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So, I have done a lot of research and I did do a giant search last night to find out some information. I found tons of stuff on CWY S/L's. But my problem lies with the function of how it actually works. I have quite a few static line jumps without the CWY unit. I recently bought two of the CWY S/L's and have yet to use one. I figure what I turned up in my search was about 15 different ways to hook one up...with rapid links, cords, etc. There was way too many ways I read about to figure out which actually works the best and most simple. So since I haven’t used one of my CWY S/L's yet, I just wondered how to hook it up with some break cord to make it as simple as possible with being safe a key factor. I don’t want to get to technical about it since I don’t really like packing all kinds of stuff around on a jump to hook things up with. Any info would be appreciated, I got a cool S to get done and I would like to keep it as low key as possible and use my CWY S/L for once. Thanks.......

What is a cary with you static line exactly? Can you post a picture?

A static line setup that
opens your parachute for
low jumps but does not a
trace you were there:

Hence "Carry-With-You".

The jumper can rig the whole set up
at home with dacron line and break
cord and then on the object hook
everything up in 10 seconds, spend
another 20 minutes in my case just
double checking, and then jump

Someone will probably help the other
guy out but if not after I get home,
work out, run an errand, shower, and
eat dinner then I will post some pics.

I guess thats my ultimate question. How do you get it rigged up and have it ready in 10 seconds? It would take me a few minutes and I only have a few seconds......

funny you should ask...

i made one just the other day (took all of 5mins) and actually test jumped it this morning.

this is how i did it...

attach cwy to bridle with break cord (in case of hang-up)

get to object, tie your break cord (in my case i like to use 2 loops) through the two loops on the cwy and your bridle (after of course looping the cwy around the object.

see picture.

hope that helps!

Attached is the setup I learned. Pardon my 3rd grade MS paint skills.

The break cord breaks leaving the Rapide link on the bridle and the dacron flies of your object leaving NO trace.

Jake

Here is a picture of my take away s/l set up.

As you can see all you have to do when you get to exit point is connect the quicklink and dacron around whatever and go

i might just be paranoid, but this is why i would not use your setup.

1. the dacron is larksheaded to your bridle. if it gets hung up on the object, so do you.

2. the way it is run around the object, it would increase the force necessary to break the cord. it may be negligible, but i don't like it.

mynamebedan, similar reason why i don't like your system.

but hey, wtf do i know?

since he uses a single "strand" of breakcord, and not a loop, it should theoretically break with the same force.

the major issue would be the dacron catching on the object. if it fails to slide efficiently across the object, the dacron and the breakcord will NOT be loaded equally. it will then take more force to break the cord.

I agree with your system. My CWY SL is almost exactly like yours....Just a bit shorter. I was wondering about the rapid link set up, I have the feeling like it would hold up nicely and can see exactly how it would take 10 seconds to set up at the exit point.

The one thing I don’t like is that in a few of the photos I see that some have tied a knot in the bridle. That seems strange...I don’t know exactly the strength of the bridle and Im sure even with a knot that it would hold up... yet as an engineer and knowing rigging on cranes and the like I know that it reduces overall strength of the bridle. Plus you have a big ass knot there when you’re stuffing it away. It seems as if it would definitely be "inside" the PC as it is stowed, but i can see some chance of it snagging or holding up inside the pouch on deployment. I think if I were to put a loop there Id have my rigger sew on a small patch so as it creates a loop for SL and the such. As of this point I use the loop on the end of my bridle where the PC is attached. But like you said WTF do I know???

So on a lighter note, how could you take blitzkriegs setup and use a rapid link safely for very quick exits? Can all of these be melded together to create a super bad ass CWY setup?

The increase in the force necessary to break the cord in baseknut's configuration is not zero or negligible, it's 100%.

It would require 160lbs force on the bridle to break the loop.

PS. Thanks for the info so far, it helps to see what everyone else does.

I still don't get it. Unless you need to setup the SL in a hurry (which is not the intent behind the "carry with you") why not just string a long piece of the breackcord around the proper bridle loop, then single overhand knot it, and then run bout ends though the loop opposite to each other and then tie off ? This way when it breaks, the remaining pieces stay attached to the bridle.

seems a hell of a lot easier. And it's field tested :)

not this again...
correct on the 160 lbs.
incorrect on the increase of force.

since blitzkrieg advocated a loop of break cord, his system also requires 160 lbs. thus there is NO increase of force.

simple statics.
frictionless pulley. (theoretically)
single line on either side of the pulley.
both systems have breakcord as one line.
the other line is either breakcord OR dacron.

I do this exactly as you say, as of now and always. Thats why I have never used the CWY SL. It just seems easier. My sole intention was how to get it setup as quick as possible. This jump Im inquiring about is on a highway that is well traveled and Id need a super speedy exit. But then again no one would think about WTF someone was standing on the bridge, so I guess I could just stand and tie knots and wave to the people whom drive by.

tfelber posted in a thread a few years back...

attach a connector link to the bridle.
tie a loop using a surgeon's not to both ends of a piece of breakcord.
wrap breakcord around object and secure the ends in the connector link.
use two lengths of breakcord if you desire back-up.

it LACKS the abrasion resistance of the dacron line.
it CAN be done quickly.

