Basejumper.com - archive

what method do you prefer to tie off for s/l?
ive heard of different ways, like doubling up for redundancy which sounds like a good idea. pics would be great if you had some.
thanks

3 wraps with electrical tape around the bridal on a decently strong and stationary piece of rail or metal or pole or whatever. can be vertical or horizontal. think no further, this will do.

3 wraps is not enough to be reliable - use 4 wraps at least and 5 wraps at most. Don't go around the bridle but place 2 wraps around the anchor "rail or whatever" then follow with 4 wraps thru the loop of the bridle.

Chased by security last month to the exit-point I only got 3 wraps around before I had to make good my exit -no time for the 4th wrap!!! Pic's taken of the jump showed the tape breaking before the canopy even started leaving the tray.

g.

We did about 11 "play around" test SL jumps as a group of 4 people.

We video taped the SL on every exit.

Tape Method:
With two wraps around the object, then trapping in the bridle with four more wraps - the bridle almost 100% of the time slipped under the tape before the tape broke. The slip often occurred after line stretch, but could have started before, causing uneven tension on the canopy lines after the container opens, possibly even putting you in freefall.

The PC, which was dangling between our legs, and the SL attached a few feet higher (just below hips) - violently shot up to the tape before the tape broke. We taped the bridle on about halfway between the container and PC.

I did not like the tape system at all because the PC moves so quickly and fast near the object. If there was a hook or bolt on the object, the PC could be torn or worse.

Break cord:
The jumps we did with a piece of break cord worked much more accurately - however one jumper did a double redundant system with two bites knotted in the bridle, each with it's own break cord system around the object. On exit the bridle broke the first break cord, but when the second took load a millisecond later, the bridle actually snapped inside the lower knot and left the PC on the object. There were 5 of us there, and I think there were 5 different theories on why the bridle became weaker than brake cord, even though it was on video and we have stills.

After watching all the tests - if I had a SL jump with my current knowledge (open to more knowledge) where the SL is a "make or break" - I.E. needs to be bomb proof - here is what I decided I am going to rig:

A bridle only used for SL, just a traditional bridle - but with two loops sewn onto the bridle. Attached to the sewn loop - a break cord system. I have to run to work so I can't build a sample and upload photos, but the break cord system method I tested actually had two break cords, one doubled up designed only to break if absolutely it needed too, with a piece of stronger line between the cords to go around the sharp edges of the object. With the addition of a rapide link or similar, the setup time on the object is only a few seconds, although not as quick as e-tape.

I have video proof that shows electrical tape and knots in the bridle all are less than 100% clean. Hence, a sewn loop and break cord I believe reduces the chance of failure.

I was introduced to this about 3 Months ago from a rigger friend of mine who made these and I just got to use it the other night off of a crane. It worked perfectly. You can build different sizes according to the size of objects that you are tying off to. I attached a PDF and JPEG of the system. I apologize for the elementary drawing, however, it conveys how the system works. I forgot to mention also that the the take away is another point of redundancy. If you have a hard break on the primary or secondary, the take away attachment will break, still taking the system with you.

We have used four wraps of electrical tape but also use a big loop of caution tape as a backup. Once the electrical breaks, the caution tape (about a 3 foot strip to make a loop) catches.

Overkill perhaps?

can you post the video ?

i use a similar system from southsidebase.
easy, no remains and very fast.
close the link, throw pc over the railing and your good to go. i used it two hours ago on a building.
very fast to setup.

I am familiar with that system and I own one just like it.

