CRTT zip line - too fast!

[Boris De Karabiner]

Hi CRTT team,

I have just completed the Croesor Through Trip with my fellows in our group.

I'm extremely grateful to those who have bolted the mine and rigged up the zip lines, the ropes et cetera and maintian this free resource for us all to use. I gather that the zip line is very new and it has the potential to be a fun addition.

I don't want to come across as "that new guy who files his first post as a complaint" - but I'm sure we all want to pursue our sport in the safest way possible, so that we can continue to do so in the future. So I will attempt to describe the problem and offer a couple of possible fixes.

The zip line runs extremely fast and terminates at a wall that is quite spiky and has very little landing platform for your feet, even if you somehow get the timing right.

As the first person who went across I was surprised at the speed with which I traversed - and could see that I was approaching the wall at great speed - I put my leg out ahead of me to stop myself at the end and am presently nursing a sprained ankle as a result. Had I impacted with my body instead I would have received a much worse injury.

i caught the next person down the line, luckily she was quite small, and rigged up a stop for the one after that hoping that neither of us would be injured in my attempt to catch her - but the sudden stop at that speed caused her to pendulum violently and she bashed her head on the wire. Luckily she was wearing her helmet.

There is a rope next to the zip line, as the fourth and further people to descend the line they were able to use the rope to control their speed - but it was a little sketchy, if you let go of the rope you very quickly gain speed again.

Can I recommend therefore that, in the first place, some very clear signage be placed highlighting the danger of impacting the wall at the end and explaining the use of the rope as a braking device? The line could also do with some form of device to slow you gradually as you reach the end of the line, some form of deformable concertina tube on the wire, such that you come to a stop on the step but cannot impact the wall?

Secondly, it might improve safety somewhat if the termination wall had some form of thick, durable rubber bolted over it, such that a user will not impact the rock directly. If that could incorporate some form of padding then so much the better - but a thick rubber sheet would at least prevent anyone whacking any pointy bits / sharp edges at high speed.

Further thought: it is necessary to climb a ladder to clip onto the zip line - clearly the start is higher than the end, as you might expect on a zip line. Perhaps the start point could be lowered a little, to slow the line? Or maybe slacken the tension somewhat, such that the droop in the line will slow the user somewhat, hopefully the droop could be set such that the line effectively goes flat as one approaches the termination point?

Thanks again, - please keep up the good work, CTT team.

 

[AKuhlmann]

Not part of the CRTT team but if it were as safe as Go Below in Cwmorthin then it would loose some of its charm. Wearing gloves and being prepared to break is definitely the best way to manage it. If you grab the cable behind you gently to lose some speed with a gloved hand it’s just fine in my experience.

The charm being the same way some people prefer trad climbing to sport climbing. The trip has been trending towards safer and safer over the years, which is a good thing, but I would say some of the bolting rather than the big lower zip is a more pressing issue (corrosion etc). That zip line while fast is well anchored, well made, and manageable. So I’d be pretty opposed to any unnecessary changes.

The zip starts high to avoid hitting anything for heavier users and if it sagged more people would get dunked in the water by it.

The point of mine exploring is both cultural, historical, and risk taking and that zip line is by far not the biggest danger on the route.

 

[Misbecaving]

Can I recommend therefore that, in the first place, some very clear signage be placed highlighting the danger of impacting the wall at the end and explaining the use of the rope as a braking device? The line could also do with some form of device to slow you gradually as you reach the end of the line, some form of deformable concertina tube on the wire, such that you come to a stop on the step but cannot impact the wall?

Secondly, it might improve safety somewhat if the termination wall had some form of thick, durable rubber bolted over it, such that a user will not impact the rock directly. If that could incorporate some form of padding then so much the better - but a thick rubber sheet would at least prevent anyone whacking any pointy bits / sharp edges at high speed.

You volunteering?
It's not a commercial installation and has avoided the fun and HSE police so far.

 

[langcliffe]

I remember the first time I went on a zip line over the first lake several years ago now, I saw the wall approaching at an alarming rate. The second time I had the sense to take a steel braking krab with me.

