Basejumper.com - archive

Disclaimer: I am a skydiver with only 82 BASE jumps,
11 objects, and a dozen or so static line jumps hence
please do NOT consider what I post as anything other
than a field report from a test jumper.

This version has a weak link made of two wraps of
break cord... not that any of my other static lines
ever had any problems, but based on the input from
more experienced guys I thought it was worth having.

I larkshead the leader to my bridle at the loop just
below the pilot chute and wrap the rest around the
strong point of an object. Then I confirm that my
rigging is clean, running from the bottom of my
rig to the object without running around my body,
then I take a deep breath and jump.

In the photos the crescent wrench is playing the
part of the loop near my bridle and the part of
gaffer's tape is playing the part of a secure,
strong anchor point on the object being jumped.

Any guys or gals with lots of static line jumps
Please feel free to tell me why this is good or
bad based on your experience.

FYI - with this set up I was able to open higher,
get faster inflation, and made the big field from
200 feet when last time from the same object I
was forced to sink it into a tight spot to avoid
obstacles near the object.

Looks like you are loading the CWY-weak link break cord loop every time.

If you are not going to be replacing it every jump, it will weaken and break before the single strand, as they both enjoy the same loading.

You still have a piece of dacron attached directly to your bridle with no weak link in case it gets hung-up somewhere.

roll on Version 4, your Version 3 is in need of some improvements

was the dacron with the rapid link still attached to your bridal when you landed? The way it's rigged it looks like it could pop at the point between the two pieces of dacron or at the rapid link. They would both be loaded about the same.

Were all conditions the same for both jumps? Two jumps does not seem like enough to make the assertion that the new SL setup was the determining factor.

Also, why not just tie directly to the object, protecting the break chord with electric tape or whatever if need be? You could save some setup time, eliminate the potential of snagging or misrigging, and if you tie a loop in each and use a quick link, you'll still carry it with you.

You are making this way too hard.

Seconded.
K.I.S.S.

Darren, can you please post your setup?

Yes, both pieces of break-cord are each taking
the load, but the single strand should give way
before the 2 wraps. Sam, how often should I
replace it? Do you have a CWY setup?

Yes Zach, I know that 1 jump is not a sample.
Winds were the same and exit points were within
9 feet of each other. Getting to the big field was
probably more due to me being better at flying
my Troll than the S/L, but it definitely felt a
lot smoother than all previous S/L jumps.

Yes Dave, when I landed it was still there.

I totally understand and agree with the idea
that simple works, I mean how often does a
hammer ever malfunction?

However, my static line does not seem complex
to me, it is just a connection between my bridle
and the object with dacron and 2 break cords.

To all who replied, thank you for the input.

It makes him feel productive.

Not saying that I fall into that category (I probably have about 30 SL jumps and have witnessed at least another 30 or so in person) but due to a lowish nature of our local stuff we have had plenty of thoughts around this subject. The main things why I would feel uncomfortable to use this setup are :

1) You are larksheading a piece of 1000lb dacron to your bridle. If this dacron snags and get entagled with the object (for example the loop goes around a bolt or something) you might be looking at some serious damage to your gear. That's why I always attach the whole SL device with a weak point (secondary breakcord) to my bridel so in case of ANY part of the device snags to the object it stays there and the secondary break cord breaks.

2) You are loading both of the breakcords when you jump. It is true that you are using double loop as a backup and single strand as a primary but I think the loading of the backup weak point is unnecessary. Even though in my setup where I don't create load to my secondary break cord I still change it pretty much after every jump.

3) You are attaching the rapid link straight to the breakcord. Rapid link is made out of metal and with this setup you must be extra careful to inspect your rapid link before every jump for any cuts or sharp edges on the metal. These can be cause by the rapid link hitting the object on exit or a rock / concrete on the landing. I would be worried that any cuts on the metal could cut through the break cord when building up the load and cause premature break. That's why I always rig my device so that the rapid link never touches the break cord and the break cord is tied between dacron loops.

I'm not to say here how people should do this but just saying my thoughts about this.

it happens. most times user error however.
ever broken the handle? missed the nail and bashed a hole in the wall?

keep at it dude. kudos for you for figuring it out as you go, and being receptive to advice...

cya -b

What about the one liners?