THIS IS NOT A RECOMMENDATION!

everyone who questions what to do should conduct simple tests at home. others have. it will help you make YOUR choice.

ok, want something REAL fast ? after looping the breakcord around the bridle looop and tying it onto it, attach a rapide to both free ends of the breakcord. keep one rapid open one closed. When at exit connect and close and jump. Should really take a few seconds. Of course you can also use a small carabiner with a spring gate for a near instant action. Still seems easier than lugging a piece of dacron around and having to watch for fricion wear every jump.

The knot reduces breaking force to something like 90lbs. It's in poynters somewhere.

agreed. knots weaken the breakcord. (I expect my static lines will fail there.)

if the breakcord is passed over a sharp edge, the sharp edge can also concentrate stresses (like a knot) and cause the breakcord to fail early. (avoided by using the carry-on static line.)

also, the load calculations assume a frictionless pulley. they do NOT exist, ever. they definitely do NOT exist on a rusty structure. (again using a carry-on static line device "protects" the breakcord from failing prematurely from abrasion.) but IF the cord binds and does NOT slide over the object, the load will be concentrated on the shorter side. (it would suck if that side lacked breakcord...)

and let's not forget static load vs dynamic load! it is easy to find a weight the cord will support if applied slowly. yet it will fail if applied quickly.

I recommend jumpers new to static lining buy a spool of the stuff and play around with it on the ground.

I have often heard this and would be wary of using a s/l anchor point that has sharp/jagged edges (even with a dacron strop). But if you use 2 loops of break cord (1 tight - 1 loose) on your average framework anchor on an A - has anyone had any experience of this being an issue?

same holds true for any rigging material tied tight vs. loose. leaving slack in your break cord as i've seen in some static line kits will also change the breaking strength.

true.
but is that really an issue?
every system will have some slack. if nowhere else, the bridal. (and some people use short bridals to minimize this.)

when ALL slack is removed, the load hits the breakcord. does it really matter if the cord itself lacks slack? hmmm...

(if the part that wraps around the structure is tight, it will add friction and change how the system functions.)

well, yes. if you look at the s/l blitzkrieg is using as well as the one mynamebedan is using you will see what i mean. they will both wrap loosely around an object but both use break cord in different ways. blitzkrieg's break cord tie will be snug and allow no stretching...it will break when load is applied. mynamebedan's has a couple inches of single line slack(not even one loop, which will also change breaking strengh)...this will not break at the same load. personally, i like blitzkrieg's; that's the style i use. at the end of the day is it going to matter if it changes it by a pound or two? probably not, unless you have ocd...like i do.

you might be right about the small loop. I don't see it - yet. (I've also heard people use a small loop to save on breakcord, as if it were rationed.)

but I'd rather not have people blindly trust either of us. especially when it is so easy to conduct simple home tests!

This is a worthwhile though slightly retreaded discussion. OK I know the physics and knots do weaken the strength of any rope/cord etc we know this in climbing because certian knots are used for certain applications which minimize the strength reduction.

However, Wwarped's comment above got me thinking. How many static lines have y'all done? I know some of you lots. where does your break cord actually break? I almost always use a single strand piece of break cord (not a loop of BC and not a cwa system) my strand is always as short as possible with an overhand loop at each end. I like to always attempt to apply the force in a staged manner (reducing the snatch force) so in this manner the total final strength of the BC should be 80 lbs minus whatever the knot strength reduction is . . . .

HOWEVER in dozens and dozens of actual jumps (and admittedly very few non-jumping tests) it NEVER breaks at the knot? it ALWAYS breaks in the middle of the cord itself? (although its only 1-2" long) what gives? others experiences?

cheers

I made a "Carry With You Static Line"
during my FJC and sold it soon as I got
home along with the log book, manual,
and all my BASE gear.

Later, when desire over rid brains I got
another BASE rig and built my very own
"CWY-S/L" set up.

So jump #12 was a solo, urban, open,
from a new object and my first S/L so
of fucking course I spent some time
testing shit myself in the back yard.

I mean the internet is great and all
and sure I love all you guys a lot but
my life and legs definitely deserve an
hour of futzy around.

At the time I had a heavy duty vinyl
covered cable running between two
trees. I tried a few different set ups
and each time broke the cord twice.

I'd do a pull up, hook it up, and then
would just let go the first time. Second
time same thing except I would ease
down until the cord was under load and
then let go very slowly & smoothly.

All of them worked, all of them broke,
and of course the dynamic loading of
falling a foot before the cord got the
load made it break a fraction of a
second faster.

If anyone is interested I would be very
happy to sell you one of my special*,
home made "Carry With You Static Line"
setups for only $12 plus shipping

Disclaimer: I only have 3 static line jumps

shit. I just tie the p.c. attachement bridle loop to object with loop of break cord. Never thought or entertained it increased break force to 160 lbs.

Clearly anywhere from something a bit less than 80 lbs to something a bitr more than 160 lbs works just fine. When I SL without a pilot chute I use a loop so there is a higher required break force because I'm scared.

I still am curious though where do people observe the cord to break? at the knots or along the length of it?

Middle on all my tests & 3 jumps

Anybody got a setup which does not involve fingertrapping and sewing, neither machine nor skills here to do it....

Can you tie knots?

Kinda the same way you'd tie your shoes...

Tie some break cord to the object and then to you loop at the end of your bridal. This is how Ive done it for years. Ill sell you a CWY SL if you want one. Fingertrapped and all.

You can make your own tool
to finger trap line and then just
for that extra safe feeling throw
a dozen stiches in by hand.

No special tools or machines.

