We are very excited to post the transcript of an interview Kitty Calhoun conducted with Bill Belcourt of Black Diamond, along with Michael Kennedy, Jack Tackle and Jay Smith about the use of leashes, screamers and ice screws.
Kitty was able to record this entire conversation on video, which we are desperately trying to upload to YouTube (it keeps getting rejected for being too big) and embed here. So, in the meantime, Kitty transcribed the entire conversation for you, which is fantastic. There is a LOT of great information here from some expert ice climbers, so please read & share!
Kitty: Talk to me about the use of leashes (or not) on the lead. Bill, you said that Will Gadd claims to use leashes on 20-30% of his HARD ice leads.
Jack: If you have leashes on you don’t put a screw in the middle of a steep pitch, you just keep going, cause if the ice is good, and everything else is good,
Michael: Yeah, there’s more security.
Jack: And now you have to put a screw in cause with leashless tools you have to put a screw in
Bill: Cause now you are going to take a fall, a massive one
Jack: So that’s the difference, from my perspective, in terms of what we used to do with spacing and reading the route, where you are going to put the gear.
Michael: Even if you have leashes, if you stop in the middle of a steep pitch, you get way more pumped stopping and putting a screw in. But if it’s a big section, you still have to stop.
Bill: You have to find a place to deal with it.
Michael: But most climbs you might have a 20 foot section that’s steep, then there is a step and you put the screw and you’ll be fine. If it gets much longer than that then you chicken out and you have to do something else.
Jay: you can’t really beat the pump – depending on how steep the route is.
So what you’re saying Bill, is that you don’t think people should automatically quit using leashes altogether?
Bill: Yeah, I think it’s a bad idea because the leash is an integral part of the safety system of ice climbing and since people have been climbing leashless there have been way more whippers on ice. Every place I go during ice fests, people have been taking leader falls. You can even find you-tube videos of people taking leader falls on ice. We used to never do that because catching your crampons on something was going to be really bad for your legs.
Do you think that you could practice leader falls on ice so you could get better at taking falls on ice and you could avoid getting hurt, maybe?
Bill: No, I think there is too much risk of catching your punts on stuff. I think that the only safe fall you can take on ice is on mixed terrain – something that is overhanging, so you don’t have any risk of your feet coming in contact.
What if a person was getting pumped while they were putting in a screw. Do you think they should clip the rope over the pick, clip the rope in the spike? What about developing an umbilical cord that was part of the belay system?
Bill: Well, looping the rope over the top of the pick – being how sharply beveled the picks are now – is a bad idea because you might cut the rope. You also introduce a lot more slack into the system – having to pull up that much rope to loop over the pick. At Black Diamond, we encourage people to clip the spike. We make the end-to-end strength very strong, so clipping the spike in a well placed tool and clipping the rope in before you place the screw is a good idea because once the screw is in, you can easily move the quick-draw over to the placed screw. You get the weight of the rope off you and you have some peace of mind while you’re putting the screw in and you’re able to relax.
As far as making tool tethers stronger – its really not possible. And that’s because a tool tether fully stretched is 48” long and you’re introducing 48” of slack into a system vs a wrist leash and you are trying to find a way to absorb the energy of the slack with factor 1 and factor 2 forces on it. It’s impossible. No matter how strong we could make the tether, ultimately, you would either break the pick, break the tool, or rip the spike out – depending on the design of the tool. You would either push the failure mode to some other place or you would never get over the fact that you just can’t factor 2 or factor 1 on a short piece of webbing. Whether it be a sling or a daisy chain, when the acceleration is really short, then the forces are infinite. So, you couldn’t build it up enough. So you are best left avoiding the scenario in the first place. If you want a moving belay, use a wrist leash. If you want to have something to keep you from losing a tool, and you want to climb leashless, use a tether. There is no way to make the tether become the moving belay or the wrist leash be as free as a tether. They are two different tools for two different jobs.
Screamers. Are those a good idea or not?
Bill: They don’t really work. That’s because we took a screamer and attached it to the end of spinner leash on a drop tower. We could break the leash for sure on a factor 2 fall, we could break the leash on a factor 1 fall, and we can break the leash and deploy the screamer on a factor .5 fall. So physically, I think people are led to believe the screamer will make a 30 or 40% difference in the energy absorbing capacity of a system, but in reality, its probably more like a 0.1 or 0.2% difference. So in the grand scheme of things, it doesn’t get you over the line. It’s just like this tiny incremental net gain but its not going to be the thing that makes the difference between your fall arresting system holding or not.
Michael: But you’re talking about using a screamer on your tether?
Bill: On your tether or using it on an ice screw.
Michael: So its not going to do much for you on an ice screw.
Bill: It doesn’t add enough capacity to the system. Its like a very, very small gain. It’s not like this tiny thing is going to make it all that much better.