1st attempt at making on last night. i only have 1 static line jump from last week, but plan on doing more. i would also like some input on what to change or can be improved or if its even jumpable. thanks

If I'm thinking of it right, you will probably leave that on the object. The long break cord is going to pull through the middle fingertrapped loop and larkshead the quick link section onto the tie off point before breaking the secondary break cord.

i made the middle finger trap enough to get break cord through but small enough that the larkshead wont fit through. tried it out this morning by tieing it to a bar and it seemed to work correctly.

Fail.

You are only using a single strand of breakcord = 80lbs, which is not how it is intended or designed to be used.

Designed to be used in a loop = 160 lbs.

If you form one leg of the loop with part of your static line, then only does it make sense to use a single strand.

Whoa


Really?

I thought the same thing till people chimed in saying
my original setup was wrong because it used a loop
which required too much force to break.

I personally think all three of mine have been fine
because they all worked when tested in my loft and
they worked when tested on my freestanding A.

Hell, maybe I need a run down on what one should
want out of Carry With You Static-Line, here mine:
1. open your container every time
2. release once you are at line stretch
3. quick & easy to rig at the exit point
4. prevent premature breaking
5. won't leave you hanging from the object

With your CWY set up the cord was taking half the load and the Dacron was taking the other half, giving a loop a breaking force of 320 instead of 160. With Noc's set up the break cord is not part of a loop around the object, so it recieves all the force and will break at 80 with a single strand and 160 with a loop.

Having some stretch in your system is key. For people who are unfamilliar, weight is a measure of force not mass, it's earths force on the objects mass. Force = Mass * Acceleration, or Decceleration in this case. It doesn't matter what your mass is, if your decceleration is insanely high your force will be insanely high. So if the only play in your system is the stretch of your dacron, break cord and bridle, you'd think you would be pretty prone for a premature break (even though in my and many others experience it hasn't happened). I came across this by trying to figure out how much force it takes to bring 20 lbs to hault after 8ft, which is .7 sec and turned out to be 226 kg ft/s of momentum, but the only way to find out how much force it takes to bring it to a hault is to know the ammount of time it has to come to a hult. If it comes to a hult instantaneously, the force is infinite. So if we used bunjee instead of dacron, we wouldn't have to worry about anything ; )

Not a static line jumper here... but out of curiosity, how weak is the fingertrap to "unusual angle" loads? By unusual angle, I mean two lines being pulled away from each other, as opposed to regular "pulled along each other" scenario in which fingertrap works excellent.

This "fingertrap ripped apart" scenario could happen if the railing has a sharp edge in which case a highly asymmetric loading of parts of your setup may occur.

Many kudos for thinking, trying, inventing something new!

First off, I won't claim to be an expert regarding s/l's.

That said, I like the idea of keeping it simple. Thus I like just wrapping the break cord around the anchor point. Many times you'll find a nice round tube. Obviously, some situations can lead to premature break.

(I also like the simplicity of using a few wraps of electrical tape.)

Has anyone ever thought about routing break cord through a small piece of tubular webbing? Wouldn't that provide protection against abrasion?

- Create 2 modified tailgates. Keep loops at both ends. Sew the fingertraps secure.
- Cut 2 lengths of breakcord. (make one noticeably shorter than the other to ensure one breaks before the other.)
- Connect the 2 "tailgates" with the 2 lengths of breakcord.
- Cut a length of tubular webbing, sealing the ends.
- Slide the webbing over the breakcord. Secure it with breakcord to one of the unused "tailgate" loops (an anchor loop). (everything should be concealed within the webbing except for the 2 "anchor" loops.)
- Secure one of the anchor loops to the bridal via a connector link.
- Pack as normal.

on the jump, simply wrap the device around the anchor point. secure the other anchor loop to the connector link, ensure proper routing of the bridal, and jump.

- the break cord should do it's job.
- the webbing should prevent premature breaking from sharp edges or abrasion.
- if the webbing gets stuck, it's lanyard of breakcord should break. the webbing gets left behind, but the jumper does not!