Just a few technicalities and comments, though:

you want to make absolutely sure your secondary break cord loop is so much longer than the first loop, that the first loop will have broken before the second loop takes any load at all

you want to make absolutely sure that your secondary break cord loop is so much shorter than the take-away break cord loop that it will have broken before the take-away loop takes any load

the take-away break cord does not have to be a loop, in fact it can be reasoned that a single strand propely knotted at both ends are preferable due to the lower breaking strength (almost 80lbs compared to almost 160lbs), which in case of an entanglement (you will have linestrecth at this point, unless your primary and secondary break cord loops both failed at low load), will probably mess up your deployment less

it is a good practice to make your primary and secondary break cord loops from different batches of break cord, I have three different batches, each a different colour, so I make primary one colour, secondary another colour, that way I highly reduce the likelyhood of making both loops from a piece of breakcord that might be flawed and will break prematurely


I have a hard time understanding what you are getting at here? The only way to take the system pictured with you is when the take-away loop stays intact.

also, this method does leave some evidence, it leaves the broken primary and secondary break cord loops

I have made a system (my own development of some other jumpers' ideas) that does not leave even any broken breakcord.
It features a primary and secondary break cord and a take-with-you break cord.
It also is streamlined in that it only drags the most snag-resistant parts of the system over/through the tie-off point.
It completely attaches to the bridle only by a rapide link and is therefore very quick to attach or remove.
The attachment to the tie-off point is very rapid and does not require any tieing of knots or tightening of rapide links .
The only reason I have not made any more of them and shipped them off to friends for beta testing is that I have only made one test jump with it so far.
I meant to do a load of test jumps with it, but almost all my regular objects are freefalls and I do like the freefall.
I guess it's time for me to go out there and do some more static lines....

PS - does anyone want to have another '80lbs vs 160lbs to break a single loop of 80lb break cord' debate?

it still leaves the breakcord as remains

a nicer way to set that system up is like this:

tie the two looped ends(of the pieces that go around the object) to the pc attachment loop on the bridle with a primary and secondary break cord loop (these things sometimes fail prematurely, so if you staticline low objects it's worth the backup)

tie the loop of the long strand of dacron to the pc loop on the bridle with a single piece of break cord (this is your take-with-you lanyard now)

you still only have to loop your loose ends around the object and rapide link them together, but you now have a back-up break cord loop and in case your system gets snagged somehow, you have a piece of break cord acting as a seperable link, that will allow the system to detach from your bridle in case of a snag (after your primary and secondary break cord loops are broken)

cya

> I use a similar system from southsidebase.
easy, no remains and very fast...
——————————————————————————————
Your system is effective but if the CWY line gets entangled with the structure, you are hanging from the object
In the system we have been using for YEARS the CWY is attached to the bridle through a (secondary) break cord loop: if everything goes smooth, you take your CWY (Carry With You) with you; if things go less smooth and CWY gets entangled with structure, the secondary break cord loop breaks, you loose your CWY but you are free to fly towards your landing.
Here are few pictures of my CWY. The green big rope is my Special Bridle (a 5.5 mm dyneema rope) I use only for SL jumps.

Hey Andrea
I still use the wery early setup of the carry on sl..

I however modifyed it so i only need to wrap arround the line to exit point,then attach the rapied link to the breakcord.I made a few whith the same "hook"/carabiner? you use but found that as it were on the werry end of the long end it tend to catch the object whith a cutaway as result.. not that it harmed me but leaving it up there wasnt a option. so i went back using rapied links again..

however see the benefit in your to me new setup.. ill build one myself,it looks smooth

Hope to meet again next year,i hate your hikes but hey

you are suposed to wrap the tape through the loop on the end of the bridle that way the bridle doesnt slide under the tape and cut it as i have seen happen. i have used and seen this used many times without any issues

980,
You are correct, the primary and secondary are left behind once broken. When I make my primary, it is about 8 inches long and tied tight enough to the bridle that it allows the link to go through. The second piece of break cord leaves about a 3-4 inch diameter loop. What is your typical diameter for your secondary? What I mean by the third cord redundancy is that the Take away line will break should excessive force be directed to the primary and secondary. Do you have any type of Mockup you can post to take a look at what you use? I am interested in the "No evidence at all" that you have figured out. Thanks.

good info thanks for that.
but usually it just dangles from a solid balcony.
is there a possibility for entanglement? on a solid surface?
i only attach it to railings and scaffoldings and always make sure there is nothing it could entangle with.
i like to keep it simple.
i'm generally not so smart

edit to add:
i just recently switched to this system and don't have a lot of experience on it.

