2 person rappelling

mission wrote: Regarding 1, their body weight continues to anchor the rope through the anchor, causing no problem for the person still rappelling. I still don't see how one person losing control is very bad for both.

OK, you are doing a 45 meter rap on two 60m ropes, tied together. You are on the side of the rope w/out the knots, and I am on the side WITH the knots. You loose control and free fall until you hit the ground.

While you are free-falling, you're weight is not on anything. That means I'm going to be falling as well, 'cuz there is nothing countering my weight. Sure the rope is wizzing through your ATC as well as the anchor above, but that's not enough friction to keep us from both falling. Once you hit the ground, you are dead, and unless the rope magically wraps around your leg or something, it's going to keep whizzing through the ATC until you get to your knot in the end of the rope. Problem is, by the time you get to that knot in the end of the rope, I'm already dead.

Now, say we are not close the ground at all and the same thing happens. You'll free-fall until you hit that knot at the end of the rope. I'll also free fall until you hit that knot at the end of the rope. Even if we don't smack any ledges on the way down, it's still going to be a nasty fall that will most certainly injure at least one of us pretty badly.

Knots at the end of the rope only keep you from rapping of the end(s). They are not really helpful in stopping an uncontrolled fall from way above them. They might stop you, but it might be to late by the time you get to them.

This is why I often (not always) use an auto-block when doing multiple-raps.

This works well.
I have simul-rapped a couple routes including a 6-pitch route with me and a partner who was at least 40 pounds lighter.
1. Most of the raps were vertical with some overhanging sections
2. we tethered together with a 4-foot runner (not a CF)
tethering can eliminate some dangers of weight imbalance.
3. Tie Stopper knots! (do this whether simul-rapping or not)
4. I used a reverso3, she used an ATC guide
Overall this felt very safe and it will be standard procedure for me from now on pretty much.

mission wrote: Regarding 1, their body weight continues to anchor the rope through the anchor, causing no problem for the person still rappelling. I still don't see how one person losing control is very bad for both.

Only after the full length of the rope pulls through their belay device up to the knot. In the meantime, their partner could fall some distance, hitting any number of fun potentially deadly obstacles along the way. Even if they don't, this is going to be a really not fun day for both of them. I think you must be visualizing this incorrectly, because it is definitely not "no problem".

Even if the partner would be 100% fine, how is it "no problem" for their partner to be dead?

Second, I do in fact use autoblocks on nearly every rappel. Reasons why people might choose to use them in this situation if they don't always use them include:
1. The reason I mentioned in my previous post. You are doubling your risk exposure.
2. You are rapping on a single strand instead of a double, and might want more control.

I wish you could do some kind of miniature simulation with weights on a string, or something, cause I really feel like there is something that isn't clicking for you here.

mission wrote:-Climber 1 falls to end of rope and gets knocked out. Nothing is wrong,

Gee, I'd hate to be Climber 1 - you don't seem to care about him much. :)

While we're on the topic:

Does anyone know at what point a weight difference in a free-hanging simul-rap can cause a problem? Some of you have said 40 to 60 pounds... I'm 150 so I don't think I'll ever run into that problem. The heavier person can go on the side of the rope w/out the knots but at what point would you need to back up those "rope joining knots" like you do in the Reepshur method (spelling)?

DannyUncanny wrote: The other thing I have seen people do for safety is link themselves together with a long sling. In my opinion this is a bit of a CF.

The AMGA tech manual shows tethering if a guide chooses to use this with a client (say, in a situation with loose rock, and the guide doesn't want to risk having the client kick off rocks on him/her). Guide is on the side of the rope opposite the knot, and uses a rap backup. Then, if the client messes up, he/she will be caught below the guide, and the knot will keep both in place. If one rope is being used, I've seen it recommended to tie a knot opposite the guide.