Thoughts?

Don't get me wrong, I totally dig these discussions, but, damn, we put an awful lot of thought and discussion and effort into a tiny aspect of the sport that most jumper will never use and even the most hardcore of static line jumpers will have need of very seldom...

Yours looks like it will open your container reliably but there are a number of issues not limited to the pully effect of the back loop that can be improved. I thought we all hashed this out years ago and came up with a design such as the one in my picture. (At least that's what I've been jumping for the last 6 years).

This, while still complicated to setup - breaks reliably at the first point without any pulley effect, then retrieves the line (pulling it around the iron etc) with a longer loop. If snagged in this phase, a second loop breaks. Don't work so hard to not leave a trace, just to leave a splat followed by media and ambulances. You'd rather get your shit open and leave that crap behind.

You can rig the loops before and just wrap the primary sling and clip in with your rapide onsite. I recommend coloring the longer line differently so you don't mis-rig it.

Don't work so hard to not leave a trace, just to leave a splat followed by media and ambulances. You'd rather get your shit open and leave that crap behind.
B I N GO and bingo was his name o. Best advice I've seen on this forum period.........

note that I am not a very experienced SL or Low jumper, lowest is a few 165'(4) 190'(2) SLs and a 180' freefall.

that said, and I am sure someone has said it, but break cord is stupid cheap, why not just use a 3/16" quick link on a knot in bridal to a full loop of break cord around the entire railing/anchor? it breaks wherever on the break cord, and it all comes with you. it works very well. It also makes a great place for the PC handle to slip into so it is situated topskin up (good)

PS- I use 80lb in a loop, making it "160lb", I also use water knots, increasing the strength of the break cord, just a little, and it makes it clean.

Hey Matt,

Haven't seen you around here in a while...
School work taking up more of your time?

Most of this is a mental exercise, since all
3 of my static-lines worked just fine, but
the reason people use Dacron instead of
all break cord is to prevent premature
breakage due to abrasion.

Could you please explain water knots?
Yes, I have Google but prefer to get it
from you since your version would be
BASE specific.

Peace,
~Tom

water knot

goomanchew's link is very close to what I use, but I use mine to terminate both ends of a SL loop, not only one knot to make the loop (as his link would suggest)

this is so I can quick-rig it with a small quick link, to a knot in bridal, right at exit point.
I understand the need to avoid abrasion on the edge, but with flat cotton I doubt that anything but intentionally sharp corners make a difference. and even if the abrasive caused a 50% decrease in the strength, it is still at 80lbs.

of course, I really like mind experiments, and building thing to do something complicated. the pics of your rig are cool, something that could be sold. even if it is mot needed on most jumps.

Seriously Tom, that setup is fucking ugly.

Way too much break cord, too many knots, some break cord is looped some breakcord is larksheaded.

Your design does not incorporate anything to adjust for the size of the anchor you are tying off to...no need to add excess slack into the mix if its not neccessary.

And why are you larksheading a piece of dacron thats going over/through an object onto your bridle???

and no, im already finished with summer semester. I have just been going huge lately. speed flying, kitelining, and BASE have owned my life lately.

Glad to hear things are good for you dude!!

Sorry it is not pretty

Just used it from 200 feet (sans camera)
off of a freestander and it worked great,
opened quick, flew over the power lines,
& barb wire fence for a standup landing.

The Dacron leader is larksheaded to the
loop on the bridle next to the PC with
the loop of break cord connecting to the
Y of the static line - reason, guys with
more jumps than me said I needed a
weak link "just in case" of a snag.

As for the diameter of the anchor point,
I could easily make the primary single
strand of break cord longer if need be.

I know we chatted via telephone about
your setup but I do not think I ever got
a photo of it. Please send it when time
and your schedule permits, thanks.

I am totally open to ideas, but honestly
all 3 of CWY-static lines have worked in
my loft and from lowish objects.

FYI - a guy named Nick has compiled a
sweet powerpoint presentation with all of
the versions anyone has posted online.
I suggested he posted it in the articles
sections because it includes comments
from lots of experienced jumpers.

