These pages give a simple introductory explanation about what can be
highly technical subjects; so please don't interpret everything here as
the final word - it's just our opinion distilled as a summary.
Types of Rope
There are two types of rope generally used for climbing and outdoor type activities:
1. Dynamic rope- this is what you need for climbing. The rope is
stretchy, so that when you fall a lot of the shock is absorbed by the
stretch. To help visualise how a non-stretchy rope would be no use,
imagine bungee jumping on a steel cable - what would happen when you
stopped? You'd snap, as none of the force would be gradually taken up by
the rope!
Therefore the stretch of the rope is a good thing, but you must also be
aware of the stretch when thinking, for example, 'would I hit the ground
from here?'...
Dynamic rope has a 'core' (the white bit in the middle) and a 'sheath' -
the coloured bit on the outside that holds the rope together and
prevents wear. It is essential that both of these parts of the rope are
in good condition, as they work together to give the rope its dynamic
properties.
2. 'Static' rope - this isn't actually static at all, but is very low
stretch rope. In technical terms it's called 'semi-static' rope, but as
that's not quite so easy to say, people use 'static' as shorthand. This
is used for abseiling, tyrolean traverses for groups and setting up
climbs for groups at the top of the rocks. Therefore nearly all
purchasers of 'static' rope are groups or instructors. 'Static' is
cheaper, but for the reasons described above you should never use it for
climbing.
3. Accessory cord - the small bits of cord that look very much like
rope. The only reason we've mentioned these is to clarify that, because
of how they're made (see next section), you should never use them in
place of rope, even if you think they look almost as thick.They are for
specific non-critical purposes only.
How is rope made?
Basically in a big machine with woven strands of plastic. The only
important thing we need to know about the process is that climbing rope
has no 'joins' inside it - the machine produces rope for kilometres
until it stops, and there's never a point when one strand runs out and
they tie a new one on This is what they do with accessory cord - when
one strand runs out of material, there's a join (weak point) inside
where they tie a new one on. This is a ridiculous simplification, but
illustrates the point that accessory cord is completely different.
This video is a bit of an advert for Sterling Ropes, but it does have some good footage on how the process works.
Rope maintenance and storage
Try this advice from Beal at their website:
http://www.bealplanet.com/portail-2006/index.php?page=entretenir_corde&lang=us
Easily the most common question we get is, 'How long can I keep my
rope?' The simple answer is that you can use it for as long as the
manufacturer says you can. Most people throw away the card that comes
with every rope, but this contains essential information- a typical time
frame would be from a year of intensive use up to 5 years of occasional
use, but most importantly the condition of the rope must be checked
every time you climb. Is it frayed? Can you feel any kinks inside the
rope? Is the sheath worn or glazed anywhere? If so, you would be best
advised to stop using the rope and get it checked. It is always tempting
to think of saving money, but in this case your life or health could
depend on it - so use your common sense!
For matters concerning the care and maintenance of all climbing gear we
refer you to the British Mountaineering Council, whose website at
www.thebmc.co.uk contains a lot of useful information. They also publish there a downloadable free booklet at:
http://www.thebmc.co.uk/Download.aspx?id=77