/ Safety Question - Twin Ropes
I'm taking two 14 year olds on some easy multi pitch Diffs/V Diffs in a few weeks. They're both 9-10st max.
Am I being totally irresponsible in considering using a my twin 8.9mm ropes? (I'm talking one climber to one rope, brought up on a self locking guide belay plate)
I realise 'by the book' the answer is probably yes, but wondered what the thoughts of the forum were before I go and I go and splash out on an extra single.
I'd do it with halves if there were no sharp edges. Never used twins but aren't they even skinnier?
Applying "common sense" I am not really sure why the thickness of the rope has anything to do with anything. The only thing that concerns me is that they are competent to belay you. Belaying two seconds on a self locking device like magic plate etc is nothing new as long as it is capable of dealing with the rope thickness.
You have probably got double rather than twin ropes so no problems at all with a 14 year old seconding on one. I haven't got much of an issue with leading on one half rope if I have to (and that happens a lot on bigger miltipitch routes that don't go straight up).
I don't think its the thickness that would be of concern as much as the strength.Twin ropes unlike half ropes are not rated to take a fall independent of the other.
These ratings are stringent and the rope in this case would undergo less force as you cant take a large factor fall.
On the other hand you are still using a rope not designed to be used on its own. I'm not sure i would risk it myself but I'm sure their will be others that think differently.
*Edit if your talking about half ropes then its fine.
As long as the ropes are HALF ropes then I think it's fine (done it as a belayer and climber many times before). 8.9mm should have a reasonable enough leeway for a second on each.
You will have to pardon my ignorance on the technicalities. So with twin ropes, you always have to clip both ropes? Whenever I have climbed with two ropes, when you fall having clipped alternatively as the route requires, you always end up falling on just one rope. Occasionally if you take a whipper, the second might take up some of the slack but that is quite rare.
In this case, the parties at risk (the youngsters) will effectively be top roping. I am always surprised at how much credence is put on forces when people are only seconding. I would have thought any rope would be well within its breaking limits for a fall on second.
like you say, if you took a lead fall using half ropes then you are effectively falling onto the 1 rope.
bringing up your second they will produce very low forces providing you keep slack to a min. so long as they are rated as half ropes to take a lead fall then you will be fine bringing up the kids.
what make are the ropes?
Cheers for all the replies - that's good then, I figured as much but thought I'd double check.
Sorry for the rushed terribly written OP - yes, I'm talking half ropes (not twins as stated). They're Mammut super dry ropes, forget the exact variant but I think between 8.6 and 8.9mm
Brilliant, that's saved me buying another single then! Thanks all
Sorry if this is yet another reply, but not sure the point has been made and there may be some confusion based on statements in the OP...
Half ropes are _individually_ suitable for seconding/top roping. That is, you can have a climber (even a fat one) seconding on a single strand of half rope. This is the standard setup with one leader (two ropes), two seconds (one strand each).
Unless you were worried about something else (like holding falls)? Guide plate is the way to go, although be EXTREMELY sure you have set it up right (as if you get it wrong you set up a nice pulley that you will not be able to stop). Also read the instructions carefully regarding (at least for a Reverso) the loss of auto-braking for the other second if one falls off?
PS when I say half ropes are suitable for top roping, they are may not really durable enough for repeated top-roping where you are lowering off...
Be aware that clipping togather (twin) you get higher impact force in a fall than clipping alternatevely (half). Try to check if your rope match the twin rope standards as well. Twin and half rope are not the same. However, nowaday Mammut half ropes mostly can use as either half or twin rope.
Is there a reason that they aren't considered suitable for leading individually? If you're using them to reduce rope drag on a wandering pitch then a lot of the time the gear that'd actually keep you off the deck will all be on the same rope anyway...
There was another thread about this just the other day, but...
Basically they will hold a lead fall but they will (generally) not pass the requirements of the single rope test - they will not take enough FF 1.77, 80kg weight falls. Hence they are not rated as single ropes (unless they are e.g. Beal Joker). You are correct that in trad you will may fall onto a single strand, but then falling off is less common in trad than sport.
Ah, okay. So presumably
a) if I'm on a single pitch route then I'm never going to take that big a fall factor anyway, so I don't need to worry about it but
b) there are a few situations where a big lob off a multipitch route (ie high fall factor but only one rope weighted) might mean it was worth retiring the rope?
I mean, I try to avoid big lobs with high fall factors off multipitch routes anyway, but it seems worth knowing...
The UIAA test is not only high fall factor, but tough in the way that there is no dynamic element in it (except the rope). Your FF 1.7 fall would not really be a true UIAA 1.7 fall. This is why wires don't snap in the real world even they should see very high forces if they are the top runner.
I would suggest that if you took a fall great enough to damage the rope in this way (rather than mashing it over an edge) you would not be finishing the route or climbing for awhile, hence you would know when a fall is so bad you need to throw the rope away.
I always find that pretending to address a judge with an explanation of why I did things focuses the mind. Addressing the parents in question in this case will have a similar effect.
I didn't follow best practice because I couldn't afford it your honour.
8.9 is the diameter of a single these days so I wouldn't be worried. I have done the same with much thinner halves ie 8mm.
You might find it a bit hard on some trad belays to make a decent autoblock anchor so a waist belay may be more effective.
Sorry just read that you said twins and not halves....i didn't know they made twins that thick....are you sure you don't mean halves?
> Sorry just read that you said twins and not halves....i didn't know they made twins that thick....are you sure you don't mean halves?
He means halves.
Just on the guide plate topic...Aside from rigging it correctly, knowing how to safely lower is a skill in itself.
Sounds like you have relatively thick half ropes. Unless there was a rope cutting hazard I'd not have a problem doing that. Of course I may be totally irresponsible too.
The main thing on my mind when taking people on multipitch stuff, is what happens if I get hurt. How will they get down, or up. A half rope breaking and consequently a second falling, would seem to me to be pretty low on the list of most likely things to go wrong.
Maybe you have a discontinued model, if you don't then the thickest half rope they sell is a 8.5mm genesis so its probably that.
Of course if you really do have a 8.7 or 8.9mm rope, that you thought was a twin... There's a chance you picked up a serenity (triple rated as twin/half/single). You'd probably know if you did, its quite a high end rope!
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