ROCK REINFORCEMENT
issues out of the way.
We go from eight to 10
steel changes to two.
Everything that we do Available in lengths from 1.8 to 3.0 m, MD bolts
are rated to hold up to 30 t. An average of 30-45
bolt installations can be performed per hour.
For seismic and weak rock conditions, the
for the operators that
makes it easier for
them, results in much recently developed Sandvik Mechanical Dynamic
Extra (MDX) bolt has unparalleled extra
expansion for extremely effective anchorage
using a unique wedge design that can expand up
better safety and
performance
outcomes.”
Just weeks into the
trial, Barminco chose
Just weeks into a trial at Dugald River, Barminco
chose Sandvik MD bolts over the previously
installed resin encapsulated bolts for
supporting all meshed headings
Barminco jumbo crew set a new single-month
world record at the project in April 2013,
developing 700.4 m with one twin-boom Sandvik
jumbo and in-cycle shotcrete. That contract was
extended to include trial stoping and additional
development, with all headings supported by
shotcrete and encapsulated resin bolts.
In 2016 Barminco was awarded a new, five-
year contract covering development and
production. The new contract’s development
scope included an ambitious monthly target of
more than 900 m using two Sandvik jumbos. At
the same time, MMG decided to transition from
shotcrete to mesh support in 90% of the mine’s
headings in an effort to cut costs while
maintaining efficiency.
Most support profiles included mesh, resin
bolts and split set bolts, and Barminco Project
Manager Werner Murach saw bolting cycle times
increase substantially. “It was clear we needed a
safer, more efficient ground support solution,”
Murach says.
Not only did the new solution need to satisfy
Barminco’s own requirements for efficient and
reliable installation, it also had to meet a
selective list of criteria established by MMG,
including considerations such as bolt life and
load capacity. Inspired by its success with the
Sandvik MD bolt at its contract at MMG’s
Rosebery mine in Tasmania, Barminco looked to
implement the efficient single-pass solution at
Dugald River.
“A lot of the risk assessments had already
been done at Rosebery and some of our
employees here had used the MD bolts there, so
that made bringing it to Dugald River a little
easier,” Murach says. The first trial started in
October 2016. Jumbo operators and management
alike quickly gained confidence in the process
and application.
“Operators and offsiders appreciated the ease
of installation and reduction in unproductive time
changing steels, since the MD bolt and split set
require the same length and size drill steel,”
Murach says. “It takes a lot of manual handling
26 International Mining | AUGUST 2019
MD bolts over the previously installed resin
encapsulated bolts for supporting all meshed
headings. “The MD bolt is the ideal replacement
for resin or grouted bolts,” Murach says. “They’re
easy to install and they’re inherently safer. You
can spend a couple of hours trying to get resin in
a hole, whereas this bolt is so strong and easy to
install you can just hammer through the broken
ground.”
As installation efficiencies improved, cycle
times decreased dramatically with each passing
to 60 mm.
Komatsu acquires Timberock
Komatsu Mining recently announced the
acquisition of Timberock International Ltd to
support the growth of its hard rock drilling and
bolting solutions for mining customers
worldwide.
Based in Elliot Lake, Ontario, Timberock is a
specialty business that Komatsu says has
developed world-class drilling and bolting
technologies by focusing on differentiation
through innovation and customer-oriented
service.
month.
“When you’re using resin bolts, you drill the
hole, then you put all the glues in and then you
put all the bolts in,” Barminco jumbo operator
Carl Chrisp says. “The new solution means you
just drill a hole and put a bolt in. It would take
nearly three-and-a-half to four hours to bolt one
heading and now you can cut it down to two
hours.”
The reduction in cycle times has enabled
Barminco to increase development rates by more
than 50%. Since implementing the MD bolt,
Barminco has developed as many as 950 m in a
month using two Sandvik jumbos and
consistently achieves 800 m.
“By changing over from shotcrete to full mesh
with the assistance of Sandvik, we’ve achieved
development rates that we wouldn’t have been
able to without the introduction of the MD bolt at
Dugald River,” Murach says.
More than two years into the MD bolt success
at Dugald River, Barminco and Sandvik have also
recently collaborated to develop a new meshing
clamp solution the mining services provider
expects will improve ground support cycle times
even further. “The new clamp we’ve developed
with Sandvik will eliminate the need for several
rock bolts, securing the mesh to an already
installed bolt quickly and easily,” Murach says.
The Sandvik Mechanical Dynamic (MD) bolt is
a 47 mm diameter friction bolt, reinforced with a
20 mm bar with a wedge arrangement at the top
end. Once the bolt is fully driven into a hole,
similar to a friction bolt, the bolt nut at the collar
is rotated to activate the wedge to firmly anchor
the bolt. The MD bolt can replace a range of
different ground support systems such as resin
bolts, stiff split sets and even cable bolting.
Timberock bolters have an option of a bolt
holding/ loading carousel assembly. The
carousel holds all types of bolts: split-sets,
swellex, rebar, rock bolts, etc. The bolt carousel
is hydraulically operated from the unit, and
increases bolting cycle efficiency
“Timberock’s history of customer driven
product innovation and focus on service makes
them a great complement to our existing
business,” said Josh Wagner, Vice President of
Komatsu Mining hard rock solutions. “This
acquisition expands our range of offerings for
drilling and bolting products, and provides
exciting product development and synergy
opportunities.”
With the addition of the Timberock portfolio,
Komatsu Mining can now offer customers a
complete range of hard rock drilling feed and
bolting head products, and expanded capabilities
in drifter repairs. Komatsu Mining’s suite of
underground hard rock offerings includes:
hydraulic jumbo drills, in-the-hole production
drills, drifters, loaders, trucks, raiseboring tools
and blasthole drilling tools.
Timberock designs, manufactures, and
supplies its own complete OEM bolter systems
for underground rock support bolters. “Our
bolters include many advanced features which