Please consider...
sawn_penn said:
UV exposure over a few days isn't a problem. You get the same UV exposure leaving the rope in a tree for 3 days as you get using the rope for three full days.
Freeze thaw cycles aren't a problem with kernmantle ropes, and probably aren't a problem with other synthetic ropes either. Kernmantle ropes were developed for mountaineering, and yep, stuff freezes!
Days in a tree isn't a problem. Months and months would be bad for the outside of the rope, but probably wouldn't cause significant damage to the core.
(I've been up 8mm fixed lines that have been in place for years in the mountains. Not really recommended, but common enough practice.)
I urge you to read the article I have written regarding postings about this very topic/issue, it could save your life!
PLEASE CONSIDER?
Arb' rope is completely different to abseiling/mountaineering rope...
The exterior sheath of mountaineering rope is ONLY a PROTECTIVE cover over a woven core of A KNOWN rated strength...
ARB' ROPE is a thick RATED SHEATH over a core that keeps the sheath in form...
Arb' rope is made as such because we use it in extreme conditions e.g. in constant ascent and descent using a rope friction hitch, around falling logs and being constantly loaded and trodden on or tensioned over limbs THEREFORE our sheath needs to be able to stand up to constant heat through perpetual friction AND we need to be able to inspect frequently the working part of our rope for damage which is the rated outer sheath...(Ignoring at this point the fact that our working environment is filthy…)
If you leave Arb' rope out in the sun the rated part (the sheath) will get sun affected as the sun filters through the canopy (or belts down directly in most cases) on the resting line WHERE AS days being actually used in the sun sees the line constantly moving and therefore not subject to constant U.V. light in any one spot...USING YOUR ROPE FOR THREE DAYS IS NOT THE SAME AS LEAVING IT IN THE SUN FOR THREE DAYS...
I have read repeatedly on here (ArboristSite) posts by even those well respected and highly experienced and qualified in the industry claiming the use of mountaineering rope in Arb’ to be acceptable...
I will attempt to list and detail the reasons IMHO I believe it is a fallacy that you can safely use mountaineering rope in most Arb' work situations (I will also attempt give reasonable examples)...
An example we use in instructing students is this; if you were to drop a large piece of wood on your line as it lay across a solid surface (potentially a common occurrence in Arb’ work BUT NOT IN MOUNTAINEERING) you can easily (relatively) see the damage (if any) to the rated (very thick, purpose built) sheath and remove the section or discard the rope if this rated sheath has been damaged…
IF the same incident were to occur with mountaineering rope the damage to the structural or integral/rated part of the rope (that being the inner core) could not as easily be observed, therefore, potentially you could be climbing (or hanging) on damaged or even partially cut rope and you wouldn’t be able to tell because the thin outer non rated protective sheath would likely hide this defect...
The other critical part I see in this argument which is one that leaves me feeling sickened when I hear about blokes using mountaineering ropes for Arb' work is;
this protective sheath on MOUNTAINEERING ROPES IS NOT DESIGNED TO HAVE ROPE RUBBED AGAINST IT AS IT IS BOTH NOT STRUCTURALLY INTEGRAL TO THE LINE AND IS EXTREMELY THIN AND THEREFORE CAN BE MELTED and IN TURN CUT BY THE HEAT OF A RUBBING ROPE OR DEVICE (LIMB ETC, ETC) RELATIVELY EASILY…
Therefore, using any rope friction hitch/prussic or ANY FORM OF FRICTION DESCENT DEVICE on mountaineering rope as is done constantly within tree work where that device or hitch heats up (which it always will) and in turn burn/s through the very thin and non purpose designed mountaineering rope outer sheath which in turn will send the climber to the deck as the sheath strips down from the point of sheath failure which then in turn leaves your ascent /descent device exposed to the now unprotected core and the same heat will then very quickly cut this also...
Arb' rope avoids this scenario by having firstly a very thick and structurally rated outer sheath both designed to accommodate and dissipate heat and accommodate ropes rubbing against it (within reason)… (We use a rope friction hitch/prussic so we can discard them regularly as the week link in the system or the disposable link in the system…)
Arb’ rope is also a thicker rope with a design that assists heat dispersion through the weave and assembly of the sheath and core and by the very nature of it being thicker in diameter...
Devices such as “whale tails” and other "heat sinking" abseil/mountaineering devices were specifically designed to both assist the mountaineer in very slow descents because of the nature of mountaineering rope and to dissipate heat from the belay/decent device preventing rope burn...
(Fall arrest (or “Dynamic”) ropes in mountaineering are completely different again in their dynamic nature and as we don’t use dynamic ropes in Arb' I won’t bring them into this post...)
NEEDLES to say Mountaineering ropes are not and never were designed for tree work, they are purpose designed and manufactured for mountaineering and therefore for the combined use with hardware devices of mountaineering under a static load system for ascent assist and descent control using mechanical ascent and descent devices...(However as it is a static application ascent by prussic is acceptable on static Mountaineering rope BUT ONE SHOULD NEVER DESCEND ON PRUSSIC WITH MOUNTAINEERING ROPE UNLESS IN EMERGENCY OR SELF RESCUE SITUATION ONLY!)