The variations and slight improvements
made by each is educational/entertaining.

I know im not an expert either. Only one static line jump, And my setup is still up on that roof. But i do know a little about this. Making a longer piece of breakcord regardless of its actual strength can break easier than if you tie a small piece with little slack. Just like trying to break a piece of wood. Sure you can snap a big piece but try to break that little piece in half with the same effort. Correct me if im wrong, because i don't know how to do anything right.

RE: punching/breaking boards

Correct!

RE: a length of line

Incorrect.

The difference is the direction of force.

Tom, I think your model 3.0 is beautiful and inventive. not ugly at all. art never has a use.

i read about half this shit and just decided to go hand held.

Anyone here know much about bunjee type ropes? Like a bunjee cord for bunjee jumping, but smaller, and their breaking strengths?

Also, hopefully crwper or 738 can comment on what I was saying about the force and that if deceleration time is 0 that hte force is infinite. Basically the stretch in your system is what creates or alleviates jerk force, and if we used a bunjee type material that was 4x stronger than the breakcord (for redundancy) it would remove all jerk force and we could use single strands of break cord without worry of premature breakage, and save the wear and tear on our gear.

this all seems very unneccessary what happened to just break cord or electrical tape?

I tend to disagree. the length of the break cord/break cord loop is fairly immaterial.

true, too much slack can break earlier than no slack. the dynamic load of the fall breaks the cord before a static load. it's just that you must consider MORE than the break cord. there normally is a ton of slack in the bridle. that is why some shorten their bridle.

You're misinformed here wwarped. That is the opposite of true. The more slack in your system the better. The reason you need to tie into the bridle at a point that shortens the total s/l length is to reduce the total s/l length, not to reduce slack. The farther you're canopy falls before it has to begin coming to a stop the more momentum it has. Momentum = Mass * Velocity.

I'm confused... and could be wrong.


agreed entirely. the distance fallen generates the "dynamic loading." a small load can snap the break cord, if it has fallen far enough. thus, arresting the descent of the canopy and getting it out of the pack tray CAN do just that.

my understanding is that Apex conducted tests prior to their Super Bowl jump. they found a noticable reduction in pre-mature breaks by shortening the bridle.

any slack will contribute to dynamic loading, whether in the bridle or s/l setup.

thus I don't follow the logic for:

True.


Interesting idea...

There are (as anybody who's done PCA's has experienced) three points at which a falling jumper applies force to a static line system...

(1) A small tug as the pins are pulled out of the container. The force is small here because the inertia of the object (the pins) is small, and really friction doesn't much care whether you're pulling gently or yanking the pins out.

(2) A bigger tug as the packjob is pulled to a stop, and extracted from the container. Again, inertia is the key here, with the packjobs mass being a few kilograms.

(3) A final, potentially huge, yank as the jumper hits line extension. Importantly, the goal here is not to bring the jumper to a stop -- this makes it a little different from steps (1) and (2).

Ideally, a static line setup would mimic a skilled PCA, holding through the first two and breaking just as the third comes into play (or even just before it). When the static line breaks before (1), somebody's towing their pilot chute, maybe for a while. When it breaks before (2), somebody's getting a little freefall on their S/L jump. When it fails to break early enough on (3), somebody's replacing their bridle and/or canopy.

Introducing a bungee cord into the system should, as you say, reduce the maximum force required to bring something (the pins in step 1, or the canopy in step 2) to a stop. What it won't change is the maximum loading on the system before the break cord goes, which means that your chances of tearing your bridle, the consequences of the S/L setup hanging up, the wear on your gear, etc. (ie, all the stuff in step 3) are unchanged.

... So, no improvements in the toll S/L jumps take on your gear, but it might well make it easier to find the happy medium between steps (2) and (3) above.

Edit to add: crwper has pointed out to me that the reduction of maximum force in steps (1) and (2) means that you could reduce the wear in step (3) by using, for instance, a 40 lb break cord. There you go!

... Which is exactly why a shorter bridle reduces the chances of a premature break. More momentum to begin with, being brought to zero over the same distance, means more maximum force, and therefore a higher chance that your break cord will go before you're even reaching line stretch.