 

1. Need just enough SL depending on size of tie-off point.
2. tie into a loop with fishermansknots or simular
3. offset knott, bring sides together and tie an overhand knott making 2 loops. Ensure they are different sizes.
4. put a link through the bridal attachment point and PC.
5. Put one end of loop in link, wrap sl around object tie off point and back into the link.
6. S-fold and rubberband the bridal

The theory is that either one of the loops will break before the other and the side that dosen't break will bring the broken side with.

To date, of the 40+ SL, I have not had this fail. Not to say it won't but so far hasn't.

I don't, but you could use another single loop (a tad longer) for backup... but hey I have only done SL no lower than 150'

> but usually it just dangles from a solid balcony.
is there a possibility for entanglement? on a solid surface?
—————————————————————————
I didn't know that YOU always jump from the same site.
My setup is GENERAL: in case of hangup, it breaks.
I generally use it from lattice structures and similar stuff, where entanglement chance is not zero.

of course not the same object. but same type. mostly.
or let me put it this way: in my very limited experience in base on my even fewer sl jumps i never encountered an object where i saw chances of entaglement. there. and i'm a very scared person.
but it brings up another thing i thought of.
i had jumps where there was some kind of little ledge the pilot chute had to be dragged over. i wasn't too worried about getting hung up, but damaging the pilot chute.
how do you do that? i thought about sewing an attachment point for the sl to the middle of the bridle(sl only bridle of course). is that dumb? i think then only the bridle would be dragged over the ledge.
of course i could run a rope loop or something over, but this again leaves obvious traces.
do you know what i mean? maybe i find a not site sensitive photo to illustrate.

Huh Leroy?
2 peices of breakcordboth tyed to the bridel then through a conectorlink?
if so your jumping 160lbs of breakcord..

why?
the setup will strech(turn on the object),therefore you´ll have double force..
that will give you a pumping canopy as it opens as it deforms too much..
Also breakcord straith on to the object is bad juju

if i got your instrutions right..

I use carry on 99% of the time(only highway brigdes so far i have used it the old way leaving a darconline up there)
I often jump A´s whith this setup.(basket whith rail and lots of stuff to hang up on)

Only place i had problems on the setup is 1 place were it keeps hanging up.. that is a rather tight and busy exitpoint through..

I'm not into any of the carry away SL systems that put the connector link through the break tape loop.

I want my primary piece of break tape to be tied tight.

I'd post pics of mine but they are too large to post here.

I am no artist so...

Now, I have not used a second single piece of SL as a backup, I am usually high enough that a large PC should work.

Hope this makes sense.

added picture and this: Only one side is breaking so I don't see that it is 160lbs breaking force... maybe if you added a 2nd single loop to the whole system?

These are not mutually exclusive. You can girth hitch a loop of break cord to the link, pulling it tight.

No mate i got your post wrong..
The setup you show gives you a breakforce at 80lbs unless there are shapedgeds on the rail
You and your gear should be ok even as i dont like the idea of tying the breakcord directly to the rail. but thats me.let me see if i can find an old SL ill upload pics over the weekend if i do,you´ll see that even 900lbs darcon line will get wear and tear from the rail.. I dont like the idea of exposing my breakcord for that..

Thanks, I appreciate the reply. It was nice that you didnt scream and yell saying your way is better. I am always about learning something new and sharing that info with others for a reality check.

Le Roy

Leroy: Could you please take a photo of your setup with the bridle tensioned and post it?

If I understand your drawing correctly, when you tension the bridle, the two loops of breakcord will slide to the same end of the rapide link, with the bridle on the opposite end.

