Ch10 Belaying
The belay location should have three attributes:
1. Good placement for anchors
2. Safe position
3. Reasonable comfort
Impact Force:
☆When considering the effects of a fall,climbers get used to thinking in thems
of force, rather than weight. The human body cannot withstand more than about
12kN.
☆Any fall of the same factor will generate the same impact force.
Static ropes, webbing slings,and accessory cord, while fine for rappelling,
constructing anchors, and other uses, do not stretch enough to safely catch a
fall.
Fall factor ＝ length of fall／length of rope fallen on
☆A factor 2 fall would gengrate the Max. impact on anchors and climbers.
☆If there is any slack rope, intermediate points of protection, or dynamic
action to the belay, the fall factor would always be less than 2.
Protecting the Leader:
☆A leader fall is twice the distance between the clime and the last placement
of protection.
☆The most severe strain on the belay system and anchors may occur just as a
leader starts up a pitch.
Applying Friction to the Rope:
☆In any belay method, the rope from the climber goes around or throuth some
friction-producing element and then to the braking hand.
☆In all cases, grip strength alone is not sufficient to stop a fall.
☆The braking hand must never leave the rope.
☆Using belay devices, the greater the degree of bend the rope is forced to
make, the greater the stopping force that is gengrated.
Types of Belay Devices:
Aperture devices: Plates: Sticht plate
－Reguire the least force to hold the climber's weight,
but are the least smooth in lowering the climber.
Tubes: Lowe Tuber II, ATC, DMM Bug, Pyramid
－Plates&Tubes must be attached to some sort of tether to
keep them from sliding down the rope and out of reach.
－Can produce a jerky ride that may put undesirable impact
loads on the rappel anchor.
Figure-eight devices －The smoothest for rappelling, but put
twists in the rope.
Self-locking belay devices: Guide plate
Reverso
－These devices May not function when used with
ropes of less than 10mm.
Grigri －The self-locking mechanism can put high
loads on anchors, and it works poorly or
not at all with icy or wet ropes.
Yo-yo, Antz, Single Rope Controller
When a climber using a belay device is facing away from the belay anchor, the
tie-in to the anchor should be on the braking-hand side.
A belay device that is dropped a significant distance should be retired.
Munter Hitch:
☆Efficient belaying with a Munter hitch requires an HMS-type carabiner with an
opening large enough to allow the hitch to feed through smoothly.
☆It's the only traditional belay method that provides sufficient friction
regardless of the angle at which the braking end of the rope is held.
☆It's excellent for belaying but not preferred for rappelling because it
twists the rope.
Hip Belay:
☆The force of a fall is dissipated as friction against the belayer's body, if
a belayer is burned badly, the belayer could drop a falling climber.
☆Because the belayer's hands provide a greater proportion of friction in the
hip belay, gloves are essential to protect the hands from burns. A tighter grip
causes less-severe burns.
☆The hip belay requires more time to attain braking position and generates
less braking force.
☆The belayer can take in rope much faster, and can be set up quickly with a
min. of equipment.
☆It's most useful when belaying a fast-moving partner from above, and also be
useful for belaying on snow, where it may be desirable to have a more dynamic
belay because anchors are often suspect.
☆Straighten the elbow of the braking arm before you begin to grip hard.
☆Then bring the braking arm across in front of your body.
☆When you are attaching to the anchor, rig the connection to the side opposite
the braking hand.
☆To clip a control carabiner on your seat harness, if you're not using a
control carabiner, take advantage of the anchor attachment to keep the climbing
rope from being pulled overhead or under your seat.
The force the belayer needs to exert with either method will not reach the
level at which the rope will start to run. When the difference between two
belay methods matters is in the case of a high-factor fall on high-angle rock
with little or nothing to produce friction other than the belay.
The Max. force on the top piece of protection is 1.5～2 times as high as the
Max. force on the climber－in a high-factor fall on the vertical rock, the Max.
force on the climber can easily be 6.7 kN.
Load-limiting runners: Yates Screamer.
When selecting belay anchors, always consider every possible direction from
which a force may load the anchors.
Nature Anchors: Trees, Bushes, Horns, Columns, Rock tunnels,
large and flat-bottomed boulders
Artificial Anchors: Bolts, Pitons. Often shown as "x" and "fp", respectively.
Tying In to the Anchor:
☆The figure eight is strong, stable, and easy to untie; the clove hitch has
the advantage of being adjustable after it is tied and is the easiest way to
back up a stance with a taut line from the belayer to the anchor.
☆When connecting to an anchor, use one locking carabiner or two regular
carabiners with the gates reversed and opposed.
☆Avoid chaining carabiners in succession.
☆Redundancy requires attaching to multiple anchors for belaying.
☆There're several different ways to rig multiple anchors, one is to tie in
separately, with the climbing rope, to a series of anchors, using clove hitches
for their adjustability. But it's far preferable to use a method that
equalizes the load among two or more anchors.
Self-Equalization:
☆It is absolutely essential to put the loop in the runner rather than just
clipping the top and bottom of the runner to the carabiner into which the rope
is tied.
☆In the event of severe loading, the system essentially locks; the carabiner
fails to slide on the runner and does not accomplish the intended equalization
of force.
☆This method also violates the No Extension principle.
Static Equalization: The current preferred method of rigging belay anchors.
Choosing an Equalization Method:
☆ FORCE ON EACH OF TWO EQUALIZED ANCHORS
Angle Force on Each Anchor
0 50%
60 58%
90 71%
120 100%
150 193%
170 573%
☆If the vertical line representing the direction of force of a downward pull
does not bisect the V but instead forms two unequal angles within the V, more
of the load will be on the anchor that is closer to being parallel to the
direction of force.
☆The smaller the angle, the more any wrong guess about the direction of force
will load the anchors differently.
☆A further difficulty is that the direction of force may not be known at all.
☆Inferior anchor placements should not be used in lieu of solid placements,
typically, the best arrangement involves equalized anchors－but not always.
Belay Position and Stance:
☆Many common belay devices may not work effectively when rigged directly off
the anchor.
☆Any stance is unlikely to be able to withstand the force of a severe fall.
☆Severe forces will result in a pull in a direct line between the Anchor,
Belayer, and Climber's line of travel.
Directional Carabiner:
The force from a fall will always come from it rather than from the climber
directly onto the belayer. Then a first solid placement is already established
as the climber begins the next lead.
The components of the belay anchor should not be used as a first protection
placement be the lead climber.
Tightly attached to anchors above your waist level so that you cannot be pulled
down more than a few distance.
When belaying the leader, never let the rope get taut, when belaying a follower
there is no slack in the rope.
When you are belaying a follower up to the belay position, it is best to
re-pile the entire rope twice, so that the leader's end is on top.
OTHER TECHNIQUES
☆Tying Off the Belay
☆Self-belayed Solo Climbing
☆Belay in Sport Climbing
－It's extremely dangerous that running the rope through a runner on the
anchor, rather than through carabiner in top-roping areas.
－Better tie a figure-eight backup knot in the end of the rope.
Ideally the anchor system should be SRENE: Solid, Redundant, and Equalized, and
providing No Extension.
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