Weak links

[Tad Eareckson]

http://www.hanggliding.org/viewtopic.php?t=31811
Weak link material

Jim Gaar - 2014/09/11 00:35:43 UTC

I use my own calculation for weak-link strength...

Fuck you, Rodie. You couldn't calculate the number of gallons of milk in a one gallon milk jug with a gun to your head.

http://ozreport.com/forum/viewtopic.php?t=30971
Zach Marzec

Jim Gaar - 2013/02/13 17:57:05 UTC

Former Flight Park Manager

Because it has the best known and accountable safety record (in my personal books anyway).

You just use whatever all your asshole buddies are using because that's what all your asshole buddies are using.

...based on FAA standards for towing...

As carefully explained in Dr. Trisa Tilletti's article in the 2012/06 issue of the magazine.

...then I put my own trust and experience into the final decision...

Trust and experience. Can't emphasize just how important those issues are in the matter of weak link selection.

...as to the type or weave or color.

Especially the weave. If you don't get the weave just right your weak link might not break when it's supposed to. Or it might break when it's not supposed to, but that's just an inconvenience.

Different bridles and how they attach to ones harness mess with the basic calculation too!

REALLY!!! Maybe you could explain to us muppets exactly how and why.

Look, it's your ass hanging out there.

Well yeah, but that's really not fair. We have neither your experience to be able to properly evaluate weave and color nor your intelligence to be able to understand the effects of different bridles and how they attach to one's harness.

Be honest with yourself about your abilities and act accordingly.

Honesty and abilities?! Damn this is getting complicated! What if we're only honest about sixty percent of the time and our abilities are only about one third Zack Marzec. What factors should we plug in? Is there some kind of guidance we can get from the FAA? DAMN! I knew Trisa's article wasn't anywhere NEAR comprehensive enough!

Never "expect" someone else to save your life.

I SHOULD be able to expect the motherfucker on the other end of the rope to know what the fuck he's doing because he's got total control of the power going to my aircraft and if he's a douchebag he can kill me when the air isn't doing what it's supposed to.

Towing is not rocket science but it is a science IMHO.

Who do you think you're successfully conning with this crap?

Gut this son of a bitch. We ANHILATED Rooney and Davis is hanging on by a thread. We've got these pigfuckers by the balls. Don't let them escape with any shreds of dignity intact.

P.S. This is what you unleashed on this sport, Donnell. I hope you roast in hell for it - for a while anyway.

[Tad Eareckson]

http://www.hanggliding.org/viewtopic.php?t=31811
Weak link material

GerryP - 2014/09/11 04:39:56 UTC

Another alternative is to stay with the green spot brand, but use 160lb. For example,

http://www.fishingtackledepot.com/TUF-LINE-BRAIDED-GREEN-SPOT-DACRON-160-LB-p/gs160150.htm
TUF LINE BRAIDED GREEN SPOT DACRON 160 LB. TEST 150 YARD SPOOL

You're not STAYING with any brand. The BRAND is Cortland and Greenspot is one word. This is Tuf Line and it's not IGFA and thus not certified to the plus/minus one percent tolerances so critical in having a weak link break consistently and in accordance with your expectations.

For my ride, if I do my maths right:
300 lb (glider and max hook-in)
if tow V-bridle with 60 degree split is 0.575 times line tension
for 0.8G, then 240lb = 138lb
for 0.9G, then 270lb = 155lb
for 1.0G, then 300lb = 172lb

And for the love o' God don't go over 1.0 Gs 'cause that leaves you vulnerable to lockouts.

What do you think, Rodie?

Jim Gaar - 2014/09/11 00:35:43 UTC

I use my own calculation for weak-link strength based on FAA standards for towing, then I put my own trust and experience into the final decision as to the type or weave or color.

How come he's only looking at the bottom seventeen percent of the FAA legal/safety range and way the fuck under what all sailplane manufacturers specify for their models?

So 160lb line (loop with grapevine knot breaks around that I think) sounds pretty good.

A loop of 160 breaks at around 160 and it doesn't make a whole helluva lot of difference how it's tied. So you're looking at 278 pounds towline or 0.93 Gs and that's DANGEROUSLY understrength.

