25 / 64
June 2016
MODERN MINING
23
TECHNOLOGY
used during regular advance operations and the
excavation chamber is also a ‘no-go’ zone while
cutting is in progress.”
The machines can be modified to support
tubbing, rock bolting, shotcrete or concreting
activities and unless there are extremely poor
rock conditions, excavation, mucking and rock
support are carried out simultaneously.
Herrenknecht shaft-sinking machines are
kept on course by a built-in guidance system,
which removes the need for a centre-core pilot
hole used when reaming technology is applied,
either from bottom-up or top-down.
The excavation sequence for all machines is
fully automated and the material is cut without
disturbing the surrounding ground and with
almost zero over-break.
The transportation of cut material can be
designed to suit customer or project require-
ments. The removal of muck from the shaft
bench can be performed dry or wet, using a
high-volume air-flow, a mechanical conveyor
system, or a fluid conveyance system.
“Herrenknecht is also in the process of devel-
oping a new generation of rodless machinery
for shaft enlargement for which a pilot hole is
used. The
SBE (Shaft Boring Machine for Shaft
Enlargement)
project is a joint venture between
Schachtbau GmbH and Murray & Roberts
Cementation and the aim is to update and adapt
existing pilot-hole technology to achieve high
sinking speeds and maximum work safety,”
says Roos.
The SBE is planned for shaft diameters of
between 7,5 m and 9,5 m and for shafts up to
2 000 m deep. Material conveyance takes place
by gravity through an existing pre-hole.
The machine, 15 m in length, braces itself
in the shaft before each drilling stroke, which
enables the thrust cylinders to push the rotating
cutterhead against the borehole floor to cut into
the hard rock.
“Herrenknecht is committed to the devel-
opment of blind-shaft technology and the
introduction of mechanised shaft sinking for
the mining industry. We look forward to dem-
onstrating the safety and productivity benefits
of our pioneering machines for upcoming min-
ing projects in South Africa,” Roos concludes.
Photos courtesy of Herrenknecht
Seen here (from left) are
Herrenknecht’s four shaft
boring machines – the Shaft
Boring Machine (SBM), the
Shaft Boring Roadheader
(SBR), the Shaft Boring
Cutterhead (SBC) and the
Shaft Boring Machine for
Shaft Enlargement (SBE).