1
25-099
Videoscope Applications to Interpret Lithology in
Underground Coal Mines
Mark Van Dyke
CDC NIOSH, Pittsburgh Mining Research Division,
Pittsburgh, PA
Yuting Xue
CDC NIOSH, Pittsburgh Mining Research Division,
Pittsburgh, PA
Joe Wickline
Leer South (Wolf Run Mining, LLC) Philippi, WV
ABSTRACT
The understanding of coal mine roof lithology is a critical
component in the determination of engineering solutions
for roof control. Coreholes were the first technology avail-
able to determine lithology of the roof in reserve areas, but
coreholes are typically drilled 500–2,500 ft apart due to
their cost and sometimes reach more than $125,000 dol-
lars per hole, depending on mine conditions. The next
method developed to bridge this gap was the fiber-optic
scope which is utilized in the roof at the faces of under-
ground development. High-end fiber-optic scopes can also
be costly (20,000–40,000 dollars) but are more affordable
than drilling a corehole, and the information can be pro-
cessed immediately to make quick roof support determina-
tions. The fiberscope can be operated wherever a roof bolter
can drill a hole, and there are no restrictions related to
property owners, proximity to streams, elevation changes,
etc. The latest borescoping method utilized by mining com-
panies is the use of videoscopes. Videoscopes and all bore-
scopes in general are limited by the lengths of the scope and
the length of the borehole drilled in the mine. Videoscopes
have the advantage of being able to record video while
examining the roof lithology. The information can be
recorded quickly underground and then be examined on
the surface which allows anyone to capture the video so
that a geologist can make lithology descriptions without
ever going underground. In the past, videoscopes had lim-
ited resolution, a short battery life, were fragile and were
relatively costly. As technology progresses, videoscopes have
become more affordable, have increased battery life, and
offer enhanced 1080p resolution. With the broader avail-
ability of affordable videoscopes, videoscopes can be more
readily used in various mine environments at every active
section underground. This paper will discuss the types of
videoscopes available, the features that will aid in lithol-
ogy description/identification, the deployment methods
pertaining to supplemental roof support recommenda-
tions, and an advanced methodology to enhance accuracy
in understanding roof lithology.
INTRODUCTION
The ability to identify the roof lithology in a mine entry
is essential in designing effective ground control systems.
Corehole drilling is costly depending on the drilling depth
and types of strata encountered. The expense of drilling a
corehole can be more than 100,000 dollars per hole and
coreholes provide sparse data points because they are typi-
cally drilled 500–2,500 ft apart. With the invention of vari-
ous borescope technologies ranging from the early ridged
periscopes to today’s high definition videoscopes, the ability
to discern roof lithology has become more accessible than
ever. This paper will discuss the types and features available
on modern videoscopes and will present methodology to
produce video stratigraphic columns of recorded images by
performing additional processing of images produced from
all videoscopes.
BACKGROUND
Borescopes were first introduced with rigid sections that
would require assembly and with a large incandescent
light source and prism. The entire assembly was bulky and
required more than one operator. The roof hole drilled
for observation was required to be larger than the normal
1-inch diameter hole needed for most types of roof bolts,
25-099
Videoscope Applications to Interpret Lithology in
Underground Coal Mines
Mark Van Dyke
CDC NIOSH, Pittsburgh Mining Research Division,
Pittsburgh, PA
Yuting Xue
CDC NIOSH, Pittsburgh Mining Research Division,
Pittsburgh, PA
Joe Wickline
Leer South (Wolf Run Mining, LLC) Philippi, WV
ABSTRACT
The understanding of coal mine roof lithology is a critical
component in the determination of engineering solutions
for roof control. Coreholes were the first technology avail-
able to determine lithology of the roof in reserve areas, but
coreholes are typically drilled 500–2,500 ft apart due to
their cost and sometimes reach more than $125,000 dol-
lars per hole, depending on mine conditions. The next
method developed to bridge this gap was the fiber-optic
scope which is utilized in the roof at the faces of under-
ground development. High-end fiber-optic scopes can also
be costly (20,000–40,000 dollars) but are more affordable
than drilling a corehole, and the information can be pro-
cessed immediately to make quick roof support determina-
tions. The fiberscope can be operated wherever a roof bolter
can drill a hole, and there are no restrictions related to
property owners, proximity to streams, elevation changes,
etc. The latest borescoping method utilized by mining com-
panies is the use of videoscopes. Videoscopes and all bore-
scopes in general are limited by the lengths of the scope and
the length of the borehole drilled in the mine. Videoscopes
have the advantage of being able to record video while
examining the roof lithology. The information can be
recorded quickly underground and then be examined on
the surface which allows anyone to capture the video so
that a geologist can make lithology descriptions without
ever going underground. In the past, videoscopes had lim-
ited resolution, a short battery life, were fragile and were
relatively costly. As technology progresses, videoscopes have
become more affordable, have increased battery life, and
offer enhanced 1080p resolution. With the broader avail-
ability of affordable videoscopes, videoscopes can be more
readily used in various mine environments at every active
section underground. This paper will discuss the types of
videoscopes available, the features that will aid in lithol-
ogy description/identification, the deployment methods
pertaining to supplemental roof support recommenda-
tions, and an advanced methodology to enhance accuracy
in understanding roof lithology.
INTRODUCTION
The ability to identify the roof lithology in a mine entry
is essential in designing effective ground control systems.
Corehole drilling is costly depending on the drilling depth
and types of strata encountered. The expense of drilling a
corehole can be more than 100,000 dollars per hole and
coreholes provide sparse data points because they are typi-
cally drilled 500–2,500 ft apart. With the invention of vari-
ous borescope technologies ranging from the early ridged
periscopes to today’s high definition videoscopes, the ability
to discern roof lithology has become more accessible than
ever. This paper will discuss the types and features available
on modern videoscopes and will present methodology to
produce video stratigraphic columns of recorded images by
performing additional processing of images produced from
all videoscopes.
BACKGROUND
Borescopes were first introduced with rigid sections that
would require assembly and with a large incandescent
light source and prism. The entire assembly was bulky and
required more than one operator. The roof hole drilled
for observation was required to be larger than the normal
1-inch diameter hole needed for most types of roof bolts,