platinum
23
06.13
Above: The Koepe winders – the rock winder is on the left (photo:
Arthur Tassell).
Right: One of the two 1 700 kN, four-rope clamping and lifting
devices (photo: Arthur Tassell).
rope Koepe winders with deflection sheaves. These
are the first Koepe winders to be used within the Im-
pala Platinum group. The winders – which are me-
chanically identical – cater for payloads of 25 000 kg
(rock hoist) and 22 500 kg (man hoist) with the length
of wind on the rock hoist being 1 640 m and on the
man hoist 1 601 m. Rope speed is 16 m/s. Both wind-
ers are rated at 4,3 MW .
The winders have been supplied by FLSmidth and
the drives and motors by ABB and were installed
in the headframe in 2009 and 2010. The deflection
sheaves were fabricated by Kimberley Engineering
Works (KEW) Foundries and comprise two sets of
6,5 m diameter deflection clusters, with each cluster
consisting of four sheave wheels mounted on a single
rotating shaft. They are the biggest sheave wheels
ever to have been supplied by KEW.
Discussing the reasons for the selection of tower-
mounted Koepe winders, RSV’s Engelbrecht said
the decision was taken – obviously years back in the
design stage of the project – based on a comprehen-
sive assessment of the three primary options – Blair
Multi Rope (BMR) winders or either ground-mounted
or tower-mounted Koepe hoists. Capital costs were
determined by issuing enquiries to local South Afri-
can suppliers for estimates of technical and cost in-
formation in accordance with a specification for the
mechanical and electrical equipment for the wind-
ers while energy costs were determined by looking
at energy consumption as specified by the manufac-
turers and comparing this with Eskom’s tariff struc-
