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Climbing ropes are UIAA rated for so many falls of an 80kg weight. After that number of falls–or a specific period of time based on amount of use–you are supposed to retire the rope.

But what if the person you are belaying is only 15kg?

When ropes pass their recommended retirement age it doesn't exactly render them useless, but if you're using a rope to belay weights more than 80% less than what it's rated for, does that mean the rope will be good for a period of time 80% longer than recommended?

In my mind, a 15kg kid using a 9.8mm rope would be the equivalent of an 80kg man using a 22.6mm rope, which would last close to forever, but you probably wouldn't want to take any big falls with it.

To what weight can you safely use retired ropes for belaying small children on top-roped climbs?

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    Safe for you as the belayer, yes. Personally, not a path I'd go down myself. The next question becomes when might it no longer be safe. Just use a not-retired rope. – Jon Custer May 24 '17 at 18:49
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    Related: When should I retire my rope – Roflo May 24 '17 at 20:34
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    The strength of a rope is proportional to its cross-sectional area, not its diameter. So if you're going to talk about equivalent diameter based on climber weight, the equivalent diameter for an 80kg climber would actually be 22.6mm, since (22.6^2)/(9.8^2) = 80/15. – David Scarlett May 25 '17 at 0:27
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    Are they your children? – davidbak May 25 '17 at 3:46
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    @OlinLathrop No one from a metricised country has any issues with calling kg "weight". Yes it is a measure of mass, but on Earth, we measure kg's by standing on a scale, ergo weight. – ShemSeger May 26 '17 at 3:10
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There is a little bit information out there (here), about falls of climbers heavier than normal which suggests (very roughly) almost a linear relationship between fall load (force) and body weight, assuming equal fall factor. Applying this in the reverse, a significantly lighter climber would apply a significantly smaller load.

This says a UIAA fall is rated for a factor of 1.77.

Children of 15 kg don't climb lead (I'd say). During top roping, forces are much less, so I'd say it is safe, if the rope passes visual inspection and "feels" otherwise "right" (e.g. no broken core).

I'd apply a rough safety margin of about 1 order of magnitude, so I'd say it's okay for people of up to 30-35 kg when top roping, and not okay for someone heavier or when lead climbing.

In the end you have to use your own judgement, and if there are any doubts, just take the safer alternative: use a fresh rope. Pieces of old rope are reusable as donations for e.g. childrens day cares.

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This is a really difficult question to answer in the abstract. The UIAA claims that

Ageing caused only by storage can almost be neglected compared with ageing during use. This also holds for ageing by the influence of ultraviolet radiation; ropes may lose their colour with time, but virtually no loss of strength (more precisely, no loss of energy absorption capacity over an edge).

The answer then depends on why you have retired your rope. Ignoring retirement due to either a single large (high impact factor) fall or exposure to chemicals (e.g., battery acid), the rope has likely been retired due to wear (fraying of the sheath or flat spots) or some predetermined life span rule that you created or borrowed.

I don't like climbing on ropes that have flat spots. My ropes tend to get flat spots near the ends where the falls occur. Most of the routes I climb are longer, and therefore once I am forced to cut off a short section from the end, I retire the rope from lead climbing. I tend to then top rope on that rope until I wear out another lead rope. I cannot recall the last time I didn't have extra ropes for top roping.

My general rule for top roping is the rope needs to have a visually intact sheath (wear is fine) and not have any flat spots or bulges. It also cannot be ridiculously dirty (although I tend to climb in cleaner areas).

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TL;DNR: If you have a safety problem climbing with children, it won't be because the rope is a bit old.

You need to define what you mean by 'Safely'. I put it that is impossible as it varies for everyone on a daily basis. This makes it one of those unanswerable questions.

However, if you rephrase the question - move the focus from just the rope - "Is a retired rope safe" to taking kids climbing as a whole- 'How much does using a retired rope increase the danger of taking children climbing' you get to question that has a useful answer.

The other answers focus on the safety of a retired rope. The difference in safety between a brand new rope and retired rope (as in 'recently retired because of standards and manufacturer recommendations' rather than damaged or had a big fall) appears small and insignificant compared to the other dangers.

So, given the dangers of climbing, I suggest using a retired rope is extremely unlikely to create or contribute to an adverse outcome for any climber, and significantly less so for child or top roped climbers. What this means for Top roped and children can only become insignificant.

All of the above being said, there is another aspect at play that will override all this common sense. If you do take children climbing on say a 30 year old rope, what will people think and say of you? Will you be treated as a cautious climber who has thought through the implications and understands and manages the risks very well, or will you be labeled an irresponsible cowboy idiot who should not be allowed near children. If you had an accident, say a child unties his harness half way up the climb for a laugh, the 30 year old rope would be used to hang you, no matter how irrelevant it was to the situation.

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My rule of thumb is, if you have to ask if something is still safe to use, the answer is always no.

We all try to minimize risk and maximize cost/benefit. When I was younger and had less disposable income, my self answer to 'safe vs cost' questions was often more heavily weighted towards cost. You can make these decisions multiple times and save lots of money, but the cost of that one time that safety should have been more heavily weighted, far exceeds all the money you saved in the earlier choices.

We each make and have to live with our own decisions. The follow-up question you need to ask yourself, is can I live with the cost of being wrong about this choice?

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We have several "retired" ropes because we no longer trust them to take 2 factor leader falls. I repelled on one of them years after it was retired. If your ropes are like mine, they'll be fine for top-roping of most adults.

On the other hand, one rope we retired due to a rock fall landing on it. Nobody's climbing on that anymore. (We cut it in two where the rock landed, and it gets used for knot tying practice now.)

We've been kinda skirting the edge of the 10 year rule for a leader rope. Somehow we believe that a rope not for lead climbing is good for something like 10 more years after that before we really retire it. But on the up side, we buy over-diameter ropes in the first place so they should last a bit longer.

On the other hand, I looked at the rope that took two leader falls in one season, and at the end of the season I said to myself, "Hmm, time to retire that." Then the rock got it anyway.

  • "the rock got it" - don't know what that means – Martin F May 25 '17 at 3:17
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    @MartinF: The one the rock caused us to cut in half in the previous paragraph. – Joshua May 25 '17 at 3:32
  • The 'max age' rule for soft gear is 5 years - hard gear is 10 years. You should not be using any climbing rope for 10 years, let alone 20. – TylerH May 30 '17 at 14:05
  • In case somebody's wondering about our gear, we inspect every piece of gear that will be used that year every spring when we haul the gear out of storage for the first climb of the year. – Joshua Jul 21 at 2:28

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