Page 19 - Rappelling

Dynamic, Low-Stretch, or Static measure of the rope’s ability to resist slicing over
When buying a rope for rappelling, the following sharp rock edges. As mentioned earlier, some of the
criteria will help you assess which rope is best for only documented cases of modern climbing ropes
your particular application. breaking in the field have been when the rope was
A dynamic rope is required for situations cut over a sharp edge.
where you’ll be using the rope for both belaying Static Elongation
and rappelling, as in rock climbing. My preferred
rope for rappelling and fixed line applications is This is a measure of how much the rope stretches
a low-stretch rope. I look for a rope with either under a weight of 80 kg (176 lbs.), telling you how
a CE EN 1891 Type A certification or an NFPA much your rope will stretch during a normal rappel.
light use certification, with a diameter of between For rappelling and fixed rope applications, I prefer a
10 and 10.5mm, to be compatible with various low-stretch rope with a static elongation of around
rappelling and ascending devices. I also check the 3 to 4 percent. Most dynamic climbing ropes have a
rope’s suppleness to ensure the rope will hold knots static elongation of about 8 or 9 percent.
firmly and handle well. Sterling makes an excel- Dry or Non-Dry
lent low-stretch polyamide (nylon) rope called the
Safety Pro. I prefer the 10.5mm diameter for good Nylon, when it gets wet, absorbs water, which
handling and durability for rappelling and fixed weakens the fibers. Nylon ropes can lose much of
rope work. their strength when wet (usually at least 30 percent;
some studies show over 50 percent loss of strength),
Diameter and Sheath Percentage so manufacturers sell ropes with a “dry coating” to
Ropes sold for climbing and rappelling commonly keep the rope from absorbing water and make it
range from 9 to 11mm, with the most popular more abrasion resistant. If you’re using a dynamic
diameter around 10.5mm. Thinner ropes generally nylon rope in snow, ice, or wet conditions, such as
stretch more and cut more easily over sharp edges. those encountered in mountaineering or ice climb-
A thicker diameter rope also affords more friction ing, you’ll definitely want a rope with a dry coating.
when used with rappelling devices. Polyester ropes do not absorb water, so for
Many manufacturers now provide information applications where you’ll need a rope for rappelling
on the sheath’s percentage of the total weight. A and rope ascending in wet conditions, such as can-
rope with a higher percentage of sheath (40 percent yoneering, but not for lead climbing, a low-stretch
or more) will generally be more durable for rappel- polyester rope is a good choice.
ling use than one with a lower sheath percentage. In dry conditions, if you’re using a rope just for
rappelling, the dry coating will wear off quickly, so
Sharp Edge Resistance it’s probably not worth the added cost, as dry ropes

The UIAA has developed a new, optional test for are generally more expensive.
manufacturers to receive a “sharp edge resistant” Rope Length
certification. The test is very similar to the UIAA
drop test, although instead of dropping the rope When I began climbing in the 1970s, the standard
over a rounded bar simulating a carabiner, a sharp length for a dynamic climbing rope was 50 meters
edge is used. This is a pass or fail test, and although (165 feet). Today the standard is 60 meters (200
not a true indicator of durability, it’s a good feet), and many climbers use 70-meter ropes (230

8 RAPPELLING

Rappelling_i-174_3pp_CS55le.indd 8 7/24/13 10:14 AM