Oh, to make a fid to finger trap
all you need is some thin wire,
like the kind used to hang a
framed photo or similiar.

you make it sound like fingertraps hold themselves
is that what you are saying ?

Cuz I'd be damned if I trust a fingertrapped piece without some zigzag or bartacking.

David brought one already fingertrapped and ready to go for you last weekend. I'll bring it to you this weekend if your not working or passed out Friday night.

Hey. That "take away" looks familiar except for the way you have it hooked up.

Not that it will probably ever hurt anything, but the way that you have it hooked up the rapide is left hanging on the end of the dacron once it breaks, and the break cord itself may contacting the object rather than the dacron. I like the rapide attached to the knot in my bridle so I know I don't have a length of dacron with a little weight on the end swinging around back there trying to catch stuff. Kind of like detaching your RSL before cutting away a two-out so you don't have the RSL shackle swinging around and wrapping up your lines.

But I still made you hold the pilot chute just in case I was wrong, didn't I?

Yes.

If I remember correctly the length of
line that needs to be finger trapped
to ensure it holds is equal to 10 times
the diameter of the line, in this case
more/longer is better.

It works like chinese-finger-cuffs, when
you pull hards it holds, when you push
the braid of the line together and pull
nice and smooth it comes out.

Now since I am a big pussy of course
I also use some stiches on my S/L to
make sure everything stays put.

I've done two sl jumps with two sls, short and long, attached to a carabiner with an overhand knot on each end. All four sls broke at the knot.

Carry on SL with fast attach feature and double break cord in primary breakcord :) what elso do you need, just put you PC on and CYA :)

FTF !!!

Here is my attempt to answer your question directly:
http://www.basejumper.com/...Static_Line_252.html

Here is a diagram that I had archived at some point or another. You can hook up the CWYSL to your bridle before you get to the object. Then all you have to do is loop it around your anchor point and complete your system with a carabiner or link. That should get you to your desired 10 sec rigging at the object. In the diagram the Red and Blue loops are break cord and they are drawn in huge loops so that you can see where they go. You will want to tie them tight. Also the break cord in Blue is there in the event that there is a snag and it doesn't release from the object. I noticed in one of the other diagrams they had girth hitched it to the bridle. The CWYSL should have slack in this piece so that it doesn't take any load from deployment. So if that break cord ever releases at that point of connection you can know that something snagged and you probably saved yourself extra wear and tear.

yes. exactly like that :)

I don't mind leaving my static line on my A's and B's. ( not on the object, but it flies around when broken).

It's a message for them: daddy was there


And makes it simple.... just 2 knots for me.

Seeya.
Andrezao.

I keep it simple. break cord is cheap as shit. Just tie p.c. attachement to object in loop, yep, 160 lbs sounds safer to me. What could be left behind?? Why is time such a factor to tie a knot. I do not see the utility of a complex system to worry about...
Signed,
old, flat and stable, warm fuzzy velcro lovin guy( with an apex DP in production...)....to make me feel younger!

Agreed.

The biggest benefit is reducing the risk of a premature breakcord break due to a "sharp" anchor point. Instead of leaving a bit of runner or something else behind, you can "carry-on" that bit.

Your set up is black fucking death. You are going to have a piece of 750 Dacron wrapped around an object that is for all intents and purposes permanently affixed to your bridle.

My break cord never breaks at the knot...

Break cord is made to be used as break cord, not a static line.

The benefits of a carry away static line setup are five fold:

1. Heavy duty static line wrapped around object itself that is resistant to abrasion - I use 750 Dacron.

2. Fast rigging - I can close a rapide link in like 5 seconds once on the object.

3. Seperation of bridle from the object

4. Allows all break cord rigging to be clean and tight - I dont know how you wrap break cord around a steel girder and tie it to your bridle nice and tight and clean without risking the integrity of the break cord itself against any rough spots on your tie off point. I want my break cord loops to be VERY snug.

5. Most of the time it allows you to leave without a trace. Sometimes they do hang up though which is why it is important that the "carry away" part be affixed with break cord and not a rapide link or a larkshead which will cause a hang up and a 90/120/180 off an object that you have next to no seperation from (see #3 above)

I also dont like systems where the rapide link around the break cord - I believe there is a chance that the link's threads could abraid the break cord, it can be pinched when it is closed in a hurry - a couple scenarios I can think of that could once again weaken the integrity of the break cord.

why?
it is hard to do a static line setup without slack, somewhere. what difference does it make if there is/is not slack in the break cord loop?

It's the same reasoning as why you "short tie" your bridle or plain use a shorter bridle...

From what I heard and
my own feeble reasoning:

Shorter Bridal = open sooner by feet

Shorter Break Cord = open sooner by 1/2 an inch

Am I wrong here? Please comment!

Oh, and when you get a chance 1108 can you
PM the reply to my recent voicemail message

dude, you just pulled a Sangi.

Yo Blitzkrieg,

I like the new term you coined:
"you just pulled a Sangi"

However, I made a statement,
not a question... Plus my S/L
setup was self made, tested,
and jumped - works just fine.

Thanks.

Please explain, cause I know you
have a lot more experience and
maybe my thinking is flawed.

3-5 wraps electric tape. I prefer 3M because it handles cold weather better. And..... I'm a cable monkey so it is always in the work van that i take to most of my jumps. And, it can be left behind on an A and no tower jockey will ever know that it was from a jumper and not a worker. keep it simple...... suckers

come here to show me how to jump with that tape, we have - 10 to -30 celsius... :) hahaa...you can borrow my 52" for that try ;)

FTF

You shorten the bridle to lessen the snatch forces on the break cord so it doesnt break prematurely.

