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25-081
Slicklines, Droplines, Diverter Boots—A Monograph
Ralph R. Sacrison
Sacrison Engineering, Elko, NV
Lauren M. Roberts
Roberts Engineering and Development,
Spokane, WA
INTRODUCTION
Pipeline or borehole free-fall transfer of material has long
been done in support of underground mining. This paper
addresses some characteristics and design elements in
selecting systems suitable to the transferred media and the
mine requirements. Though aspects of overall systems are
discussed, principal attention is directed to the slickline/
dropline/transfer line and the discharge diverter/rockbox/
energy dissipator/boot. These terms are common to these
systems, often used interchangeably, and will be used as
appropriate to the material, equipment and construction.
Following several design sections, fabrication and construc-
tion, and system operating and maintenance procedures are
discussed.
Glossary
Though typical technical terms are used, it is reasonable
to state selected usage common to these free-fall vertical
transfer systems.
Bank moisture – inherent or bed, that is, natural moisture
within media (sand, aggregate, etc.) without mechan-
ically wetting or drying. The range of bank moisture
includes precipitation influx due to seasonal cycles
and individual events.
Boot – the diverter, transfer ELL, rockbox, energy dissipator
used in slickline/dropline systems for the diversion of
the falling material stream to further placement or
handling. In large, the term is from the heel and toe
configuration of typical pipe or chute fabrications,
where the heel is the rock ELL and thrust block por-
tion, with the toe being the portion discharging to
further conduit(s) or open space.
Collar – the surface intercept of a mine opening (shaft, raise,
borehole), typically associated with shafts, raises, and
boreholes. Also refers to the initial or topmost sup-
port at the mouth of a vertical or sub-vertical entry.
Not interchangeable with portal – referring to the
ground surface intercept of horizontal or sub-hori-
zontal adits and drifts.
Dead bed – the material at the bottom of a chute or bin
beyond the active transfer zone. Can be designed to
provide rock-on-rock impact rather than rock-on-
structure, thus minimizing wear.
Dropline – vertical free-fall transfer conduit for dry media.
Aggregate (coarse, fine, or graded), dry-mix concrete
and shotcrete and unmixed binder (cement, pozzo-
lans, etc.) are the principal media transferred in these
systems.
Dry transfer – this is the transfer of dry media, run-of-
bank, -silo, -stockpile. It is media which is not wet-
mixed as a condition of transfer and end use, though
in periodic weather conditions can be relatively high
moisture.
Hang-up – in vertical transfer, whether raise, slickline, or
through transfer points (gates, chutes, boots), a hang-
up refers to flow having slowed or halted. Common
resolutions are vibration (if access and configuration
allow) or lancing (air or water), done from the dis-
charge end. Drilling/reaming/brushing out borehole
installations can be an option.
Lancing – cutting, typically with high pressure air or water.
Pass/raise – in some settings, open passes or raises are used
for free-fall transfer of development, construction,
and mining media. These typically do not entail the
25-081
Slicklines, Droplines, Diverter Boots—A Monograph
Ralph R. Sacrison
Sacrison Engineering, Elko, NV
Lauren M. Roberts
Roberts Engineering and Development,
Spokane, WA
INTRODUCTION
Pipeline or borehole free-fall transfer of material has long
been done in support of underground mining. This paper
addresses some characteristics and design elements in
selecting systems suitable to the transferred media and the
mine requirements. Though aspects of overall systems are
discussed, principal attention is directed to the slickline/
dropline/transfer line and the discharge diverter/rockbox/
energy dissipator/boot. These terms are common to these
systems, often used interchangeably, and will be used as
appropriate to the material, equipment and construction.
Following several design sections, fabrication and construc-
tion, and system operating and maintenance procedures are
discussed.
Glossary
Though typical technical terms are used, it is reasonable
to state selected usage common to these free-fall vertical
transfer systems.
Bank moisture – inherent or bed, that is, natural moisture
within media (sand, aggregate, etc.) without mechan-
ically wetting or drying. The range of bank moisture
includes precipitation influx due to seasonal cycles
and individual events.
Boot – the diverter, transfer ELL, rockbox, energy dissipator
used in slickline/dropline systems for the diversion of
the falling material stream to further placement or
handling. In large, the term is from the heel and toe
configuration of typical pipe or chute fabrications,
where the heel is the rock ELL and thrust block por-
tion, with the toe being the portion discharging to
further conduit(s) or open space.
Collar – the surface intercept of a mine opening (shaft, raise,
borehole), typically associated with shafts, raises, and
boreholes. Also refers to the initial or topmost sup-
port at the mouth of a vertical or sub-vertical entry.
Not interchangeable with portal – referring to the
ground surface intercept of horizontal or sub-hori-
zontal adits and drifts.
Dead bed – the material at the bottom of a chute or bin
beyond the active transfer zone. Can be designed to
provide rock-on-rock impact rather than rock-on-
structure, thus minimizing wear.
Dropline – vertical free-fall transfer conduit for dry media.
Aggregate (coarse, fine, or graded), dry-mix concrete
and shotcrete and unmixed binder (cement, pozzo-
lans, etc.) are the principal media transferred in these
systems.
Dry transfer – this is the transfer of dry media, run-of-
bank, -silo, -stockpile. It is media which is not wet-
mixed as a condition of transfer and end use, though
in periodic weather conditions can be relatively high
moisture.
Hang-up – in vertical transfer, whether raise, slickline, or
through transfer points (gates, chutes, boots), a hang-
up refers to flow having slowed or halted. Common
resolutions are vibration (if access and configuration
allow) or lancing (air or water), done from the dis-
charge end. Drilling/reaming/brushing out borehole
installations can be an option.
Lancing – cutting, typically with high pressure air or water.
Pass/raise – in some settings, open passes or raises are used
for free-fall transfer of development, construction,
and mining media. These typically do not entail the