UKC

I think that there needs to be some definitive advice to give on the longevity of a modern climbing rope.

At the moment all I am reading is hear-say and guess work.

In reply to The Lemming:

http://theuiaa.org/upload_area/files/1/About_Ageing_of_Climbing_Ropes.pdf
http://theuiaa.org/upload_area/files/1/Conference_on_nylon_and_ropes.pdf
http://www.fishproducts.com/tech/Ropeshelflife.pdf

In reply to EddInaBox:

Thanks for the links

Plodding through the first one. Very illuminating.

In reply to The Lemming:

The problem is that we are not dealing with a closed environment. I've had/got loads of ropes. Some are well past their official retirement date but have had very little use and look quite new, and i've had one that had to be chopped down after its first use.

There is quite a lot of evidence to suggest that age is not itself a danger (the links above) but usage or exposure to acids make a huge difference. I would welcome some further research, but I think that there is ample evidence available to guide us in our decisions. One area of research I would be interested in is some research into nylon thread itself - over what timeframe does it degrade in certain environments etc.

In the end, I think that it comes down to an irrational judgement - even if a rope never snaps in use, if you have doubts about the strength of your rope when you are making hard moves above your gear it will mess with your mind. A new rope is probably going to be needed.

In reply to EddInaBox:

From the second link




5. When to retire a rope; a study of rope wear:
- it is hardly any news that the principal factors of rope wear are the combined effects of rubbing
against rock, mechanical reduction (rappelling and belaying devices), dust and microcrystals that
penetrate the sheath and the number of meters climbed (not the time used),
- the enemy of rope wear is friction
- most intense in abseiling and top roping, made worse by dirt, and the inevitable rubbing against
rock, - some abseiling devices produce much more wear damage than others,
- after only 50 descents with a figure-eight, the dynamic resistance of a rope is reduced by one
third (number of drops). The descents were undertaken with extreme care
- slowly and without impact,
- rappelling with a Robot (a multi-use device manufactured by Kong) does not appear to
compromise the dynamic resistance of the rope. The device functions like a carabiner brake,
- not surprisingly rope wear is much more severe on granite than on limestone,
- rope degradation is approximately proportional to the number of broken textile yarns of the
sheath,
- current work confirms previously published information. After climbing approximately 5000
meters, the dynamic resistance of the rope is reduced to half and after an additional 6000 meters it
is down to 30 % (UIAA Bulletin # 146, June 1994, in German),
- see also The Journal of the UIAA #3, 2000, pp. 12 - 13.

In reply to Monk:


Why? I suggest a more rational judgement is needed, it would certainly be a damn sight cheaper.

In reply to EddInaBox:

Interesting that the shelf-stored 12 year old rope (Blue Water) was as strong as the day it was made - so much for the degradation of nylon over time!


Chris

In reply to EddInaBox:

True. What I was trying to say is that for most people, your mind is probably going to snap before your rope does. I think that in general, a rope will usually be retired because it has become difficult to handle rather than because it will snap.

In reply to Monk:

And Marketing companies will want to play on this fact, if they are to sell ropes.

In reply to The Lemming:

I still have some old nylon rope slings from 1966, that are very worn and wirey. But one day I think I will get them strength tested to see how bad they really are. (I have this suspicion that ropes stored in the dark, away from harmful substances, may not age nearly as much as the marketeers would have us believe.)