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Thread: Is this safe to be used as is for work/rescue?

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    Default Is this safe to be used as is for work/rescue?

    This comes from another forum that I read. The question was would you work/rescue with this system as is (this is the whole setup for lower raise, and backup). Just so I can clear where I stand on this before we get going, I said no for one big reason. Most will get this fast but can you explain why it is not a good look?Name:  post-5916-0-64700400-1383064836.jpg
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    Oh, so it is clear.... the two Gibbs are ASAPs.

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    its only a single rope system, no second rope for the belay.

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    cctrtlt,

    If you can use one rope for climbing ( splitting the rope with two Figure 9s at the anchor ) would this be the same logic? We have two separate capture devices with two separate anchors. Not saying you are wrong, just looking to get some deeper thinking on what will most likely happen here.

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    While it does meet the critical point test: if any one point failed, the load would not hit the ground. However, there were to be a failure, you would load only one ASAP which would then cause the resultant to be outside of the AZV rather than straight down.

    For a confined space setup in a hole, I would probably want to use an independent belay line.
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    If the critical point was the pulley at the load and that was where the line failed, would it still be captured?

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    Quote Originally Posted by Fairfield View Post
    If the critical point was the pulley at the load and that was where the line failed, would it still be captured?
    Yes. the ASAP would presumably lock up on the rope and prevent the load from falling.
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    What is the distance that the ASAP is designed slip/travel before a full stop? That with the fact that the ASAP has the problem of falling downward while not being used. So that leaves you at or just shy of a foot of line to deal with (from pulley to ASAP). Thoughts?

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    One of our ConSpace MA systems is a simular reeves system, though we use a belay line and don't use Gibbs/Accenders/ASAPs on the traveling pully. Also a double pully at the top would clean up the system.

    My question would be: Wouldn't/shouldn't the Gibbs on the haul side of the traveling pully lock up when hauling or the anchor side one lock up if decending? So it would have to be minded to remain open, making it impractical for hauling a victim out of the hole?
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    What is the ASAP anchored to? Are those the purple lines? It can not free float on a rope and must have a static attachment somewhere, therefore it could not travel with the system.

    What orientation is it in? I believe during the lowering part of the operation you will have issues with the ASAP actually locking up. If you take a look at their user experience, http://www.petzl.com/files/all/produ...PE-ASAP-EN.pdf

    you will note that a downward evacuation requires the ASAP to be installed upside down, and to have the free end of the rope coming back up through a biner to be tended. So I am not sure the intent of this would work. Plus with a heavy load at the tail end of the system the ASAP could be more prone to lockups, not a 100% on that though.

    Would love to know if it does though. Like to see some various uses of gear, even if just in theory.

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    Lyman, the Gibbs you see in the pic are supposed to be ASAPs. In theory rendering them not minded due to they travel independently.

    AFD, both ASAPs can be placed in an orientation that would be traveling back up, due to they are connected to the load below and not the anchor above. Just the same way it is connected to a climber that would be ascending or descending. Although I would think that it would have to be minded on one side during travel so one does not lock up on the pulley below. Think of it as having a climber, climbing with two ASAPs.

    I am going to put together a drop test with this and see if they catch in time before running off the cut ends of the rope. I have my doubts but cant be 100% sure unless I had seen it. No matter how it is to go though I still say second independent line for a backup.

    Oh, something else that is a factor to think about. Do you think that with two ASAPs the speed of fall could be slowed just enough to have an effect on the distance to being caught??

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    If you run a reeving system like this, the ASAPs are more for controlling a fall in the event that the haul/lower team let go of the rope, because there is no prusik on the anchor. You should still have a separate belay line.
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    Interesting system. It is essentially an English reeve as used in a Kootenay Highline, except with mechanical devices instead of prusiks. In that context it is accepted by many in the rescue world as a workable solution that has enough safety built in.

    Quote Originally Posted by Fairfield View Post
    What is the distance that the ASAP is designed slip/travel before a full stop?
    If anyone has access to a copy of EN353-2 standard it should tell you...

    I am not sure what the typical stop distance is for the ASAP, but I would also be concerned about the possibility of it running off the end of the line if the line failed at the lower pulley. I did find reference in Petzl literature to a stopping distance of 21-32cm, but this was in a 3m pendulum fall. I also wonder about that in the case of using prusiks there. In reality I would be very unconcerned about the line actually failing there. It's well protected by the pulley sheaves, and it's in sight of the technician on the end of the line.

    Quote Originally Posted by Rescue 2 Training View Post
    However, there were to be a failure, you would load only one ASAP which would then cause the resultant to be outside of the AZV rather than straight down.
    In the case of a line failure, I argue that while it would dynamically load the a-frame, it would not change the resultant to outside the legs. The pulley that was still loaded would have the same force vector as it does now, except twice the load. In the static condition as shown, the resultant vector is straight down, which is ideal, but if you remove one pulley the total vector is still inside the legs.

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    I agree the resultant forces will still remain inside the A frame do to the line still running through the upper pulley.