Snatch isn't neccessary on a static line, although it's great before and after...

-30C!!!!! at least it'll be nice dense air to fill that 52 after the tape snaps.... Way too cold to tie knots or turn a rapide link, in that case- I love low FF's and occupied (heated w/elevators) buildings in the winter.

lesson learned last time: "open your rapid link before you climb!, then you only have to close it" ;)

With a longer static line there is more chance you will have it break by dynamic vs static force.

With that said I wil and have use use longer cord (6" - 12" of total Break cord) down to 150 ft with no issues...

I wouldnt do it in here http://www.facebook.com/photo.php?pid=235704&l=25835&id=672241601

i mean icy metal could have some sharp points or something

point taken... object dependant

150 feet of break cord seems excessive

bumped.......

is making a CWY static line out of 400-lb dacron as opposed to 600 or 750 black death, or will it simply wear out quicker?

It will wear out quicker.

It's actually a little bit better from a technical standpoint, because it will fail earlier and act as a better failsafe point to protect the canopy from damage.

thanks tom. since this discussion is a bit older, i must ask - has anyone had any close calls/serious issues with premature breakage of the breakcord when using a CWY setup, configured with one short and one long straight piece of breakcord, as in this shitty picture i made with paint?

also this is assuming that your bridal is attached to the CWY at the 4' mark (and disregard the bridal attachment method since everyone has their own opinion on that one)

cheers

nob, the other way round, your CWY setup will need a force of approximately 320lbs to break if your anchorpoint (eg. railing) is assumed frictionless, and a lot more if its a rectancular shaped, maybe rusty piece of metal. friend of mine ripped a bridle with a setup like that.

see attached pictures of a better setup

 are those 2 straight pieces of breakcord from the bottom of the CWY to the bridle? or is it one loop? its hard to see
thanks for the info

Friction's a bitch :) Just to emphasize what you said, that setup (the paint one, not yours) is bad, it has been used and it has damaged equipment. Do not use it!

gotcha. im not super farmiliar with the dynamics of climbing anchors and shapes and im assuming that they relate in this situation..........
im gonna talk to the BASEr's at the DZ next weekend and learn me some shit
cheers

Can you explain why?

I'm only seeing 160 pounds of force necessary in Transient's setup.

Assuming that's a loop of break cord in your setup, I see the same 160 pounds necessary there.

How does friction change the breaking load? Wouldn't the break cord break before any sliding of the anchor takes place?

It's three loops.
Two different sized between the dacron and the bridle.
And one between the white CWY-part and the bridle.


And I also advice you to not use the setup in your picture.
Unless you need the PC as a windsock, because that works great! Jump, open and you have a windsock behind you.
Inspecting the gear after the jump is rather boring though

no, its not about sliding, friction affects static forces aswell...
the point is, to lift a weight off the ground (-> therefore apply a certain force to it) is way easier if the rope is going over a roll with no friction, than over a climbing hold. even before the weight is moving anywhere, and the rope actually moves, you need to apply a lot more force.

next thing is, that if you apply the breakcord on only one site of the SL setup, there has to be 160lb on that side to make it break, therefore also on the other site, so you end up having double the force on the "stem" of the whole system.

the bitch with friction is now, that friction force depends on area (constant in our case) and the "weight" that presses the object down on the surface we are trying to move it to. so loading a 900lbs dacron piece with 320lbs and trying to move it on a rough surface is already a bitch, now we need more than 320lbs since it wouldnt break here, now we got 400 and friction is even more, so we need a bit more that also heightens friction force again, and there you go, easily ending up needing more than 500lbs and then one will hit the point where a 900lbs square weave 1" bridle is giving up if you put a knot in it (as most of us do for staticline jumping). all that happened to a friend of mine, bridle ripped straight at the knot, whole SL setup was still up on exit, anchor was a rectangular piece of metal, breakcord still in perfect shape, pc and everything still dangling there...

try it out, get a SL setup like the one in the picture and set it up with E-thread on a roll and on a climbing hold, and youll see that break force triples or even more...

Please explain why.



I don't understand. Can you explain what you mean?

Why? I don't understand how a single strand of break cord creates a 160 lb breaking force on that side.

Can you please explain?

My understanding is that the loop in Transient's system (loop of Dacron) doubles the breaking force of his break cord (to 160 pounds). But the loop in your system (loop of break cord) will do the same thing. Won't both systems yield 160 pounds of breaking force?

> no, its not about sliding, friction affects static forces aswell...


???

I'm really confused.

If there is no sliding, I can't imagine that the friction coefficient matters at all.

Until the system moves, how can the coefficient of friction between the two surfaces matter at all?


> try it out, get a SL setup like the one in the picture and set it up with E-thread on a roll and on a climbing hold, and youll see that break force triples or even more...

I will do that. I'm having a lot of trouble imagining that it will change anything, but I'll try it out.

sorry for being unclear, im always using loops, therefore the thing thats supposed to break in my setup needs 160lbs.

well theres 2 different types of friction, static and kinetic, static friction plays a role since you have to cover it before any of the applied force reaches the other side. (other way round, if a put a pullscale with a string tightly to a rock, i would have to overcome the rocks static friction before any of my applied force reaches the scale...)

another picture that maybe helps attached, imagine a piece of elastics instead of the breakcord (loop of breakcord kinda stretches aswell, knots get pulled tight, has to be stretched to be actually broken,..). so in order to stretch the rubber on the right side you actually have to overcome friction on the anchor to do so.
another idea to explain this, if friction would be very very high, that thing would never break/stretch and you could load it until the stem would break...