If that is the case, then you will have 2 loops of breakcord = 4 strands of breakcord = circa 320 lbs force (reduced by the stress concentrations from the rapide link radius, the tie-off point radius and the knots) required to break that setup.

for the record, one single loop of 80lb breakcord (as used in the classic breakcord staticline setup) requires around 160 lbs static force to break, as it has two strands, each strand takes 80 lbs force to break. If you have trouble believing this, please do some practical tests, for me a really easy one is to set a single loop breakcord staticline up above my head height, then connect a loop of 1" wide webbing to it with a rapide link (where the bridle would usually go) and I can pull myself up completely off the ground on this if I do it slowly. I weigh 168 lbs.

Will take a pic once I get home, but...

the above is correct



That is static force, why you don't talk about dynamic force requried to break? I am not sure that it scales as such... maybe?

Further explain, because not all 4 strands break... only 1. Usually the smaller loop. I have had a couple break at the overhand knott, though.

When "compared" it does not "feel" like it takes that much more force to break. ( I know that is scientific, but...)

All of my SL's (40+) are usually done on my BJ rig and I see no signs of wear and tear.

I weigh 160 without gear.

ADDED: Note that the I start out with a piece of SL that is no longer than 10-12"

I remember discussing this a while ago on dropzone.com with all the fun equations and stuff. When it comes to loads on break cord, static force does not equal dynamic force. A static line base jump is not modeled by static loading, it is modeled by dynamic loading. Holding yourself up if you weigh 168lbs is not the same as applying a shock (dynamic load) of 168lbs. Not even close.

If I'm ever able to get some time on the large force gage in the lab I work in, I'll get some exact numbers. I doubt it'll be anytime soon though.

I also don't see how the radius of the rapide link or tie off point have anything to do with when the cord will break. Maybe if they were extremely small, but it shouldn't have any bearing on any practical use.

The dynamic force, or actually kinetic energy, is the key.

Anything with mass and speed has energy, and it requires a certain force over a certain time to stop the moving thingy. By increasing the time you can apply less force. Imagine catching a falling egg, if you don't flex with your arms the egg will break. With a SL setup you can increase the time it takes to transfer the kinetic energy that the falling canopy has, onto the SL setup by having some strecthability from the canopy attachment point to the rail you tie off to, which should make it less likely for the break cord to break when the canopy is pulled out of the container. But still when reaching line stretch the same force is needed to break the cord => not increasing the force on the bridle attachment point on the canopy.

I'm getting some climbing rope that I'll do some tests with. Or has anyone tried that already? Results?

I never said it did.


agreed


agreed also and again I never said that it was the same

usually after giving the demonstration where I hold my weight up on the single loop, I break a single loop simply by swinging my arm through a distance of about 1 metre while holding onto the webbing loop that goes through the rapide link

I do this to illustrate the difference between static and dynamic load.



that would be interesting, but not really neccessary

the reason I mentioned the static load strengths is that the break cord commonly used is rated at 80lb static load strength

the standard setup uses a single loop of this, I believe this procedure was derived from the way the military uses it for static line jumps

this setup has stood the test of time and the only improvements that have been made are the addition of a backup loop (prompted in some cases by reports of premature breakcord failure) and some of the carry-with-you setups and it can be argued that the carry-with-you setups aren't even really an improvement

based on this, we can safely work with static load strengths to evaluate whether a new setup or variation will give us less or more force before release, as compared to the classic single loop setup

the actual dynamic load that the breakcord fails at isn't relevant, as we know that the classic setup is about right (from empiric evidence)

so there is no real advantage to increasing (or decreasing) the force required for release, as both ways lead to increased risks of failures of the system


I only included them for the sake of completeness.
Technically I should have said the radius of the cross-section of the rapide link.
Agreed that they will have very little effect unless they are extremely small (= big stress concentrations).

