If you are considering climbing or traveling on glaciers on one of the
trips I organize consider the following. I decided to post this after
one pair of skiers on our first trip were going to bring kayak throw-bags for
glacier travel in the spring. On one hand, crevasse falls this time of
year on many glaciers are unlikely. On the other hand, it can happen.
And these areas are typically remote, all immediately necessary equipment
will either need to be on-hand within the travel party (preferred) or
brought to the site by others in our group if they can be summoned from
the hut/base camp or their own route.
As these trips are unguided (short of special advanced arrangements to
the contrary) the decision on what to bring and what to carry on climbs/tours/hikes
is yours. The following information is taken from the written guidelines
for professional guides in Canada and is posted here to assist you in
making your own decisions on equipment.
From: Mountain Guides Professional and Technical Guidelines
Light Equipment
While there are many appropriate uses for light equipment it cannot be
considered a replacement for standard weight gear. Guides must carefully
assess the situation and determine if lightweight equipment is an
appropriate alternative.
Simply having a rope and a few carabiners on a glacier is not enough.
Guides must carry materials or equipment for harnesses and anchors suited
to the terrain on which they will be working.
It is common, especially in mechanized skiing operations, to carry light
equipment (5.5.mm spectra/gemini rope, superlight carabiners, 12mm
webbing, micro-ascenders, etc.) for rescue purposes.
Limitations
Consider the following when determining if light equipment is suitable:
- Strength: 5.5mm cord is not designed for climbing and rescue applications.
Strength over edges, around carabiners, through pulleys, and under shock load
is unproven (by either laboratory testing or practical field use) in comparison
to standard equipment. Superlight carabiners and other hardware is more susceptible
to breaking than similar standard gear when used in less than ideal load configurations
(e.g. crossloading, over an edge, etc.).
- Coefficient of friction: Spectra and gemini materials have low
friction and are not very compressible. This makes gripping hitches and
ratchet systems far less effective on lightweight gear. It is common for
the sheath on cord/ropes to slip with use and under load.
- Low melting point: spectra and gemini have low melting points and
poor resistance to abrasion.
- Brittleness: spectra and gemini cord is relatively brittle in
comparison to standard materials. These fibres, which provide great
strength with low weight have poor resistance to constant flexing and
strength is consistently reduced in situations that, with standard
equipment, are "normal" applications (e.g. running over an edge, through
a carabiner, around a pulley, etc.).
Advantages
There are only two real advantages to lightweight equipment: they have
high strength to weight ratio and are compact.
When to consider lightweight gear
Lightweight equipment is appropriate only in situations where:
- The chance of an accident requiring rescue techniques is low (e.g.
deep snowpack on glaciers, skiing vs. climbing objective, etc.).
- Standard rescue equipment is readily available.
- Time is not likely to be an issue (e.g. you can wait for help to come).
- There is no shock load potential.
- There are no edges that the rope might have to run over.
In practical terms, this means primarily in mechanized skiing operations.
Uses
Lightweight gear is used for:
- Stabilising an accident until standard equipment arrives.
- Supplementing standard equipment (e.g. as secondary or backup systems).
- Carrying out extrications only in life-or-death situations.
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