OT: Belaying anchor?

- J
- JayCups
  
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posted
17 years ago

Tue, Mar 20, 2007 2:12 AM

This is way off topic but does have to do with metal rods.

I was watching Josh Bernstein "Digging for the Truth" tonight and he did something that just didn't look right. He was repelling into an underground cistern. The way he anchored the rope was strange, but seemed to work. And I know nothing about repelling.

He had 5 metal rods that resembled eyebolts. He pounded them into the ground 12"- 18" apart in the shape of a pentagon. He then threaded his rope through each eye and tied the rope together and descended on the remainder. He then stated that this was the proper way to set up the anchor. Why would forming a hexagon/circle as an anchor be better than a linear or radial configuration?

Jay Cups

- M
- Martin H. Eastburn
  
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posted
17 years ago

Tue, Mar 20, 2007 2:36 AM

He could have used a long line of them - but it is a troublesome issue of making them perfect... If one is tight the others are perfect or not. If not - they don't help and one or more tie-downs are used.

When you use a helix or halo tie down all are working at once.

Martin

Martin H. Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net TSRA, Life; NRA LOH & Endowment Member, Golden Eagle, Patriot"s Medal. NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member.

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JayCups wrote:

- B
- Bob Engelhardt
  
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posted
17 years ago

Tue, Mar 20, 2007 3:56 AM

Right, anytime you have 3 or more in a row, the middle ones aren't doing anything. Even if perfectly aligned. That is, if the rope just passes through each eye and isn't tied to each one. Bob

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- woodworker88
  
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posted
17 years ago

Tue, Mar 20, 2007 4:28 AM

What other people have said, plus the issue of strength of the material and vulnerability to cracking. Just as placing several woodscrews closely in a line is a recipe for cracking and splitting, rock in particular can crack under load when the load is concentrated along a natural axis of failure (the "grain" of the rock). Placing the anchors in a wider, noncollinear area helps reduce this problem.

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- Leo Lichtman
  
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posted
17 years ago

Tue, Mar 20, 2007 4:08 PM

"JayCups" wrote: (clip) Why would forming a hexagon/circle as an anchor be better than a linear or radial configuration? ^^^^^^^^^^^^^^^ I got this out of an old Army manual: Drive the stakes in a row, leading away from the direction of pull. Tie the top of each stake to the bottom of the one behind it. The rope line will look like a sawtooth profile. The leverage between top and bottom of each stake makes the stakes less likely to move.