Let me know if you ever get those dynamic load numbers. Some structures fail at a higher load under dynamic load than static load, especially if the dynamic load is applied rapidly enough.

I agree with you on this Sam. From the drawing it appears an equilibrium point will be reached where you will have four pieces of SL between the link and the attachment point on the object. It doesn't matter if only one strand of the SL breaks, it still requires four times the force. On top of all that there is no redundancy in this setup. So either the drawing is incorrect, Leroy did say he wasn't much of an artist, or I am misinterpreting the setup.

I left the bridal and PC out of the picture.

Note quite sure about everything else, but I will say that I "feel" more comfy using my setup than a single loop or even a single loop with a larger backup loop.

I am no scientist but I think that if i had 4 single equal loops, or even 4 loops of gardually larger sizes, that it would need greater "force?" than the setup I use to break. Hell I would even rough estimate that it would need half the force....

I may be missing somthing, but in my setup there are only 2 loops that pass through the link, not 4...

I will take a REAL picture in a short while.

Real picture added... (forgive me I only had an old skydiving PC available..

After reading the last couple posts I think I understand what they were saying.

I was thinking the single loop was onestring, whereas it has "2 strands" inbetween the object and link...

So where does this leave us (me)? I now know that I have 4 strands....

so 1 loop = 2 strands... simple = 80 static lbs

therefore

2 "loops" in my case shoudl equal 4 strands.. should be 160 lbs...

In anyevent, this setup works for me, leaves nothing on the object, breaking force doesn't feel much more than a single breaking loop...

I will most probably stay with this setup, unless I get a convincing argument

1. why it is bad.
2. how is is worse than a single loop?
3. other reasons..

all without saying that I already agree that a real carrywithyou SL might be better,
BUT not simpler... somtimes simpler may be the better choice.

So I ask is it?

hey guy's thanks for all the good info. i made my first 160 ft s/l jump last night with a take away system i built from the ideas in this thread. the jump went perfectly! huge rush!!!! police arrived as we were getting in the car, put the spot light on us to see 2 guys with HUGE smiles across their faces and just kept on rolling by. wheeew!
so THANK YOU everybody.
peace
j

So you Built a SL system from postings you read on the internet and then test jumped it from 160ft?

yes i did. its possible to build something of this type and be able to know for sure that it is going to work. the reason i chose this design was because its very fail safe. as long as the materials do not have serious flaws the system i made and used was no more dangerous than tying off directly to the rail. as long as my finger traps and sewing where correct there is no way this could have failed. i also had another rigger double check my work. i feel confident in my decision for myself but i do understand your concern.

If you take one strand of break cord and load it gradually it is rated to break at 80lbs. If you take two strands it will break at 160lbs, and three and so on. When you loop the break cord you are effectively creating a pully system that multiplies the force necessary to break the cord. Knot's and tight radius loops decrease the breaking force necessary so it's somewhat less than the rated 80lbs. The dynamic loading you create when you decrease the amount of time you apply the force over, as the load suddenly changes from near zero to 160+ lbs as you hit line stretch also decrease the magnitude of the force necessary to break the cord.

The real problem I see, which is the dangerous issue, is there is no redundency in your setup. Once the break cord breaks, wherever that may be, no more force is applied to the bridle. The secondary loop is a backup for if the first loop breaks prematurely for whatever reason. Let's say you accidentally snag the bridle with your arm as you exit with enough force to break the first loop but luckily clear it before you load the second loop or a rough surface on the structure cause the break cord to fail at less than enough load to extract your canopy. Now the second loop will apply the force to extract your pins and canopy and save your life.

As for enough force, I believe it is tried and proven that a loop of break cord, which has a static breaking force of 160lbs minus the effects of knot's and dynamic loading is adequate. That you're applying more force than that isn't necessarily a problem but is overkill for the job.