The problem with a system where you have a loop of e.g. dacron with break cord on one side like the one drawn by TransientCW is that you're looking at it in a way where you load that loop equally on both the dacron side and the break cord side. This is not the case in reality. Best case scenario, equally loading each side, 160 lbs to break single strand. Worst case scenario, only loading dacron side, bridle breaks, or only loading break cord side, 80lbs minus the knots etc. BASE is about eliminating variables, and that CWY set up creates a very variable state.

Ok. I will build a system and experiment with different friction surfaces at the anchor.

Can you explain why the friction will change the breaking force required in Transient's system but will not change the breaking force required in your system?

It's not?

The loop is loose at exit, and slides down tight when the jumper exits. I'd assume this means that it will load very close to evenly across the two sides at the point it breaks.

I need to review some of my slow motion footage of breaking systems. I have it on video hundreds of times and I don't think I've ever seen a noticeable difference in the loading of the two sides. But it's been a while since I've gone through them frame by frame, too, so maybe I'll find something different than I expect when I review the video in depth.

because i basically use the breakcord in the "stem" of the system, so even if theres theoretically infinite friction (like its tied to the object and doesnt move at all) i still got 160lbs of force on the "stem" -> my bridle -> my breakcord...

What you need is better data. Your videos are of little value, I'm afraid, unless one of them actually depicts gear damage, in which case I guess we wouldn't have different views on this :)

I actually have two good videos showing system failure, which is what I used when I arrived at the system I presently use (which is different from the system Transient showed). I consulted with some statics engineers (from the climbing field), reviewed the video and gear damage, and came up with the system I presently teach.

I'm always interested in designing a better system, though.

I jumped with a guy whos break cord didn't break. Luckily his CWY did.

I thought the previous posts was obvious enough, but ok.

I jumped a static line system as the in the picture but the breakcord did not break. My bridle broke where the knot was (the knot stayed at the B) and left about half my bridle and my PC at the top of the building.

Maybe it was bad luck, but the one Hirshi has picture of seems like a much better design.

The load at line stretch is very great. There are numerous components that will fail at that loading. I think it's basically impossible for the jumper to hang from the object. If the break cord doesn't break, the carry on cord will, and if that doesn't break the bridle will.

The question is engineering the system to (a) reduce the chance of gear damage; and (b) direct the gear damage to the least expensive components if it does occur.

Do you think the failure was due to friction at the attachment point?


Thank you for elaborating. "Don't do that because it sucks" is a lot less helpful than actual descriptions of failures and thoughts as to the causes.

Do you have any ideas as to real word numbers for the "additional load due to friction"?


Transient's system uses a single strand of break cord, not a loop so it will only be 160+friction in your diagram. I wonder what the magnitude of the "+friction" is likely to be.

Yes I believe it was friction.
There was no other damage to any other part of the gear.
The dacron had some fraying, and I guess that was because of the force it had to take.

i tried a few times with E-thread, and found that the resulting force needed to break it is 3 times the force to just break the fuse itself...

i will do a few more test pulls here and will post here. wheres that guy that had access to the pull force machine to do it with 80lbs breakcord?

Gauleyguide jumped with a guy whos break
cord didn't break. Luckily his CWY did.

Yep, our first jump from Ruby, I miss her.

So I took Tom A's course in 2006 and was
taught his older CWY method, then came
home to the Florida panhandle where I
was the only BASE guy for a long while.

Jumping solo, often without ground crew,
and being older/bigger/injured my ladder
climbing skills took years to slowly grow;
hence I have done 70-80 static line jumps
with different kinds of setups and methods.

I ALWAYS use break-cord but now ONLY use
a pre-rigged CWY if I am doing a low jump
from a stealth object in low light.

I have video of my current method, which
has evolved with experience, maybe this
week I will edit the footage and share it,
if anyone is interested.

please do tom, im interested. the whole reason i dug up this thread is because i watched todd's apex video in regards to setting up a proper static line (in their opinion), but the only problem is leaving something behind on the object....

This is what I use. wwarped showed me this on a jump once...

-Tie a loop in the middle of your bridle. I use a figure 8 because it is easier to untie once it has been shock loaded.

-Use a small quick link rated at 220 lbs, Lowe's for around a buck, and attach it to the loop in the bridle.

-Take a length of break cord and tie a small loop in each end with an overhand knot.

-Place the small loop of one end of the break cord on the quick link, close the gate and let the other end hang there until you are at the exit point. Simply wrap the free end of the break cord around the rail open the gate, insert small loop and close gate. Check your shit. Jump.

You leave nothing behind and the system is simple. Less components to fuck up.

Unless you have to tie off on something with an edge to it. Then a dacron CWY comes in handy.

Negative. I have jumped off of "A's" that have Ice shields/platforms that have angled tie off points. I simply tie a longer piece of cord on as a back up. Jumped it like this many times. Never had an issue.

Some people will swear their method is better. Others will be haters. All in all, it's up to you to decide. The way I do works well for me. I'm comfortable knowing I don't have a CWY that "could" get hung up, or not break away, peeling the top skin off my canopy. It's worked on a whole bunch of jumps. It's clean and to the point.

