HIGH PROFILE
MTB configuration will have a bunker backup unit
that allows for the continuous excavation of the
machine on long headings, merged with a
capability to allow for batch haulage trucks behind
the machine and support the rock concurrently.
There will be applications where conveyor belts
could be applied on straight, relatively flat layouts.
But as soon as one considers a tight turning
radius, flat or spiral with declines or inclines,
trucks seem to be a logical solution. A balance
between productivity and mobility is made. We
continue to challenge the status quo to provide
clients with adaptive and integrated drilling
solutions and that is what the MTB does.
PM: Is it the MTB that was tested at Cullinan or
have the MTB tests been conducted elsewhere?
Where will the first machine be commissioned and
is this still on track for Q3 2018?
KJ: The undercut contact tunnel constructed at
Cullinan was done by horizontal raise boring at a
length of 180 m and 4.5 m diameter in a kimberlite
pipe, traversing through softer clay type
kimberlites and harder gneiss, quartz and gabbro.
The experience gained through the trial proved to
be valuable and shaped some of our ideas on how
hard rock cutting and tunnelling should be
approached. It also provided worthwhile
information for the constructability of a circular
tunnel and the stability thereof. Many of the
potential tunnelling applications require a blind
heading for instances such as access tunnels;
where pilot and reaming used in horizontal raise
boring could not be applied. The HRB can replace
conventional drill-and-blast mining and promises
to increase mining productivity thanks to its
continuous process of rock boring, and in addition
offers significant safety benefits. The first MTB will
be commissioned in a short setup and curved
tunnel limestone quarry trial during Q3 2018
before being shipped for field trials to start in Q4
2018. We are currently still engaging with clients
for securing a project and application where the
field trials can be conducted. There is considerable
interest with cautious optimism. Our energy will go
towards a successful commissioning and field trial
and we envisage f