Hello friends. You're listening to Exit Point, a podcast about the advancement of BASE jumping and an exploration of its culture. I'm Laron Frat producer and co-host. If you would like to support this independent production, you can visit our buy me a coffee link in the description and give us a review wherever you listen to podcasts, tension. They might be the scariest and least understood malfunction in BASE.
In 2019 and 2020, Squirrel conducted surveys in an attempt to get a better understanding of tension knots and their occurrence. In this episode, Blank and I sit down with Will and Matt from Squirrel to have them share what they learned, and some suggestions on how we could train our emergency procedures. So with that, let's get Matt and Will on the track. So let's just kick it off right away with, uh, what inspired you to learn more about tension knots?
Um, let's see, I mean, people getting them, just the occurrence, right. And I'm not going away. So it seems like something that we should look at to try and make go away, or at least reduce the chances. So like right now, that's how I look at tension knots is a, uh, statistical examination, like it's, uh, what's the probability of having it. There's a lot of malfunctions in BASE where you can really point to the cause and say, ah, that's what caused this.
And you kind of clearly understand the root of it and tension knots for us were more of a mystery. Um, I think they're kind of the scariest and the least understood malfunction BASE. And those two things are hand in hand, right? Like they're scary because. We don't really know a lot of people think they know or thought they knew, you know, twisted up break lines, furry lines lined up, stuff like that. And then there were some myths out there that were totally unrelated to the actual causes, but.
Um, still it's a little hazy and that increases the fear factor. So yeah, the goal was to first try and figure out what the deal was, what's causing them. And then secondly, to see if we can mitigate it. Great. So before we dive into some of the reasons and some of the common misconceptions, can you tell us a little bit about the survey you conducted and was that in 2019? Yes. You had a couple of versions of, of your survey, correct? Yeah. So the first one was.
Um, it's been a while now, 2019 was a while ago, but, um, the first study that we did, the first survey we sent out, we really didn't have any intention of this becoming a larger project. Um, and then we realized that the answers we were getting were super interesting. This could actually be useful and helpful. And then we relaunched it to more people. So there was like a initial group. A modification to the questions, which didn't really help the cleanliness of the data, honestly.
And then a second group that was wider, and then we kind of tried to blend those answers as best we could. But we ended up with, I mean, I'd have to refer back to the paper, but, um, I think around 600 respondents or 540 jumpers responded actually. Can you, uh, briefly touch on some of the issues and problems that you faced collecting data within the BASE jumping community?
I don't know if there were major problems, but it was challenging because, um, well, first of all, I was hoping that more people would, you know, do the survey, right? It's the sort of thing that I feel like. If I had received it or heard about it, I would want to contribute to because it's clearly maybe going to help. I think that some people got caught up in the fact that it was us doing it.
Um, some people felt like they shouldn't respond unless they'd had Attention Knot or some sort of malfunction, probably. So there's all these biases that we can expect to have occurred in the collection of the data. People forwarding it to people they knew had had Attention Knot, for example. People not wanting to respond to it for various reasons. Stuff like that.
What we're looking for, I think, um, just to get an idea, like the survey, surveying people about tension knots, whether or not they've had them, Matt touched on the biases that creep in or kind of blast in, right?
That's a good way to, to preface it, but what we're, one of the main things we're looking for with the survey is if we can find any correlations, all right, correlations to search that then if we did find correlations between any given set of data, then try and narrow down what we're looking for to see if those correlations mean anything. And I think the survey.
shed light on, there may not be any correlations, like any common factors, like the tension knots just kind of occur across the range of BASE jumping. Uh, would you say that's fair, Matt, like it's like, uh, a result of the survey? Yeah, it was, there was nothing obvious. That's for sure. It's not like, um, chutes being too large or lines being too old or brake lines being twisted, like none of those things. We're indicated by the answers that we got for sure.
Um, you know, we were expecting, we were hoping that there would be some type of packing or configuration or even parachute type or break configuration that would show a statistical. You know, for causes of tension knots and there totally wasn't, um, if anybody that's listening to this, hasn't read through the paper that we wrote BASEd on the survey results, I would strongly recommend that because it'd be super boring if we just read it to you.
And there's a lot of really interesting answers in it. I think, um. But what we sort of figured out early on was that, um, plenty of tension knots have occurred on very new line sets, you know, line sets that are too new really to have the break lines twisted up a significant amount, and also have occurred to jumpers who we trust when they say, my break lines were not twisted, right? Online sets that weren't furry online sets that were spectra or dyneema and line sets that were Dacron.