So why introduce a quicklink? Why not use break cord tied direct to bridle? Tying a knot or closing quick link is about the same amount of time at exit point?

Not hating just asking.

No, the quick link is much quicker. Although, if you could tie the bridle and the cord together somehow...

ok. heres my thoughts, cause this is a good issue. first, youd want more than one attatchment point (not just for cwy, but all sl's) so avoid premature breakage and putting any work at all on your pilot chute. one in the middle of the bridal, and one on the end near the pilot. second, you dont want the break cord on the object, ( to avoid any cutting or premature breakage before line stretch/tension) youd want the dacron on the object, and third, the only place Id put my rapid link is on my bridal. this way, the link is flying around on your bridal and not extended from your bridal after the jump. seems cleaner and more organized to me. when you get to the object, everything would be ready, all you have to do is slip the dacron on the link, double check and look it over and jump. aslo, Im thinking break cord surgeon knot on both ends, one on link, one on dacron. when you jump, no trace would be left, your dacron and link would be on your bridal, and the halves of your break cord would be on both the dacron and the link. check my attatchment. Im no artist but you get the point.

Seems twice as likley to have a hang up. Personally i wouldnt want dacron direct to bridal incase of hang up.

dacron is not direct to canopy

I used to teach that technique.

I stopped using it because I had to replace the bridles a lot more often, because they were picking up friction burns from the object. The 24" piece of dacron was much cheaper and easier for me to replace than the whole bridle. Although, now that I have the ability to make bridles on site, maybe I should re-visit that technique...

How did you set that up?

almost finished product, need to bartack everything, and shorten the top part a bit to make sure the link clears the top of the railing/object. link is 220 lb rated so if all else fails and the CWY gets hungup, it SHOULD fail before my gear does.

i feel good about this setup, now its time to test it

also thanks for all the info and PMs from everyone

Looks nice, but very long.

Are you SURE the link will break at 220 pds? or is that the work load. Tested to break at 1380 lbfs?

Exactly.

Chris, that link aint breakin' dude.

What does it matter if the link brakes or not? There should anyways only be brakecord between the sl and the bridle.

Because he mentioned that the link was a back-up. Get off me, homey!

2' climbing strap sewn shut in the middle leaving two end loops. Bridle uses 2 loops, load is half on each rather than all on one loop. Two different length single-strand break cords. Neutrino biner hooks up quick with little possibility of error. Setup is pretty bombproof but with extra snag points. Pick your poison.

I'm using the identical method as Gauleyguide. One pice of break cord for non-critical SL's and 2 pieces (One longer than the other) on super low jumps.

If I know i'm planning to SL I do the same as him as well. Pre-set the quicklink on the bridal so when I get to the exit all I have to do is wrap the break cord around the object and put it into the quicklink. I actually carry a pre-made one strand and quicklink setup in the tiny pocket behind my shoulder strap. I have it with me on every jump for that, "Ahh shit.. this was supposed to be much higher than this!" moment.

Simple, clean, straight forward setup that's difficult to screw up and leaves nothing behind. Used it on materials from smooth tubes to rusty angle iron on the handrailing of those all too famous red and white freestanders we all love so much. Never any problems.

I personally think that using a dacron is a much much safer option. I see how damaged my dacron static lines are and am pretty sure that if I would have used only break cord it would have failed on me many times. (e.g. rusty, damaged or sharp railings)

I don't know from what heights you guys jump SL but I had few jumps that if the SL would have failed the best scenario would be smashed legs, which means SL is the only way to survive the jump.

In any case I always tie the SL AND the back up with break cord to bridle. This way you don't have to worry about links or any other hang up problems tearing your canopy/bridle. Just go look for SL or make another one.

I have designed, used, tested, and video'd
maybe a dozen different styles from just a
single piece of break cord to elaborate Y
straps made of dacron, para-cord, sewed,
carrabiner'd, snap linked, quick linked, and
or lark's headed on to the bridle...

A few sucked and a few were simpler/cleaner
than the rest but honestly, they all worked.
This is one of the easiest areas of BASE to
examine because you can do it repeatedly
on the ground.

For Example: Todd of Apex BASE

My current M O for lazy day time jumping:
always carry 2 pieces of break cord, 1 piece
of old canopy line, and a couple rubber bands
in a snack size zip-lock baggie any time I am
packed slider-OFF or slider-DOWN.

The old canopy line is tied around any rusty
sharp anchor if necessary, the break cord is
tied in two places, middle + end of the bridle,
with the slack s-folded and contained in a
tail-gate band with the PC held out of the
way by a longer office style rubber band.

Benefits: no metal, super light, very clean,
and as close to 100% reliable as they come.

Cons: it takes a minute, light, and practice
to properly assemble; leaves a small loop
of old line at the exit point

I now only use CWY's when jumping some
dark stealthy object where leaving z e r o
trace means we can return & enjoy again.

I can't view the video, but if it's the one where he drops a weight attached with BC to a bridle, that setup is flawed as it fails to account for the change in acceleration (and thus kinetic energy) over time when the system gets loaded. Not saying the conclusions made are wrong though, but something worth testing is worth testing right.

I am not saying Todd's method is the best
just showing how easy it is to try different
set-ups on the ground till each jumper is
comfortable with their conclusion.

I ground test mine by tossing a dum-bell
then test-jump them from 315 feet in the
day light with video. That is how I have
come to my personal approach to SLing.

