UNDERGROUND RAIL
In October 2019, Russia’s Nornickel said it had
completed pilot testing of an electric-trolley
locomotive from Ferrit at Komsomolsky
mine of Nornickel’s Polar Division
remote fashion. The new electric locomotive for
transportation (haulage) of rock mined was
provided for pilot testing to Komsomolsky mine in
March 2019. The objective was to determine
whether it can be used in mines of Nornickel’s
Polar Division. The technical and engineering
experts from Komsomolsky mine concluded that
the pilot tests were a success. The technical
capacity of the Czech locomotive helped
significantly improve the haulage at a depth of
−471 m. The engine is capable of pulling up to 12
loaded cars, four cars more compared to the
current eight-car configuration (with the same
parameter settings). This means two such
locomotives can replace three engines the division
uses now. The company’s management considered
the use of new-type locomotives at the company’s
mining facilities as part of its objectives
to increase production and develop the
Digital Mine system and resolved to
purchase eight such machines. The
engines are still being delivered to
Polar Division’s mines, three of them to
Komsomolsky. The Polar Division’s fleet
for haulage of rock mined currently
includes over 70 eight-car locomotives
manufactured in Russia. The new
equipment will help the company
optimise the use of underground rail
transport and personnel management, and
considerably improve the operational safety.
Trident’s electric EIMCO Rocker
shovels
The Eimco range of rail-mounted Rockershovel
loaders have been supplied by Trident South
Africa Pty Ltd for decades but being exclusively
pneumatic they consumed large amounts of
expensively generated compressed air, through
maintenance heavy piped systems. The pneumatic
units sometimes also didn’t operate at their
optimum performance because of poorly
maintained and expensive plumbing, having a
direct effective on loading cycles and general
efficiency. This was addressed first with the arrival
of the Trident 26H hydraulic version some 10 years
ago and now with a full electric versions, which
eliminates these issues as electrical power
delivers consistent performance.
Trident embarked on this mission a few years
Sierra Metals Yauricocha – a classic rail haulage level mine
The Sierra Metals Yauricocha mine (Sierra acquired 82% of operator Minera Corona SA in 2011) is an
underground polymetallic operation located in western central Peru in the Yauyos at an average
altitude of 4,600 m and has been producing for more than 70 years. Ore is processed at the on-site
Chumpe plant. Existing primary haulage is through the 4 km Klepetko Tunnel (3 m high x 3 m wide)
located on level 720 which handles 3,500 t/d of ore and 1,500 t/d waste. The haulage is achieved by
five Clayton Equipment 20 t electric trolley locomotives delivered between 2007-2012 with 65 cars of
3.1 to 4.5 m 3 size supplied locally. The maintenance service is carried out in the mine’s own
Yauricocha facilities. The performance of the locos is exemplified by the fact they have not been
updated since installation.
A new Yauricocha tunnel excavation (3.5 m x 3.5 m) was completed from the surface (Chumpe) in
April 2017. The tunnel is 4.7 km in length and accesses the mine at the 720 level. In addition to
providing additional haulage capacity to the mill and additional ventilation, the new tunnel
completes the circuit from the mine at the 720 level directly to the concentrator plant.
The site currently has three shafts in service, The Central shaft, Mascota shaft, and the Cachi-
Cachi shaft. A new Yauricocha shaft is in construction currently. The shafts are typically used to move
men and materials but can also move ore and waste to the surface if necessary. The shafts are also
used to move ore and waste from depth to the 720 haulage level where the material is then hauled
through tunnels by rail from the underground to the surface. All ore and waste hauling to the surface
is currently moved through the tunnels only.
Ore and waste generated in the Central Mine is moved to a series of level ore passes by LHD. The
ore passes load into rail cars to be trammed to the loading pockets in Mascota shaft to be hoisted to
the 720 main haulage level. A winze at Cachi-Cachi hoists production from lower levels in that area to
the 720 main haulage level. For mining at depths between 1170 level to 1370 level, the Yauricocha
shaft is under construction and will provide ore and waste handling for material below the 1070
level. Ore is transported by rail to the mill through the Klepetko and Yauricocha Tunnels.
back to electrify the range and began with the
diminutive 12B, the smallest unit in the range, and
has subsequently added the 21E, with the 26E
additionally replacing the 26H. In order to keep
the units simple Trident decided that most of the
proven mechanical elements of the units should
remain the same and just the pneumatic motors
and the controls should be replaced with electrical
substitutes. This also allows customers to
maintain existing stock levels of Trident spare
parts. The units now being electric now provide a
platform for innovation that was difficult to
achieve pneumatically – an example would be
lights, monitoring technologies and umbilical
remote control which in some niche applications is
required by customers. Electrical power also
reduces the noise levels the pneumatic units were
famous for to almost nothing thereby reducing any
potential damage to operator hearing.
The 12E consumes about 30 HP and is up to
30% more power than its pneumatic predecessor
and has two electric motors, one driving the unit
along the rails, and the other operating the bucket
in the same way that pneumatic motors did
previously. These motors bolt into place where the
pneumatic motors were fitted. This innovation
means that buying an electrification kit for an
existing Trident/Eimco becomes possible as the
conversion is a relatively simple job for a trained
technician and does require special facilities. The
21E is a slightly larger model that replaces the 21B
pneumatic model. Both the 12B and 21B have
been the mainstay of many a loader fleet globally
for decades so having an electrification option
allows fleet operators a feasible option to extend
their mining method indefinitely by continuing to
use rail bound shovels and not having to convert
to expensive trackless options. This is particularly
pertinent to deep mines where the physical size of
trackless is equipment is a limitation as are their
diesel engines. Trident has also managed to keep
costs of these units close to the costs of the
equivalent pneumatic machines which also helps
fleet operators make cost sensitive decisions.
Trident currently maintains fleets of pneumatic
machines globally but there are other
manufacturers of these units that manufacture to
the Eimco standard so there is also the potential
to electrify those fleets and bring the economic
benefits of electric conversion to more operators
of a proven mining technology.
China’s influence at home and abroad
China like in other mining equipment and
technology areas is a complex actor in the world
of underground rail. It has its own domestic
players in locomotive supply, including XEMC and
Hunan Yutong which can both supply diesel,
battery, battery-trolley and trolley solutions of
more or less any kind and any size that would be
used in mining. Both of these companies are
24 International Mining | JUNE 2020