So, they sort of occur indiscriminately. Um, and it took us a while. through observation to get to a better sort of place, understanding what was going on with them. And the survey itself was maybe helpful in that it wasn't helpful, I guess. Well, I mean, it, it helped us understand that we weren't going to find sort of a design concept or packing configuration that was causing these. That wasn't it.
Yeah. Like from a manufacturing point of view, Like one hope might have been, not saying this was a hope in the survey, but imagine you had a bunch of survey results that pointed at something that said, Hey, if you do this, the chances of a tension knot go way down. We didn't find that. We didn't say, Oh, if you use this type of slider and these type of lines or anything like that. Turns out that no one with this parachute X gets tension knots. That was not the case.
So that hope kind of gets dispelled real quick. So then the work of trying to come up with theories about how to tension knots get created, and then try and attack that, I guess, begins after that, um, from our point of view. So like the most basic, the conventional wisdom around tension knots is, uh, well, first of all, I think that a lot of people believe that if you have five upper control lines, that equals tension knots. And if you have four.
That equals not tension knots or fewer tension knots, definitely not supported by data at all. Like that is not true. As far as we can tell. It is true that one extra line on the upper control lines is an extra line that can become entangled with things. Right. And that's part of the reasons why part of the reason that we caved when we were making the heyduke two and decided to do it with four control lines, right? Because first of all, people are scared of five.
Which kind of is a bummer when you're trying to sell a product. And second of all, you can't argue with the fact that one line equals one more line to entangle with. That was just kind of the basic conclusion that we came to. But the data do not support that five upper control lines are worse than four. Right. What were some of the other things that the data didn't support as causal? I think Matt touched on the one that like old, old versus new lines. Oh yeah.
And then my favorite was Twisted brake lines. Um, one of the things that Will did is he, he took a drill and wound up a brake line, you know, brake cascade to, I don't know how many twists, dozens he put a hundred in it. Dozens and dozens of twists. Yeah. A hundred twists on the brake line, just on one side and jumped it repeatedly and zero sign of it, even, you know, trying to become attention. Not at all. So, It's frustrating when you can't make it happen.
It's frustrating when you don't understand why it's happening. And it was only through months of observation. Just literally thousands. Of video, thousands of 360 cam openings on BASE canopies that we started to understand what was probably happening. So can we get into that? Because I do believe that in the study, you have at least a series of events that lead to tension knots, maybe not a cause and effect relationship, but, uh, some precursors and then some.
Uh, you know, later happenings that lead to them. I want to, uh, state that I wouldn't say we have figured out what causes tension knots, but we have a good theory of what leads to some tension knots, right? There may be multiple causes for the a hundred percent of tension knots out there, but for a lot of tension knots that we see in video, we can see how they start. And it's some lines dancing around other lines, basically a twist happening.
Like, uh, imagine two pens drawing a barber pole, a spiral, and as that twist twists up, the slider starts to descend and basically slides past it and locks that knot in that, that loop of line that is looped wound around another line is now kind of locked in with the tension of the parachute inflating. So it's a timing issue. You can see a lot of openings where this. Orbiting line wraps around a separate group of lines. And then before the slider sends, it unwinds itself.
And then the slider descends and now no tension, not everything's fine. You'd never notice it unless you had a camera pointing up, but in some small percentage of those times, the timing lines up and that loop. That winding locks in and creates a tension knot. And we can see this in almost every single video of tension knots that we actually captured. You see one line group, which is tensioned less than another group, orbiting around the tensioned line group, right?
So the most common would probably be the brake line group, so your main control line going up to the upper cascades, has less tension on it a lot of the time than your CD line group, right? Because of the way the canopy is trimmed and the way it can inflate at times. So those less tension brake lines begin to orbit around the more tension CD lines, and then the slider descends.
And if there's enough orbits, if it's wrapped around enough, and the slider descends at the right moment, Or the tangles don't sort themselves out before the slider descends. If the lines don't shake out into an organized pattern before the slider comes down, the slider tends to lock them in. I would say the timing of the slider, like it's not the slider doing the work.
