PRODUCT News
50
MODERN MINING
July 2014
Marthinusen & Coutts (M&C), a leading
South African based repairer of rotating
electrical equipment and a division of
Actom, has again demonstrated its ability
to undertake complex on-site engineering
assignments in remote locations in Africa
with the successful installation of four mill
motors at a copper mine in north-west
Zambia. The massive electric motors, with
diameters of 40 and 28 foot respectively
and with each stator quadrant weighing
approximately 100 tons, are the largest
M&C has helped install to date and prob-
ably the largest in Africa.
M&C’s scope of work comprised the
installation of stator quadrant windings
Martin offers safety solutions for conveyors
A global leader in conveyor safety technol-
ogy offers a suite of products and services to
protect workers from fast-moving rollers and
belts, helping bulk material handlers main-
tain safer and more productive operations.
The components and training from Martin
Engineering can be used alone or together
to help prevent accidents and injuries,
reducing risk while benefiting productivity.
Designed to prevent workers from
being drawn into a moving return roller,
the
Martin® Return Roller Guard
is an
economical way to raise safety awareness
and reduce injuries. The solid upper section
delivers pinch point protection, and the
slotted lower area allows visual inspection
while preventing contact with the roller.
Installation is straightforward, with brack-
ets included to mount the guard directly to
either the side or bottom of the stringer.
Quick-release pins allow easy service, with
side and bottom panels that swing open for
cleaning or maintenance, while removable
end plates provide access to roller bearings.
The guards are designed to fit all major roll
manufacturers’sizes (CEMA C, D & E).
The
Martin® Return Roller Basket
is
designed to prevent a return roller from fall-
ing in the event of a mechanical failure and
is recommended for rollers that are more
than 7 feet (2,13 m) off the ground and out
of reach for any workers. The combination
of guards and baskets provides a system-
atic approach to conveyor guarding that is
easy to use and safety compliant.
Like the Return Roller Guard, slotted
panels allow easy inspection, while keep-
ing workers protected. Brackets designed
to fit all major roll manufacturers’ sizes are
included to mount the basket directly to
either the bottom or side of the stringer.
Quick-release pins allow easy access, and
side panels swing open from either top or
bottom for cleanout or service. Both the
roller basket and guard are available in
painted steel and two grades of stainless
steel.
Martin® Conveyor Guards
simplify con-
veyor guarding to improve plant safety and
productivity. The heavy mesh guards allow
easy inspection, while keeping moving
components and pinch points isolated from
workers. The rugged modular design is sup-
ported by a supplied angle iron structure,
and attachment to the conveyor equipment
is not required. Installation is straightfor-
ward, with wedge clamps that allow panels
to be removed and re-installed quickly.
The guards conform to OSHA 29 CFR
1910.217 when installed with a minimum
of 140 mmbetween the guard opening and
hazard. Available in a range of sizes from
610 mm x 610 mm to 914 mm x 1 270 mm,
they feature a universal design that can
be used in a variety of combinations to fit
almost any application. Systems can be eas-
ily expanded or relocated as needed.
Martin Engineering, tel (+27 13) 656-5135
M&C installs windings on massive mill motors
on the four mill motors, which were manu-
factured by Siemens, Germany. The four
motors are gearless mill drives (GMDs),
also known as wrap-around motors, and
include two 26 MW ball mill motors and
two 28 MW SAG mill motors.
Among the challenges on this project
were the remote location of the mine,
approximately 400 km north-east of Kitwe,
and working during a heavy rainy season
while also trying to meet an incredibly
tight deadline.
M&C was able, at short notice, to mobil-
ise a team of highly skilled technicians to
undertake the winding of the 16 quadrant
joints on the motors. Each joint on the
motor has seven large (uninsulated over-
hang) ‘flexible’ coils, which are used to help
contend with the connecting of the stator
coils at the quadrant interfaces, while the
balance of the coils are normal resin-rich set
diamond type coils, each weighing 44 kg.
A fully equipped 20 foot container,
equipped with the correct tooling and
test instruments, was prepared and dis-
patched to site. Each SAG mill motor was
completed in less than 25 days, while the
ball mill motors were completed in less
than 23 days.
“We’re well versed in carrying out
site work in remote locations on the
The massive dimensions of the gearless mill
drives are visible in this photograph of the partly
completed installation.
African continent,” Richard Botton, M&C’s
Divisional CEO, says. “We fully understand
the various work practices and cultures of
the local people and we’re able to draw
on a well-established network to deal
with complicated cross-border protocols.
Marthinusen & Coutts owns and manages
a fully functional service shop in Kitwe,
Zambia, with technicians on call to support
our customers in the region.
“Marthinusen & Coutts has become
an expert in gearless mill drives (GMDs),
winding termination and testing of motor
segments. Our track record in the GMD
arena includes the installation of two
wraparound electric motors at Lumwana
Copper Mine in the north-west of Zambia
a few years ago and, more recently, the
completion of an on-site rotor and stator
rewind of a 70 MVA synchronous con-
denser in the DRC.
“ The latest contract underlines
Marthinusen & Coutts’flexibility in carrying
out complex and difficult on-site installa-
tions and services within a short lead time
and completing these jobs to world class
standards. We’re one of only a handful of
companies worldwide capable of offering
these services.”
Richard Botton, Marthinusen & Coutts,
tel (+27 11) 607-1700
