catching falls with half ropes

Ive never used half or twin ropes but my partner and I have been considering giving it a try. We climb mostly in the Gunks so using half ropes to minimize rope drag is a strength.  However, one question that we haven't found answered is when catching a fall (or taking), and all the weight will be on the highest piece, wouldn't that also mean one rope in the ATC is responsible for all the braking?  My concern is, how much more difficult is it to brake/catch with a rope under 8mm? how big of a difference is noticed by the belayer? any strategies for managing this?

Get a different belay devise if using ropes under 8mm.
Basically you belay with one rope at a time-sort of- witch ever is “hot” ... that’s the last strand that moved.
Beware... 90% of the climbers you meet will not know what your doing, or why.
IMHO it’s the only way to go when you are doing real climbing.... oh yea, it’s called trad on MP.mp

I´ve both taken falls and caught falls as a belayer with half ropes using normal ATC. I´ve never had problems with braking and often the load gets spread over both ropes although one is with a higher piece. That offcourse is dependant on where the pro is located on each rope but due to the stretch it often ends up loading the other rope to some extent.

Unless you're really proficient at belaying with an ATC device then going to half ropes would be problematic and even if you are it's a learning curve. Also, doing it with today's sub-8mm skinny ropes could make learning somewhat harder. In general, it's best to be shown how it's done and then have that person standing next to you when you first try it.

Note: this really isn't a beginning climber topic.

JRZane wrote: However, one question that we haven't found answered is when catching a fall (or taking), and all the weight will be on the highest piece, wouldn't that also mean one rope in the ATC is responsible for all the braking?

Usually, yes. If you've clipped both pieces fairly close together the rope clipped to the lower piece can come into play, but often only one rope is tensioned in a fall. In practice this doesn't affect your belay technique much--just keep your hand on both brake strands at all times and there's little issue.

My concern is, how much more difficult is it to brake/catch with a rope under 8mm? how big of a difference is noticed by the belayer? any strategies for managing this?

I don't have any experience with < 8mm half ropes as that's too thin for my tastes, but I just want to point out that half ropes thicker than this exist, and have almost all the rope drag benefits. I climb fairly regularly with 8.5 mm Mammut Genesis ropes and have caught a handful of falls with a DMM Pivot with no issues. Just recently caught one which was around 0.75 factor. I've also used a Petzl Verso once with halfs and hanging on that was fine, though I don't remember catching any real falls.

My point is, if you're starting off with half ropes, it might be better to start with thicker half ropes so that being able to catch a fall on one thin rope isn't a concern.

Twins need to be used like a single, and not separated to different protection. 1/2's can be used for wandering routes and protection. Just as Healyje noted, it is definitely not a beginner system. Rope management needs to be on point: flaking both ropes properly, clipping the right rope to the right pro, feeding or taking in slack from one rope without removing the brake hand from the other rope, not over relying on one, etc... The thinner the rope, generally, the less friction. It will change your repel technique. Their use is covered pretty well in MP forums.

This is what I can achieve before the rope starts sliding through my hand, I fall in the above-average category of hand strength (I´m 6 ft, solidly built and bend metal for a living). The Italian Alpine club also reported a ca. 40% loss of braking performance if only one strand of two is loaded.
the options to improve matters especially with thin ropes (I use 7.8´s sometimes) is either add one or two extra belay karabiners between the belay loop and the device OR change to a Climbing Technology Alpine Up.
The ATC XP is measurably still the best performer of the conventional plates, the Reverso and Pivot aren´t as powerful despite what others will no doubt say (they are roughly 10% weaker).
Wearing belay gloves generally reduces the braking perfomance but happily reduces the risk of rope burns which is probably the more desirable. Knitted Kevlar work gloves with rubber palms/fingers will increase the braking performance by 50% or more but the durability is a bit limited as the rubber shreds off.

This:
https://youtu.be/lYSzOP_SVLE

Get a DMM Pivot belay device also

I use the Climbing Technology Alpine-Up for lead belaying with double ropes, works great. Highly recommend, great device. 

stolo wrote: I use the Climbing Technology Alpine-Up for lead belaying with double ropes, works great. Highly recommend, great device. 

Also recomend,off topic but if you want to take someone new muktioitching and may need to rap this is s good option. Makes me feel less likely to get dropped and is still as functional as a guide plate

JRZane wrote: Ive never used half or twin ropes but my partner and I have been considering giving it a try. We climb mostly in the Gunks so using half ropes to minimize rope drag is a strength.  However, one question that we haven't found answered is when catching a fall (or taking), and all the weight will be on the highest piece, wouldn't that also mean one rope in the ATC is responsible for all the braking?  My concern is, how much more difficult is it to brake/catch with a rope under 8mm? how big of a difference is noticed by the belayer? any strategies for managing this?

There is an easy way to answer all your questions. Try it with an appropriate back-up.