You're basically right about the force required to stop something from falling. After an object with mass m has fallen a distance h, it has energy E = m g h, where g is the acceleration due to gravity (9.8 m/s^2). To stop it, you need to do work equal to that energy. We can use the equation W = f d, where f is the applied force and d is the distance over which it's applied, to figure out how much force needs to applied over some distance to do that work. If the distance was zero, the required force would be infinite.

To get an idea what the real forces look like, I cooked up the attached graph of force vs. distance for a hypothetical jump, with the following assumptions:

• The length of bridle from the anchor point to the pins is about 2 m; to the canopy is 2.5 m. From the anchor to the jumper is 10 m.


• I assume a 2 kg (19.6 N) pin tension.


• The canopy is lifted over its own height, about 1 m. I assume the canopy weighs about 5 kg, so it has about 122.5 J of kinetic energy when it begins deceleration.


• Finally, it takes about 80 lb to break the break cord, or about 356 N.

The jump is made up of three events:

• Event 1: The pin is extracted. This event is dominated by pin tension, since the energy required to decelerate the pin is quite small. The force continues to build until this threshold is reached, and then the pin is freed and the event is complete.


• Event 2: The canopy is lifted. This event is dominated by the energy of the falling canopy, since the canopy needs to be completely stopped. The canopy is stopped over its own height, assumed to be about 1 m. At the time it is lifted, the canopy has about 122.5 J of kinetic energy. Since the canopy is a pretty homogeneous thing, I figure the force is evenly distributed over the height of the canopy. Using the equation W = f d, we get about 122.5 N of force over 1 m.


• Event 3: Line stretch is reached, and the jumper is decelerated. The applied force increases until the break cord breaks. Thus, the jumper's vertical motion may not be completely stopped by the break cord. Indeed, if it were, the jumper would be hanging off the object.

Looking at the graph for the hypothetical jump, there are a couple of things that catch my eye:

First, the key point as far as the break cord is concerned is that it should break at a force higher than the maximum force in Event 2, but as low as possible otherwise. Any additional force is just contributing to wear and tear on the gear, and also shocking the canopy (which results in some altitude loss). Now, we don't know exactly what force it will take to lift the canopy, and we don't know exactly what force the break cord will break at, so we build in a bit of a safety margin. In this case, 80 lb break cord seems just about ideal.

Second, I wonder how a bungee cord would affect this graph. Event 3 would be mostly unchanged, since the peak force still needs to reach 80 lb if we are using the same break cord. Event 1 would likewise be unchanged, since the threshold force must still be reached. Event 2, however, might be smoothed out a bit, so that the peak is lowered and the bump becomes a bit broader.

For the benefit of those who are not familiar with calculus: When we look at an equation like W = f d, what we're really saying is that work is the area under the curve, when force is plotted against distance. That means we can do the same work with a short, broad bump, or with a very high, narrow peak. When we add the bungee to the system, we increase the distance over which the canopy is decelerated, which means we can apply a little less force, and get the same work.

So, a bungee might bring the Event 2 peak down a little bit. However, unless we change to a weaker break cord, the peak forces are unchanged, since these occur in Event 3.

Michael

I like your use of 1m (the height of the packjob) as the distance over which the canopy is decelerated. That does suggest, though, that in order to reduce the height of the second peak by a factor of 2, you'd need a bungee cord that did its thing over about a metre (so doubling the distance over which the canopy is decelerated). Probably not worth the additional snag hazard...

Thanks for all the info, glad someone understood what I was saying. 738, 736 my bad Jason

I put a little thought into the canopy unfolding, but for some reason didn't put much though into it. Now I can see how in a way that adds distance for the bringing to a stop, but since the canopy attachment point still stops before that it basically is slowly adding the mass to the load as the material tension of canopy becomes taunt. That explains my conundrum of no slack (only the systems almost static stretch) should mean everyone is having premature breaks, but we're not?

Since APEX did those tests though and was having premature breaks, apparently at certain distances the canopy unfolding isn't enough play in the system and premature breaks happen, so I still think a carry away made of a very strong and highly elastic material, and using an 80lbs setup, might be a good idea. I wonder if APEX used an 80lbs setup for their tests or if it was 160 or 320. I'm assuming it was 80 because of the results.