Michael: So it’s a pretty marginal gain. Like if you have a stubby in the ice, and the ice is not that good, its not going to do anything much.
Bill: In certain circumstances, maybe it will make the difference. But I think believing that its going to make a big difference in the system is the mistake. And everybody wants to believe if I add this, its going to make something bad good, or acceptable and the reality is its going to make it ever so slightly less bad.
Jack: Its like you aren’t going to make an A4 placement an A1.
Bill: Yeah, people use that like it’s a panacea.
Michael: So, its still the same distance. So when a screamer gets deployed, you’re only going to add that much distance.
Bill: Yeah, and in a way, its like you start a fire and you put it out. I can call it a victory. You put the screamer in the system and its adding distance and its solving the distance that its added by absorbing some energy. So you don’t necessarily get a net gain. And if you do get a net gain, its very small.
Last question – about screws. Is a short screw as strong as a long screw given the same quality of ice?
Bill: Yes. IF the ice is good, we pull-tested a short screw at 7-8,000 pounds and the ice is plenty strong and its just the wall thickness of the screw and the strength of the hanger that determines failure. Its not the length of the screw that determines failure. If the ice is good, then all screws are equal. Just like with bolts – with granite you can put in a 3” bolt, in sandstone you put in a 4-5” bolt. So the better the quality of the stuff you are putting the pro into, the shorter it needs to be to be full strength.
The threads – what role do they play?
Bill: There are some debates between reversing the threads, how high the threads are, the pitch of the threads all determine somewhat the strength, but also the place-ability of the screw – how many rotations it takes to go in. So the faster you pitch it the less rotations it takes to go in but the more force it will take to turn the screw as its cutting into the ice at a faster rate. Conversely, if you make the threads really fine, the crank pressure would be really low but it would take a lot of revolutions to get the screw in. So you are trying to look for an optimum balance between how much force it takes to crank something in with your hands and how many rotations it takes to get it in so you can get it in and clip it the fastest. As far as reversing the screws, vs with the steep side outward, we’ve frozen a block of ice inside a large steel case, put it in a pull-testing machine – clamped onto the head of the screw with angle iron because the hanger wasn’t up to the amount of force we wanted to put on the screw – and drilled a hole through the angle iron, which allowed us to pull straight out on the threads. In good ice, we pulled the screw to 7 or 8,000 pounds before we started bending the angle iron. Then we just stopped the test. So in good ice, an ice screws resistance to a straight out pull is really high – certainly way stronger than the hanger. The hanger is probably good for 3 to 4,000 pounds. The screw was good for far more than that in a straight out pull.
Jack: That would support the fact that we have done the thread pitch with the vertical side facing the downward pull on the screw to be a supportive part of the power vs if you were to have the threads facing the other way?
Bill: Yes, and we have pulled reverse-thread screws and they are also strong in the same tests. I think some of the theories out there are that with the 45 degree angle of the threads facing outward when you pulled it – it would direct more force into the ice. But we’ve done numerous tests with cold ice and with warm ice and we haven’t been able to verify that that indeed happens. So lots of times in climbing there is anecdotal information and theory with pretty good thinking behind them and when you actually lab test it you find that it sounded good but it doesn’t really occur.
Michael: So in the real world, we don’t always have ideal ice. So when you get to the ideal ice, you put the perfect stubbie in, and its going to be just as strong as when you put the mega-long one in.
Michael: But when you are out and the ice isn’t as good, then you put the long screw in and you feel better about them because somehow they get to some good ice some place. So there is still some place for some longer screws.
Bill: If the ice is crappy, the long screw is the only choice that you have because you try to get down into something good and at least the screw, as its bending and pulverizing the crappy ice – its only able to do so because its anchored to something better that’s deeper. You will bend the screw, but even the act of bending it is absorbing force. So, you need the long screw. What’s also good to know is if the threads go all the way to the top, it makes the screw heavier, but it also makes it stiffer. So a 13cm screw with threads all the way to the top is pretty stiff. That’s why 13 cm is such a good size. You can even leave it out a little bit, if you have to, and it resists bending a lot. They don’t want to bend and start pulverizing the ice.
Is it true that once a screw has gotten dull, that you can’t make it as sharp as the factory?
Bill: It depends on how good you are with a file. When the screw is fresh, its like a brand new drill bit… Its like guys doing the same thing with disposable razors. You have five or six in a drawer and you just keep grabbing them and trying them and you aren’t quite willing to throw them out so you just keep cycling through them a few times until you finally get around to getting rid of them. Ice screws are the same way.
Thank you, Kitty, Bill, Jay, Michael and Jack. We will be also posting this under “Tech Talk” and will link to the video which we will (soon) hopefully get online.