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danl
Aug 25, 2009, 7:19 PM
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I assumed attaching the haul line to the anchor is a no no. But what about putting a screamer between (the haul line and the anchor)? Would this be enough to mitigate things?
(edited for clairity)
(This post was edited by danl on Aug 25, 2009, 8:00 PM)
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shimanilami
Aug 25, 2009, 7:44 PM
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Since when is attaching the haul line to the anchor a "no no"? What types of "things" are you talking about?
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danl
Aug 25, 2009, 7:58 PM
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Um I always figured it was bad form to attach the haul line directly to the anchor since if you lost control of the bag it would probably bust the anchor. I figured it would be better to lose the haul bag than lose your life.
Sorry about the unclear post.
Things being as follows. Say you lose control of the bags and they go rocketing down ward. If you attach the haul bag to an anchor (either the main or a separate hauling anchor) would the deployment of the screamer be enough to mitigate the forces exerted by the falling haul bag?
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majid_sabet
Aug 25, 2009, 8:12 PM
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danl wrote: Um I always figured it was bad form to attach the haul line directly to the anchor since if you lost control of the bag it would probably bust the anchor. I figured it would be better to lose the haul bag than lose your life. Sorry about the unclear post. Things being as follows. Say you lose control of the bags and they go rocketing down ward. If you attach the haul bag to an anchor (either the main or a separate hauling anchor) would the deployment of the screamer be enough to mitigate the forces exerted by the falling haul bag?
let's ask one of these math experts to see what they say so here is the problem;
Pig weight ; 65 lbs
Anchor ; 2 piece cam
Slack in the system 50 feet
Rope; 8.5 mm static
Rope Elongation; 3%
I put $10 that this pig will end up at the bottom of the base with a broken screamer.
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shimanilami
Aug 25, 2009, 8:13 PM
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I'm trying to figure out how one would lose control of the pig. The only situation I can think of is if your hauling device fails. Perhaps your ratchet gets jammed open. Or perhaps your protraxion explodes. The only thing I can think of is to NOT anchor the other end of the haul line to the anchor. Seriously, if you lose control of it entirely, just let it go.
A screamer might help, but I don't think I'd want one integrated into my system.
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tomtom
Aug 25, 2009, 8:20 PM
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majid_sabet wrote: let's ask one of these math experts to see what they say so here is the problem; Pig weight ; 65 lbs Anchor ; 2 piece cam Slack in the system 50 feet Rope; 8.5 mm static Rope Elongation; 3% I put $10 that this pig will end up at the bottom of the base with a broken screamer.
This is a poorly-posed problem. Not enough information to compute.
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coastal_climber
Aug 25, 2009, 8:44 PM
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tomtom wrote: majid_sabet wrote: let's ask one of these math experts to see what they say so here is the problem; Pig weight ; 65 lbs Anchor ; 2 piece cam Slack in the system 50 feet Rope; 8.5 mm static Rope Elongation; 3% I put $10 that this pig will end up at the bottom of the base with a broken screamer. This is a poorly-posed problem. Not enough information to compute.
There is no equation known to man that could compute what is going on in Majid's head.
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ptlong
Aug 25, 2009, 10:00 PM
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tomtom wrote: majid_sabet wrote: let's ask one of these math experts to see what they say so here is the problem; Pig weight ; 65 lbs Anchor ; 2 piece cam Slack in the system 50 feet Rope; 8.5 mm static Rope Elongation; 3% I put $10 that this pig will end up at the bottom of the base with a broken screamer. This is a poorly-posed problem. Not enough information to compute.
No doubt, but a simple spring model estimate is illustrative. In that approximation the peak force is a function of pig weight, elongation, and fall factor. For majid's case it would be 660 kN or 150,000 lbs. Ouch! What would break first?
Don't drop the pig if you use a static line. Don't drop it. Don't drop it. Don't drop it. Don't drop it.
