23 / 64
June 2016
MODERN MINING
21
TECHNOLOGY
developed by Herrenknecht
The Shaft Boring
Roadheader (SBR) was
developed for blind-shaft
boring in soft-to-medium
rock or frozen ground to
depths of 1 000 m.
design and detailed engineering for it was
completed in 2013.
The SBM is capable of sinking shafts
between 10 m and 12 m in diameter at three
times the rate of conventional shaft-sinking
methods. “We are talking about a machine that
was designed to achieve a sinking rate of over
10 m a day – and for a performance such as
this a massive machine with plenty of power is
needed,” comments Roos.
Most of the technology used in the develop-
ment of Herrenknecht’s blind-shaft machines
– such as drilling and rock support – was
adapted from technology developed for the
company’s internationally recognised tunnel-
ling business. As a result, the SBM is similar
to a conventional tunnel boring machine,
except that it is suspended vertically in the
shaft and employs conventional disc cutting
in a unique setup.
Herrenknecht engineers chose the disc-cut-
ter option for the SBM when it was ascertained
that roadheaders could not be used effectively
when cutting rock with a compressive strength
of more than 120 MPa. The massive cutting
wheel employed in Herrenknecht’s Shaft
Boring Machine has a diameter that equals the
excavation diameter of the shaft (10-12 m).
The 60-m long SBM is self-suspended by
a set of grippers. Up to three systems brace
against the shaft wall to stabilise the entire sys-
tem during cutting.
Herrenknecht’s
Shaft Boring Roadheader
(SBR)
was developed for blind-shaft boring in
soft-to-medium rock or frozen ground to depths
of 1 000 m. Two of these machines are currently
in operation on the Jansen project in Canada.
“The two SBRs were manufactured and
assembled at Herrenknecht’s premises in
Germany, where cutting tests were performed
to the customer’s satisfaction before being
shipped to Canada where they have been in
operation since 2013 at the project,” says Roos.
This rapid rock excavating machine is
equipped with a rotating cutting drum installed
on a telescopic and slewable boom with the
result that it is flexible and can be used to cut
shafts of variable diameters. The telescopic
boom also allows for the excavation of the
entire shaft cross-section to a depth of 1 m in a
single operation.
While sinking a shaft, the unit is suspended
by ropes connected to shaft winders on the
surface. As with the gigantic SBM, this smaller
machine had to provide safe working con-
ditions for operating personnel while again
exceeding the sinking rates achieved by con-
ventional shaft-sinking practices.
The
Shaft Boring Cutterhead (SBC)
is the
third machine in Herrenknecht’s stable of blind-
boring equipment. One-third shorter (40 m)
than the SBM and with a mass of 350 tons, it
is well-suited for the excavation of deep blind
shafts up to 9 m in diameter in hard rock con-
ditions and is capable of delivering an advance
rate of 6 m a day.
The SBC utilises a conical-shaped, full-
faced, cutter head equipped with disc cutters
and the cutting sequence is highly automated.
This mechanical shaft-sinking unit is sus-
pended from and moved by shaft ropes.
“For all machines across the range, the three
basic functions – excavation, rock support and
installation decks – are common,” notes Roos.
“During normal operations the crews are not
exposed to an unsupported shaft wall and hence
falling rock, nor silica dust. No explosives are