You lost me here.

Acceleration is constant, provided by gravity. The time from exit to load is controlled by the length of the bridle, which is what Todd was demonstrating. And the third factor is mass (canopy + lines or simply pin tension). Todd was talking about dynamic load, aka momentum. The product of acceleration, time, and mass gives you momentum. Acceleration is constant. Todd controlled for time (with the bridle). And the mass is dependent on your canopy's mass and how much pin tension you're rocking.

I thought Todd's experiment did a pretty clean job of demonstrating how too much available bridle (i.e. 9 feet) in the system can result in premature failure of the break cord, as the accelerated mass of the canopy can cause cord failure before line stretch.

Todd didn't demonstrate anything about CWY devices.

Did I miss something?

Also, here's a functioning link: Mad functioning link!

~ Chris

and exactly here is the flaw in that demonstration, because time is not only controlled by the lenght of the bridle, since it the peakforces are a completely different thing if you drop a 1 lb rock on a string, or a 1lb of stretchy foam.

therefore dynamic deformation/stretch must be accounted for.
so the right way to demonstrate it in the video would have been to drop a packed canopy onto a bridle instead of a bag of sand.

So wouldnt a bag of sand " hit" harder, then a canopy? (proving this method is safer for a canopy)

What Todd proves is shorting bridle will encounter less of a dynamic force, making sure you get to line stretch before break cord seperates.

Its not rocket sugery....

Peak forces? Peak forces occur at line stretch in our game. And Todd's demonstration was specifically that conventional static line setups can fail WAY before peak forces are achieved.

I agree that if we're talking about truly balancing the equation between momentum and impulse that we have to account for the elasticity in the system. But I don't think Todd was trying to be Stephen Hawking. I think he was trying to show that a SCARY LOW amount of weight reveals a failure mode in a common static line methodology.

We're not peer reviewing physics papers here. We're trying to disseminate life-saving information. And when people hyper-criticize what I think is an elegant demonstration of the risk, we erode the credibility of the message by highlighting that the experiment was not in keeping with all tenets of the Scientific Method. And I don't want people thinking, "Oh, that Todd didn't properly account for the time dimension in the equivalency of momentum and impulse, and therefore I'm just tying off the old-fashioned way."

But we should certainly criticize an experiment if it leads to wrong conclusions, wrong advice, or if it proposes certain actions outside of their proper context/use.

Earlier in this thread, a link was posted to a video that clearly demonstrates what Todd is warning us about: We saw a static line hold fast while pins were extracted and the moment the bridle was taught against the attachment point, the mass of the bundled canopy broke the break cord. The lines were still paying out. The canopy was still neatly folded. That's a REAL WORLD example of how little elasticity there may actually be in a conventional pack job.

So we should ask ourselves: where does our personal system 'equal' five pounds? Is it your pin tension? Is your bridle stuffed under your flaps a little too much? And we've all seen clamps left in packjobs. Would that be enough to keep the canopy bundled past break cord failure? Are the four corporate logos on the canopy just enough to make a difference? We don't know! So in the context of our game, the length of the bride DOES equal time.

I'm simply being argumentative because we shouldn't discount Todd's message when he was clearly demonstrating one lateral limit of the system.

~ Chris

ive seen BC break right when canopy is lifted off the back of the jumper.
and im with todd when he advises people to keep the slack bridle between jumper and anchor as short as possible to prevent premature breaks.

i just wanted to correct you since you were bringing accelerations, momentums, mass and times in here, that this interpretation of it was flawed.
im taking back my critizism for todds video, because:

- either keep it simple, which todd did, and he proved a point without the audience requiring a physics phd
- or do it in an "accurate scientific" way, but then you have to do it like that and not just use scientific terms while oversimplifying the whole problem.

and yes, im totally aware that the biggest peak is at linestretch, although if you would draw the force over time, there would be a peak right where the canopy is lifted off the container.

Agreed!


Good point.

~ Chris

PS - Thanks for all the wonderful learning material you post on your site! Great stuff.

In my opinion (and I think this is what Sebcat is thinking of too, as we have talked about it) the Apexway is perhaps not flawed but not perfect.

In the video the following is told:

Tieing on to the end of the bridle is dangerous as it breaks before linestretch.
At half the bridle is much better.
Two loops will fail (or break) at the same time, so one or two loops doesn't matter.

But then setup they use have one loop at half the bridle (good) and one at the end of the bridle.
So... If the loop at the end of the bridle WILL fail, what's the point of having it there?

Scenario:
First loop at half the lenght of the bridle is damaged/worn, you jump and the first loop prematurly breaks.
What will then happen? The second loop at the end will not work, as the tests show, so you end up with a "let go PCA" and not a static line.

Using two loops at half the bridle might help this scenario because the other might be in good condition.
But I agree with Todd, two loops in good condition will break at the same time.
But thats because it has reached it's tensile strenght, not because it "failed". If you need it to fail at a higher force you need to rig differently.

So... Conclusion.
I say it's not flawed. It most likely works but the logic in the video is a bit off in my opinion.

However, there is much less dynamic load on the loops at the end at that point because your pins should be popped from the first loops and you are already pretty much to bridle stretch, so that last loop at the end of your bridle is only holding the weight of the canopy as your lines are being extracted from the tail pocket. But I guess thats only if your pins are popped.
Still, I agree, not perfect.