Adding a screamer would "mitigate" the force very little if the pig goes 50 feet.
If you're planning on dropping the pig use a dynamic haul line.
(This post was edited by ptlong on Aug 25, 2009, 10:06 PM)
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shimanilami
Aug 25, 2009, 10:05 PM
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It would be fun to watch. What gives first? The rope? The cams? The rock? The pig? All I know is that I'd want to be far away when it happens.
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majid_sabet
Aug 25, 2009, 10:20 PM
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ptlong wrote: tomtom wrote: majid_sabet wrote: let's ask one of these math experts to see what they say so here is the problem; Pig weight ; 65 lbs Anchor ; 2 piece cam Slack in the system 50 feet Rope; 8.5 mm static Rope Elongation; 3% I put $10 that this pig will end up at the bottom of the base with a broken screamer. This is a poorly-posed problem. Not enough information to compute. No doubt, but a simple spring model estimate is illustrative. In that approximation the peak force is a function of pig weight, elongation, and fall factor. For majid's case it would be 660 kN or 150,000 lbs. Ouch! What would break first? Don't drop the pig if you use a static line. Don't drop it. Don't drop it. Don't drop it. Don't drop it. Adding a screamer would "mitigate" the force very little if the pig goes 50 feet. If you're planning on dropping the pig use a dynamic haul line.
so lets check this pig's problem
Cam is rated to 10-20 KN
Biner 14-25 kn
8.5 mm rope @ 12-15 kn ?
So based on your 660 KN, I'll say, pig will die from broken knot right at the fig 8 attachment next to haul bag.
Also, not sure who said that to me (may be Ceder or Micha) that he was on the top of a pitch next to a tree and somehow, haul bag which was attached to his harness got dropped. when he noticed it, rope was rolling down like a bullet . he jumped on the tree and grabbed it as hard as he could but then the haul bag yanked him off the tree but he was stopped by act of god from falling down.
(This post was edited by majid_sabet on Aug 25, 2009, 10:30 PM)
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danl
Aug 26, 2009, 2:36 AM
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660kN?
how did you get to that?
using 30kg bag from a height of 50ft (15.42m)
where PE=mgh
and KE = 1/2mv^2
v=sqrt(2gh)
the velocity on impact would be 17.4m/s and the KE before impact would be 4533.5 Joules
assuming a penetration of 0.3m using work energy principle Wnet=1/2mv^2final-1/2mv^2initial
force on impact would be roughly 15kN
so maybe a screamer would mitigate the force on the anchor?
assuming a solid anchor ie bolts losing a bag 20 pitches up would be a death sentence in many cases
please comment I am resurrecting some high school math and math is definitely not my strong suit
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tarsier
Aug 26, 2009, 4:51 AM
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If you're doing a solo climb that is set up to counterweight haul then it is imaginable that the pig could fly; and maybe in some other weird scenarios as well. Suffice it to say that if a haulbag falls on a static rope some part of the system is going to break and a Screamer is only going to delay your fate by a nanosecond.
I've used a toy 'biner to attach the haul line to my harness and you could clip it to the anchor when setting up a haul.
Edit: I use a toy carabiner only for securing the rope when it will not be weighted (duh) and the bag is set for a counterweight haul and just hanging off a fifi hook.
(This post was edited by tarsier on Aug 27, 2009, 4:46 AM)
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skiclimb
Aug 26, 2009, 5:02 AM
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holy fucking shit... do you use an ANCHOR when climbing or fucking spaghetti??? for gawds sake...
lemme think here... I clipped the damn haul line into the back of my harness when leading the pitch,...but holy crap i'm too scared to clip it into..the anchor when i'm done with the pitch...
how the fuck am i supposed to haul the pig up if i dont use the anchor???...ok there really is an answer for that but it's stupid.
reality is.. I brought a flute up with me on the pitch and charmed the rope up to mybelay... then i used time stasis to make it levitate in mid air while...
the rocket packs on the pig then fired bringing it up to me and hovering while i dug around inside for my cheese and summer sausage
(This post was edited by skiclimb on Aug 26, 2009, 5:16 AM)
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patto
Aug 26, 2009, 1:21 PM
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skiclimb wrote: holy fucking shit... do you use an ANCHOR when climbing or fucking spaghetti??? for gawds sake...
