Are biner blocks a good or bad idea for long rappels?


Original Post
ckersch · · Unknown Hometown · Joined Apr 2013 · Points: 150

I was reading this thread , in which someone mentioned carrying some cordelette and doing biner block rappels instead of carrying a second rope, for a pitch that required a 70 meter rope to rappel, where the poster only had a 60m rope, rather than carrying a second rope.

In my (admittedly limited) trad climbing experience, I've always lugged a second rope up any rope that has long raps without giving it a second thought, but it seems like, in many cases, the biner block would offer a lighter, easier solution. I know my canyoneer friends tend to rig rappels with a biner block, but I've never given it a thought for climbing. The only issue I can see with it is that the biner+clove hitch is bulkier than something like an EDK for joining two ropes, and hence might be more likely to wedge in a crack on the way down.

Are there any other reasons not to go for a biner block + tag line as the default for long rappels?

FrankPS · · Atascadero, CA · Joined Nov 2009 · Points: 15

The problem arises if the fat rope gets stuck when pulling it and all you have to ascend back to it is the skinny tag line. Lower margin of safety.

Twin ropes are a good way to go when you know you are going to have long rappels.

Edit: But you can use the tag line option; the second would carry it. I'm sure you'll get many other opinions, though!

Em Cos · · Boulder, CO · Joined Apr 2010 · Points: 0

To be fair, I'm not sure anyone would've suggested the biner block as a more sensible alternative to carrying two ropes, or even moreso to climbing with the proper length single rope - just as a more sensible option than treating a single bolt as a rap anchor.

Then again, maybe some would. Personally, if I plan to rap and the raps require a 70, I bring a 70. If the raps require double ropes, I bring two ropes. It is good to know other techniques though for when your rope may come up short unexpectedly.

FrankPS · · Atascadero, CA · Joined Nov 2009 · Points: 15
ckersch wrote:I was reading this thread , in which someone mentioned carrying some cordelette and doing biner block rappels instead of carrying a second rope, for a pitch that required a 70 meter rope to rappel, where the poster only had a 60m rope, rather than carrying a second rope. In my (admittedly limited) trad climbing experience, I've always lugged a second rope up any rope that has long raps without giving it a second thought, but it seems like, in many cases, the biner block would offer a lighter, easier solution. I know my canyoneer friends tend to rig rappels with a biner block, but I've never given it a thought for climbing. The only issue I can see with it is that the biner+clove hitch is bulkier than something like an EDK for joining two ropes, and hence might be more likely to wedge in a crack on the way down. Are there any other reasons not to go for a biner block + tag line as the default for long rappels?
Are you sure that's the link you meant to put in this thread? The one you gave is the "passive-pro only" thread. I think you meant the "rap on one bolt" thread?

Yeah, if you need a 70, get one. Twin ropes for longer rappels.
Bill Lawry · · New Mexico · Joined Apr 2006 · Points: 1,407
ckersch wrote:The only issue I can see with it is that the biner+clove hitch is bulkier than something like an EDK for joining two ropes, and hence might be more likely to wedge in a crack on the way down. Are there any other reasons not to go for a biner block + tag line as the default for long rappels?
Frank already mentioned that the only "rope" you have in your hands for a bit is the tag line - lower margin of safety.

There are long threads out there about the subject of tag lines. Still, other disadvantages of going with a biner block + tag line that come to mind ...

  • skinnier cord tangles more easily; leads to extra steps / measures to avoid tangles;
  • the skinny cord is harder to pull and so it takes less added friction anywhere for the rope to feel stuck and it gets tiring; matters a lot when using, say, 6mm tag line;
  • a biner block + 6mm tag line + fat single rope is not so very different in weight than two common double ropes;
  • because this is a different rap system compared to two same-diameter ropes, the special care needed - some listed above - warrants both in the climbing pair to be familiar with needed special care;
  • the special care needed also often takes up time which could be valuable if getting down before dark is important.
Bill Lawry · · New Mexico · Joined Apr 2006 · Points: 1,407

From my view, the primary advantage of a biner block + tag line is the lower cost.

A single rope plus tag line usually doesn't cost as much as double ropes.

A single rope is often more durable in some environments and so will stand up to wear and tear longer.

With care, when it is time to replace the climbing rope(s), the tag line is good for another cycle ... depending on your sensitivities.

Danger-Russ Gordon · · Orem UT · Joined Nov 2011 · Points: 200

I've come across a few routes where I decided to use a block and a 40 foot piece of chord instead of a full second rope. Its rare that its the best solution, but every now and then, when there is a long enough approach, its only one rap (in my experience it was the last one to the ground), and a regular 70M wont cut it, I would say it makes good sense.