Fair enough.

your setup looks ok.
what I don't like is that you connect metal with metal for the quick fix set up. metal on metal is never a good idea. I would change this with a screwd riser link on one side and a loop on the other side to connect.

good idea, that was my only concern i had. i purchased 2 of each hardware pieces to test them to destruction. i really let them have it with as much force as i could. neither failed so i figured it would be less confusing to walk up and attach metal to metal but i think i will take your advice and remove the steel ring.
thanks

after reading these posts about dynamic force and such would it be better to tie the breakcord with little to no slack or make an O shaped link with the cord to allow some snatch force?
also what are the negative effects of using 2 sepprate loops of breakcord for redundancy? is premature breaking of 80lb cord common?

I would be very very very very cautious about applying static load data to new setups people create. My gut tells me that the dynamic force will greatly differ from the static force in a couple of ways - mainly time ( F = d^2 s / dt^2) and actual breaking load in dp/dt (m*dv/dt). I don't think they will hold a linear relationship either. In a case like Leroy's setup, I don't think you can apply any data gathered from static loads since his throws several variables into the mix - more cord, cord tied together, etc. All this will greatly effect dt^2 due to the stretching. I don't have time right now, but if I do later today I'll draw up a force diagram to see if he's actually putting 4x80lb static force on his setup. For some reason I'm think it'd only be 2x, as if the second piece of break cord were just a steel rail. This is one where the load being dynamic is very important, since that will determine how each cord is loaded.

Basically, I don't think the data we have on static loading can be of any use to us in extrapolating what will happen on different setups. Since it does not model a base jump, and AFAIK no one has any data on dynamic loading, it would be quite a leap to use that data to determine anything.

Does anyone know what the exact MIL spec entails and what company initially supplied the military? I glanced around on google but couldn't find anything. I've also been awake for a day and a half, so I could have missed something obvious.


Ya, I was talking about the cross section of the link as well. I didn't even think about the radius on each end of the link, though that could also have an effect if it were very small.

This has my curiousity again. Wonder if I can borrow a several thousand dollar force gage from the lab and take it to an exit point without anyone noticing... btw anyone who says that it's pointless to take it to exit obviously isn't a base jumper

I don't think the extra 2 inches is going to make much difference to a dynamic loading generated by the other 25 feet of fall in the system. The primary driver of the dynamic force is the jumpers body weight (which falls somewhere between 20 and 30 feet).



More complex rigging.


Fairly, yes.


If you're worried that your 2, or 3 or 4, or 5 loops of breakcord won't actually break, try setting up your system and dropping a 15 pound weight 10 feet onto it. That's about a tenth of the real weight that will hit it, and about half (or a third) of the distance it will fall.

Personally I've got no worries about the break cord failing to separate. Maybe the bridle will break first, and the break cord will never go, but you're not going to end up hanging on the object.

Anyone want to do the math and tell us how much force will be generated by the jumpers body weight (say 150 pounds) falling to line stretch (say 25 feet)? I don't know the answer, but I bet it's a lot. And while you're at it, can you give us an estimate of the force exerted when 10 pounds (canopy weight) hits the end of the bridle at 9 feet (or 4 feet, if you tie into a point halfway down)? That ought to give us an idea of how much force hits the system on first touch, and so how much we need it to withstand to avoid a premature break.

Here's a drawing with some detail, clearly four strands of break cord.

I had a jump off 180ft whith a SL(carry on) were i had forgot to use the cutaway breakcord,sh!t happened and my sl hung up My bridel stayed intact even whith minor damegeds onto it(enough that i replaced it-as its all about your mind) the carry on SL broke were it were fingertrapped and sewn.
I had a rather bumpy and unpleassant ride down and landing but walked away.not sure that had been the case if it were 150ft or lower..

Howdy,

Flex is the key! NO flex => infinite force!

