Rapping with tag line - which strand to pull to retrieve ropes?

Hello Everyone,
I just got a 75m 7mm tag line yesterday and have been thinking about how to set up rappels with it. Do you typically set up the rappel so that you are pulling on the lead rope (fatter rope) to retrieve the lines or the tag line (skinny rope)?

I guess the advantage of pulling the skinny rope is that the knot might mitigate the issue of the skinny rope sliding through the ATC faster than the fat rope. However, I see the disadvantage of this being that should the ropes get stuck, you would only have static line and not the lead rope and you wouldn't be able to lead back up to get the ropes unstuck.

I can also see a disadvantage with pulling the fatter rope - there is probably a higher chance of the skinny rope snagging something as it whips on the way down. But in this case, you would at least get your lead line back first.

Is there a standard protocol here? Also, does using an autoblock backup seem to equalize the rates at which both ropes feed through the ATC on rappel?Thanks!

Jake Jones wrote:Rap the big line, pull the small line. When you set it up, it'll be obvious.

+1
Also, I usually do a single rope rappel on the fat rope. The advantage is that you don't have to trust a skinny rope as all while rapping, you can extend the rapple if needed, and you can climb a single line more easily.

The picture on page 6 is pretty much my setup.

caves.org/section/vertical/…

If you are doing many raps in a row, it is often a pain to do them all the same way. It works out faster to alternate, threading the end you pull into the next station. If you always want to pull the thin cord, you will have to pull the entire rap before threading the next station. There is also another advantage to pulling the fat rope: it is heavier and makes pulling easier.

So if it is just one rap, I would pull the thin rope. But on a 10 rope rappel, I usually alternate. Unless you're seeing the knot migrate a lot.

you carried them both..rap them both. pull the fat

I'll never understand rapping one line in 2 rope set up

john strand wrote:you carried them both..rap them both. pull the fat I'll never understand rapping one line in 2 rope set up

From:
climbing.com/skill/tech-tip…

"Exercise caution when rappelling on ropes of different diameters, as the difference in friction through your rap device can cause unequal rope tension and possible slippage at the anchor. In extreme cases the knot can migrate far down from the anchor and you’ll get dangerously unequal rope lengths at the bottom of your rappel. You can solve this problem by always threading the thicker rope though the anchor so that the natural slippage (the knot will migrate in the direction of the thicker cord) will wedge the knot against the rings or biners. The disadvantage to this method is that you then have to pull the skinny rope to retrieve your cords, which can wreak havoc on your already-tired hands."

If the knot acts as a biner block at the anchor, then no big deal rapping on both lines, but if you alternate as suggested by George Bell's reply, then it can become an issue.

I call bullshit on the above quote. for many years i have rapped both cords at once and always pulled the lead line..no issues

Unless I feel 100% sure that I will not stick my rope I pull the lead line. I know going into the rap that the static tag line will pull through the anchors but it is easy to adjust for that by stopping at a ledge somewhere, or worst case feeding the lead line backup up through your ATC while you are hanging.
I always tie knots in my tails so any tagline slippage is just a minor annoyance.

I know you just got your 7 mm tag line, but I used to rap on a 7mm and ended up chopping it up and using it for other purposes around the house and bought an 8 mm. The extra 1 mm in dia does not sound like much, but an 8 mm line is much less likely to get blown around and snagged on stuff. That may be due to climbing in the southwest and Front Range where it always blows.

john strand wrote:you carried them both..rap them both. pull the fat I'll never understand rapping one line in 2 rope set up

What is the advantage of doing a double rope oppose to a single rope?

The solution is simple if u have a partner ... Stack da rap !!!

- patner sets up their rappel device on a leash before u rap, if he/she holds the strand through their device as you rap there will be no unevenness

- once yr down ull either hold both ends or tie em off at the anchor when yr partner raps ... No unevenness

- also note that this effectively prevents the accident where a climber clips only one strand as if that happens and yr partner has their hand on the brake of their device the rope should hold ...

- its also means u can check each other before u go down

As to leading back up if it gets stuck ... Use a half rope rather than a static tag line

;)

George Bell wrote:It works out faster to alternate, threading the end you pull into the next station.

