various prussik applications

[Kashmire]

So I've been reading about various techniques for using prussik loops and other auto blocks and friction hitches for safety, ascending a rope, etc... some say above rappel device some say below... Is this preference or depending on application?

[Iceaxe]

I'll make this real simple for ya.... as a general rule we don't use Prussiks, friction hitches or auto blocks in canyoneering while on rappel for various reasons. We also don't normally knot the ends of our rappel ropes.

[Kashmire]

I'll make this real simple for ya.... as a general rule we don't use Prussiks, friction hitches or auto blocks in canyoneering while on rappel for various reasons. We also don't normally knot the ends of our rappel ropes.

I just thought it to be valuable information to keep in the arsenal... "Much to learn, I have"

[Brian in SLC]

When I'm with someone who doesn't have much experience or is nervous about the rappel, I'll rig them, double check them, then, rappel on the same rope. Once at the bottom, I can provide the fireman's belay as a safety for them. Works pretty well.

That said, I have a few friends who rappel with a back up, especially off high angle rock climbs. They use an autoblock below their rappel device and extend their rappel device off their harness. Seems to work quickly for them and fairly secure.

No back up's in running water.

[deagol]

I have never really understood why some people put a prussic above their rap device. seems weird to me. I don't use one in either position and find that with a good rap device, like a CRITR, I don't need a fireman's belay either, much less an autoblock

[jman]

I don't need a fireman's belay either, much less an autoblock

People might disagree with me - but this shouldn't be encouraged, in regards to a firemans belay.

No one is too cool for a belay (or at least having the person in a ready position).

Regardless, if you choose not to do it and have been safe.....so far....

[Slot Machine]

No one is too cool for a belay (or at least having the person in a ready position).

X2

Fireman belays sometimes seem silly, until you NEED one.

[skiclimb3287]

No one is too cool for a belay (or at least having the person in a ready position).

X3

If someone is standing at the bottom watching, why not hold the rope and pay attention? My wife saved someone in Behunin by proactively giving a firemans on the 7th rappel or so of the day. Everyone seemed comfortable, until that moment.

[Iceaxe]

X4

We always provide a firemen's belay for everyone that follows when practical, it just makes good commonsense.

And for the record I've caught several people over the years using the fireman, a couple would have ended in disaster, and one was a highly experienced canyoneer. My daughter also saved someone's ass on the Mystery Springs rappel because she was paying attention and had been taught to always provided a fireman when practical.

[deagol]

People might disagree with me - but this shouldn't be encouraged, in regards to a firemans belay.

No one is too cool for a belay (or at least having the person in a ready position).

Regardless, if you choose not to do it and have been safe.....so far....

I go down first a lot, so no one down there to do a fireman's belay...
YMMV

But no one has any justification for a prussick above the rap device? I know people do it, so there is probably a reason, but is it a "good" reason

[Iceaxe]

I go down first a lot, so no one down there to do a fireman's belay...
YMMV

We generally keep our most experienced person up top to rappel last, as most problems and rescues can only be completed from above. Now if everyone in your group has mad skillz it's a different story. Noob's should certainly be put in the rocking chair position (in the middle) when given the opportunity. The ideal situation is to have skill both above and below the inexperienced. If I'm the only person with god like skillz in the group and I'm with beginners or kids I generally top belay the first person down.

[Scott P]

But no one has any justification for a prussick above the rap device?

I don't typically use one, but I've been with climbers who have. If you get hit by a rockfall, for example, a backup is useful.

[PhysWiz]

In my group the first person down almost always uses an autoblock below the rap device. If for some reason they unexpectedly let go of the rope the the autoblock will catch and hold them, this technique does require some practice to get it right. I think the prussik above the rap device is an old and out dated technique and a good way to get yourself stuck on a rope. We always provide a fireman when practical. Just the way we do things. We also say that nobody is too skilled or above a double check from somebody else in the group. Obviously not the only way to do it, this is just what we have found works for us.

[Kashmire]

While practicing with my son I have been using a fireman's belay or just let him climb up and I give a tight normal belay and let him down slow so he can practice his footing and sitting down in his harness. I have really been urging him to use his feet and create distance from the rock so he can see and choose footholds... he has a tendency to grab the rope, so the fireman's has proved useful on the Lil 15ft limestone block wall we have been using for this!... I hope to build his courage, confidence and skills in preparation for the trip!