Some are moving to stronger...

Not SOME - "MANY of us".

...(I think Davis is @ 200lb)...

And let's all keep following Davis's lead.

...to reduce the risk of low altitude weak link breaks.

The RISK of low altitude weak link breaks? WHAT "RISK"? A weak link break is NEVER more than an inconvenience. You find me a quote from Davis EVER implying that there's any danger associated with ANY weak link failure.

http://ozreport.com/forum/viewtopic.php?t=31052
Poll on weaklinks

Davis Straub - 2013/03/06 18:29:05 UTC

You know, after all this discussion I'm now convinced that it is a very good idea to treat the weaklink as a release, that that is exactly what we do when we have a weaklink on one side of a pro tow bridle. That that is exactly what has happened to me in a number of situations and that the whole business about a weaklink only for the glider not breaking isn't really the case nor a good idea for hang gliding.

I'm happy to have a relatively weak weaklink, and have never had a serious problem with the Greenspot 130, just an inconvenience now and then.

I'm thinking about doing a bit more testing as there seemed to be some disagreement around here about what the average breaking strength of a loop of Greenspot (or orange) weaklink was.

http://www.hanggliding.org/viewtopic.php?t=31717
Weak link?

Davis Straub - 2014/08/20 13:47:27 UTC

There has been plenty of discussion of weaklinks here previously. I suggest reading Jim Rooney's posts.

http://www.hanggliding.org/viewtopic.php?t=31747
Lockout

Davis Straub - 2014/08/29 14:50:20 UTC

From the link to the Oz Report forum above: Jim Rooney - "The "purpose" of a weak link is to improve your odds of survival when things go wrong."

http://www.hanggliding.org/viewtopic.php?t=31747
Lockout

Davis Straub - 2014/09/01 15:22:41 UTC

I can tell you that I fly with a 200lb weaklink on one side of my 750lb pro tow bridle. I am happy with it.
I feel that my 140lb weaklink was too weak (broke too easily in circumstances where a weaklink break wasn't necessary to protect me).
What I want, of course, is a weaklink that breaks only when needed. I believe that there is a picture here of me showing where it is needed.

Those are Davis's official "positions" on weak links and they're NEVER gonna change. Also... Try to find a quote from the motherfucker acknowledging that weak links should be proportional to either glider capacity or flying weight.

I think a stronger than 130lb link, and faster release is a good combo.

Define a "faster" release. Do any releases within easy reach fall into that category? What are you using for a faster release?

P.S. There was a critical smiley ( ) I missed from Rodie in my previous post. Doesn't change anything of any significance though - he's still a duplicitous little worm.

[Tad Eareckson]

http://www.hanggliding.org/viewtopic.php?t=31811
Weak link material

Tiberiu Szollosi - 2014/09/11 11:34:55 UTC

Good find , i'll try the 160lb

You'll TRY it? And what? See if it meets your expectation of breaking as early as possible in lockout situations but being strong and reliable enough to avoid frequent breaks from turbulence?

You just went up thirty pounds from a piece of fishing line that Quest pulled out of its ass over twenty years ago and declared would put all solo gliders at one G and would break before the pressure of the towline reached a level that compromised the handling of the glider. Your towline tension limit went up 52 pounds - a 23 percent increase. What are you hoping to accomplish?

http://ozreport.com/forum/viewtopic.php?t=30971
Zach Marzec

Jim Rooney - 2013/02/13 19:09:33 UTC

It was already worked out by the time I arrived.
The reason it sticks?
Trail and error.

Every now and then someone comes along with the "new" idea of a stronger weaklink. Eventually, they scare themselves with it and wind up back with one that has a very proven track record. I mean really... no exaggeration... hundreds of thousands of tows.

Say what you will, but if you want to argue with *that* much history, well, you better have one hell of an argument... which you don't.

It amuses me how many people want to be test pilots.
It amuses me even more that people...
A) Don't realize that "test pilot" is exactly what they're signing up for and B) actually testing something is a far more involved process than "I think I just try out my theory and see what happens".

Allow me to repeat... hundreds of thousands of tows.
Sure, there's other stuff out there too. Some of it even has a number of tows behind it... but hundreds of thousands is a very large number.

