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Gabo

Tension Knot

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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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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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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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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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How many jumps on the canopy/lines? What kind of lines?

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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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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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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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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').
-- Tom Aiello

[email protected]
SnakeRiverBASE.com

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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.
-- Tom Aiello

[email protected]
SnakeRiverBASE.com

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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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I would definately concur !

jon


Quote

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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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.
Looks like a death sandwich without the bread - Steve Deadman Morrell, BASE 174

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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.
-- Tom Aiello

[email protected]
SnakeRiverBASE.com

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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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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.
Looks like a death sandwich without the bread - Steve Deadman Morrell, BASE 174

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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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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

Quote


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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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.
My grammar sometimes resembles that of magnetic refrigerator poetry... Ghetto

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>>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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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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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.

- Z
"Always be yourself... unless you suck." - Joss Whedon

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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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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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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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