You could make the tie in loop on your bridle at the pins if the elastic material needed to be a meter long. And if the length of bridle to PC put the PC in a bad spot, you could s-fold as much bridle as needed and put a rubber on it in a way that it would come right off when the pc was being drug through air.

I remember hearing stories, when I'd just started jumping, about jumpers years (decades?) ago who got bored static lining the deck of a local span. They started attaching the pilot chute to a length of rope, with the other end tied to break cord, so that they could get 10, 20, 30 feet of freefall before the static line kicked in. I can only assume they were using zip ties or something as a break cord with that kind of dynamic loading. :)

Well, with 80 lb break cord, you could go perhaps three times as far as my example before you had problems, so about 7.5 metres to the canopy. With a complete loop of break cord, which is what I've always used, you could go twice as far, so almost 15 metres.

Michael

P.S. This is obviously contingent on a whole lot of assumptions, not the least of which are:

• That the canopy is, indeed, slowed down over one metre.
  
• That the break cord, with knots, retains its strength of 80 lb. This is certainly not the case.

Other than that, there are assumptions about the weight of the canopy etc., but I think I've got those in the right ballpark.

I call bullshit!

ha ha ha, one of the guys smart
enough to know what sans means

Textbook example of: You Can't Win For Losing

If you don't have video it didn't happen...
But how does one prove they do not have
any video or photos of a jump, actually it
is often difficult proving a negative.

"You so smart."

You are getting there....way to finally make a jump "sans" camera. Now can you make one without a camera and not post about it on the internet?

But then...why would you basejump if you can't show someone the video or spray about it?

The way I see it, I don't have anything to prove to anybody, even me.

WTF?

 

Hey Dude,

Thank you for posting your setup!

Yours looks cool, real clean & totally functional

Just like mine, except mine is ugly to you

Peace, ~Tom

 

Don't get me wrong bro, version 4.0
is gonna be a total rip-off of yours

This is the one I made 4 years ago. Works great.

This is similar to what I have seen before. I like this setup. Tonight I am going to build one, I am no rigger, so is there any difference in strength in bartacking vs zigzagging in the fingertraps?

Finger trapping alone should work but
of course to feel better I always put a
few stitches in, have used both hand
& regular straight stitch, no problems.

If you use zig zag just run it back over itself twice. I would use #69 thread if you can.
If anyone is interested in one PM me.

In the old days, canopy lines were joined together by zigzag sitching. Nowever days all canopies use bartacks. There must be a reason for this, so I would say use bartacks only.

It probably has more to do with the fact that lines were JOINED, not FINGERTRAPPED :) Which by the way was done a lot with the 308 (double throw) not the conventional 304 zigzag.

alas I agree, bartack when you can. Afterall how many of us have access to a bartacker as opposed to a zigzagger :)

I gave a couple dozen of these that I made up (while drinking beer sitting on the couch) to a master rigger friend of mine and asked him to bartack them. This guy owns a balloon loft and built containers for years. His take was that bar tacking for this application could actually weaken the dacron because of the number of holes punched in the dacron / fibers broken by the bar tacker. He suggested using a straight line stitch instead, then 'tested each line by picking up a 250lb envelope straight line pull no problem'. As has been said, it is the finger trap holding the weight, not the stitching. It is just there to keep the finger trap in place if there is no tension on it.

I'm certainly NOT anything other then an info geek-NOT rigger, only one who reads the rigger course manual, and loves technical math-

so here's some IDEAS & QUESTIONS since I've started thinking of trying methods of testing out your version3 indoors.

here's my thoughts:

I had to think a fair bit about this as it has been a while and I never got into the fine details of carry-with-you static lines.


So I don't have "answers" only "thoughts".

Everything seems reasonable to me.

Initially you would start with one "strand" of break cord in the part around the object, and one "loop" of break cord at the weak link spot, because the force at the former is half of the force at the latter. (In the ideal world with the loop around the object moving frictionlessly)
So you need twice the strength at the weak link spot. OK.


