower was inspected for collapse and was found to be
in its original shape. In addition, the base elevations of the six columns were
surveyed to check for differential settlement. The column pedestals were acceptably
level and, therefore, a foundation settlement failure was eliminated as a possible cause
of the collapse.
- It is possible that the connection of the No. 17 belt truss to the top of the No. 4 tower
may have failed prior to the fracture of the truss at midspan beneath chute No. 4.
Under this scenario, overload of the No. 17 belt may have over-stressed the connection
of either the front or rear legs of the No. 17 belt support. The front connection could
have either sheared downward or the back leg lifted upward. If either connection
failed, the truss between towers No. 3 and No. 4 would dip downward over-stressing
and fracturing the bottom chords, then top chords, before ultimately rotating to the
ground. The connections at this location were partially corroded, however no
measurements were taken. If the structure failed in this manner, the truss could still
have fallen through the No. 4 tower causing impact damage to the cross members
and destabilizing the common columns with the No. 16 belt. As with the previous
failure scenario, the events following a destabilization of the No. 16 belt would be
similar. In addition, this type of failure could also have been the result of steel
corrosion and belt overload.
- Based on the structural analysis, it appears that four events occurred to ultimately
collapse the structure:
- The top chord near midspan had to first buckle, as it experienced the highest
compressive loads. As mentioned earlier, this chord under chute No. 4 had, in fact,
- Once the top chord buckled, the load redistributed, over-stressing the bottom
chord of the suspended gallery section near its end location, where the truss
connects to the intermediate gallery section. This chord would then buckle from
the load increase.There was evidence under chute No. 3 that its end chord buckled near the interface
of the two truss sections. The similar section of truss under chute No. 4 had been
damaged by the failure, and it was not possible to verify whether an identical
buckle had occurred in this location, although it seems likely. Its observed condition
was buckled, however, there was the possibility that the chord bent after the main
truss was rotating downward. Based on the previous experience of the condition of
the suspended gallery under chute No. 3, it seems reasonable to expect a similar
buckling behavior in the suspended gallery supporting chute No. 4.
- With both the top chord under the chute and the bottom chord at the end of the
suspended gallery buckled, the tension loads in the bottom chord directly beneath
the chute increased significantly. The results of the analysis indicate that the tensile
force at the time of failure, in combination with the reduced cross sectional area
measured during the investigation, produced a stress in the bottom chord near its
yield level. This yielding member elongated or "necked" to the point where its
cross-sectional area further reduced. The reduced area in combination with the
member tensile force, caused the member to fracture. Field measurements along
the feathered edge of this member further substantiated that the stress in the member
along its fractured edge was at its predicted fracture strength.
- After the bottom chord fractured, the entire load transferred to the support connections at the top of tower No. 4. The connections became over-stressed and failed, then the truss began to fall. The rotation downward then failed the top two chords at midspan. This final fracture occurred when there was considerable sag at midspan of the suspended gallery. The skewed frame showed that the top chords were being pulled upward when they failed. Based on the direction of the skew, it appeared that the plant side chord was the last to break.
- The top chord near midspan had to first buckle, as it experienced the highest compressive loads. As mentioned earlier, this chord under chute No. 4 had, in fact, buckled previously.
The failure of the No. 17 stacker belt was most likely the result of a sequence of buckling and fracture of truss chords within the suspended gallery section, which supported chute No. 4. The evidence indicates that the belt was fully loaded and the load carrying capacity of the No. 17 truss had clearly been reduced by the amount of corrosion on the structural steel members. A load redistribution from these events led to a failure of the connection at the top of tower No. 4, allowing the belt to fall through the tower and destabilize the No. 16 beltline. Ultimately, these deteriorated conditions of the structure caused it to collapse, resulting in the fatality of an employee.
- A 103-K Order No. 3397389 was issued to ensure the safety of miners until the investigation was completed.
- A 104-A Citation No. 3021236 was issued for a violation of 30 CFR Section 77.200. The No. 16 and No. 17
conveyor belt lines and support structures were not being maintained in good repair, so as to prevent accidents to employees.
- A 104-A Citation No. 3021237 was issued for a violation of 30 CFR Section 77.1713. Daily inspections were not being performed during each working shift on all active working areas.
Respectfully submitted by:
Walter W. Deason
Coal Mine Inspector
Stanley J. Michalek
Terence M. Taylor
Michael J. Lawless
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