I experimented with this back when I was guiding, and I found it to be workable, although often awkward. The key element is the length of the tether - too long and it will get caught on legs/arms/belay devices/etc. Too short and the partners will be pulling each other around. I found that I liked a ~triple length runner when I was positioned a little bit above my client.

Bang, in my opinion this thread will answer your question.

im not quite sure why one would simul rappel instead of a tandem rappel if one wanted to go down at once ... at least with a tandem you can have 2 sets of hands backing each other up ....

ive seen quite a few people simul rappel off single pitch climbs or other places where speed is not an issue ... while i do understand some of it may be for practice, other times it didnt seem so ... IMO thats just introducing additional danger into rappelling

i believe there was recently a situation where SAR had to be called out because 2 people simul rappelling did something wrong and couldnt re ascend the rope ...

Ryan Williams wrote:While we're on the topic: Does anyone know at what point a weight difference in a free-hanging simul-rap can cause a problem? Some of you have said 40 to 60 pounds... I'm 150 so I don't think I'll ever run into that problem. The heavier person can go on the side of the rope w/out the knots but at what point would you need to back up those "rope joining knots" like you do in the Reepshur method (spelling)?

For hanging over a round carabiner, it is usually 1/3 of the body weight of the heavier person. So someone 100 lb would not be able to counterweight anyone 150 lb or heavier.

Wow...smells like I just walked into Freshman Gym Class.

Ryan Williams wrote:While we're on the topic: Does anyone know at what point a weight difference in a free-hanging simul-rap can cause a problem? Some of you have said 40 to 60 pounds... I'm 150 so I don't think I'll ever run into that problem. The heavier person can go on the side of the rope w/out the knots but at what point would you need to back up those "rope joining knots" like you do in the Reepshur method (spelling)?

Is this two questions?

At what point is the weight difference significant enough to cause an issue with a free haning simul rappel?

And...

At what point is the combined weight of both partners on a set of knotted together ropes an issue for the integrity of the knot?

Be an interesting calculation for someone. Obviously, I wouldn't care to outweight my partner by 100 pounds if we were simul rappelling off a pulley (which I've done in North Carolina, at the top of Zoo View, someone's installed a pulley there to aid in rope pull I suppose, but, that's the rappel anchor: a pulley).

I've done a number of fairly steep simul rappels with a partner who weighs 100 pounds less than I. Depends on the anchor. If its a single ring, I wouldn't. If its a long radius summit block with no fixed anchor? No problemo.

Not sure what the weight percent diffence would be, but, maybe its close to the theoretical loss in friction when compared to a pulley? Say, 60% or so for a single ring? WAG, but, close?

If you're question is about the knot and a back up, I guess I wouldn't have an issue with any knot I'd use holding both my and my partner's weight. I typically use an EDK. I can't imagine two people causing an issue with an EDK at even above average climber weights.

Recently (couple weekends ago) simul rappelled with a partner who I outweighed by around 60 pounds. I was on a knot block and gri gri from the anchor (single ring). He wanted to rig his rope too, so, we wouldn't be on the same line. But, I suggested, hey, I outweigh you, am already on the rope, why don't you just rappel the other side? So, he did. Guess who kinda forgot their partner was on the rope? Me. So, when I unweighted slightly to climb up a bit, whoosh, he drops a couple feet. Steep rappel. Partner yelled and dropped a quick draw. Was kinda funny at the time, but, made me think I need to do less simul rappelling...

Simu-rappeling is great if you want to yell at the other person constantly while you rappel, too. Otherwise you have to wait until you meet up at each rap station.