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    If the resultant would still be within the legs and you feel it would not topple the A frame , why would you bother with all of the extra rigging to make this a reeving system? You have to find an inline anchor, use twice as much rope for the lower, and have a stationary, loaded line potentially rubbing against an edge with the non moving leg of the 2:1.
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    Quote Originally Posted by Fairfield View Post
    This comes from another forum that I read. The question was would you work/rescue with this system as is (this is the whole setup for lower raise, and backup). Just so I can clear where I stand on this before we get going, I said no for one big reason. Most will get this fast but can you explain why it is not a good look?Attachment 23193

    Oh, so it is clear.... the two Gibbs are ASAPs.
    Need to recheck the drawing. The pulleys at the AHD are not shown at the correct angle. Point them correctly and you'll perhaps reconsider whether or not the resultant would remain in the footprint when you fail one side.

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    Ohhh, oops, I think Eric is right... It's really borderline, and could go either way, probably not the good way. Nice catch!

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    I would say if the load is out of the hole then you could be right, but in the hole the load would most likely go to the wall (still in the foot print) and be safe. Yes I know you still have to come out of the hole though.

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    Whether or not the load is in the hole or out doesn't change where the resultant at the pulley will be if only one of the ASAPs lock up.
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    It seems to me that the rope length is essentially shortened by half, and then the 6:1 MA a real big bag of rope would be needed. Or am I mistaken?

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    yup this is all around just bad. I would just love to know if someone thought this was a good plan. Never did get an answer on that.

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    Quote Originally Posted by Fairfield View Post
    yup this is all around just bad. I would just love to know if someone thought this was a good plan. Never did get an answer on that.
    I don't see where you asked the question of whether it was a good plan or not. You said you thought it was bad and asked if we knew why... and then asked for deeper discussion.

    We've discussed our opinions: What is the "big reason" from your original post why YOU said no?

    To clarify, I think the basic premise of the setup is sound for the vertical reeving element of a highline. To rig for failure of the rope at the pulley with yet another rope to be managed, would probably be too complex versus the chance of it being used successfully. For a confined space, however, I would stick with an independant belay line
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    Strange I wrote another reply after my last to clarify and it didn't show.....

    I was thinking out loud, The pic comes from a rope access site and to have one line like this just doesn't fly. The foundation of this I will agree is not that bad all in all. I would not use the ASAP in this spot though. knowing that the ASAP was designed to slip a given distance (in this case pushing close to the distance) and there is other mechanical devices out there that could be better fitted for this. I have never had much issue with a prusic being used here but having devices that mind them self is a huge advantage in my mind.

    Although a good talking point was brought outwith this. If the line breaks and one backup catches, will the load be outside the foot print of the A frame? I say due to the wall being (seemingly) close the resultant force will stay in the A frame. Not centered but still inside. I dont see it causing any kind of failure. If you see it different, explain why, so I can see your side.

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    Quote Originally Posted by Fairfield View Post
    Although a good talking point was brought outwith this. If the line breaks and one backup catches, will the load be outside the foot print of the A frame? I say due to the wall being (seemingly) close the resultant force will stay in the A frame. Not centered but still inside. I dont see it causing any kind of failure. If you see it different, explain why, so I can see your side.
    The resultant is not the load pulling downward on the A frame and the moving over a little bit in the hole. The resultant is the sum of the forces being applied. The simplest way to envision it is usually the halfway point of the angle where the rope changes direction. This is where the force is actually being applied.

    The setup in the picture works because the two pulleys on top of the A frame create resultants that cancel each other out and put the A frame into compression. When you only load one of those pulleys (an ASAP locks up), one of the resultants goes away and the system is no longer in balance. In this case with the resultant outside of the A frame legs, even while load is with in the legs.
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    Quote Originally Posted by Fairfield View Post
    ----------------
    Although a good talking point was brought outwith this. If the line breaks and one backup catches, will the load be outside the foot print of the A frame? I say due to the wall being (seemingly) close the resultant force will stay in the A frame. Not centered but still inside. I dont see it causing any kind of failure. If you see it different, explain why, so I can see your side.
    If you're using a D-carabiner to support your high directional pulley, the spine of it is the arrow pointing at the resultant. Or think of the spine as a finger pointing at the resultant, accurate to within a fraction of an inch. The resultant bisects the interior angle of the rope at the pulley.

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    Rescue 2, The way I see the resultant given the load being placed fully on one side of the line would still be centered fairly well inside the foot print of the A frame due to the pulley at the A frame being connected to both left and right intersecting members of the frame. This in my view places enough force to both legs of the frame to remain stable. This does not go to say though that some stabilizing rigging may need to be done before a lift or a lower is resumed (especially when approaching braking the plain of the hole) . If the pulley and its resultant force was to be close to or outside the leg of the A frame I would then see a problem.

    This all does not go to say I am disagreeing with when it is all ok and it is in tacked like in the pic that both resultants are equaling each other out. I do think though that this is well equaled out and important due to the raising and lowering (as to not fluctuate the force to one leg or another.

    I could very well be wrong with how I see this but am having a hard time seeing the resultant within the frame pulling the hole thing back and over. Have you seen this in this setup with a failure to one line side flip over? Or have you loaded an A frame with one leg only loaded and just not work?

    I am only guessing that this A frame is made from two ladders or to the nature due to it presumably being stable left and right from tipping over.

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