It's the parachute finishing its inflation and the, all the upper halves of the lines getting tension while they're wound around each other. So that coincides with the slider coming down. Right. So what we, what we really want is for the lines to shake themselves out and organize into parallel untangled groups before the slider descends. That's really important. So it sounds like having a stage deployment is really the most important thing for avoiding tension knots.
Yeah. So, so here's, here's like the causal factors that we observed uneven tensioning across the line groups cord wise, right from nose to tail, you've got lines that have more tension than others. And the less tensioned lines start sloppily orbiting around the more tensioned ones. That's causal factor number one, right? Then, you've got the slider coming down before those lines are able to shake out into organized and parallel groups separately.
So, if you've got uneven tensioning and a rapid slider descent, Your chances of tension knots go way up. If you have even tensioning across the line groups because of a nice symmetric inflation, all parts of the parachute are sort of starting to inflate and billow and pull tension on the line attachment points evenly. Then you're eliminating. Or at least reducing the chances of those less tension line groups dancing around the more tension ones, right?
So the first thing we want is like, it's a nice, even pressurized inflation to start pulling on all those line groups equally. Then we want those lines to dance around and shake out into parallel untangled groups. Before the slider descends, you could say that sliders are the leading cause of tension knots, right? That would be an oversimplification and ignoring a lot of the problem, but sliders really are what kind of lock in the tangles. Great.
So before we go too much farther about study and research and, and trying to reduce the number of tension knots, can you guys talk about what we should do, our emergency procedures when we get a tension knot? Sure, yeah, and it depends There's sometimes we should we should start by saying like you sometimes there's nothing to do, right?
It's like before we get too far into like we're gonna save your life with this information It should be said that you can get attention not that can't really be dealt with just got to get that out there There is a lot you can try the other side would be that you may have attention not and Not notice it because it's so minor that you don't notice that your parachute is flying differently. Uh, tension knots sometimes happen on the A lines and sometimes that doesn't make a big difference.
When your control lines are entangled, you're actually pulling on that. So you notice when something weird is happening, a suspension line. You might not notice it might have just a slight turn, but you can still fly, flare and land just fine. Where, where it is on your line groups, like how high it is on the lines. Where it is on the span, how far out towards the tip of your wingtip it is matters, and then what line group it's in matters. Those are all like the factors for the severity.
So if the entanglement, the tension knot, is nice and high and way out towards the tip of the parachute, And in the brake line, it's going to create a very effective turn. It's going to be hard to deal with. You're going to notice it. If it's lower down and kind of between the A and B and more subtle, you might not. Right. And then there's everything kind of in between. And for tension nuts that will be hard to fly with, there are differing factors of how gnarly it is, right?
Like the more distal, the farther out to the wingtips, the more dramatic the turn. is if it's inducing a turn and the harder it is to deal with. I did a handful of test jumps with permanent tension knots into a tertiary canopy that I would eventually cut away just to experiment. And I found, I believe it was the center, most lines, even with the brake line tied together with some CD lines, I would probably find landing it.
Like the speeds I could just hold it into a controlled descent and then PLF would have been fine. But the more distal, the tension knots closest to the end cells would create a rapid turn that any, any input to try and stop the turn would, would create a dramatic stall, just you couldn't deal with it. And so the descent rate was barely survivable in those cases.
So it's definitely a roll of dice of what type of tension knot you might get and what you can do to deal with it or whether you can deal with it. Yeah, so what we wrote in the article is that doing nothing usually doesn't help, right? Which we think is true. So you might as well try something. And on the list of things you're going to try, for me first, it would be cycling the brakes pretty aggressively, right?
Firing brakes, getting the canopy as close to stall, stalling it if you can, and then rapidly releasing them. And then start working through the riser groups. And I think, uh, Will might remember this part better because the article was... BASEd mostly on his training tips. Yeah. And so that's a good precursor to what to do if you have a tension knot is what you should be doing, preparing for having a tension knot, right?
In your skydiving and pace jumping training on as many jumps as you can pretend like you have a tension knot. That means imagine you have a tension knot and try these things to prepare for what to do in the situation, because if that situation happens. You're not going to do what you think you should do. You're going to do what you've trained to do. So train to do it. And like Matt said, cycle the toggles up and down rapidly.
Then if that doesn't work, try pulling down on the rear risers and letting them go, which will create a tremendous amount of slack until it hits line stretch again. And I don't mean pull down and push back up with your hands still on it. I mean, pull those risers down as far as you can to stall and then let them go with your hands still down by your sides. So you create a ridiculous amount of slack.