Now your photos show a two loops around at the weak link spot. That should make sure the normal spot breaks first.
Two loops around isn't too strong?
Technically that would be 4*80 = 320 lbs, minus whatever big percentage is lost for that type of knot. (30 or 40%?)
That brings it down to 200-220 lbs roughly.
Of course there's all the momentum to include so it should break with any jumper's weight, yet still it seems a fair bit.

I'm thinking of starting to set up a few experiments just indoors with hooks and dacron line and break cord, with someone hopping onto a stirrup in a line to load test samples of break cord. If the break cord is strong enough to easily support someones static weight hanging on the line, how easy is it to break the cord if someone dynamicly loads it by a little jump to add load to the line?


But all that's about the safety weak link.
Was that where it was breaking???

If it wasn't, any issues of higher or lower opening should be affected only by when the main break cord is breaking.
There it would be nice to have someone else around to say (or video) whether the cord was breaking a little early, say while extracting the weight of the main rather than when the lines are stretched out.

The standard is a single strand of break cord, isn't it?
Doubling it up seems like a little bit much of a change!

If one needed a little more strength, without doubling it, what to do?
Maybe some knot that takes away less of the theoretical 80 lb strength?
Would a figure-8 knot then be better than an overhand, as the radii may be bigger and thus stress the break cord less?
Or come up with a compact sewing method that is more efficient than the knots?
(But I see the dacron is assembled with hand tacking -- which is perfectly OK in holding fingertraps in place.)

Still it all comes back to the question why a single strand isn't enough, if that's what works for other base jumpers?

Or, if this is about the safety weak link instead, the same ideas on strengthening knots could apply to it too, to up the strength "a little" instead of going so far as to double it.


What about the bridle attachment point? I've heard that some attach the static line part way down the bridle, so there's less distance to travel and thus a lower snatch force of velcro or yanking out the canopy. That reduces the chance for premature breaks.
What the best way to deal with the pilot chute then I'm not sure. In any case one has to make sure the pilot chute isn't going to snag on something.

As for other entanglements, I don't know anything about the whole issue of the static line system dangling from one's bridle near the PC. I thought the carry-with-you thing is common enough, suggesting there isn't an entanglement issue with the PC. One just has to make sure nothing will catch on the object.

Hope that some of this makes sense.

What do you guys reckon about this set-up?

After doing many jumps off different objects with slightly
different set-ups I realized that their differences are minor.

I just got home from a a jump, well from a bar, but before
that it was a solo, static line from a low building with zero
ground crew. This was the 5th jump from this object and
I am much more worried/focused on the way I un-stow
the brakes than I am on the different static line set-ups.

Honestly almost all of them work, as long as you DON'T
wrap the bridle around your body, other than that it is
just a matter of beautiful green angels dancing on a pin.

inconsistent, unknown break strength and slow at quick set up locations. otherwise, just fine.

why not?
who needs a camera?
-no one told me that was required equipment damn! the 1st jump course manual needs to be reprinted, this important element was left out.

so does it mean I can stop worrying about snag points if I just use lots of duct tape to retro fit a camera on my helmet?

you mean all my math was useless! your still walking...

AWESOME! good news my friend- so do I have to stop tossing the fattest guys we got in our FJC's off our hangar loft to test the static lines
(I did tell them it was a requirement to get their chance to do their 1st static line from 4.5-saying they can handle this, they can handle a static line out the 206)

damn-that was half the fun- almost as much as watching the videos of the 1st FF jumpers tossing their pilot chutes between their legs while on their back

hhmm.... after Tom's last post, now I know I got a new method to try out on those FJC fellows.

Thanks for the awesome idea-never would of thought of it.

Which all of a sudden reminds me of the time @ one of our neighbour DZ's the JM fell out, and the FJC static line fellows all thought it was time to get out also-without their static lines hooked...
would of loved to see that DZO's yes popping out of his face as he watches all those students popping their reserves

turns out that JM went walking after that jump, probably down the same path that tandem master who forgot to hook up his passengers top snaps

in here with all that minus celsius we have, thats a big NO NO