Truck Loading

Waste-rock loading is carried out using two 1900 AL
P&H 11-cu.-yd electric shovels, power being supplied
from one of two 3000-KVA sub-stations, located in the
pit, depending on shovel location. Power transmission
from the main diesel power plant, located 6 miles (9.6
km) away, is by 24-kv pole line. Power to the shovel is
carried by No. 2 A.W.G.S.H.G. 5-kv trailing cable at
4160 volts. The cable is lifted off the ground at all pot
head connectors to ensure that it is visible during
winter snow as well as to keep the pot heads dry
during the spring snow melting period.

Shovel maintenance, which is scheduled at 8-12 hours
per week during daylight hours, coupled with pre-
planning major overhauls, has ensured good mechan-
ical availability for a northern location; it is currently
running at 81% since the inception of the shovels.
Major spare items have been purchased recently to
ensure that components can be sent for overhaul with-
out reducing the mechanical availability of the ma-
chine. Hoist cables with socketed ends, and also a bail
pin unit without sheaves, have been installed to reduce
the time required to change broken hoist ropes.

Shovels and other major equipment units are
equipped with radios to ensure contact with the mine
shift foreman or the mine garage in the event that
re pairs are required. The high standard of radio main-
tenance has assisted in ensuring excellent control of
operations and minimizing downtime on equipment.

A Caterpillar 824 rubber-tired tractor is used for
cleaning up rock spillage around the shovels, moving
cables during blasting operations and generally assist-
ing in material movement. To maintain an acceptable
grade elevation, Caterpillar D9G tractors are equipped
with single-shank rippers. The digging limits with
reference to the toe or crest positions are marked by
stakes in the field and a daily reference survey is
carried out by the surveyors to ensure that strict
adherence to the line and level is maintained.

To supplement the waste rock production units, a
Caterpillar 992 10-cu.-yd front-end loader is used dur-
ing the periods when the shovels are not available.
Special emphasis is also placed on keeping the catch-
ments clean, using the 992 front-end loaders (Fig. 5),
to ensure that equipment or personnel working below
the waste-rock excavation levels can work with safety.
The 992 front-end loader was selected on the basis
that it can load 50-ton, 75-ton and 85-ton trucks with
ease, thus complementing the shovels.

When using the Caterpillar 992 front-end loader, a
dramatic increase in production has been achieved
when a D8 or D9 tractor is deployed in pushing rock
to the loader. The additional cost of using the tractor
is more than compensated for by the increased produc-
tion. A tractor is always used with the loader during
catchment cleaning operations.

Shovel production is running at 400 cu. yds per hour.
However, when mining the less-competent serpentine
rock associated with the orebody, production of 540 cu.
yds per hour is not uncommon.

All support equipment is Caterpillar supplied and
maintained on a contract basis by Finning Tractor and
Equipment Co. Ltd., Vancouver. A spare parts depot
is located at the plant complex and a repair facility has
been built in the pit.

Haulage

The haulage fleet employed on waste rock consists
of eight R85 Euclids of 85-ton capacity, powered by
Detroit Diesel 16V 92T 820-hp series engines with

FIGURE 5— Caterpillar 922 front-end loader cleaning catch-

FIGURE 4—A.N. prill storage silos—total capacity 210 tons.

ments to avoid rock spills onto the ore faces below.

DP8961 Allison transmissions, as well as six Wabco
75-ton-capacity trucks powered by VTA 1710-12V
700-hp Cummins engines with Allison DP8961 trans-
missions.

The 14 trucks are assigned to hanging-wall waste
production. Normally, nine trucks are required to
service the two 1900 AL P&H shovels and the Cater-
pillar 992 front-end loader. Trucks are double-side
loaded by the shovels whenever possible. Studies car-
ried out indicated that a 40% increase in production
can be obtained as compared to single-side loading.
The shovel or drill trailing cables are protected at
truck crossing points by inserting the cable in an
Irathene elastomeric crossover pad containing a slot
for the cable. A strip insert is placed in the slot to
protect the cable, and the pad is covered by fine rock
to protect the pad from damage during cold weather
(Fig. 6).

Haul ramps are designed 70 ft (21 m) wide at an
8-10% grade and are graded by a Caterpillar 16G
grader, using serrated ice blades in winter. Grading
on the dumps is maintained by D8 tractors with the
assistance of the grader. A dump person is employed
when trucks are dumping over the edge. All dump
areas are lighted at night by portable light units; the

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