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Tension Knot
Hello All
I just wanted to share these pics of a friend of mine who had apparently a tension knot on a Bridge jump last week and after this an object strike , it was a slider up jump with 4.5 seconds of delay ,he didn´t have canopie control and he had a slight left turn ,the canopy was sinking very fast .
My friend was lucky and landed on a bush without hurting himself.
The pictures are not high res. cause they were taken from a video.

If anybody has a similar experience please share .
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Re: [Gabo] Tension Knot
An object strike on a bridge? Not may out there have done that one. Glad to hear he's O.K. I wonder. Is there an object strike numbering system out there simular to the BASE number system? If so then this guy got the hardest object to get.
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Re: [KevinMcGuire] Tension Knot
Hey Kevin
My friend was jumping from one of the the towers that hold the tension cables above the road, it´s a 670 ft jump .

See you soon Kevin,

Gabriel
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Re: [Gabo] Tension Knot
Hey Gabriel
Help me out here. I'm just trying to
compile some Knowledge for my Brain.
Might come in handy Latter.

I have only seen, Three different jumps
with tension Knots.
They Two were slow spinners.
One progressively got faster on decent.

All were Slider Up.

On the last pic.
He is pulling hard on rear Riser. so the C & D lines
are distorting the bottom skin, so hard to tell exact
Lines.
This one looks like the slider made it all the way down.
* Lucky Boy *

Which, Lines were involved in this ???
Was the knot still in after Landing ???
Hard to tell from Pics.
Looks like it was up high.

Also did he un-stow his Toggles ???
Or just attempt to control Spin with Risers ???

Thanks... Ray
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Re: [Gabo] Tension Knot
How many jumps on the canopy/lines? What kind of lines?
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Re: [RayLosli] Tension Knot
Hey Ray
It was a slow spinner as you say ,also he was trying to control the canopy but didn´t have enough time to unstow the brakes , the problem was that after he landed safely on top of a big bush with many branches and such we had a hard time getting the canopy untangled from the bush , so after that we couldn´t see the tension knot or anything wrong with the lines , as you say on the last pic the slider finally is all the way down but the canopy wasn´t flying it was sinking fast .
I checked the canopy and found nothing wrong so I jumped it (over 7 times now) and it worked fine , this is a canopy that has no more than 30 jumps so it is almost new , the lines are also in good condition .

I think my friend was lucky ,cause he didn´t have scratches or bruises after that .

Be safe

Gabriel
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Re: [Gabo] Tension Knot
Thanks for geting back to me.
That is to bad you could not get the Knot
on a visual inspection after landing.
Tension knots are just plain scary.
There seems to be no rhyme or reason.
The few I have seen, Canopies were old and
New.
I was Sabia's roommate in Malaysia when he
Had that, Knot and a Spinner. I watched him
hook up that canopy up a couple nights
before. It was brand new, just out of the bag
from B.R.
Freaky shit !
Don't want one.
There is somthing to be said for No
Slider Jumps. Seems that less is more.
Never heard of a tension Knot on a No Slider Jump.
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Re: [RayLosli] Tension Knot
Hello --

This thread would be a good time for me to bring up a theory that I have.

I've been using direct and indirect control on every slider-up jump for the last 4 1/2 years. It is my opinion that direct control may help to prevent tension knots by ensuring the slider is not released until you have full tension/line stretch. Once the lines are tensioned, the slider will travel cleaner during this part of the deployment phase. In theory, it may reduce your chances of a tension knot.

It's all about staging the deployment...

Bryan
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Re: [KevinMcGuire] Tension Knot
In reply to:
Is there an object strike numbering system out there simular to the BASE number system? If so then this guy got the hardest object to get.

As far as I know it's only up to BASE strike #1. Span strike was a pillar strike similar to this one.

I know of one other span/pillar strike. It's on one of the Aussie videos (BE, I think?), when they launch a 4 way from some silly low altitude (I think it was less than 200').
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Re: [bps] Tension Knot
In reply to:
I've been using direct and indirect control on every slider-up jump for the last 4 1/2 years. It is my opinion that direct control may help to prevent tension knots by ensuring the slider is not released until you have full tension/line stretch. Once the lines are tensioned, the slider will travel cleaner during this part of the deployment phase. In theory, it may reduce your chances of a tension knot.

