The economic impact of collisions
between large mining equipment is
also an important consideration. Some
estimates indicate that unplanned
downtime on a large electric rope
shovel can result in as much as
US$ 50,000/hour in lost revenue.
1
A
single incident can result in significant
unplanned downtime for repairs and
incident investigation, resulting in
hundreds of thousands of dollars in
lost revenue.
Shovel operation: a
challenging environment
Primary excavating equipment, such as
electric rope shovels and hydraulic face
shovels, are extremely important to
mining operations. Operators of these
machines face several unique
challenges, including: large blind spots,
a wide swing path, the need for
clean-up equipment to work in close
proximity to other equipment, as well
as operational pressures to reduce
downtime.
In a mining shovel, the operator’s
visibility is very limited and usually
restricted to the area in front of the
shovel and a partial view on the same
side as the cab. Many operations
supplement this through surveillance
cameras mounted around the
equipment. However, the design of
shovels requires a large counterweight,
which puts the back of the shovel far
from the centre of rotation. In addition,
as the equipment rotates, the
counterweight follows a wide swing
path. This geometry can make it
difficult for the operator to correctly
judge whether nearby equipment will
be hit as the shovel swings. As a result,
counterweight collisions with haul
trucks and clean-up equipment are
common incidents.
Shovels require regular clean-up of
their vicinity. Generally, dedicated
clean-up equipment, such as a
wheel-dozer, is paired with the shovel.
As material falls from the bench face
and the bucket during loading, it is the
responsibility of the clean-up
equipment to ensure the area stays
clear of large debris. This can be done
safely through operational procedures
that require the shovel to stop during
clean-up. However, due to production
pressure, it is not uncommon to see
clean-up happening during active
loading operation. This creates a
potentially dangerous situation, as the
shovel operator is focused on the
loading operation.
The importance of collision
avoidance systems
Given the importance of shovel uptime
and the potential for serious and
possibly fatal incidents, it is important
to have a collision avoidance system.
Figure 1.
A variety of large equipment operating in close proximity in a coal mine.
Figure 2.
Left: The right collision zone of an RH200 shovel is indicated in red. Right: the
warning zone of an RH200 is indicated in orange.
Figure 3.
A rugged radar sensor being installed on the counterweight of a P&H rope shovel.
30
|
World Coal
|
September 2014
