Electricity + Control

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TRANSFORMERS + SUBSTATIONS
“And the knock on savings were outrageous. We
closed a site with running costs of R150 M per
month five months early. As a result, 1,4-million
tons of ore were put through the mine before it
was due to open – and the capital expenditure
for the development of Kolomela, which was
about R8,4 billion, was paid off in 24 months,”
Jackson reveals.
From electrical to mechanical plant?
Pit dewatering at Kolomela is achieved via
16 boreholes that lower the surrounding water
table. “The water is fed into an eight-million litre
water tank and it is then pumped 18 km as pota-
ble water to Beeshoek, into the Vaal Gamagara
municipal intake at up to 1 500 m3/h.
“While the mine had moved towards offsite
modular designs with respect to its substations
and MCCs, the pump house itself experienced
civil delays. We had a fully functional MCC
control room and all of the medium-voltage
infrastructure onsite and operational, but the
pump station building hadn’t been completed.
So, while massively successful on the electrical
side, we were still being hampered by delays
on the civil andmechanical side,” Jackson says,
adding, “the budget for the pump station build-
ing was originally in the order of R1,8 M, but it
ended up costing well north of R4 M – and it
was more than eight months late.”
“Onsite construction of plant at remote
mines is such an onerous thing. A project can
be hampered by continuous delays, due to late
deliveries of inputs, the wrong people being
sent to site and a host of safety and security
restrictions that make rapid progress impos-
sible,” he explains.
Have there been similar projects?
Following the success of Kolomela on the
electrical side, therefore, when another pump
station project emerged, Jackson, with Kevin
Hundley who was with Aurecon at that time,
began to explore a similar approach. Themining
pit at Sishen, which is one of the largest open cast
pits in the world, is becoming deeper, so an ad-
I n C o n v e r s a t i o n W i t h