opposing passive pro

[dan_forester]

A question for all the gear experts - what's your preferred method of opposing 2 passive pieces to create a multi-directional point of protection? I usually clip a long runner through both biners, then wind the runner around the top biner to tension the runner, then tie off with an overhand knot (& clip the rope to a biner on that loop). Is this how you do it, or do you have another way? I've tried using a clove hitch on the top biner but it seems way too awkward.

 

Also, how many of you prefer to make a pair of opposed passive pieces your 1st point of protection rather than using a cam? The talk about cams in another thread got me thinking about how we sometimes might automatically consider cams bombproof/multidirectional when in fact they might be marginal, and we might be better off with a pair of opposed passive pieces. Obviously, it's all situation dependant, and you have to consider position of belayer, condition of rock, the stance you're at, where your next bomber placement is, etc, but I'd like to hear thoughts from the folks who place a lot of gear, especially those who started climbing in the pre-SLCD era.

[selkirk]

Place 2 pieces, use long skinny ass (6mm or 8mm) sling, to clip one, and then clove hitch the sling to the second piece and tension the system a bit.

[chucK]

Don't you have to clove-hitch both?

 

[letsroll]

not if your clove hitching both strands.

 

I clip the upper piece then clip through both strands on the bottom. Clip through the bottom piece two more times, you will end up wrapping the webbing arond the spine this way. Then through in an overhand knot.

 

Not sure if I explained it very well.

 

I know what you mean about placing the first piece as a cam. When I started I always put in a multi at the bottom of the pitch, but lately I have been just using a cam. Think I have become overly dependant on cams.

[dan_forester]

I clip the upper piece then clip through both strands on the bottom. Clip through the bottom piece two more times, you will end up wrapping the webbing arond the spine this way. Then through in an overhand knot.

 

Not sure if I explained it very well.

 

no, that makes sense - that's how I do it, except I think I usually wrap the top biner. any difference between wrapping the top biner vs the bottom biner? if there's no slack in the runner it should distribute the force more or less evenly in the even of a fall, right?

[rob]

wrapping the biners seems very wrong -- it seems it can transfer force to the other piece, and if the other piece pulls, you've got a lot of extension, and it seems the sling could pull right through the "wrapped" biner after the piece popped?

 

A girth hitch seems better because it is fail-safe if the other piece blows, and also limits the force being transferred to the other piece.

[chucK]

I guess it depends on the purpose of opposing them.

 

If you are opposing them because there are two possible directions of pull (e.g. down if the leader falls before placing a piece, or up if after) then there doesn't really seem to be a need to attach them together at all.

 

If you are opposing them so they will stay in the rock (mutually hold each other into directional placements) then if one piece blows it would appear that the other piece may be rendered useless anyway.

[selkirk]

I always think about the Multi as more important anytime the rope is changing directions significantly. I actually rarely place one cragging as my belayer is usually directly underneath me, so the rope line remains straight.

 

not to mention that in a lot of cases, one well placed passive piece can be plenty multi-directional so long as it's seated both above and behind a good constriction. Cams may be naturally "multi" but anytime a cam might rotate I start get squirmy, i've seen lobes invert during rotation too often.

 

But then I'm a passive gear junkie....

[dan_forester]

wrapping the biners seems very wrong -- it seems it can transfer force to the other piece, and if the other piece pulls, you've got a lot of extension, and it seems the sling could pull right through the "wrapped" biner after the piece popped?

 

well, you'd want to clip the runner through both biners before wrapping the runner around one of them, so it shouldn't pull through.

 

A girth hitch seems better because it is fail-safe if the other piece blows, and also limits the force being transferred to the other piece.

 

how would you tension the pieces with a girth hitch? I don't think you could.

[dan_forester]

I guess it depends on the purpose of opposing them.

 

If you are opposing them because there are two possible directions of pull (e.g. down if the leader falls before placing a piece, or up if after) then there doesn't really seem to be a need to attach them together at all.

 

If you are opposing them so they will stay in the rock (mutually hold each other into directional placements) then if one piece blows it would appear that the other piece may be rendered useless anyway.

 

that's a good point. I guess I'm imagining a situation where you've got 2 pieces that are each very solid from 1 direction of pull (one good for upward, one good for downward), where the lower piece needs to be tensioned to keep it from falling out of its placement.

[hafilax]

I've always questioned the utility of opposing passive pro. It seems to be a technique for marginal placements in order to hold the upward piece in place. In tensioning the pieces to hold them in place you are creating a 'death triangle' of sorts to forces perpendicular to the line of the pieces. If it is set with the intention of an anti-zipper kind of thing this is fine because the forces are small but it can potentially be weaker to a leader fall. I'm imagining something like an overhanging crack where a leader fall with have a large force outward from the wall.

 

It always seems like the first placement has to be magical. It has to hold a leader fall and prevent zippering all while not causing much drag. While a cam may be compromised to a leader fall by rotating I've never seen a cam pop due to rotating into a less than optimal position as an anti-zipper piece. I've seen many first piece nuts pop out when the leader starts to lower while cragging. I've had good success with tricams as a first piece as well. Thankfully, I've never seen a zipper during a lead fall.

 

I guess it's still a good skill to have. You never know when you may need it.

 

I just had a thought. Clove hitch each piece in tension and then use the remaining sling to clove hitch a draw with plenty of slack. This way it is likely that only one piece will be weighted at a time. Maybe I'll just place a tricam, they ARE magical.

[goatboy]

When opposing two pieces of gear, a good thing to be aware of and avoid is the idea of increasing the forces on the pieces by making a pulley-like rigging (i.e clipping into the bottom piece, then running both strands of the sling up through the top piece and straight down to the rope)....

 

 

[Bug]

Isn't this why mounties carry cordettes?

 

I use slings to equalize the load. I still have tied runners in my rack for times like these.

You do have to be careful not to leverage the load but for an anchor that can hold an upward and a downward yank, you just have them holding each other in. Only one is yanked either way.

[plexus]

Same here Bug. And I usually use a clove hitch on both pieces. Rarely do I oppose the pieces as protection but have done it a number of times building anchors.

[hafilax]

Anchors is a different story.