Any person that's landed a tension knot, as far as I know, when they go to inspect their canopy on the ground, the tension knot has magically disappeared. That means as soon as the tension of your weight under the canopy has been released, that knot just falls apart. It's a very easy to untangle knot by itself if you can induce slack. So that's what you're trying to do in this training.
You're trying to induce slack by pulling down on the risers and letting them go so that they create enough slack for that knot to pop out. And this training is super fun, actually. If you're a BASE jumper and you never stalled your BASE canopy and you never spun your BASE canopy, when I say spin, I mean yaw axis. Rotation, not spin as skydivers often refer to, which is a steep bank turn. So an asymmetric stall or a spin where you stall one side of the can.
If you see the other side rotates around it on a yaw axis, full stalls, releases, full stalls on toggles, full stalls on risers, single. riser, rear riser, full inputs, single break, full input cycle, all those things, really aggressive, full control range inputs of your BASE canopy. If you haven't done that in your BASE jumper, you're tripping.
Uh, well, while you were testing all of this stuff, um, what was your success rate using these techniques, getting out of tension knots that were not locked in? So it's important to remember, uh, or to focus on the fact that I didn't create a, the same kind of tension, not that any of one of us would have in a real I actually tied knots that would not come out at first. I tried some knots that I thought might hold, and then the opening pop those knots out.
So I tried to create tension knots that just themselves cleared by themselves. I wrapped, I want to say 25 wraps of tape of a two inch masking tape or painter's tape around. A few lines to try and keep them together that blew apart just from the opening shock. And then I resorted to a sheet bend that, uh, would not come out. So no amount of slack I put in it would, uh, would pop it open. So that was my testing was a permanent, not, not a releasable, not interesting.
So you didn't get any, uh, opportunity to try and clear attention, not like one would exist in the, in the jumping environment so far that. I don't have a good way to recreate a tension knot, like people get in real life. Yeah. If we could do that, we would have a lot more testing that we could success. But then there were a couple of stories of people who had tension knots that reported them and then reported getting out of them. Correct. Yeah, for sure.
Yeah. A lot of people, people tension knots all the time. I think it was 60%. It was 60% cleared with some jumper action and plenty more probably go unnoticed. And sometimes they look up sought. And it just started flying and it came out. Yeah. Sometimes people had to work to get it out, but the minority of tension knots people have had, they did not get out of them.
I think it's worth reiterating what Matt said and Will said there about the fact that You're just going to sink to whatever, um, you know, your training is. So it's not like you're going to like get an S on your chest. All of a sudden there's some action to take and that if you haven't stalled or spun your parachute, you're absolutely being a complete fool because. It's fun and it's going to be one of those things that are going to save your ass if it happens.
If you're opening your parachute over 500 feet or so, and you're not stalling it, spinning it, doing something aggressive to learn the control range of a parachute and the result of inducing. Rapid inputs with full release to test these things, then you're wasting your life as a BASE jumper. And just, it may be worth touching on just to be totally fucking obvious. But when you say working your control lines or your breaks, you're talking about going through the, the entire stroke length, right?
Like we're talking, not just like making turns, but like actually using the entire break range. Or take a wrap and use the entire break range, right? Like. Take a full wrap, put your hand through the toggle, and then take a wrap on the lines, or take your hand on the bottom of the toggle and take a wrap, put your hand through the toggle and grab the line, something like that, to choke up on it essentially, and stall your parachute.
You know, you should definitely know exactly how to hold your BASE canopy in a stable stall, what happens if you, you know, do a dynamic stall and then release the controls rapidly if you hold it. What the timing of the release does for the surge and recovery of the canopy, what single full break inputs result in an asymmetric stall where you just stall one side of the canopy and it begins to spin.
Um, and then the same thing on risers, you know, both risers, rapid, slowly, stable, unstable, single risers, rear, front, et cetera. I'll go down a little bit of a rabbit hole on, uh, those control practices. Uh, there's valid reasons to use stalls. Even in the BASE jumping environment as a flight mode, um, a lot of people get into that debate about what to use. What control do you use on a 180 when you're facing a wall?
Um, and stalling depending on your parachute could be a valid control input. Um, if you don't know how your parachute behaves in a stall, then you can't use that effectively because you won't know which direction you'll go if you stall on which control. So for me on the parachute, I jump at the moment. I know that if I stall on rear risers, I'm going to go straight down. No movement forward or back, but if I stall on toggles, I'll be backing up at a reasonable speed.