It was actually a sensible enough question and it is a valid concern.
If you are worried about dropping the haul bag onto static line then just add a fuse to the system.
A single 6mm cord between you pig attachment and your anchor should be an adequate fuse to prevent loads going over 10kN.
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moof
Aug 26, 2009, 3:57 PM
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danl wrote: Things being as follows. Say you lose control of the bags and they go rocketing down ward. If you attach the haul bag to an anchor (either the main or a separate hauling anchor) would the deployment of the screamer be enough to mitigate the forces exerted by the falling haul bag?
Better solution: Don't lose control of your bags!
1. Back up your pulley with a sling/quickdraw so that if the pulley fails the rope will get caught by the draw.
2. Keep the slack end through your ascender/grigri (however you preferto yard on the rope), and don't tear down your attachment to the rope until either the bags are docked, or the slack end is tied off. By this way if the ratchet on your hauling system (ascender, traxion, whatever) slips or breaks the load will be on you, and not send the bags for the big ride.
3. If for some reason you have someone jugging the line with the bags (i.e. first pitches of WFLT or similar, depending on strategy) then for god's sake fully back things up so the hauler is not holding the load (i.e. thread the rope in the hauler, don't engage the cam, and tie it off with a munter-mule knot on the slack side of the hauler).
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patmay81
Aug 26, 2009, 4:29 PM
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patto wrote: skiclimb wrote: holy fucking shit... do you use an ANCHOR when climbing or fucking spaghetti??? for gawds sake... It was actually a sensible enough question and it is a valid concern. If you are worried about dropping the haul bag onto static line then just add a fuse to the system. A single 6mm cord between you pig attachment and your anchor should be an adequate fuse to prevent loads going over 10kN.
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ptlong
Aug 26, 2009, 8:06 PM
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danl wrote: please comment I am resurrecting some high school math and math is definitely not my strong suit
Hooke's Law, conservation of energy, plus Majid's questionable assumption about static rope elongation.
Read this: http://www.rockclimbing.com/...t&postatt_id=350
A screamer wouldn't do shit for a drop of any length.
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ptlong
Aug 26, 2009, 8:09 PM
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patto wrote: If you are worried about dropping the haul bag onto static line then just add a fuse to the system. A single 6mm cord between you pig attachment and your anchor should be an adequate fuse to prevent loads going over 10kN.
Yeah but would you really do this Patto?
Soloists sometimes use a fuse on their harness when hanging a bag off of a hook at the previous belay so that they can rap & haul simultaneously. But when you've got someone at the other end to manage things using a single strand of skinny cord to attach the bag to the wall is just a bad, bad idea. If I had a partner suggest we do this I'd find someone else to climb with.
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summerprophet
Aug 26, 2009, 9:19 PM
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The standards (as I was taught them) for a typical three bolt anchor was this.
Far Left bolt - left leg of V anchor for climbers
Center bolt - Shared between hauling and climbing anchor
Far Right Bolt - right leg of V anchor for hauling,
Initially when arriving at the belay, you clip your daisy into the far left bolt. your other daisy into the center bolt and remove the haul line and clip it to the far right bolt. You are now safe and ready to build the anchors.
-obviously this can be mirrored to suit your circumstances
- While this certainly does not eliminate any hazards (really you are aid climbing.... there are risks) it does put the tail end of the haul line as far away from you as possilble in the event of catastrophy. In addition, it preps things for clean rope management.
Essentailly if the worst were to happen, Right bolt would act as the screamer..... and you hope to god your anchor strands fail before the next bolt.
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