When to use screamers
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I realize that the judgement of when to place a screamer is up to personal preference. But I would like to hear some feedback from the community. I place my screws at a slight angle going up into the ice, or perpendicular and use screamers sparingly, when I think the placement is in questionable ice. But I have also heard of leaders using them at every screw. Any thoughts? |
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you shouldn't place screws in such a fashion...place them downwards rather than upwards. |
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No, Ben. Sally is correct. The way to place ice screws is perpendicular or slightly upwards. |
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I read that you should place it in a downward orientation so that the threads hold a fall, rather than torque from the weight of a fall. |
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Ben Botelho wrote:I read that you should place it in a downward orientation so that the threads hold a fall, rather than torque from the weight of a fall. It also reduces shattering of the ice around the placement rendering a useless placementIf it faces up, the threads hold it. If it faces down, it will torque under a fall doing exactly as you describe and shattering the ice. You place it pointing slightly up. |
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but wait...most people fall downward...putting more torque leverage on an upward placed screw than a downward one. |
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Will Gadd says screamers are outdated. |
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Okay, first to back up the upward vs downward angle debate... |
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Gotta love this place! |
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"This question was investigated by placing screws to the hilt at various angles. Perpendicular is chosen as the reference and labeled zero degrees. The conventional "place the screw at a 10 to 15 degree angle against the direction of pull" is a negative angle. Placing the screw in the direction of loading is labeled a positive angle, see Figure 1. As can be seen in Figure 2 there is a very dramatic change with angle of placement. What we observed is that placing the screw in the direction of loading is significantly stronger. In fact, at 15 degrees from perpendicular the screws are over two times stronger when placed in the direction of load than when placed against the direction of load. The data included in Fig. 2 is a compilation of all three lengths of Black Diamond ice screws using the highly variable test conditions described above. It is amazing that such a strong trend exists in such a variable experimental setup. |
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"The screws (BD style threads) actually are stronger when angled in the direction of the fall. The reason for this is that the threads do in fact have a high pullout strength. What I have seen is that the ice around the surface of a screw placed as you describe is the limiting factor. For a screw placed perpendicular to the surface or slightly angled back the top surface layer of ice breaks at fairly low loads (500 to 2000 lbs) and then you have the lever effect going on which is weaker. When the screw is angled down there is much less force on the top surface layer and it helps support the shaft so the screw does not flex and bend. However, placements are always limited by the ice quality. In "good" ice I think all screws will hold regardless of the angle (within limits of course)." |
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I used to place screamers on every piece of ice gear. I have opened one completely in a fall and think that without the screamer in place I would have decked. As it was I ended up hanging upside down looking my belayer in the eyes. After talking with the guys at Yates a couple of years ago they explained that as you get further out on lead the rope does more of the work. |
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Will Gadds views on screamers: |
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Ben Botelho wrote:I read that you should place it in a downward orientation so that the threads hold a fall, rather than torque from the weight of a fall. It also reduces shattering of the ice around the placement rendering a useless placementhttp://www.blackdiamondequipment.com/en-us/journal/climb//bd-sales-rep-roger-strong-on-how-to-properly-place-an-ice-screw For a little clarification. Sally is correct, "up in to the ice". |
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Ben Botelho wrote:"This question was investigated by placing screws to the hilt at various angles. Perpendicular is chosen as the reference and labeled zero degrees. The conventional "place the screw at a 10 to 15 degree angle against the direction of pull" is a negative angle. Placing the screw in the direction of loading is labeled a positive angle, see Figure 1. As can be seen in Figure 2 there is a very dramatic change with angle of placement. What we observed is that placing the screw in the direction of loading is significantly stronger. In fact, at 15 degrees from perpendicular the screws are over two times stronger when placed in the direction of load than when placed against the direction of load. The data included in Fig. 2 is a compilation of all three lengths of Black Diamond ice screws using the highly variable test conditions described above. It is amazing that such a strong trend exists in such a variable experimental setup. A general trend shows that screws are stronger when placed in the direction of loading. " needlesports.com/catalogue/… you guys need to read some books or something...ha haThat graph clearly shows that the failure load is higher (ie takes more force to make the screw fail) if the screw is placed at a positive angle, ie with the tip placed upward. Craig Leubben showed similar results in drop test done in Boulder Canyon. Reginald, Ben, what am I missing here? I'm pretty sure this is what Sally was saying: Sally G. wrote:at a slight angle going up into the ice |
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I think Ben and Sally are saying the same thing. Sally says that she places at a slight angle going up into the ice. Ben says that he places in a downward orientation. If you look at the way it is placed in the video, the screw is angled slightly up going INTO the ice, thus positioning the crank downward coming OUT of the ice. You're both saying the same thing. |
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I have 6 and plan to use them first on every pitch even with double ropes. I'm scared shitless of actually falling on a screw and would like any mental cushion to trust my placement a little more. My mentor used a screamer on almost every screw and always emphasized the importance of low impact forces. I've seen screws hold 2000+lbs of force in pull tests on flat river ice, but I never get placements like that on climbs. Being the ice will always be of variable quality, I like to know I have that extra bit of security. |
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ha!! |
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Everyone is saying the same thing... When placing a screw, the teeth should end up higher in the ice than the head (see photo). |
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yup |