 

[wormster]

A steel braking crab on the side rope, plus use the correct pulley: Petal Trac is rated for about 45kph, tandem and the tandem speed are rated for about 70kph!!

 

[wellyjen]

Double wheel pulleys seem to run rather fast on this. I used a single wheel one, with a steel krab via long cowstail on the side rope and had no problems. Ground to a halt a few feet out and hauled myself the last bit to the landing. A colleague with a twin wheel pulley saw this and decided to take a running jump from the take off, reaching warp speed just before hitting the wall. Was lucky to get away with no damage.
There is the tension traverse line, with low and high wires alongside to sidle your way across, if you are not happy taking a chance on the death slide.
Don't expect something like this to be all 'ealth'n'safety.

 

[Boris De Karabiner]

Thanks all, for the replies and the discussion.

My feeling is that the line can be used safely, one simply needs to understand 1. That the line is dangerous, 2. What the danger is, 3. What the remedy is.

It would not hurt (quite literally in this case) to have some remediation for when people get it wrong, as they inevitably will. Consider: if the cave rescue teams are called out too frequently then we will lose access.

For the moment though, an easy and simple remediation would be to place some signage, which will help a great deal and cost almost nothing.

Member Misbecaving asks if I am volunteering to help fix the problem.

I live East of Manchester, far from the site. But yes, as someone who has benefited from the use of the site, I am prepared to go back and help the team if, for some reason, they don't have the resources. Just needs booking into the diary.

 

[wormster]

Quick way to arrest the end:

Take 3 scrapped car tyers drill 2 20mm holes 180 degrees apart, undo the turnbuckle at the wall end, thread tyres on and rehang, simples!!

(YES, I did think of this 20 years ago after my first trip!!)

 

[cavemanmike]

I’ve been going in there for what seems like centuries and have never had an issue. I’ve also led tens of people through there and have NEVER encountered any problem. You need to be aware of the environment you are in and respect the equipment you are using. If the zip line is too fast for you, you would have noticed picking up speed and should have taken action immediately. Like I said. It can be a hostile place so respect it. As for cave rescue this subject has been discussed to death and the common denominator seems to be people ill equipped or experienced enough. Tupence worth
😉😉

 

[ChrisB]

one simply needs to understand 1. That the […] is dangerous, 2. What the danger is, 3. What the remedy is.

This applies to any natural cave or abandoned mine which is openly accessible. Unlike show caves, places like Go Below or most of the UK above ground, nobody is responsible for ensuring that those places are safe except the individual using them. Knowing how to be safe may require training or other learning. Signage should not be expected.

The starting point is that if you don't know it's safe, through your own knowledge or somebody you trust, assume it's dangerous and protect yourself. If I were using a zip line with no previous knowledge of it, I'd look for a way to control my speed, and if I didn't know how to use the rope next to it, it would be because I'd not educated myself sufficiently. I appreciate this is philosophically different to how things work elsewhere but it's important to understand it. Your safety is your responsibility and nobody else's.

 

[langcliffe]

Thanks all, for the replies and the discussion.

My feeling is that the line can be used safely, one simply needs to understand 1. That the line is dangerous, 2. What the danger is, 3. What the remedy is.

It would not hurt (quite literally in this case) to have some remediation for when people get it wrong, as they inevitably will. Consider: if the cave rescue teams are called out too frequently then we will lose access.

For the moment though, an easy and simple remediation would be to place some signage, which will help a great deal and cost almost nothing.

Member Misbecaving asks if I am volunteering to help fix the problem.

I live East of Manchester, far from the site. But yes, as someone who has benefited from the use of the site, I am prepared to go back and help the team if, for some reason, they don't have the resources. Just needs booking into the diary.

This all reminds of the wonderful advice Traister offers in his book "Cave Exploring", published in 1993, in a section called cave safety: "For example, if a drop occurs suddenly in a passageway and is not readily recognizable until the last second or so, you might smudge the phrase 'DROP HEAD' onto the cave floor or wall".

