Deadman Anchor Advice

[TheBird]

Deadman anchors are still a bit intimidating to me. because of this i have chosen canyons that were either bolted or had natural anchor possibilities like chockstones or trees, etc. I would like to be confident enough to descend canyons where building deadman anchors is necessary.

Any advice from the group on how to properly tie the webbing to the bottom rock. I understand it must vary somewhat on the rock itself, but any specific knots or techniques? And what about the rocks stacked on top? How are you thinking about weight, stability, geometry, etc.? Also, what is the safest way to back up the deadman with a "meat anchor"?

Any tips greatly appreciated. (Tom, any chance of seeing the answer to this in Tech Tips?...with some pictures perhaps.)

[ratagonia]

This is high on my list of Tech Tip topics - might try to do photos at the Death Valley Fest in February. I used to tie it just any-old-way, but Rick Green of Escalante showed me a very good method, so that is what I will show, when I get the chance.

Backing up via Meat should probably be treated as a separate topic... also on the agenda.

Tom

[dweaver2130]

Death Valley fest?

[kiwi_outdoors]

probably by invitation only for the old farts of canyoneering

[dweaver2130]

I figured as much just interested in the canyon tales!

[SRG]

Here is a video from Middle Leprechaun, at 2:50 we build a deadman.
<span class="Apple-style-span">
http://www.youtube.com/watch?v=V79w4mkD8eQ
The anchor we found when we arrived was causing rope grooves, so it was re-rigged. There are probably better ways to do this, but here's what I usually do.
I typically take a length of webbing and at one end tie an overhand on a bight(3:38 in the vid), I then thread the other end of the webbing though it creating a loop. Secure this loop around either the least crumbly rock, the heaviest rock or the rock with the most surface area that you can find(3:47). Stack more rocks on top as needed. Extend the webbing over the edge of the rappel(4:01).Attach a quick-link and tie another overhand on a bight with the quick-link in it (4:05).
In order to avoid ROPE GROOVES in the sandstone, extend the quick-link over the edge of the rappel. If this makes for an awkward start to the rappel, you can tie-off a bight of webbing close to the deadman in a more comfortable spot to start the rappel. Attach a carabiner and rope to to this bight and the entire group can rappel down in comfort, then the last person down can switch the rope to the quick-link and do the awkward start with a fireman's belay from below.

Probably best to try this in a controlled setting 'cause in order to build a safe deadman you should know not only what works, but also what anchors will fail, it's best to figure this part out when you aren't in a canyon.

A "meat anchor" backup is when you clip someone into the anchor as a backup, if the anchor fails the weight of the rappeller is transferred to the human anchor's harness. The human backup anchor needs to be hunkered down. The person should be tied into the anchor with as little slack as possible to avoid shock loading in the case of anchor failure.

[Mountaineer]

When creating a deadman anchor, it's strength will depend on: a) surface area of the object you place b) density of the soil c) the depth d) pull direction angle (shallowest inclination best)

You can "simulate" additional depth by adding rocks on top. There are times when you can't dig very deep in a canyon.

[ratagonia]

Here is a video from Middle Leprechaun, at 2:50 we build a deadman.

The anchor we found when we arrived was causing rope grooves, so it was re-rigged. There are probably better ways to do this, but here's what I usually do.

I typically take a length of webbing and at one end tie an overhand on a bight(3:38 in the vid), I then thread the other end of the webbing though it creating a loop. Secure this loop around either the least crumbly rock, the heaviest rock or the rock with the most surface area that you can find(3:47). Stack more rocks on top as needed. Extend the webbing over the edge of the rappel(4:01). Attach a quick-link and tie another overhand on a bight with the quick-link in it (4:05).

In order to avoid ROPE GROOVES in the sandstone, extend the quick-link over the edge of the rappel. If this makes for an awkward start to the rappel, you can tie-off a bight of webbing close to the deadman in a more comfortable spot to start the rappel. Attach a carabiner and rope to to this bight and the entire group can rappel down in comfort, then the last person down can switch the rope to the quick-link and do the awkward start with a fireman's belay from below.

Probably best to try this in a controlled setting 'cause in order to build a safe deadman you should know not only what works, but also what anchors will fail, it's best to figure this part out when you aren't in a canyon.