Dynamic energy, aka Kinetic energy =
Ek = 0.5*m*v^2
v^2 = 2gs (for a falling object, ignoring air resistance)
=> Ek = mgs, g=gravitiy's acceleration

150 lb, 25 feet => 68 kg, 7.6 m:
=> Ek = 68*9.8*7.6 = 5064 Joule

10 lb, 9 feet => 4.5 kg, 2.7 m:
=> Ek = 4.5*9.8*2.7 = 119 Joule

10 lb, 4 feet => 4.5 kg, 1.2 m:
=> Ek = 4.5*9.8*1.2 = 53 Joule


If this energy is transferred to the bridle over a short period of time => large force.
If this energy is transferred to the bridle over a longer period of time => smaller force.

I mean, think of a bungy jump: the reason your legs don't snap off is because the bungy gives in and absorbs the kinetic energy over some time!!!!

So, let's assume your SL/bridle/folded canopy can stretch/flex/give in 5 cm when reaching bridle-stretch.
In order for the break cord not to break, it would have to withstand a force of approx:

F = Ek/d, F= force, d= distance

Flex is the key! NO flex => infinite force!

This gives these shocking numbers:

10 lb, 9 feet => 4.5 kg, 2.7 m:
=> F = 119 J / 0.05m = 2380N
= 242 kg
= 535 lb

10 lb, 4 feet => 4.5 kg, 1.2 m:
=> F = 53 J / 0.05m = 1060N
= 108 kg
= 238 lb

And at line stretch:
If the lines also stretch with 5 cm, then:
150 lb, 25 feet => 68 kg, 7.6 m:
=> F = 5064 J / 0.10m = 50640N
= 5167 kg
= 11392 lb

These numbers assume a solid mass, which the folded canopy is not... which probably contributes to load the cord in 3 stages => so can divide the numbers above with 3 ?? If so the numbers make more sense.

As I said in a previous post: I'm getting a climbing rope and will do some tests with that.

real picture attached


On a seperate note.... what if I were to have a piece of SL setup with a bowline on both ends... and use 2, One longer that the other...

That would create the backup, but it would reduce the effective breaking force to something less than 80lbs due to only one strand breaking at a time. IMO, that is better than no backup. I like that your setup collects the broken break line, leave NO trace and just don't like the fact there is no backup and the force is clearly greater than necessary. If you took two pieces of break cord, one longer than the other and looped them around the object and bowline all four ends to the rapid link you would have a system that would keep all break cord attached and provide a load force equivalent to what's general practice. if you made the bowline loops large enough to slip over the rapide link easily, you could pre-tie everything, loop the break cord around the object, put the bowline loops over the rapide link and be ready to exit fairly quickly and be pretty damn confident you're good to go. As a matter of fact, I will probably use that setup on my next static line jump. Thanks for the ideas.

Tony

I will test my idea out tomorrow... more tomorrow

Sometime I will have to tell you about my plastic grocery bag Static Line setup... Serious... PS I think it was stronger than even my SL setup...

Using the setup we discussed with a single strand of break cord (I used a Surgeon's Loop instead of a Bowline), I dropped a 10lb weight from 6ft and the break cord did not break. I tried it from 8ft and it broke.

Using two strands, one longer than the other, I got the same result; 6ft - no break, 8ft - both broke.

Using your original setup, the break cord did not break from 6ft or 8ft.

Using a single loop tied with a Surgeon's Knot the break cord broke when dropped from 6ft.

If you take a 10lb weight, tie it to your bridle and drop it off the bridge I'm sure your canopy will be at line stretch below you.

With all this, and realizing I need more samples to draw conclusive results, being able to tie the knots before you get to the exit point, leaving no break cord at the exit point, and quick and easy setup prior to exit make this one of the best methods I have seen. It can be used on carry-with-you SL as well as standard static line configurations. This very clean solution even eliminates the need for a carry-with-you SL except in the case where you need distance between the attachment point and your PC to clear the object.

Woah... I am getting all tingly and stuff... I just added something to BASE...

k, that makes sense then. definitely 4 strands.