Personally I prefer to wear gloves when belaying using sub-9.5mm ropes (OK, this is not accurate proposition. Due to my skin health issues I do prefer to wear belay gloves any time this option is accessible). Although there are folks giving a perfect belay with no gloves when climbing on sub-8mm halves.

+1 for wearing gloves. And consider using a second locking biner in your belay device.

Jim Titt wrote:

This is what I can achieve before the rope starts sliding through my hand, I fall in the above-average category of hand strength (I´m 6 ft, solidly built and bend metal for a living). The Italian Alpine club also reported a ca. 40% loss of braking performance if only one strand of two is loaded.
the options to improve matters especially with thin ropes (I use 7.8´s sometimes) is either add one or two extra belay karabiners between the belay loop and the device OR change to a Climbing Technology Alpine Up.
The ATC XP is measurably still the best performer of the conventional plates, the Reverso and Pivot aren´t as powerful despite what others will no doubt say (they are roughly 10% weaker).
Wearing belay gloves generally reduces the braking perfomance but happily reduces the risk of rope burns which is probably the more desirable. Knitted Kevlar work gloves with rubber palms/fingers will increase the braking performance by 50% or more but the durability is a bit limited as the rubber shreds off.

Jim, can you weigh in on whether the 10% difference between the ATC XP and the Pivot is something users should be concerned about in the case of a high factor (> 1.0) fall?

I've used both devices to catch lots of falls, and can confirm that the 10% difference is noticeable, but I've never caught anything more than a factor of about 0.75 with the Pivot (total fall was about 6m) since my main defense against high-factor falls is preventing them. I've chosen to use the Pivot most of the time due to other factors (guide mode is much easier IMO). The Pivot has had enough catching power for every situation I've come across so far, but I can't help worrying about those multipitch situations with double ropes.

Gunkiemike wrote: +1 for wearing gloves. And consider using a second locking biner in your belay device.

Any reason the second biner has to be locking? It seems like the second biner is just there to provide friction and doesn't need to lock. I'd probably use a second locker just because the free single biners I have are all locking, just wondering for that case where I might pull a biner from one of my cams in a pinch.

Using a second biner is something I have heard a bazillion times but just never did it, but using halves a lot lately I should maybe integrate this.

My thought is that, assuming you're wearing gloves to avoid rope burn, a decrease in peak braking forces means a more dynamic belay, and therefore less impact forces on the gear. Unless avoiding a ground or ledge fall is a matter of inches, this is a desirable outcome.

David Kerkeslager wrote:

Any reason the second biner has to be locking? It seems like the second biner is just there to provide friction and doesn't need to lock. I'd probably use a second locker just because the free single biners I have are all locking, just wondering for that case where I might pull a biner from one of my cams in a pinch.

Using a second biner is something I have heard a bazillion times but just never did it, but using halves a lot lately I should maybe integrate this.

Doesn't have to be a locker. More important is that it is the same size as the locker. Since my belay locker tends to be large e.g. Petzl William, the second one is usually the same type.

Gunkiemike wrote:

Doesn't have to be a locker. More important is that it is the same size as the locker. Since my belay locker tends to be large e.g. Petzl William, the second one is usually the same type.

Cool. I usually use the DMM Rhino, so I'd definitely need another big biner with that, but sometimes I use Petzl Spirits, so the non-locking Spirits I have on my quickdraws would probably work then.

I might start using two lockers by default, since I'm climbing mostly with halves these days Jim Titt is bringing up that the Pivot has less braking power. :)

Keep in mind it's tough enough belaying with half ropes with bare hands let alone adding gloves into the mix.

David Kerkeslager wrote:

Jim, can you weigh in on whether the 10% difference between the ATC XP and the Pivot is something users should be concerned about in the case of a high factor (> 1.0) fall?

I've used both devices to catch lots of falls, and can confirm that the 10% difference is noticeable, but I've never caught anything more than a factor of about 0.75 with the Pivot (total fall was about 6m) since my main defense against high-factor falls is preventing them. I've chosen to use the Pivot most of the time due to other factors (guide mode is much easier IMO). The Pivot has had enough catching power for every situation I've come across so far, but I can't help worrying about those multipitch situations with double ropes.

Well the other factors like rope diameter and condition, fall, hand strength etc make more of a difference but it doesn´t make any sense to me to use a weaker device in an already marginal situation when I own a better one. I never use guide mode so that aspect doesn´t interest me.

So if I wanna give half ropes a go, anything wrong with just grabbing a couple ~9.8mm ropes and trying it out? Sounds like someone backing you up while you figure it out is a good idea. What other concerns are there?

Sam Cocchia wrote: So if I wanna give half ropes a go, anything wrong with just grabbing a couple ~9.8mm ropes and trying it out? Sounds like someone backing you up while you figure it out is a good idea. What other concerns are there?

I've done this in a pinch when bringing up two followers when I didn't have actual half ropes. It works, and might give you a feel for the technique.