So if I had the altitude on a 180 and I wanted to back up, I would go into a stall on my toggles and fly away and then let up on one toggle and spin around and fly away. Now, in the case of a tension knot. If you've never stalled your canopy before and you start manipulating controls, the chances that you will stall your parachute sooner than you realized will be high.
Meaning you start pulling your toggle down and it gets to your shoulder and now your parachute stalling and you don't know what's happening. If you've not trained at stalling and comfortable with stalling, that will probably freak you out and you will no longer want to control. With that control input you just did. And you will probably ride whatever that thing is into the ground. But if you recognize that as a stall, you can use that.
And now you say, Oh, this parachute is now stalling earlier than it should. I probably have attention knot. Now I can use that stall harder, let it go and try and get out of that situation. So not only is it good to stall your parachute because it's fun, because it's good for flight mode practice, but it's also good to be intimately familiar with how your parachute flies in all situations and in all controls. So, you know, what's happening when it's behaving or misbehaving.
I believe that every parachute or really, I believe every BASE jumper should be comfortable enough with full stalls to be able to use it as an accuracy technique, right? Like on final within a couple hundred feet of the ground, you should be comfortable flying your parachute on the verge of stall or briefly allowing it to drop into stall and then letting it search to recover. Right. As a, I'm going to go long. This is, this will help technique, right?
And the effect of your control inputs and the type of the action of the stall is going to depend on your wing loading, the parachute you're jumping, the control line length, et cetera. So you got to get to know that yourself individually and. Over the course of many jumps, understanding how much altitude you're going to lose in a stall on toggles will be difficult to do at a thousand feet.
So work your way down until you get a sense of how much altitude consumption you have, whether or not you're going forward or backward can be deciphered by looking at your pilot chute. You know, you're flying backwards a little bit when you see your pilot chute past your leading edge and sort of.
Um, and then flying relative to your friends helps too, but being low on final is eventually once you get comfortable with it and you understand the results, a good time to start figuring out exactly what happens to your canopy when you do this stuff. And I realized that telling someone to stall, telling someone to stall their canopy low on final, you know, might make some skydivers or BASE jumpers itch or get a funny feeling in their tummy.
But we're BASE jumping and this shit is about not hitting objects. It's about saving your life. And these control inputs and actions are actually very, very basic. So you got to know it and it's not wrong to do it low. Matt, I wanted to ask a follow up question, but if you had something pertinent to what's going on right here, go for it. Uh, yeah, I just wanted to add one more thing on the training for that one.
Um, if you're going to jump your canopy in the sky, uh, one other helpful thing to do is just. Take a six foot length of caution tape, tie it around your left ankle, stuff it in your shoe. As soon as you jump out of the plane, let it go. And that's a little easier indicator to tell whether you're sinking or going backwards and can give you a little bit more precise feedback on whether you're stalling, whether you're flying backwards or whether you're still in flight.
Yeah, it makes it super obvious when this, when you're new to this stuff, it can be a little bit overwhelming and the fear is there, right? So having it as easy as does identifiable as possible, uh, could be helpful. Hey, will, I wanted to ask something really quickly, cause I think you brushed up on it and, uh, or brushed by it quickly. Um, the, the, the speed of your release, right? When you're, when you're practicing these drills, are you letting it up or are you letting go?
Because it feels like those are two different things completely. Yeah, I don't think it's, so in the case of a tension knot, you want to introduce slack into the system. And I don't think anyone can reasonably push their hands up as fast as you would need to, in order to create tension. So the easiest way to create that slack would be to pull down on risers and just let go of the riser. So it has some amount of feet to spring back up and create slack.
I think I said tension before, but creating slack is the goal. Obviously, you might not be able to do that with your toggles. It's, uh, if your toggles are, the brake line is routed through the ring, presumably that's how you would do it. If you were jumping slider up, then you could also do that with the toggles. But the thing I recommend doing is doing that with your rear risers in the case of tension knots with the rear and the brake line.
Okay. Well, moving on from the techniques that one can use in a situation where they have a tension knot, can we get into the testing on the slider that you guys have invented to try and reduce tension knots overall? I don't think we invented anything. Fair enough. So it's, it's been on the market. Yeah. I mean, we're, we're selling something that is a little different from what's been used before, but it definitely wasn't our idea. One of the things we learned really early on.