That's not "religion" my friend.
The shit works. It works in reality and it works consistently. It's not perfect, but Joe-Blow's pet theories have a very high bar to reach before they are given credence.

How very odd that with all that trail and error work to dead center on 130 not one single individual in the history of the sport, no matter how light, has tried to nudge down to 120 - even after having watched their buddies lock out and fatally slam in on 130. Every single adjustment or recommendation that's ever been made has been UP from Industry Standard.

Well, brace yourself for the inevitable wave of lockout deaths and aerotow operations paralyzed by the bodies of test pilots all over the runways. Should start kicking in any time now.

[Tad Eareckson]

http://www.hanggliding.org/viewtopic.php?t=31811
Weak link material

Mike Lake - 2014/09/11 14:52:45 UTC

Playing the devil's advocate.

http://ozreport.com/forum/viewtopic.php?t=31052
Poll on weaklinks

Jim Rooney - 2013/03/04 19:31:36 UTC

You don't get to "make shit up". I don't "make shit up" for that matter either.

We all play by the same rules, or we don't play.
Morningside decided that they were happy with 200lb weaklink. They changed their tug's link and they don't just pass the stuff out either. If you'd like to know more about it... go ask them.
The law of the land at comps was 130lb greenspot or you don't tow. Seriously. It was announced before the comp that this would be the policy. Some guys went and made their case to the safety committee and were shut down. So yeah, sorry... suck it up.

Why settle on 160lb? Other than reduce the chances of a dangerous weak-link failure near the ground what do you think would happen to you if you go for 200lb like that spookily sensible Mr. Straub?

http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?

Davis Straub - 2011/08/28 15:26:28 UTC

Then again, Russell Brown had us double up behind him after six breaks in a row at Zapata. We couldn't figure out why we had so many breaks so quickly. Maybe just coincidence.

Brian Scharp - 2014/09/11 15:07:36 UTC

Fine tune the weak link to the inadequacies of the release.

http://www.hanggliding.org/viewtopic.php?t=22540
LMFP release dysfunction

Diev Hart - 2011/07/14 17:19:12 UTC

I have had issues with them releasing under load. So I don't try to release it under a lot of load now.

Tiberiu Szollosi - 2014/09/11 15:42:33 UTC

I hook in at 175- 180 and the glider is only 54lb so 200lb might be too much.

- Too much to WHAT?

- Since when did we start scaling weak links with glider capacity or flying weight? Davis doesn't say anything on that issue. He just says "many of us".

Mike Lake - 2014/09/11 15:58:33 UTC

Too much?
If I may I'll ask again.

Other than reduce the chances of a dangerous weak-link failure near the ground what do you think would happen to you if you go for 200lb?

This is kinda fun. GerryP's statement that low altitude weak link breaks are dangerous has gone unchallenged and everybody and his dog is bumping up from the Marzec Link. It's just a matter of time before it will be impossible for these worms to deny that Zack was killed by the safety device Quest had spent twenty years perfecting.

[Tad Eareckson]

http://www.hanggliding.org/viewtopic.php?t=31811
Weak link material

Tiberiu Szollosi - 2014/09/11 16:43:17 UTC

Don't know but doesn't Davis fly a 100lb Atos , i'm guessing that's why he uses 200lb.

Davis doesn't specify what he flies. He flies all kinds of shit - from Falcons through toplesses to Atosses. What he says is:

http://www.hanggliding.org/viewtopic.php?t=31717
Weak link?

Davis Straub - 2014/08/20 19:48:26 UTC

Many of us are now using 200 lb test line from Cortland.

You try to get that motherfucker to start talking about glider capacity, flying weight, skill level. You will NEVER get a straight answer - just crap about happiness, never had a serious problem, convenience. If he EVER gives you a straight answer / says anything specific he's blown his foot off what with all the other rot he's been saying and doing over the years.

Try thinking for yourself and not basing what you're doing on what a bunch of other highly respected assholes are happy with at the moment. Answer Mike's question. What do you think is gonna happen to you if you go to two hundred? Assuming you're flying at max hook-in you're flying at a hair under one and half Gs which is just a bit over the middle of the legal/safety range and right on the money with USHGA's bullshit recommendation.