It's all about staging the deployment...

I agree. It should be noted, however, that direct control can noticeably slow the opening, so if you are in the habit of pulling low (by BASE standards, I mean--so more freefall than canopy time) you may want to pull a bit higher as you play with this.
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Re: [bps] Tension Knot
I've been using direct and indirect control on
every slider-up jump for the last 4 1/2 years.
>>>>>>>>>>>>>>

Most definatly Direct Slider Control is the
way to go.
I use Direct Slider controle and my own
personal mechanical habits. On all Slider
Up jumps. from 450 ft. to Big wall .
Have worked on Direct stow for several hundred
jumps. I am a firm believer.
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Re: [bps] Tension Knot
I would definately concur !

jon


In reply to:
Hello --

This thread would be a good time for me to bring up a theory that I have.

I've been using direct and indirect control on every slider-up jump for the last 4 1/2 years. It is my opinion that direct control may help to prevent tension knots by ensuring the slider is not released until you have full tension/line stretch. Once the lines are tensioned, the slider will travel cleaner during this part of the deployment phase. In theory, it may reduce your chances of a tension knot.

It's all about staging the deployment...

Bryan
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Re: [jonstark] Tension Knot
Brake lines can easily twist and therefore enhance the chance of a tension knot. These lines should be untwisted with care while walking each one from the tail to the keeper ring. A twist on a single line can have enough energy for the line to spontaneously form a loop or coil and hence drastically increase the probability for a tension knot.

On an uncertain side note, I have thought that maybe applying (vegetable-grade not petroleum based) silicone spray to the lines will decrease the chances of a tension knot by increasing the slickness of the lines. There is minimal risk to adverse consequences of doing this.

I agree with Ray regarding some form of slider control. I have had two different malfunctions resulting from slider up entanglements/tension knots, but was able to fix them before impact.
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Re: [460] Tension Knot
In reply to:
Brake lines can easily twist and therefore enhance the chance of a tension knot. These lines should be untwisted with care while walking each one from the tail to the keeper ring.

Hmmm. I do this as standard practice on every pack job. It hadn't really occurred to me that perhaps some people do not.

Gabriel, do you know if this practice was part of the packing of the rig in question here?

I could easily see how twists could build up over time (you see it in skydiving canopies, if people don't untwist the lines). If they weren't straightened out, and greatly increase the potential for this kind of malfunction.
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Re: [TomAiello] Tension Knot
Hello
Yes the lines were not twisted in any way , I personally checked the packing , hwat do you mean by "direct slider control"? I leraned to pack from a Mexican friend and everything was in Spanish and I don´t know what that means, can you explain ?

Thank you
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Re: [Gabo] Tension Knot
There might be some variations in the semantics or definitions, but:

indirect slider control: using a locking stow at the base of the tailpocket before stowing the lines. This stow can prevent premature slider descent if the tailpocket fails and dumps the lines too early.

direct slider control: usually means taking a small "bite" or section of the middle of the slider and stowing it to a rubber band attached to the center C or B line. The jumper should be careful doing this since stowing too tightly can dramatically affect the speed and heading performance of the opening.

direct slider control #2: stowing a bite of the brake lines to a rubber band attached to a tab attached to the rear tape of the slider. i use this on terminal jumps with good results - heading is great and opening speed is fine.
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Re: [460] Tension Knot
Thank you .
On this jump It was with the indirect slider control , the direct slider control I have only used it when I have more than 8 second delays .

Gabriel
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Re: [460] Tension Knot
In reply to:
The jumper should be careful doing this since stowing too tightly can dramatically affect the speed and heading performance of the opening

>>You're not kidding. It's easy to give yourself a coronary watching your canopy snivel snivel snivel while you go "oh god oh god oh god!" Makes for a soft opening tho', but I've learned to start small with it and work up till you find a bite that works for your system

In reply to:
direct slider control #2: stowing a bite of the brake lines to a rubber band attached to a tab attached to the rear tape of the slider. i use this on terminal jumps with good results - heading is great and opening speed is fine

>>Never heard of this, how big of a bite do you take for your particular setup? Ever used both methods of direct w/ indirect at the same time?
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Re: [ZegeunerLeben] Tension Knot
I use both.

