There are basically three different types of rope, each best
suited for different applications, which are tested according to
different standards.
Single Ropes
Single
ropes are the most common type of ropes used. Depending upon diameter
and length they can be used for most conditions. The main advantage is
simple handling. A disadvantage is that only routes up to a half rope
length high, with subsequent lowering or rappelling, can be climbed. Single
ropes come in diameters of approximately 8,9 to 11 mm and weigh between
52 to 77 grams per meter. Single ropes, withstand at least five falls
with an 80 kg mass.
Twin Ropes
Twin
ropes must only be used in pairs and are clipped together into each
piece of protection, as with single rope technique (= Twin rope
technique). The two ropes offer redundancy and thus, increased safety
in the case of shock loading over a sharp edge. They are therefore
especially suited for alpine climbing or demanding routes where retreat
may be necessary. They offer the highest safety margin and allow full
length rappels. With diameters from approximately 7,5 to 8,5 mm and a
weight of between 38 to 45 grams per meter they are, together, about as
heavy as the heaviest single ropes. With standard testing the ropes
must withstand 12 falls with an 80 kg mass.
Half (Double) Ropes
Half
ropes, with regard to strength and weight, lie between single and twin
ropes. They only offer standard safety when they are used as a pair.
But here you have the choice between twin rope technique, where both
ropes run parallel through the protection and half rope technique,
where the «left» and «right» ropes run separately through different
protection points. This technique allows friction to be reduced in the
case where protection points are widely spread and reduces impact
force. This is of benefit when climbing traditionally protected routes.
A belay method which enables the independent control of each rope must
be used. Half ropes are tested singly with a 55 kg mass and must
withstand five standard falls. They come in diameters from 8 to 9 mm
and weigh 41 to 55 grams per meter. In single strand form they are
suitable to belay two seconds.
Purchasing Tips
The
intended use determines which rope is best. It therefore makes sense to
have a number of different ropes that can be used according to the type
of climb. So, for high friction use, such as working routes or, top
roping, a rope with a higher sheath proportion is useful. For alpine
use, especially with ice, a drytreated rope is recommended. With
possible sharp edge loading, or for longer rappels, twin, or half ropes
are the first choice. The following gives examples of typical usage,
each with the specific performance characteristic required by the rope.
Alpine Rock Climbing
i.e. High Sierra, Bugaboos, Wind River Range.
As
soon as more difficult rock with a uniform level of difficulty comes in
to play – meaning that a fall is possible at any time, classic belaying
from anchor to anchor is necessary. Whether single or double –
respectively twin ropes are used, depends mainly upon whether
rappelling, or down climbing will be undertaken. In broken terrain,
shorter rope lengths can be sensible.
Long Ice and Mixed Routes
i.e. Moonflower Buttress, Walker Spur, Droites North face, difficult waterfalls.
Only
half or twin ropes offer the highest safety margins and enable long
rappels in difficult terrain. Dry-treatment, easy handling and low
weight all help with quick, efficient rope management. Long rope
lengths are particularly useful on ice routes where pitches can often
be run together.
Ice Climbing / Dry tooling
i.e. Vail, Ouray.
The
requirements are similar to those of sport climbing, though
dry-treatment is essential. With bolted mixed routes a single rope can
offer simpler handling, though in sharp edged rock terrain the safety
margin given by twin ropes is welcome. On poorly protected mixed
routes, as typically found in Scotland, the half rope technique reduces
the load on the «safety chain».
Mountaineering
i.e. Mt. Rainier, Denali, South America.
With
classic tours in mixed terrain and single climbing pitches up to grade
4 or 5 it is usual to down climb rather than rappel. Here it is
advantageous to use a single rope. Or, a doubled half rope length can
be used, though then only half the ropes length can be used. A
dry-treated rope is also recommended here.
Multi Pitch Sport Climbing
i.e. Mt. Charleston, Red Rocks, El Portrero Chico, Wenden, Verdon.
Twin
rope and half rope techniques offer the best safety margins and full
rappelling distances. Dry treatment is useful in changeable conditions.
Sharp edge resistance is guaranteed by the appropriate ropes. (Half or
twin ropes).
Sport Climbing
i.e. Rifle, Smith, Rumney, Thailand.
With
frequent falls, a burly rope is important. The impact force can be
reduced by a dynamic belay. Handling and weight should be optimized for
performing at the edge. Longer ropes (70/80 m) are needed at many
modern sport climbing areas to allow safe lower-offs.
Climbing Gyms
Climbing Gym surfaces wear a rope more quickly; sturdier ropes and thicker sheaths are an advantage.
Working routes with Frequent Falls
i.e. Training on a local crag.
Frequent falls cause extensive wear. Therefore, a «work horse» of a rope is required. Weight is less important than longevity.
Top Roping / institutional Use
To combat lots of
abrasion and hard wear, a tougher sheath construction is an advantage.
As long as falls by the second only are possible, then, circumstances
allowing, a half rope can also be used.
Big Wall Climbing
i.e. El Capitan, Baffin.
A
single rope is most often used for big wall climbing, while a static
rope is used to haul. It’s desirable to have a large safety margin and
tough sheath.
Rescue
i.e. Mountain rescue.
High safety reserves and low elasticity are the most important properties of a mountain rescue rope.
All info found on www.mammut.ch