I've found that I can pull to the knot and retie an overhand knot faster than I can rethread 60m of rope.

john strand wrote:I'll never understand rapping one line in 2 rope set up

It's used much more common in canyoneering. In a lot of canyoneering the spots you rap down are smooth and water worn often without defined or sharp ledges-not a spot when you need to worry about a knot (or in this case a huge locking biner you're using as a block) getting stuck on a ledge. Some people are also using much skinnier tag lines that you might not want to rap off of.

Personally I rap on both lines and pull the fatter lead line because it's easier to pull. I'm not saying it can't happen, but I've never had an issue with the knot moving unintentionally. Maybe the size difference in my ropes isn't enough.

Questions like this are somehow always scary in an online context. Is there some specific and particularly urgent need for this? (at least you've got a grip on basic physics).

will ar wrote: I've found that I can pull to the knot and retie an overhand knot faster than I can rethread 60m of rope.

Just curious...what measures do you take to endure you won't drop your ropes?

Threading as you pull can be a pain, but it's good insurance.

Dylan B. wrote:120 meter rope. Pull either end. Link pitches. No knot. Problem solved.

Unless you link pitches for like 80-120m worth of rope and your second falls on a low crux 20-30ft off the ground / ledge and breaks an ankle due to rope stretch (true story).

Healyje wrote: Unless you link pitches for like 80-120m worth of rope and your second falls on a low crux 20-30ft off the ground / ledge and breaks an ankle due to rope stretch (true story).

plus I cant imagine having to find a place to stack 120m or rope at each belay

Pulling the tag line has the potential to create a serious epic. The fact that folks get away with this for years doesn't make it a really good idea, because you just have to be stranded once with nothing but a 7mm tag line, or be forced to reascend the rappel because you just can't develop enough force with the tag line to budge it, to realize maybe you shouldn't have been doing this in the first place. (A solution to this very serious problem is to use a very thin half rope as the tag line, but then one has to ask why not use a pair of half ropes or twin ropes for the entire climb.)

On the other hand, individual carefree experiences notwithstanding, there have certainly been cases in which setting the ropes up for pulling the fat rope has resulted in the knot shifting and the ends becoming dangerously uneven. This can be prevented if the rap lines are consciously hand-over-handed into the device, rather than letting them slide through the brake hand, and this might account for some people never experiencing the shift.

The usual solution was to use one of several simple ways to anchor the system for the first person down so that the knot couldn't shift, but this had the drawback that if the last person forgot to remove the anchor set-up, the rappel could not be retrieved.

Now Bearbreeder has supplied the perfect solution: install the last person's rap device on the ropes and either attach it to the last person if they are using the extended device method, or attach it directly to the anchor if the last person likes to have their device on their harness loop. Since the device is needed for the rappel, it can't be forgotten and there is no danger of accidentally leaving an unretrievable set-up. As Bearbreeder says, the first person down has to anchor or hold the ropes for the rest of the party. Since a "fireman's belay" is arguably preferable to a prussik backup for all but the first person down, this is a practice that ought to become more universal anyway.

Dylan B. wrote: Oh yeah, there are down sides, like running out of gear/slings 50 feet before the anchor. But there are advantages too.

"I had a 30ft whipper on a BD#3 stopper..but it was only a factor .1 fall, so the gear held!"

Is that one of them?

Eliot Augusto wrote: "I had a 30ft whipper on a BD#3 stopper..but it was only a factor .1 fall, so the gear held!" Is that one of them?

With 100m+ of rope out, the static elongation is about 10m. So you didn't whip but just sat on the rope.

rocknice2 wrote: With 100m+ of rope out, the static elongation is about 10m. So you didn't whip but just sat on the rope.

lol!

Larry wrote: Just curious...what measures do you take to endure you won't drop your ropes?

Clip a bight in to something.

Dylan B. wrote:120 meter rope. Pull either end. Link pitches. No knot. Problem solved.

Actually saw some guys in Europe with this setup. It was rated as a half rope and one climber has to tie in to the middle of the rope. Seemed a lot less versatile than using a set of twins or doubles.