A "meat anchor" backup is when you clip someone into the anchor as a backup, if the anchor fails the weight of the rappeller is transferred to the human anchor's harness. The human backup anchor needs to be hunkered down. The person should be tied into the anchor with as little slack as possible to avoid shock loading in the case of anchor failure.

Good summary. I like to emphasize doing a really good job of securing the webbing to the bottom rock, and rarely use a single wrap around unless the rock is perfect. I usually:

A. choose the bottom rock carefully for tieability, in addition to other attributes such as weight and solidity;
B. Put a noose around it;
C. from the noose, go back around in the opposite direction, and put the end through the endloop used to create the noose;
D. pull everything tight as much as possible;
E. tie off solidly against the endloop;
F. pick up the rock with the webbing and dance with it, trying to dislodge the rock from the webbing.

A third wrap, and/or using separate pieces to hold loops of webbing in specific places is sometimes a very good idea.

Tom

[ratagonia]

When creating a deadman anchor, it's strength will depend on: a) surface area of the object you place b) density of the soil c) the depth d) pull direction angle (shallowest inclination best)

You can "simulate" additional depth by adding rocks on top. There are times when you can't dig very deep in a canyon.

Rarely have I seen real "deadman" anchors used. Almost all I have seen are really hybrid deadman/cairn anchors. So piling rocks on top is not a sometimes thing, it is usually the main thing.

My observation is that the geometry of the placement is very important, in some ways most important. If you have a pothole, you can rig your anchor so the force on the bottom rock is upward, or largely upward. A small amount of favorable geometry will add considerably to the strength; negating the need to build a big pile.

Tom

[Mountaineer]

Certainly any geometry that prevents the object from slipping will help. I've seen rocks that just sit on top of the sandstone, and actually "slip" up toward the lip when they are weighted. A bit scary, and perhaps for some would induce finding another anchor. ;-)

Also, keep in mind if you are investigating a deadman in a pothole full of water, it can make it impossible to reliably check. (Or find for that matter). One of the best reasons for the aqua-anchor, leave no trace argument. But that has been debated in prior threads...

[kiwi_outdoors]

Good summary. I like to emphasize doing a really good job of securing the webbing to the bottom rock, and rarely use a single wrap around unless the rock is perfect. I usually:

A. choose the bottom rock carefully for tieability, in addition to other attributes such as weight and solidity;
B. Put a noose around it;
C. from the noose, go back around in the opposite direction, and put the end through the endloop used to create the noose;
D. pull everything tight as much as possible;
E. tie off solidly against the endloop;
F. pick up the rock with the webbing and dance with it, trying to dislodge the rock from the webbing.

A third wrap, and/or using separate pieces to hold loops of webbing in specific places is sometimes a very good idea.

Tom Sounds like just the right balance of paranoia and safety, thanks for the very full description

[MrAdam]

Also, what is the safest way to back up the deadman with a "meat anchor"?

I dont know if it is the safest way to back up a deadman, but we will rappel single strand blocked with a biner block and have the meat anchor tie into the pull side of the rope. We tend to back up any marginal anchors, deadman, rock chocks, knot chocks, cairn anchors with meat this way.

Although, I think one of the most important things when it comes to rappeling off of cairn anchors/deadman is your rappelling technique. Make sure to ooze over the edge and try not to weight the anchor until you are over the edge and gain friction from the rope on the rock.

Here is a great pic stolen from Rick at the Las Vegas Slots facebook page.

62865

[dweaver2130]

I dont know if it is the safest way to back up a deadman, but we will rappel single strand blocked with a biner block and have the meat anchor tie into the pull side of the rope. We tend to back up any marginal anchors, deadman, rock chocks, knot chocks, cairn anchors with meat this way.

Although, I think one of the most important things when it comes to rappeling off of cairn anchors/deadman is your rappelling technique. Make sure to ooze over the edge and try not to weight the anchor until you are over the edge and gain friction from the rope on the rock.

Here is a great pic stolen from Rick at the Las Vegas Slots facebook page.

62865

We use the same method as you and have never seen an issue with that.

Btw that picture is awesome!