Is that we don't know anything, right? Like we know jack shit. Um, and it's not safe to assume that we do know anything and. The people who we tried to learn from who thought they knew everything turned out they didn't. So we learned from their mistakes too.
Um, and when this started happening, we just, you know, Assumed we were starting from zero and we started looking for answers elsewhere And one of the clear things that was happening in the defense and aerospace world was multi grommet sliders Like there's very few very large complicated parachutes that only have four grommets and this is one of the reasons So the first thing we did was we isolated The break line group so that we could sort it out, sort of, you
know, strain it, separate it from the CD line group as a slider is descending. Yeah, so the, the most common tension out we see is break lines interacting with CD lines. So the goal is to separate them with some amount of space so that instead of the control line orbiting around the CD line group, it can just be out in its own space without being pressed up against those lines to orbit around it. And that's the real simple idea of what the, the six grommet slider is.
Just get a little bit of space in there, try and separate them. And it has some. Sliders with more than four grommets have a long history in, you know, more complicated parachutes outside of recreational space. So we definitely didn't invent it and we're not starting from completely zero there. Um, but we did put quite a few jumps on it in quite a few situations before we sent it out into the wild. And, uh, the results have been incredibly promising, actually.
One of the first, most obvious questions about the sixth grommet slider is what happens if there is an entanglement below? The slider between the break line group and the CD cascade. And so that was one of the things we tested for. Um, another interesting thing. And again, if you haven't looked through the article that we wrote, which is online, definitely do. If you find any of this stuff interesting, cause there's some photos in it that you'll like.
I was just scanning through it a moment ago while you guys were talking. And it wasn't a hundred twists that we'll put into the break line group. It was 120 and there's a photo that resulted in the whole line group being 16 inches shorter than, um, than it was before. So pretty, pretty massive. You know, malfunctions that we were intentionally creating to try this stuff to test the entanglement between the CD line groups and the break line groups.
Um, we started taping those line groups together and what the six grommet slider sorted through was really impressive. So yeah, it's looking pretty good for sorting that shit out. Right. Another way to look at it, like from that idea of. Entanglements below the slider where the slider would descend into a ball of stuff. Right? So our worry is separating out those lines that are traditionally through a single grommet is entanglement below. And now the slider basically locks it in above.
So you have a slider locked up at the top, at the bottom skin of your canopy. But we don't really see that malfunction happening with all the other lines that are in different grommets, right? Like there's roughly the same amount of space between the B's and the C's that there are between the D's and the control lines. On the bottom skin of the parachute, right? So that's how close those upper connections are.
So you can kind of think that why wouldn't those lines entangle below the slider if we're introducing something where these other lines will entangle below the slider. So there's not really good evidence that that is something that would happen given the chance. Like I've never heard of that malfunction. I've only heard of sliders being locked up with lines and tangling with other things like a tail pocket. Not with each other, not with other lines.
That's not to say it won't, it couldn't happen, but it's a, it's not a malfunction I've seen or heard of before. So hopefully that's not something that does happen in the future. What, why is it bigger? The six grommet slider is, is significantly larger than the four grommet slider previously. Bigger is better. The dimension thing, you know, this is the result of. Trial and error testing and observation.
And I actually don't want to get too far into that because I feel like, um, might be product specific and it's something that we figured out after a lot of work and beggars better. Okay. We'll leave it at that. Well, uh, moving on, can you take us through, uh, some of the information on slider gates and tailgates? Do they contribute to tension knots? Should they be used? Should they not be used? What did you find? There's two things.
First of all, there's the myth that slider gates cause tension knots and second of all There's the fact that we haven't really tested that specific configuration enough to be positive that it's a myth. Kind of seems like a myth right now There was one video that got posted on Facebook Maybe a year or so ago could be longer where somebody was like My slider gate very clearly, or my tailgate in that scenario, I believe, very clearly caused a tension knot.
And if you actually watch the video, it very clearly does not. And we also didn't see any correlation between those two things. So while we didn't do a deep dive into that scenario specifically, we don't really see or feel a strong correlation there. Um, I'm not gonna, you know, Swear on my life that slider gates have never contributed to tension knots for sure, but I'm also not afraid to use one. Is it something that you've cut out of the sliders that you're offering on new canopies?