Allen Sanderson · · Oootah · Joined Jul 2007 · Points: 1,115

Given that I was one of the people who suggested the biner block for the rappel let me give some insight as to why. Basically because it was a one off. Namely one rappel and the last rappel. So if there is an issue like a stuck rope in the big scheme of things there would be no harm no foul other than a stuck rope to deal with. Would I suggest that when there are multiple raps - probably not.

Bill Lawry · · New Mexico · Joined Apr 2006 · Points: 1,407

Some background: Many times I have used a tag line for multiple raps where the risks are higher; but these days money is not so tight and so the doubles usually come out ... or more rarely the 70m single. Still, I do have a long scramble loop I do solo (but no rope soloing) where a 40m tag line with a 35m rope are perfect for going light while still being able to do the three raps and continue the loop.

Much more could be said in that other thread. Perhaps it will if the OP becomes a little more forthcoming about experience, etc..

Jonathan Croom · · Unknown Hometown · Joined May 2015 · Points: 95

I use blocked rappels all the time; commonly I use a blocked rap with a single rope so I can rap on a grigri, which is increasingly becoming the only device I carry. I think blocked rappels are very useful and never understand why my partners and other climbers sometimes seem opposed to them.

One set up I really like is a 40 m single, with a 30 m tagline. It is super light and low bulk, but maintains the advantages of a single rope. I use it a lot when I am solo, either for rappels or to self belay a section of a multipitch route. I also have doubles/twins, and sometimes carry one of those to rap, but the single + tagline makes it much easier to self belay. Often my solo days include both free soloing and top rope soloing, which is a big pain on twins. Also jugging a single is much easier than jugging twins.

I don't like the way a cloved locker is loaded against the anchor, so I always use an overhand on a bight with the loop clipped back to the rap line. I generally tie the tagline directly through the loop in the rope. The locker is never loaded, it's just there to make me feel better since the knot will be out of sight. Often I'll double over a meter or two of rope, then tie an overhand on a bight with the doubled section and clip the resulting three loops of rope back to the rap line. This creates a bulkier knot to jam against the rings/chains/etc, and if you're rapping off of biners, may be necessary to prevent the knot jamming in the anchor.

As far getting the rope stuck while pulling...yeah that would suck. Especially for me because I generally use 5 mm cord. Maybe one day my rope will get stuck and I'll be screwed, but it hasn't happened yet. For me, that possibility doesn't outweigh the benefits of using a tagline. Maybe if I knew I'd be rapping a lot of slabby/flaky terrain I'd use a different system. For the areas I frequent, most rappel descents are on steep terrain, and few routes require more than a couple raps, so there aren't many chances to get a rope stuck.

One other use for a blocked single line rappel (no tagline) would be for a simul rap. Sometimes with a new climber it would be nice to rap along side them, but a regular simul rap exposes both climbers to the risk that the other might screw up and drop them. If you rig a blocked rap from the middle of a single rope, then simul rap, one of the strands is isolated from the other, allowing the more experienced climber to simul rap without fear of the other climber killing both of them. Of course this puts more responsibility on the experienced climber, but it means that you can be with the new climber the entire time and do not have to trust them to do anything alone.

One other thing, regarding using a tagline that is shorter than the rope, as I often do: rather than trying to find the halfway point of the entire rope+tagline, set up the rap from the end of the rope, and feed the tagline from a stuff sack while rapping. Then, as you come to the end of the tagline, pull up the free end of the rope, and tie it to the tagline. Now you have a big loop of tagline and rope. When you pull it, untie the knot. This allows you to max out the full possible length for your setup, rather than trying to precisely measure out rope at the anchor.

Rob Warden...Space Lizard · · Between Zion, Vegas, LA, an... · Joined Dec 2011 · Points: 0

Its really hard to rig the tagline against biners, instead of chainlink, rapides rings ect.

Jack Servedio · · Raleigh,NC · Joined Feb 2016 · Points: 20

When I am doing multi-pitch climbs with a walk off, with optional long raps down, I always bring a thin tag line so I can bail as a last resort.

If I am doing a long single pitch or short 2 pitch with a rap off where where a single 70m won't work, and it's only one or two raps the entire day, I use the biner block a lot to save carrying a second rope.

If I know I am going to rapping a bunch, I just bring a second skinny single.

coppolillo · · Unknown Hometown · Joined Sep 2009 · Points: 0

Check out the Edelrid Rap Line...you can double it and lead on it in a pinch, in case your dynamic rope gets stuck...just did so in Vegas last month. Worked great, quick solution for a snagged rope!

As for using a tag line or twins/etc...ideally you own both systems, weigh the options, choose what you're psyched on...so BAM, just spent another few hundred dollars for you!

Guideline #1: Don't be a jerk.

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