I have a half small rubber band (same as tailgate) attached to both of the inner C line attachment points. Usually I will take a small bite of slider into both rubber bands, say, about 1/2 inch. Double or triple wrap it. I forget whether it's 2 or 3 wraps but I'm nearly certain I use 3. While packing I just go by the tension.

To test what it takes to release the slider, just pull it out of the rubber bands. It doesn't take much much force at all.
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Re: [hookitt] Tension Knot
 
>>Thanks for the info Tim! I tried one inch and it was too much, 1/2" worked better for me as well. Have you ever tried taking a bite of the brake-lines as well when using direct control as 460 suggested?
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Re: [ZegeunerLeben] Tension Knot
No. But I have used 2 single wraps of masking tape. It also works well as a make shift Tail Gate.

I didn't make that up, many I know do that.
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Re: [hookitt] Tension Knot
In reply to:
To test what it takes to release the slider, just pull it out of the rubber bands. It doesn't take much much force at all.

True, but the force that the canopy (via the suspension & steering lines) exerts on the slider is going to be more lateral than downward isn't it?

So would the addition of resistance to downward motion have a significant impact of the lateral force necessary to free it from the stows?

I don't know the answer... just thinking out loud.
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Re: [Zennie] Tension Knot
Well, yes.. however, think about how much force that opening canopy will exude.

I'm not a physicist or anything but my spider sense tells me it's alot.
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Re: [460] Tension Knot
In agreement with 460, A note on Brake line twists; A twist in the lower makes for twists in the upper 4-5 cascaded lines also. Dynamically, the twists will manifests themselves on the lighter loaded lines which would be the outer lines. Which brings up a point that many of these scenarios happen and clear but still leave obvious signs. How to check? Look up or down the lines (laterally), one by one before the pack job, as opposed to to looking at it in a perpendicular angle. the obvious burn marks will stand out like a sore thumb, will be melted on the ends of the severed fibers, Check em.
Thanks 460 for bringin that up!
have fun,
take care,
space
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Re: [hookitt] Tension Knot
HEY.....I been working a lot with the masking Tape and the Break Lines.
Also on Direct Slider Control.
I dont know about you but Tension Knots and Line-Overs
Scare the hell out of me. If you have either one you probablywill not die, but just get Really F##ked UP.

NOTE : These things are only my personal Mechanical Habits.
There are many ways of doing things.
These Mechanical Habits have been refined over my
7 years and 691 BASE jumps.
.* And my not be Kosher for everyone's Taste. Read it,
throw out what you Don't like, Keep what you like.
Or Disregard it all together.
***Also my mechanical Habits are constantly growing and changing
over time. That means that I am still learning.
This is what I am doing Right Now.
* To keep control of those Break Lines on deployment.
* To keep control of that Slider. To promote a Firm line stretch.

> Rape tape around break line cascades
> That is with 1/2 inch paper masking tape.
> Large Hole Mesh Slider.
> Vented Canopies both with valve and with-out.
> Never roll the Nose of canopy for any pack job
Slider-Up or down.

Examples of what I been using ....# of rapes of tape.
1.- 2 rapes on short objects slider up 450 ft. 600 ft.
like delays of 3 sec. (low air speed)
Small amount of direct slider control, Only.
42 inch pilot chute

2.- 3 rapes for delays of 5-10 seconds
Good bite of direct slider control, Only
38 inch pilot chute.

3.- 4 to 5 rapes for big delays ? like 18-20 sec and up
Good bite direct slider control + Primary stow in tail pocket.
32 inch pilot chute.
I do not roll the nose. I even rape the center cell nose around
the pack job. I do not get hard openings at these air speeds
even with a large hole Slider. and Vents.