I remember it being kind of standard on a couple of canopies that you put out and then It sort of disappeared from the later models. Sliders still ship with the anchor for the slider gate and the slider gate included But they don't come attached. You have to attach it yourself now. Gotcha. And another question on slider. Um, since you've kind of said that, uh, the slider prematurely deploying into unshaken lines is a contributing factor to tension knots.
Is there anything to be said on the, in the realm of direct slider control and keeping that slider up through a line tension? I don't know if there's anything to be said about direct slider control being used or not used when it comes to tension knots. That would be a hard thing to say, in my opinion, uh, cause I think there's like a, a sweet spot of how long the slider can stay up.
If this slider descends incredibly flat, like let's say the slider snuck down to the top of your risers before you even hit line stretch somehow, basically you've just jumped to slider down and the chances of tension knots, I think are now lower, right? You see less tension knots. slider down jumping, right? Like it's not very common. It happens every once in a while, but the prevalence of tension knots slider up to versus slider down is like huge percentage more slider up.
So there's some amount of time where it's sliders up lines are wiggling around and then the slider descends to soon. And now you've got a tension knot because the lines are wrapped around each other. before they finished untangling and then the slider came down. Now if you could have some kind of magic slider control that's not what we currently have, indirect or direct, and it was able to know when all the lines got tensioned and then descended, I think you'd be on to something.
But That's really more of a case of the difference between drag and pressure inside the canopy and all sorts of things. Um, I may be kind of rambling at this point, but to answer your question, I don't, I think it's better to use direct control and indirect control rather. So basically the primary stow, keeping that slider up as high as it can before you hit line stretch. Makes the most sense. Can you just explain that?
Can you explain direct and indirect just for anybody who's listening is getting into bass that may not know this yet. Yeah. Direct control would be a rubber band attached to the center C line, and then you take the center of the slider and you poke it through that rubber band. That holds it up against the slider stops, which are the little washers in your stabilizers. So that's as high as it can go.
Indirect slider control is also known as the primary stow that you take the first bite of line as close to the slider as possible, wrapped rubber band around it twice and stuff it underneath the tail pocket. It's called indirect slider control because what that primary stow is doing is it's stopping the slider from descending down the lines until that stow has popped out and now the lines have hit line stretch. That doesn't happen until you've.
Fully stretched out the lines that is the last stow to open up and that allows the slider to begin its descent when it's ready. It's indirect because you're not actually touching the slider whereas direct Control means there's a rubber band actually attached to the slider. That's the difference between direct and indirect.
Can you tell me, is there an ideal length for, um, the bite that you take, meaning like the bend in the lines when you stuff or you wrap a rubber band around it, is, is there an ideal length that you've guys have found that is for that eight centimeters, roughly three fingers ish. Yeah, about two and a half to three inches double stowed standard band. That's not to say we did a lot of testing with huge bites or tiny bites, but that seems to work the best. Well, people ask us why, why two?
And I answer the same way that Martin Tilly answered me 20 years ago. He's like, because one's not enough and three's too many. Rubber band technology hasn't changed. Not really. Do you, do you think that the weight of the slider contributes in any way? To the hike up. Yes. And for the descent down, I don't know. I think it would have to be a drastic weight difference to make a noticeable difference, but I mean, who knows, maybe, um, we didn't test for that.
Yeah, we didn't try extremely heavy or extremely crazy light. I think, I think when it comes to small differences between sliders, the most important thing is. The, uh, size and the amount of drag. So like how much the lines can spread out and how much air resistance it has. I think that's the dominating factor. Sweet. Well, let's, let's go back to the top and kind of sum this up. Um, so, uh, first there is a great study out here. Um, we will post it on our page so that you can click it.
And, uh, it's also available on the scroll page. Um, What y'all found was, uh, some pretty interesting information about, uh, some of the precursors that lead to tension knots, but not so much any causal relationship. Um, we've gone through a couple of techniques for training for tension knots, and, uh, highly recommend that everybody take their canopy into the sky and try these out so that, uh, you get an idea of stall points and Flying backwards into the different control inputs.
And finally, um, there's now a six grommet slider on the market, which looks like it does reduce the, uh, occurrences of tension knots, something that wasn't just invented, but, uh, been used in the aerospace industry for a lot of years, um, and just adapted for the BASE jumping environment, anything that I've missed here that, uh, we want to add to, I feel like. Calling it a study might be unfair to some studies.