It controls the pilot chute and remaining bridle. i.e. not dangling below you, or flapping off in the breeze somewhere, and possibly getting entangled on the object.

at least, that's why i would do it.

http://www.watchthybridle.com/2012/01/cwy-staticline/

Hell Apex put it out there even how to hook it up....(sweet you can buy it from them too)


I dont know why everyone wants to complicate this,

Its freakin break cord !

tie it and jump... and if you dont have time to tie a knot at exit. You shouldnt be jumping it!

[quote "Huck"
I dont know why everyone wants to complicate this,

Its freakin break cord !

tie it and jump... and if you dont have time to tie a knot at exit. You shouldnt be jumping it!



Amen to that!

I'd prefer to spend as little time at some exit points as possible.

Plus, if you tie the break cord around the object, it can catch an edge and break prematurely.

the nice thing with this setup is, if one anchor point should fail, you still have a backup. and you still dont leave no trace.

also, once you're on the object, it's just a matter of connecting the lines with the carabiner and off you go.

 
Just buy it from Apex. Watch the youtube video too, to make sure you know how to operate it....
http://www.youtube.com/watch?v=AKb36rd3_wo

buy all three sizes, you dont want too much dynamic force building.

What happend to KISS.

What happend to KISS

Really who is confused at this point??
Probably only guys/gals who have
never done a static line jump...

Seriously, how many static lines have you ever done?

Seriously, how many static lines have you ever done?

I would have said 50+ but after a quick glance
at my digital logbook it appears I have done 36.

I dont know everyone and their respective jump numbers, this is a 5 year old thread and there seems to be alot of confusion. You have people complicating a simple thing. We have to dumb everything down. Now we have a manf selling and giving out 'trade' secrets. I think alot of experienced S/L's are confused.

out of your 36 S/L ever have one you coulndt tie a knot at exit point?

I personally jump alot of s/l in cold weather. No way am i going to tie knots up there, if i don´t have to. I use the version some linked from watchthybridle and it really is simple. But something might be simple to someone and same thing can be complicated to an other one, so i agree with the KISS but the KISS isn´t same for us all.

Huck,

I know this thread is old, I am not confused,
nor I am responsible for people complicating
or simplifying how they choose to static line.

I've personally tried a dozen variations, all of
them using break-cord (no tape/condoms/thong)
They all worked, some better than others. I am
not for or against any method that uses break-cord.

There are definitely a few stealth, dark, low, urban
objects were you need to have your S/L already
set-up and ready to simply attach and jump!

You have 36 SL jumps and you have already tried dozen of variations? Which means that you have on average 3 jumps on each one? If all of them work, why not just stick with one to simplify your setup? Why take the extra risk of having a new system every 3 jumps?

I've done my fair share of static lines and am proud to say I have never used any break cord of any sort. Just fucken tape that shit.
But then again, I also believe that most people are fags who static line objects that somebody else would readily free fall :-)

I had previously used a CWY SL setup for a fairly long time... then it went missing so I began just tying off directly to the object.

Recently I was hanging off the side of a a shitty 170ft freestander right next to a highway in a compromising position trying to tie off and thought, damn, it'd be GREAT to have my CWY anchor again...

But I agree that it can be done simply and repeatedly w/ break cord only.

I also see some flaws w/ that bungee bridle test with the weight. The way a canopy is folded acts very similarly to the bungee itself... By no means should a canopy be accurately simulated with a solid 5 lb weight.

Yes, I tried several subtle CWY variations,
dacron, paracord, spring link, rapide link, etc.

In the end it was just basically a loop with
the weak link being made of break-cord,
or rotting underwear, whatever you got.

I have come to prefer and use 2 methods:
a) simple tie knots style for day time jumps
b) a pre-set CWY for special urban jumps

I think this thread is dead... most experienced
guys are already convinced of their own method
and newbies have little to no experience to share.

I don't have a lot of S/L jumps but after doing a little research and watching videos like http://www.youtube.com/watch?v=U8-dcw8Vy6o and http://vimeo.com/34468248 I am changing my approach to them.

I guess it all comes down to your level of comfort.

Do you clean the tape up? Or leave that chore for the cops to handle?

A good carry on system is much faster than tape.

FWIW, I have done several static lines from active highway bridges where time really was critical and fumbling around with tape (or tying knots) would greatly increase exposure to bust.

I've always cleaned up my tape afterwards to prevent it piling up. 1 piece really isn't going to draw any attention, 50 might.
I think it's ridiculous that people believe a piece of tape or some left over break cord is going to be what tips off the cops to you jumping an object. I mean seriously, that few inches of tape I left behind on that 20 story construction site couldn't possibly be there for any other possible reason than those damn BASE jumpers.

I was more thinking that the hundreds or rolls of left over tape might be something that irritates them enough to stake out an object.

But you'd never see jumper leaving hundreds of rolls of tapes on a single bridge railing, right?

Never Those soft fuckers should be free falling it

Edit to add: That is hardly the norm though and is for sure an extreme example. However, I still don't see it as any reason to go running to the opposite extreme either.

The big reason to use a carry on system is that it's faster at the exit point. Road bridges in particular can be very time sensitive. I also prefer to do as much of the rigging as possible beforehand, in well lit and relaxed conditions.

i prefer to take a PCA from a competent jumper/friend.

even simpler, just someone has to sit it out... usually not hard to choose.

for the next six months that'd be you, right!?

sheeeeeet, if i can get out of a car on my own... i'm in.