I am finding out that the opening force when the Tail bangs open
is Extremely, Under Estimated. Look what happens if you don't stow
your break setting properly on packing. (you blow your break lines)
* If it Can Do That. I also think that it has the force to do a lot more than
that if given a chance.
A logical guess would be that the Break lines and there upper cascades
would be whipped through or around the other lines on, deployment and
opening. Maybe a possible cause for a Tension Knot, or Line-Over.

** Also, the Rubber-band for Slider Stow, is on the opposite in-board C line than that of of the Tail Gate. It is set for the optimal Bite. For the Height of the Slider when set to the top of the line-set for deployment.
All sizes of canopies are going to have a different height for the Rubber-Band stow. On the in-board C line. in relation to Slider Height .
* * If you take the Tail-Gate off and use that spot for your Rubber
Band stow. I find that it is, To High of a Factory setting for a
Proper Slider Stow. ( make a custom setting for your slider) for that
particular Size and Brand of conopy.

*** I do not use the Mesh of the Slider in the Stow.
I use the Reinforcement Tape, (that is around the perimeter of the slider.)
when making the stow for the Rubber-Band.
Both Front and Back of tape on Slider.
The mesh does not touch the Rubber-band. It is folded inside the
Tape.
The tape is folded with mesh inside, then folded over.
WHY.....
** The Mesh when used for the Stow is Bad **(in my opinion)
It Rolls out of the stow on opening and is not very consistent.
It Rolls and burns the hell out of the Rubber-Band when it gets
yanked through it on opening.
*** My reasoning behind This***
* The Reinforcement Tape around the Slider is much more of a
Consistent surface texture. Mesh is Not. Grab it and just pull
through your hand.
.
That's what I am looking for is Consistency in Slider Release.
With control.

Does anybody have the perfect formula ? I think not.
Never Had a Tension Knot (yet), but have seen on video, on two
of my openings in the past of a line over starting, then cleared
by it self. also My pack jobs are immaculate. -Scary shit.
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Re: [RayLosli] Tension Knot
In addition to the direct and indirect control that I use, I too have started to use masking tape on the control lines. I've been doing 1 1/2 wraps of 3/4 inch masking tape about two inches from the top of the control lines. I've heard of others doing this, and then started doing it myself after watching some of JJ's openings at the Potato Bridge using the same set-up.

I only have 40 jumps (+/-) using the masking tape, but so far I'm very happy with it.

So for now, I use indirect control, direct control, and masking tape on every slider-up jump I make. Like Ray, I'm always learning, and therefore, always changing what i do...

Bryan
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Re: [Zennie] Tension Knot
In reply to:
True, but the force that the canopy (via the suspension & steering lines) exerts on the slider is going to be more lateral than downward isn't it?

Actually, I suspect that it would be downward.

Look at it like this: As the canopy hits line stretch and the lower surface of the canopy begins to spread, the 4 grommets will be spread apart until the slider is fully tensioned and all four grommets will be as far apart as they can go. It's this action that pulls the slider out of the rubber band. Assuming that you stowed the apex of the slider in the rubber band, the force will be a downward pull rather than lateral.

Bryan
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Re: [bps] Tension Knot
Quote:
True, but the force that the canopy (via the suspension & steering lines) exerts on the slider is going to be more lateral than downward isn't it?
.............................................

It is Most Definatly Downward.

Bryan, dont be afraid of using more wraps of tape.
No joke, Try it.
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Tension Knot
Another tension knot video,,seems like there is a lot of people that have them recently. I wonder why....

http://www.vimeo.com/22397324?ab
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Re: [TomAiello] Tension Knot
TomAiello wrote:
In reply to:

It's all about staging the deployment...

Tom, what are your thoughts on using a tailgate on SU jumps? With all this talk of masking tape and wrapping lines, it seems like some are using a makeshift tailgate. I talked with a jumper whom I respect, and has over a thousand jumps, and he uses a tailgate on SU jumps and has never had a problem with the tailgate hanging up the slider. I believe he jumps with direct and indirect control and tailgate for SU jumps and has tested this set-up so many times that he feels that it is safe.

If anyone else wants to share their thoughts, info, insight, please share. Thank You
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Slider down tension Knot?
Thread revival to keep the discussion in one place.