I switched back and forth between saying it's a study and just an article, but study sounds a little too self important. It's definitely an article. So check out the article. It's pretty cool article. It's got cool pictures too. If you're into pictures. We did put some pictures in there. Yeah, I do. I do remember the reception of it, uh, being called a study was a little iffy. Like people were like, Oh my God, was this peer reviewed? Does it have tens of thousands of data points?
Like, what are you, what are you doing out here? And like my response to that was like, dude, this is the peer review. Like we've put it out online for all of you. Yeah. It's peer review it. Do your job. You've got problems. Exactly. Oh. So, you know, we didn't, we, we did brush over and, uh, maybe we could circle back to is some of the misconceptions of, uh, like what caused it, right? We talked about fuzzy lines and we talked about twists. Was there any other factors or.
Misconceptions that were thrown around that you guys can think of. I remember years back, someone saying that we should, uh, wax our lines to make them more slick. Um, that was one of the most ridiculous ones I had heard. And I, you know, I don't want to like, I would rather go back to like what you said, as far as like, Just admitting that we don't know anything. Um, but, uh, um, those are some of, it just seemed ridiculous at the time.
So please, is there anything else that you heard that felt ridiculous or that uh, you'd like some myth that you'd like to squash? If anybody says that, Hey, this one thing is what causes tension knots. It's probably not that one thing first and foremost, right? Like it's a, it's a combination of factors that occur as a result of various things. So it's like we said, initially, if that canopy can have really nice, even inflation, right.
Cord wise and span wise, the entire bottom surface is sort of getting air. To the right places at the right moment to maintain an equal amount of tension across all the line groups from the nose to the tail. That's the first ingredient to a good opening is even tension. The second ingredient is those lines being able having time to shake out into parallel, organized groups before the slider descends. Right.
And then we want the slider to come down, not locking in any tangles at a rate that's comfortable for you. So when those things start to go wrong, we start to get. the tail inflating too late or too soon, one side of the canopy inflating drastically before the other, we start ending up with massive amounts of unequal tension between the line groups that gives them the opportunity to dance around and orbit each other and tangle up.
And if you combine that with a slider descent that is either premature or just at the wrong moment. Now we're increasing the prevalence of tension knots. We're getting more into the likelihood of having them. So it's, you know, three or four or five plus things that are happening at the wrong moment or the right moment, BASEd on how you're packing, how fast the canopy is opening and all the other random factors that are just a, a part of parachute openings.
So speaking of less lines, you guys talked about earlier, you guys developed a new parachute, the five light. Can you talk a little bit about it? The idea for the five light was the simplest and most reliable parachute design that we could possibly make. So fewer lines, lower aspect ratio, overall, more basic, less things that can contribute to malfunctions and cause problems. And it kind of feels when you jump it and it opens. It kind of just goes, um, it's really fun.
It is fun in a way that is sort of counterintuitive. It's not necessarily fun because it's agile and fast or turns great or anything like that, or has awesome flair. It's fun because it's just so dependable. And basic feeling I've been using in my sky rig to jump out of aircraft and fly wingsuits near terrain and open low ish, depending on who's listening. And that's a pretty useful tool for that. It's really nice. It's very confidence inspiring for a pseudo BASE jumps.
Before we go, I just want to thank you guys because, uh, this is, uh, your, your paper slash study has, uh, helped me, you know, form a better thought process around tension knots and how to prepare for them and what are the contributing factors. And I think that's says that's true for a lot of people. And, uh, if there's anything that we could do to help more participation, if you guys do another survey in the future, um, I hope you'll let us know.
And I hope everybody who's listening will be more open with their, uh, cases of tension knots. I know that there's been other, you know, avenues online where people are sharing information about close calls and whatnot. And, um, I think that the more people speak openly about these, the, the more information in general we'll all have, but thank you very much for doing this. And, um, looking forward to, to, to learning more from, from you guys and whatever it is you're doing, studying this.
Thank you guys for doing this. Yeah, thanks a lot. Thanks for digging in. Appreciate it. We hope you enjoyed this episode. If you have any thoughts about what you've just heard, please don't hesitate to hit us up. A big shout out to Mark Stockwell, our sound mixer and co producer. We love you, man. If you'd like to learn more about the podcast, please visit exitpointpodcast. com. See you on the next one.