[GeoJim]

I generally use a French wrap (Kleimheist) below my descender - particularly on longer rappels or when there is a chance of rockfall. Simple and added safety - rappelling is when many/most accidents occur - especially when tapped out at the end of a trip. I would not consider a Prussik. Too easily jammed.

[Brian in SLC]

Well...for climbing...there's the ANAM data:

http://steinmetz.org/ANAM/primaryCause.png

[Canyonbug]

We don't encourage auto blocks when giving instructions, but a fireman's belay should always be done. If anyone is to use a hitch for a back up, I like to use a VT French Braid Prussik. If anyone uses an "Auto-Block" no matter what kind it is, they should know how to set it up properly, test it, and then be able to get out of it if it engages before trying it out on a real deal rappel. Reading the concept of how to tie it out of a book is a lot different than using it. We generally shy away from them as much as possible in canyoneering. I know it's always a "What if", but in a decade + of doing this, I've never had a need for an auto hitching back up.

[GeoJim]

And never, ever would I use a safety ABOVE my descender.

[GeoJim]

No one ever needs one - until they do.

[deagol]

I guess I should clarify my earlier post in that when I don't go first, there is always someone there at the bottom ready to do a fireman's, but they are not actually pulling on the rope- but could in a moment's notice if they needed. I have gone with one person in particular that always wants an "active" fireman's belay (in that I am helping them increase their own friction by pulling down on the rope). I know this isn't probably what most people do and this person should be able to rap without that assistance (and probably could with a better device)... so, the "active" fireman's belay is a bit different than just having someone there not pulling the rope, but ready to pull if needed.

It's like leaning on a crutch needed someone at the bottom to pull down all the time to help you increase the friction to descend at your chosen rate. So what I could have said is I don't feel like I need an "active" fireman's belay.

[WorkBad]

X3

If someone is standing at the bottom watching, why not hold the rope and pay attention? My wife saved someone in Behunin by proactively giving a firemans on the 7th rappel or so of the day. Everyone seemed comfortable, until that moment.


YES! I've still got the video footage somewhere around here.

[harness man]

Great thread!
When developing the CRITR, Desi and I experimented a lot with 'auto-blocks' (prussic type back-ups) and had very mixed results, especially rappellng
single line.
Just when you think you have the perfect diameter and finish of prussic cord and the perfect knot set-up, you get the whole thing wet and it does not work for s----!
We were very pleased, however, to learn the VT Prussic! (best one made by Bluewater)
The VT, when properly tied, holds well and is one of the few hitches fully releasable under load, so you can (should) use it above your device and it is very handy also for rigging in rescue situations.
That said, when first down, I just rig the CRITR with a CONSERVATIVE level of friction and firemans everyone to follow.
The only time first down I am tempted to use the VT is for big wall style rappels of unknown length (where is the anchor?)...

[darhawk]

The VT, when properly tied, holds well and is one of the few hitches fully releasable under load, so you can (should) use it above your device and it is very handy also for rigging in rescue situations..

I want to second the idea of a VT Prussik above the rappel device. It is a very useful tool in some circumstances, such as first one on rappel when facing a long or unknown rappel or when very tired. It is useful for the first one on rappel in any circumstance where an extra safety measure could be desired. The potential problems include rigging it so tight that it is somewhat difficult to move down the rope. This can be prevented with practice or, if in the field, by simply locking off the rappel device and re-rigging. Another potential problem is that if you do in fact begin to go too fast, it is human nature to grab onto the rope and you might hang onto the prussik knot rather than let go. Again, practice will help prevent this problem. Also, on a long rappel or when I'm tired, plan ahead to rest part-way down by releasing the prussik while also stopping myself on the rappel device. It's nice to lock off and dangle for a moment with the help of the prussik before finishing.

I of course agree that a top belay is also helpful in the conditions described, but I find the VT prussik a quick and easy solution. As always, with practice.

[Brian in SLC]

I want to second the idea of a VT Prussik above the rappel device.

How's that go? Those that don't know history...

http://storrick.cnc.net/VerticalDevicesPage/Misc/RappelSafetyPost.html

[harness man]

Yup!
Every form of 'auto block' including VT Prussic has it's downside.
But having had many issues with auto blocks below the device, I have come to prefer the VT above the device as Darhawk has.
But it ain't perfect.
And requires practice to be effective.
Agree with most of those posting here that the firemans is awesome when ever it can be provided.