14
Controls and communication typically are commensu-
rate to the level of operator presence and attention. When
material is transferred for each individual load, common
with binder and the norm for concrete and shotcrete, imme-
diate operator attention to the transfer typically occurs on
both the top and bottom of the system. In surge systems,
such as aggregate delivery, underground bins or chambers
are filled prior to distribution for individual loads, and
attention to bin filling typically is not as intense or frequent
as filling static mixers, transit mixers, or haul trucks.
The aggregate surface operator often is a front-end
loader operator, dumping to a hopper which feeds a surface
conveyor that continuously moves material to the transfer
line for delivery underground. The surge bin or chamber
is charged in a continuous operation which may include
belt scales or bin level indicators to monitor and control
the process.
In remote operation, instrumentation may be more
elaborate than for immediately attended operation.
Essentially, the level of controls and communication typi-
cally is inversely related to the level of operator presence –
immediate and continuous operator presence can preclude
the need for extensive instrumentation, whereas remote
and intermittent operator presence calls for relatively
extensive instrumentation to maintain safe and reliable sys-
tem operation.
A minimal communication system would entail lights/
screen(s) and voice contact between the upper and lower
stations. Those assist confirmation of status and action
prior to subsequent steps being undertaken, in operation as
well as maintenance.
OPERATING PROCEDURES
Whether shaft-mounted or sited in a borehole, slickline
operation entails common characteristics. Wet and dry
transfer have differences which warrant separate discussion,
but can be addressed in a common narrative.
Initial Setup
A fundamental aspect of transfer boots or elbows is to
achieve the energy absorption (thrust block) capacity of
the unit. For example, for a 670-m (2,200-ft) transfer, a
30-cm (12-inch) diameter unit will hold a nominal 0.06
m3 (2 ft3) of concrete/shotcrete from the base up to the
invert of the discharge orifice, 0.9-m (36-in). If a cemented
block is desired, it can be poured into the unit and, if pos-
sible, allowed to cure prior to placing the unit in service.
An approach is to insert this block prior to attaching the
Figure 8. Loadout station, 4900 Level, Lucky Friday Mine (Courtesy Hecla Mining Company,
2023)
Controls and communication typically are commensu-
rate to the level of operator presence and attention. When
material is transferred for each individual load, common
with binder and the norm for concrete and shotcrete, imme-
diate operator attention to the transfer typically occurs on
both the top and bottom of the system. In surge systems,
such as aggregate delivery, underground bins or chambers
are filled prior to distribution for individual loads, and
attention to bin filling typically is not as intense or frequent
as filling static mixers, transit mixers, or haul trucks.
The aggregate surface operator often is a front-end
loader operator, dumping to a hopper which feeds a surface
conveyor that continuously moves material to the transfer
line for delivery underground. The surge bin or chamber
is charged in a continuous operation which may include
belt scales or bin level indicators to monitor and control
the process.
In remote operation, instrumentation may be more
elaborate than for immediately attended operation.
Essentially, the level of controls and communication typi-
cally is inversely related to the level of operator presence –
immediate and continuous operator presence can preclude
the need for extensive instrumentation, whereas remote
and intermittent operator presence calls for relatively
extensive instrumentation to maintain safe and reliable sys-
tem operation.
A minimal communication system would entail lights/
screen(s) and voice contact between the upper and lower
stations. Those assist confirmation of status and action
prior to subsequent steps being undertaken, in operation as
well as maintenance.
OPERATING PROCEDURES
Whether shaft-mounted or sited in a borehole, slickline
operation entails common characteristics. Wet and dry
transfer have differences which warrant separate discussion,
but can be addressed in a common narrative.
Initial Setup
A fundamental aspect of transfer boots or elbows is to
achieve the energy absorption (thrust block) capacity of
the unit. For example, for a 670-m (2,200-ft) transfer, a
30-cm (12-inch) diameter unit will hold a nominal 0.06
m3 (2 ft3) of concrete/shotcrete from the base up to the
invert of the discharge orifice, 0.9-m (36-in). If a cemented
block is desired, it can be poured into the unit and, if pos-
sible, allowed to cure prior to placing the unit in service.
An approach is to insert this block prior to attaching the
Figure 8. Loadout station, 4900 Level, Lucky Friday Mine (Courtesy Hecla Mining Company,
2023)