Brian in SLC wrote: Is this two questions? At what point is the weight difference significant enough to cause an issue with a free haning simul rappel? And... At what point is the combined weight of both partners on a set of knotted together ropes an issue for the integrity of the knot? Be an interesting calculation for someone. Obviously, I wouldn't care to outweight my partner by 100 pounds if we were simul rappelling off a pulley (which I've done in North Carolina, at the top of Zoo View, someone's installed a pulley there to aid in rope pull I suppose, but, that's the rappel anchor: a pulley). I've done a number of fairly steep simul rappels with a partner who weighs 100 pounds less than I. Depends on the anchor. If its a single ring, I wouldn't. If its a long radius summit block with no fixed anchor? No problemo. Not sure what the weight percent diffence would be, but, maybe its close to the theoretical loss in friction when compared to a pulley? Say, 60% or so for a single ring? WAG, but, close? If you're question is about the knot and a back up, I guess I wouldn't have an issue with any knot I'd use holding both my and my partner's weight. I typically use an EDK. I can't imagine two people causing an issue with an EDK at even above average climber weights. Recently (couple weekends ago) simul rappelled with a partner who I outweighed by around 60 pounds. I was on a knot block and gri gri from the anchor (single ring). He wanted to rig his rope too, so, we wouldn't be on the same line. But, I suggested, hey, I outweigh you, am already on the rope, why don't you just rappel the other side? So, he did. Guess who kinda forgot their partner was on the rope? Me. So, when I unweighted slightly to climb up a bit, whoosh, he drops a couple feet. Steep rappel. Partner yelled and dropped a quick draw. Was kinda funny at the time, but, made me think I need to do less simul rappelling...

I am not worried about too much weight on the EDK or whatever knot people use. They are all rated at like 5000lb or something.

What I am wondering is at what point will I notice an imbalance in the system. According to you, if I (150) and my g/f (100) simul-rap, then I will notice that as we rappel at the exact same rate, I will go down faster because the rope will be running through the anchor?

So in that case, she (the lighter person) would rap on the side with the knots, and I (heavier) would rap on the other side. This brings me to a second question:

At what point do I need to back up that EDK w/ a fig. 8 on a bite and a locker? Not to prevent the EDK from coming untied, but from preventing it from slipping through the anchor ring. There is a method to rap on one line and keep it retrievable. It's called the Reepschur method or something like that. Some guy died in Yosemite a few years back because he did not use the fig. 8 and locker back up. His knot slipped through the rings and he fell.

So obviously it can happen under normal human body weight (depending on the size and shape of the anchor ring). SO, if it can happen under body weight, could it happen at 100 lbs? 50? If so, you'd have to use this back up when simul-rapping w/ someone of a different weight than you.

The answer is probably to always use the back up if the weight difference is that large, but then you are kind of offsetting the speed of simul-rapping with that knot and locker business, not to mention that you are pulling down a locking biner on top of you every time you pull the ropes.

Just wondering. Thanks.

Ryan Williams wrote: There is a lot of information missing here.

What other information do you need. If you are on the side opposite the knot, you have an added margin of safety. Period.

Ryan Williams wrote: Just saying "make sure you're on the safe side so if you're partner fucks up he's the one that goes splat! ;)"

This quote is your assumption of my attitude, not an actual reflection of my attitude towards partners' safety. It is also incorrect. It should read, "make sure you're on the safe side so if YOU FUCK UP, YOUR PARTNER IS THE ONE TO GO SPLAT."

Ryan Williams wrote: I understand what you are saying, but I don't exactly understand why you are saying it. And your statement is certainly not an end all. Can you elaborate?

Well, I was saying it to add some pertinent information that wasn't already offered. How you choose to use it is up to you.

I'll elaborate on how I use this information: I choose not to simul-rap on the non blocked side. Simul-rapping is not worth the risk given the time savings in my opinion, and, yes, I've done it. I'm always willing to do a traditional rap, but, if a partner insists, I'm insisting on the safe side. Another pertinent way to use this information is to put the most experienced person on the "safe" side since this is a situation where your partner's life is in your hand, it follows that the more experienced person should have the greater responsibility for others' safety.

Ryan Williams wrote:Are you joking?

Yes, the tone was joking, but, the information is still salient.

