The last 6 years saw a close cooperation
between the rope manufacturer CASAR,
the distributor Nobles and the Telfer
gold mine, based in the Pilbara region in
the state of Western Australia. is wholly owned by Newcrest Gold and copper are extracted, above as well as underground. The copper gold deposits were discovered in 1972,
and mining began in 1977. In
2008 it was decided to increase
the extraction capacities to over
6 million tons per year. This provided
the basis for initial talks between
Telfer and CASAR, as Telfer happy with the service life of the of a South African manufacturer hoisting machine and now the capacities
were due to increase too. machine is a ground mounted friction winder
which transports a payload of 34.5 t at a speed
of 16.25 m/s from a depth of 1132 m to the top.
The service life of the original ropes was
maximally 95,000 cycles, corresponding
to almost a year. The costs incurred by
downtimes and the rope replacement
after 95,000 cycles were immense and
had to be drastically reduced to make
extraction cost-effective. That‘s why they
asked CASAR to help. After a profound
study of the site and application, CASAR
decided to deploy CASAR Starplast construction.
This is a rotation-free rope construction
made of compacted strands. A
rope set consists of 4 hoist ropes, each
with a length of 1360m and a rope
diameter of 45mm.
CASAR succeeded to continuously increase the
lifetime up to 210,000 cycles reached with the
3. version of CASAR Starplast. The result was
overwhelming as the lifetime was more than
double the previous figure. Furthermore, the
ropes were in perfect condition even after these
210,000 cycles and only had to be discarded as
a result of mechanical damage due to rockfall,
not because of wear and tear.
In addition, it was possible to virtually exclude
undesired effects such as rope elongation and
rope slipping on the drum, and wear on the inlays
of the rope discs was reduced to less than
a quarter of the previous value. In particular the
reduction of the elongation effect is really valued
by Telfer as the usually necessary shortening of
the ropes after occurrence of the setting effect
is no longer necessary. At present the value of
elongation for the 4. version of CASAR Starplast
is less than 800 mm.
CASAR, Nobles and Telfer are confident that
they are able to use the knowledge gained to
further increase the service life to over 300,000
cycles. In this case the ropes would not have to
be replaced for at least 3 years. This alone would
represent major cost savings for the mine and
also save a lot of time which could be used for
other maintenance and repair work. It is estimated
that at least 10 working days that would
normally be needed to replace the rope could
already be saved during the service life of the
rope currently being used.
The ropes currently in use already reached
170,000 cycles in March 2015 and are still in
perfect condition. We are therefore confident of
reaching the set goal.
What Telfer particularly values in CASAR is that
the efforts started in 2008 aimed at increasing
the service life were back up throughout with advice
and support. Not only were system measurements
and destruction-free rope examinations
carried out on site, but there were also intensive
examinations of discarded rope pieces at CASAR,
always focused on improving the product.
Overall, this package of customised products
coupled with outstanding expertise and technical
support on-site has justified the higher purchase
price of CASAR ropes for Telfer. As a result,
Telfer have therefore purchased their hoist ropes
exclusively from CASAR in Germany since 2009.