 

[langcliffe]

This all reminds of the wonderful advice Traister offers in his book "Cave Exploring", published in 1993, in a section called cave safety: "For example, if a drop occurs suddenly in a passageway and is not readily recognizable until the last second or so, you might smudge the phrase 'DROP HEAD' onto the cave floor or wall".

Sorry - "DROP AHEAD".

 

[cavemanmike]

Sorry - "DROP AHEAD".

Freudian

 

[Boris De Karabiner]

Thanks all for your opinions - I accept that one must acquire experience to adequately understand the hazards. However, in this case, the hazard only becomes known once you are actually experiencing it. I have done a number of zip lines, this is my first experience of one that tried to seriously injure me. There was little time or opportunity to improvise a braking system once actually engaged in the activity.

All I'm suggesting, as a minimum, is some simple signage. All the other stuff is cream on the cake. But this hazard is known and, reading the above, has caught others out.

However, we have all said our piece. I don't feel the discussion can be moved along greatly.

I suggest that the maintainers of the mine, if and when they read this, may take whatever action they feel is appropriate, which may be none whatsoever. I felt it my duty to raise the issue, it is up to them to decide whether it's something they wish to action.

 

[Fulk]

I have a vague recollection that the second time I did the through trip some of us had a 'slow' tandem pulley system and some had a 'fast' one. Now from what's been written above I deduce that the zip wire (over the first lake?) has been changed, so my comments might no longer be pertinent. However – I wonder – if you use the 'fast' tandem are you at risk? And if you use the 'slow' one is the risk more reasonable?

 

[Boris De Karabiner]

Our party all had twin pulley systems, mine is the high-efficiency Petzl item.
So: Mine may have been marginally faster than the others - but all three of the advance party were coming down at very high speeds , then we worked out that the rope was the best solution for controlling speed. I don't pretend to have massive experience with zip lines but I have traversed a few and this is the first occasion where I have needed to control my speed. Usually the problem is that you don't make it all the way and have to haul yourself up.

Our party leader commented that, upon their last visit, the line was not there - only the rope / wire bridge was present, if I understood them correctly.

This rather suggests that the line has been replaced relatively recently, so for some of the above commenters their experience may have been with an older version of the zip line.

 

[Boris De Karabiner]

...and, re-reading the above, it would appear that the experience of WellyJen shows that yes, single wheel pulleys run rather slower on this line and probably do not present an issue, whereas twin pulleys can run very fast.

 

[Pete K]

FYI running an alloy pulley on steel cable will probably mean you end up wrecking the sheave (wheel) and making it unsafe for use on rope in future. I've got a couple of good examples in my PPE course kit of this. The soft alloy on the sheave gets chewed up, especially on the cheaper 7x19 zipwires. Single pulleys also have rotational play around the single axis, meaning you might get some good sharp scars on the inside of the pulley cheeks as well.
A stainless steel sheave slower pulley like the yellow/gold Petzl Tandem Cable would be better for your wallet in the long run. They suck for everything else though, being super slow. Grey Tandem Speed, leather gloves, short attachment lanyard, and always rolling across slowly and under control (hand to hand if needed) for unfamiliar zips is the way to go. IMO.

 

[Cantclimbtom]

Interesting... I like the new zip, tried it when it was still very new so cable very taught. Noting that there's the cable "bridge" so zip is entirely optional fun

I tried it with a double pulley, it claims ball bearings not bushing (I think it doesn't have ball bearings?), it's a Chinese rip off with misspelling on the safety inscription so who knows (backup krab required). Anyway it was a bit bloomin' brisk and triggered some adrenaline and worried pulling on my backup krab for marginal breaking but I survived. My son followed with my genuine Petzl tandem and it was perfect for him. I think bodyweight may be a factor in the speed. Plumpness is punished.

Anything like that means caution. You should have some plan on braking before you get on it, especially if you've not tried before. Probably a bit of prusik cord or nylon tape would be ideal to pull on in emergency? The krab wasn't a powerful brake.
It's not GoBelow

 

[Boris De Karabiner]

Useful advice, thank you Pete.