Evan

Coz Teplitz wrote: The AMGA tech manual shows tethering if a guide chooses to use this with a client (say, in a situation with loose rock, and the guide doesn't want to risk having the client kick off rocks on him/her).

I'm not sure when that manual was published-I'll have to 2x check mine but I don't think it's in there. Currently (at least in the RIC course took Nov 2010), the AMGA instructors we had didn't recommend simul-rapping (highly discouraged), but instead tandem rapping (if this is best choice-a belayed rap or a prerig could be better...) Much safer imo to tandem than simul. There are a lot of variables in simul rapping that are eliminated when you tandem...it's also how you get the client down in the rescue scenario.

Ryan Williams wrote:At what point do I need to back up that EDK w/ a fig. 8 on a bite and a locker? Not to prevent the EDK from coming untied, but from preventing it from slipping through the anchor ring. There is a method to rap on one line and keep it retrievable. It's called the Reepschur method or something like that.

According to wiki: "Reepschnur is a static rope with small diameter (4-8 mm). As a component of personal protection equipment (PSA) it is subject to the European Union standard EN 564."

So, the method is to just use a small diameter static rope as a "pull cord". I'd stongly advise against having a partner rappel from it.

That said, to answer your question, how do you know? If its a small rapide or ring, then, most of the thicker single dynamic ropes, when knotted, won't fit through. You can kinda eyeball it. Obviously, you don't want to f' this up if you're rappelling against the knot.

I use a 6mm kevlar pull cord quite often. In the Tetons, I used it to get off a route, and, the rap ring was pretty large, and, I thought there'd be a good chance the knot would pop through. And, it did. I usually rap both ropes, though, so, had control of the skinny cord and just managed the friction on it with my other hand (tricky at best, but, I'm used to it). So, not a problem but "interesting". Amazing the felt tension difference, too.

You can always tie a bite and clip back into the rappel side. If the knot pops through, then, it kinda girth hitches onto the rap ring. You're pretty screwed for pulling your rope down, but, at least you won't crater.

Canyon folk routinely use a "biner block" instead of a knot block. They clove hitch on the spine of a carabiner and set the spine against the rappel ring. Works fairly slick, but, folks that see it for the first time kinda wonder "wtf". A guy died in Zion on the last rappel out of Heaps Canyon when his biner block shifted on the anchor and popped through the biner he had rigged his rappel line through (end of the day, didn't want to feed 300 feet of rope through the smaller anchor rings). So, scary.

has anyone actually roughly measured the time savings in normal raps vs simulraps? I remember having this discussion in EPC where you are routinely doing 12-20 raps at the end of a route, and a fairly experienced pair was adamant that you really don't save enough (if any time) to warrant simulrapping.

Phill T wrote:has anyone actually roughly measured the time savings in normal raps vs simulraps? I remember having this discussion in EPC where you are routinely doing 12-20 raps at the end of a route, and a fairly experienced pair was adamant that you really don't save enough (if any time) to warrant simulrapping.

Bingo.

To me the time savings doesn't outweigh the piece of mind of not depending on the other person to not screw up their rappel or unweight the rope suddenly without thinking.

IMO ... not too much ... but thats not measured

in a single person ... the first is the only one who might need a prussic, you set up the rappels at the same time, first gives a fireman, second is down, voila .. the second can actually rap very fast because of the firemans

in simul ... you should have prussics on both, you may want a biner block or not, you both may not rappel as fast as a single person so as to manage the weight, etc ...

at best the savings is the time it takes for the second to slide down 30-60m ...setup time is more or less the same if you both setup at the same time

as note by others ... i dont see any reason to simul if you can tandem ... actually a faster setup IMO ... the real advantage of a tandem IMO is that there are 2 sets of hands on the rope meaning you may forgo any prussic and do other assorted things fairly safely on rap ... you just need to be REAL friendly with yr partner ... and it dont look as "cool"