How many slider down tension knots have you heard of?

We had one at the Croatian S recently (guy compensated with other toggle and put it down in trees without incident)

Canopy was brand new, no twists in brake lines and tidy line stows...

Apparently Yuri K had one back in the day.

Others?

Prevention:
-Change old hairy lines
-Untwist brakes
-Stow lines neatly
-Keep red tailgate lines on 'top' of primary stow bight.
-Lubricate lines with silicon
- something else?

I hear about tension knots slider up quite regularly (a few each season..)
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Re: [unclecharlie95] Slider down tension Knot?
I had another thread, and a spreadsheet going.

Spreadsheet:
https://docs.google.com/..._EzGcQSfM/edit#gid=0

Another thread: http://www.basejumper.com/...ost=2977381;#2977381

Video of a few (from the spreadsheet): https://vimeo.com/74722519


My black lines are noticeably more "tangly" than my white lines.
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Re: [base698] Slider down tension Knot?
Nice work on the spread sheet.

So we need to add Marta, Domenico, Jill, 3 recent ones that spring to mind.. Karina also
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Re: [unclecharlie95] Slider down tension Knot?
unclecharlie95 wrote:
-Keep red tailgate lines on 'top' of primary stow bite

Spelling nazi here!
"bight", not "bite".
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Re: [unclecharlie95] Slider down tension Knot?
unclecharlie95 wrote:
Thread revival to keep the discussion in one place

Prevention:
-Change old hairy lines
-Untwist brakes
-Stow lines neatly
-Keep red tailgate lines on 'top' of primary stow bight.
-Lubricate lines with silicon
- something else?

Yes! I think you have missed the most important aspect of all,.... Keep Tension all the way from the risers to the D lines in each group of lines (A, B, C, D ). I have been jumping crapped out, fuzzy, Dacron lines for over 30 years in Skydiving, and 25 years in BASE and have never had tension knots except on certain Tandem rigs with Dacron lines, that somebody else packed. How often do you encounter tension knots on anything other than Dacron? Sloppy packing probably accounts for that.
I believe that being " anally " attentive to line tension will exclude all tension knots. Just a personal observation and opinion.

Regards, B.
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Re: [StealthyB] Slider down tension Knot?
So my interest in this is who has had tension knots in base (slider up) with non-dacron lines? Anyone?
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Re: [base698] Slider down tension Knot?
im really interested in getting this discussion going again...

i added one more slider down tension knot i witnessed 2009 (dont know the exact date anymore)

StealthyB wrote:
How often do you encounter tension knots on anything other than Dacron?

i know of at least two, i will check with the jumpers involved about more info and add them to the sheet.

some time back i tried to find as many videos of tension knots that i could find to get a better idea on what knots up and where.
i found that:
- all involve brake lines
- at the height of the brake line cascade
- knotting up with C/D lines
- most involving far out C/D (pulled in stabilizer)

since those seem to happen at the brake cascade height its at a point of the line that is stowed inside the tailpocket. so i would be really interested to see what exactly is going on there and why. anyone able to reproduce this on the ground?

so any more ideas besides the ones listed by unclecharlie and packing nice as stealthyB proposed?
the indirect stow rubber band possibly also has a role in this, since it could give way to inner lines easier than outer ones. (this is why stane once explained to me that one should double wrap it to hold the whole bunch of lines a bit tighter)

moving the location of the brake cascade? make shorter, or maybe longer splice in lower brake line at cascade? changing the design of the brake cascade to some continous design not involving looping the upper cascade to lower brake line, but haveing one continous line and splicing the others into that? using spectra for upper brake lines? lubricating especially the brake lines?
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Re: [84n4n4] Slider down tension Knot?
84n4n4 wrote:
since those seem to happen at the brake cascade height its at a point of the line that is stowed inside the tailpocket. so i would be really interested to see what exactly is going on there and why. anyone able to reproduce this on the ground?
I was always of the opinion that it was due to the drastic difference in line tension on opening. Brake lines are short and take a whole bunch of load during opening where as your D lines are the longest in the lineset due to canopy trim and the last to take any load. So I have always believed that as the brake lines load up it pulls the cascade into the D lines causing the tension knot. Why slider up? Because the inflation phase is longer (relatively) allowing for more interaction between lines and the slider grommet keeps the lines in close proximity to each other during this phase increasing the chance of interaction.

