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The following sections discuss climbing shoes, rope, general-purpose
devices for connecting things, nylon cord, harnesses for connecting
climbers to things, devices for applying friction to the rope, and
devices for wedging into the rock.
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Shoes |
 The most useful piece of climbing equipment is a pair of climbing shoes. Improvements in shoe design alone have allowed climbers to climb many things previously unclimbable. The modern climbing shoe has a stiff, smooth rubber sole that protects the foot from sharp, rough rock, and provides more friction than a bare foot. A pair costs between $100 and $150.
Climbing shoes fit tightly to prevent the foot from sliding around
within. This makes them uncomfortable, but the improved friction and
control they afford far outweigh the discomfort.
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Rope |
A modern climbing rope, a key piece of safety equipment, is of
kernmantle construction, consisting of continuous braided nylon
fibers, the kern, surrounded by a continuous braided nylon outer
sheath, the mantle. Such construction is superior to the more
traditional laid rope (three large strands twisted together) because
the outer sheath protects the inner core, where most of the strength
lies, from the elements.
Climbing rope is dynamic: able to stretch a bit under tension. This
is because the rope must stop falling climbers. If the rope did not
stretch, a falling climber would be jerked suddenly as the rope stops
him. Instead, the rope slows his fall more gently.
Climbing ropes are usually ten to eleven millimeters in diameter and
fifty meters (about 165 feet) long. Such ropes cost between $100 and
$180.
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Carabiners |
Carabiners, used constantly in climbing, are rings of solid aluminum
with a spring-loaded gate that allows them to be opened. Normally,
the spring holds the gate closed, but the gate can be opened to admit
a rope.
Carabiners are inexpensive (between $5 and $20), strong (most are
rated to hold at least 20 kN, about 2.2 tons), and versatile.
Virtually every climbing technique uses carabiners.
There are many variations on the basic carabiner design. The
carabiner shown above is a ``D'' because the ends have an asymmetric
shape that tends to push the rope against the solid side, away from
the weaker gate side. An older variant (below left), the oval, has no
such asymmetry, and is not as strong. Another variant, the bent-gate
(below right), has a curved gate that makes inserting a rope easier.
However, the bent gate also makes it easier for the gate to work
itself open, making it less safe than other varieties.
A carabiner is safe until its gate opens. To increase security, two carabiners can be used in tandem with their gates reversed (i.e., opening in opposite directions). It is less likely that something would cause both gates to open at once.
An alternative to a pair of carabiners, the locking carabiner (shown
above) has an additional mechanism that makes it harder for the gate
to open accidentally: a sheath that covers the gate and the outer
C-shaped portion of the carabiner. This sheath either screws into
place, or uses a spring to hold it in place.
Each variety is well-suited to certain applications. The ``D'' is the
most versatile, although it must sometimes be used in pairs for added
security. The oval is used where its symmetry is desirable, typically
on longer routes. The bent-gate is excellent for rapidly securing the
rope, although it is slightly less safe. Locking carabiners are best
when taking the extra time to attach them is not a problem.
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Webbing |
Tubular nylon webbing is used frequently in climbing. It is made of
nylon woven into a flat tube an inch across. It is very strong (its
tensile strength is about 18 kN, about 2 tons) and inexpensive---about
$0.25 a foot.
Unlike climbing rope, it does not stretch under tension. If not
expected to stop a long fall (and it is never used in a situation
where it is), this is preferable.
Nylon webbing is most often used tied into a a loop. Climbing stores
sell it by the foot, and it can be easily cut to any desired length.
The ends are cauterized with heat to prevent fraying.
Also popular is pre-sewn webbing---loops of webbing sewn (as opposed
to tied) together at the factory. Pre-sewn webbing is more expensive,
more convenient (since there is no knot), and may be safer, but
custom-tied loops are cheaper and adjustable.
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Harnesses |
To attach herself to a rope, a climber uses a sewn harness. A typical
one has a wide nylon belt for the waist and a pair of leg loops for
the thighs. When a climber is supported by such a harness, most of
her weight is placed on her legs, rather than her waist, making it
fairly comfortable to hang in.
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Belay Devices |
A belayer's job is to hold the rope to stop a falling climber, which
is difficult without the aid of a belay device---an object capable of
stopping the rope or passing it through smoothly. There are many such
belay devices, and are all easy to use, making them very safe.
One common belay device is the figure-eight: two metal rings about an
inch in diameter joined in the shape of an 8. A loop of rope is
passed through one of the rings, then around and under the other. The
ring without the rope is clipped to the belayer's harness with a
locking carabiner. When pulled tight, the rope is bent into four
ninety degree angles in the space of a few inches, making it very
difficult to move. A figure-eight costs between $15 and $20.
A disadvantage of the figure-eight is its tendency to twist the rope
as it passes through. Another style of belay device, typified by the
ATC (Air Traffic Controller) depicted at left, avoids this problem by
twisting the rope less. These devices typically have two holes just
large enough to pass a loop of rope through. The loop of rope is
attached to a carabiner such that when one end of the rope is pulled,
the belay device approaches the carabiner and pinches the rope. This
provides highly variable rope friction, ranging from very little to
enough to support a falling climber.
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Protection |
Protection refers to objects that can be placed securely in rock and later removed. The two types are monolithic protection, with no moving parts, and spring-loaded camming devices, with many moving parts. |
Monolithic Protection |
There are two common types of monolithic protection: tapered wedges
and hexes. Both are made specifically for climbing from lightweight
aluminum. In use, both are wedged into cracks in the rock so that
they are difficult to remove in one direction (usually down) and easy
to remove in another (usually up).
A tapered wedge, shown above, is a trapezoidal piece of aluminum (one
to three centimeters across) attached to a loop of steel cable.
A hex is a hexagonal tube of aluminum with a diameter roughly equal to
its length, between one and six centimeters. A strong piece of cord
is threaded through two pairs of little holes on opposite sides of the
hex and tied into a loop.
Monolithic protection is inexpensive (a typical piece is under $10),
and, when carefully placed, strong (they can support at least 5 kN,
about half a ton), but they cannot be used in all situations. For
example, they do not work in cracks with nearly parallel sides.
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SLCDs |
A spring-loaded camming device (SLCD) consists of a stem with an axle
at one end holding four spiral-shaped spring-loaded cams. When
placing an SLCD, the climber pulls a mechanism to retract the cams
places it in a crack with the stem pointing down, and relases the
mechanism, allowing the cams to spring back against the rock. When
the SLCD is pulled downward (say, because of a fall), the
spiral-shaped cams are forced harder against the rock, making it more
secure.
SLCDs are much easier to use than monolithic protection. They
can adapt to the rock and hold themselves in place, making them usable
in more situations. They have allowed climbers to climb many routes
that were too dangerous to climb using other types of protection.
The main disadvantage to SLCDs is cost: $50 to $100 each is
typical. However, since each SLCD can adapt to a wider range of
crack sizes than their monolithic counterparts, so only four or five
sizes are needed.
SLCDs also have the dangerous ability to ``walk.'' If not under
tension, a SLCD can easily move in one direction, usually farther
into a crack. This can make it difficult to remove, or more
dangerously, move it to where it no longer holds. Monolithic
protection usually doesn't do this, since it is usually firmly wedged
into the rock.
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Written by Stephen Edwards.