84n4n4 wrote:
so any more ideas besides the ones listed by unclecharlie and packing nice as stealthyB proposed?
I always make sure I clear the control lines above the slider as well as below.

84n4n4 wrote:
changing the design of the brake cascade to some continous design not involving looping the upper cascade to lower brake line, but haveing one continous line and splicing the others into that?
This could also contribute to tension knots due to the stiffer multiple finger trapped cascade. It could also introduce other problems as we know brake lines are a high wearing line and finger trapping causes wear points.
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Re: [84n4n4] Slider down tension Knot?
I read or heard somewhere that a guy had found all tension knots he knew of to happen at the cascade, and as a result he made his brake lines all separately attached or cascaded or something like that, which created a smoother transition from one size bundle of lines to the larger size including the cascaded brakes (aka one line at a time)
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Re: [CF36] Slider down tension Knot?
84n4n4 wrote:
since those seem to happen at the brake cascade height its at a point of the line that is stowed inside the tailpocket. so i would be really interested to see what exactly is going on there and why. anyone able to reproduce this on the ground?

I started looking for solutions to tension knots some years ago. There was a belief that the 5th control line was the generating factor. At the beginning it didn't made sense, and I wanted to understand the mechanics behind. From all the data I manage to collect - I reached the same conclusion : tension knots happens at the brake cascade height, with a C/D line. If not all of them, at least the large majority. To this day I still haven't heard about or seen any tension knot not involving the brake cascade. I don't believe the knot forms in the tailpocket, but more likely later when the whole lineset is still slack and suddenly gets tensioned when the bottom skin starts to expand. High speed footage of this particular instant shows very chaotic line configurations, rather than perfectly clean spindles of lines.

But what's exactly a tension knot? From the topological approach of knots, we can only make trivial knots or "unknots" as long as we don't open the rapid links and rig the canopy improperly. As opposed to non-trivial knots, this configuration will clear itself when the lineset is under tension, all the lines being parallel to eachothers, following the easiest straight route.

The simplest form of a tension knot is basically a loop around another loop (illustrated below). If we tension the outside line (white) first, it traps a bight of the inside line (red), but when the red line gets under tension the knot usually untangles.

But a tension knot shows the capability of staying locked. And this stable transitional configuration can be obtained if we introduce a rigid part in the line forming the inner "trapped" loop.

The second image is showing an example of a real tension knot between a line and a brake line at the cascade level..it now becomes easy to get a configuration that stays locked as long as it is under tension. The knot will untangle only if the outside line (white) tension is released. Hence, releasing the brakeline with WLO's will not undo the knot, and pumping on the riser won't help either. But cutting the C line could actually solve the problem.

Back to the rumor about the 5th control line inducing more tension knots. We can easily change the "lockability" of this junction by changing it's rigidity or bulk. On some canopies, the upper brake lines are made of 600lbs dacron and the 5th brake line is looped inside the top loop of the main brake line, adding a 3rd loop inside the junction. This results in a very bulky junction, way easier to lock inside another line under tension compared for instance to the classic config of 4 upper lines made of #525.

To make an analogy which would show the same extra volume, imagine changing a C-D line on a canopy. If instead of fingertrapping the D inside the C, we make a big figure 8 knot to bind the 2 lines together...wouldn't it look like a recipe for very unfortunate results?

So far my conclusion is that the factors impacting the ability to form a stable, locked trivial knot between two lines are :
- length/diameter ratio of the lines
- flexibility
- friction coefficient

And all this lead to the Outlaw brake line design. The goal was to keep constant characteristics all along the lines, avoiding the classic configuration that shows 2 bulky, rigid parts, separated by a free moving articulation.

I'm expecting this design to solve the tension knot problem. By solving I mean reducing the occurrence by an order of magnitude - I'm sure there will always be one of these Australians to prove me wrong out there!

So now we only have to wait a few years to have a statistically meaning sample and we'll know if all that is just bullshit Smile
01-trivialKnotMorphology.jpg
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03-BrakelinesConfigs.jpg
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Re: [Lucifer] Slider down tension Knot?
This is very interesting.
Could it be something to do with the slider grommets - as if, as the slider comes down, it is putting pressure on the lines within the grommets and causing knots?
Whereas with the slider down all the lines normally just spring away from each other instantly.

Perhaps the slider coming down the lines is causing slack to bunch up then release once it's passed, which is creating an environment for knots to occur.
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Re: [Lucifer] Slider down tension Knot?
Lucifer: Damned fine post and illustrations! Thanks.
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Re: [Lucifer] Slider down tension Knot?
Perfect. That's exactly what I was referencing with the lines in your third picture.
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Re: [Lucifer] Slider down tension Knot?
Lucifer,
I was going to thank you for your post but I cant because, well, you're the devil and the devil is exactly what causes malfunctions! DaVinci knew this hundreds of years ago and is the reason he didn't further develop his parachutes. He wanted to wait until the devils of the time had been beaten back by the forces of good which unfortunately was not within his lifetime. The forces of good have prevailed since then but evil is always lurking, awaiting it's opportunity to strike, but you know this don't you Lucifer?! Oh, DaVinci also didn't believe in steering lines because he felt steering a canopy was for pUsSies!
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Re: [84n4n4] Slider down tension Knot?
I think Tension knots are foremost due to huge slack in the D lines. The Slack is more the deeper the Brakes are set*. I have seen some slow mo SD deployments where Ds and Brake lines are wrapped like Hell with one another and clear possibly only thanks to the huge forces of the SD Deployment. The Slider makes the lines-separating forces smaller/more parallel...
A possible mod I might try is to wrap Cs and Ds(from each row individually) above the cascades with one wrap of blue painters Tape(don't have the balls for more wraps). Brake line involvement is what makes you spiral so .. some blue shit there as well..Smile and.... ..."blue tape black death!"Tongue ... but if you are willing to try first I'm just as willing to bring some Go Pros, Bier or PainkillersTongue

*I still think that deep enough(witch is good) or too deep(witch is not good) brake setting with a nasty TK will result in a stall you cant recover from. An thats whats scares me about TKs most.

some thoughts?
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Re: [kiwibaser] Slider down tension Knot?
One of the slider down knots was using a wrap of tape.
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Re: [base698] Slider down tension Knot?
Where?
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Re: [kiwibaser] Slider down tension Knot?
The moab one in the spreadsheet.
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Re: [base698] Slider down tension Knot?
So you are meaning she used Tape instead of a regular Tailgate for a slider down. I didn't suggest that.

I meant Cs with Ds from each row for SD an SU and/or maybe some tape on the brakes cascades for the SU. Taigate for SD as usual.

.. I know too much tape..

Disclaimer: not a Suggestion just brainstorming

I mean whats the best way to separate Cs and brake lines during the deployment? C/D-cascades and brakes-cascades are the ones with most slack in the deployment, no wonder they always play a role in TKs
any thoughts?
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Re: tension Knot
I have attached 2 more photos of tension knots for those that are keeping track of them.

They both happened at KL Tower in 2013. Both slider up.

The first one is similar to other tension knots discussed here. The person spiralled all the way in. Fortunately he swung out over trees on the last turn, rather than impacting on the road.

In the second photo you can see the canopy deformation at the nose during opening on a night jump, but does not show much else. The A line attached to the center cell was found to be melted while it was being packed the following day. The tension knot (or whatever was happening) cleared about 4 seconds after opening after the person pumped the brakes.
Tension Knot 01.jpg
Tension Knot 02.jpg
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Re: [Gary_C] tension Knot
At the first photo you can see.. well no C lines playing any role at the TK, but you see all sort of lines locked at the brakes cascade level. I think that if the brake lines at the cascade level are intertwined they make loops. If any other line passes through that loops as soon as brake lines get loaded and spread this extra line will get trapped..

.. what if you tape the 4 brake lines together at several intervals.. it could prevent other lines getting in between...
Untitled.jpg
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Re: [kiwibaser] tension Knot
I guess it highlights the importance of having a decent primary stow on all jumps. Good line tension before the lines start to separate is a must.
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Re: [Lucifer] Slider down tension Knot?
Thanks for the fantastic post lucifer!

One would hope that manufacturers will start to implement the finger-trapped design that the outlaw has. It seems pretty clear that the brake cascade is the main issue.
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Re: [Zebu] Slider down tension Knot?
Who knows what other unforeseen issue that will cause. I'll wait a few years. It seems good now but you never know until its been in the wild.
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Re: [Zebu] Slider down tension Knot?
Recent one from Lauter. No Injury. Looks like the brake line looped around the line group at the height of the cascade. No injuries.
tensionknot.jpg
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Re: [FrankieB] Tension Knot
Yeah anyone else keen on the SU tailgate?
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Re: [unclecharlie95] Slider down tension Knot?
wonder if people still untwist brake lines when there packing these days :)
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Re: [MBA-PATTO] Slider down tension Knot?
well... thats just a silly idea, brake lines never get flip threws or twists when you pound into a corn field under no moon @ 2am and shove your gear into a bag while giggling like a 5yr old girl.... no need to untwist Tongue
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Re: [udder] Tension Knot
udder wrote:
Yeah anyone else keen on the SU tailgate?

Many many people use a tailgate for slider up.
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Re: [hookitt] Tension Knot
What about wrapping your tailgatelines into the slider? Seen it a couple of times now.
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Re: [Absolut] Tension Knot
That's a slider gate and not as popularly used these days because some believe it causes off headings.
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Re: [base698] Slider down tension Knot?
base698 wrote:
Who knows what other unforeseen issue that will cause. I'll wait a few years. It seems good now but you never know until its been in the wild.

+1
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Re: [udder] Tension Knot
I almost sniveled in once using a tailgate slider up. If you use one I recommend not making it too tight.
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Re: [themexican] Tension Knot
themexican wrote:
I almost sniveled in once using a tailgate slider up. If you use one I recommend not making it too tight.

Did you capture all the usual lines? Inner C-D lines, and Control Lines?
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Re: [hookitt] Tension Knot
Yes, usual (red) lines were in the tail gate.
I think i had been jumping for about a year at the time. I was convinced that controlling the brake lines with the tail gate was beneficial even with the slider up. My main concern was line overs (i hadn't considered tension knots). I made a few jumps with 2 wraps with a larked rubber band which went fine, i noticed no difference. Then I went to 3 wraps thinking that there would be no issue opening the tail gate with a 5-6 second delay. I remember getting stood up and just sniveling and sniveling, i realize something is wrong and i look up and the slider is stuck all the way up and i'm not decelerating any more it seems. It came down just in time.
That was the last time i used a tail gate with the slider up.
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Re: [Bealio] Tension Knot
I usually use slider gate at terminal jumps in the way describe here, more or less.
http://www.watchthybridle.com/...ct-control-tailgate/
I assume that I'd use anyway a direct slider control (little rubber at inner c lines) in any case in SU jumps (to have a proper opening sequence). So adding another one little rubber in the other c line to make a gate doesn't seem to affect the on heading opening (just less than 50 jumps on this method, so not a valid statistics provided).
Anyway I untwist my control lines....just in case. And when lines start getting older, I use silicon spray (very little) on my brake cascade lines (stupid?).
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Re: [unclecharlie95] Slider down tension Knot?
Jumper had a slider up tension knot at the recent China wingsuit event.

Despite the jumper being a douche bag he managed to clear it by pulling on the affected riser and toggle (stalling canopy at one point)
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Re: [unclecharlie95] Slider down tension Knot?
So would it be better to stall only the canopy side affected by the TK?
doing that doesn't produce an aggressive turn on that side?

just to avoid wasting time with the wrong maneuver...just in case :-)
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Re: [1687] Slider down tension Knot?
Canopy was stabilised throughout with opposite brake input