[Tad Eareckson]

http://www.hanggliding.org/viewtopic.php?t=31811
Weak link material

Davis Straub - 2014/09/12 01:00:16 UTC

Wills Wing T2C 144.
200-210 lb. hook in weight.

OK, Davis, now give us the data for the many others of us - including bridles.

And why don't you tell us what you're advising Tiberiu to use - seeing as how if he shows up at one of your pecker measuring contests you'll be dictating to him what he'll use.

[Tad Eareckson]

http://www.hanggliding.org/viewtopic.php?t=31811
Weak link material

Mike Lake - 2014/09/12 08:32:19 UTC

Mike Lake - 2014/09/11 14:52:45 UTC

Why settle on 160lb? Other than reduce the chances of a dangerous weak-link failure near the ground what do you think would happen to you if you go for 200lb like that spookily sensible Mr. Straub?

Tiberiu Szollosi - 2014/09/11 16:43:17 UTC

Don't know...

Anyone?

Nah. A third of a century's worth of Hewett lockout protector religion is crumbling and people are scared too shitless to go on the record with anything.

michael170 - 2014/09/12 09:00:09 UTC

Given that Davis wants the weak link to save the pilot's bacon, and the one sixty is forty pounds weaker than the two hundred then it only stands to reason that the one sixty has forty more pounds of bacon savingness.

Eighty when it's on the end of a pro toad bridle.

And that's a lot of bacon!

Simple arithmetic. Davis and many of us probably just weren't aware of the availability of 160. Or maybe...

http://ozreport.com/forum/viewtopic.php?t=30971
Zach Marzec

Davis Straub - 2013/02/13 15:45:22 UTC

We have no agreement that a stronger weaklink would make it safer (again, I fly with a slightly stronger weaklink).

...Davis and many of us just find the whole numbers thing hopelessly confusing.

2014/09/12 09:12:54 UTC - Sink This! -- Paul Hurless

Hey Paul...

Why don't you grow a pair and engage in the discussion? Stupid cowardly little troll.

[Tad Eareckson]

http://www.hanggliding.org/viewtopic.php?t=31811
Weak link material

Brian Scharp - 2014/09/12 14:51:59 UTC

Is there a place using stronger weak links that we could use to compare data?

Yes. We've got decades, quite literally hundreds of thousands of tows worth of trail and error on this. All these Aerotow Industry shits have been putting 200 hundred pound little girl gliders up on the same stupid piece of fishing line they pulled out of their asses at the dawn of civilization that they use for three hundred plus pound gliders. The little girls are all flying substantially high G weak links and they'd be getting massacred IF:
- low level lockouts were significant hazards in aerotow operations; AND
- light weak links were of any significant value in "stacking the deck in your favour"

But neither of those conditions lines up anywhere close to reality. Low level lockouts are easily preventable ('specially if you've got a release that doesn't stink on ice), rare as hens' teeth, and deadly. You get into one don't plan on walking away no matter what you're using for a release, weak link, and helmet.

The ONLY thing that light weak links are good for is...

http://www.youtube.com/watch?v=r1LbRj-NN9U
Mitch teaches weak link break strategy

http://www.youtube.com/watch?v=r1LbRj-NN9U

Mitch Shipley - 2011/03/20

If you take this away that angle goes from there to now there and the... You're stalled. You're stalled.

...stalling gliders close to the surface.

Or is there nothing more substantial than inexplicable happiness when trying to determine weak link strength and its effectiveness as a release?

Yeah, if you talk to these guys you're gonna hear a lot about happiness, appropriateness, comfort level, pressure, timing, dragging, track record length, bacon conservation, Rooney's keen intellect...

Brian Scharp - 2014/09/12 16:43:37 UTC

michael170 - 2014/09/12 09:00:09 UTC

...pounds of bacon savingness.

Speaking of which, is there a formula one could use to arrive at optimum bacon saver level, or is everyone just making it up?

Yes and overwhelmingly yes.

Use one and a half times your max certified operating weight. That'll keep the total load on the glider under three Gs and be strong enough to prevent virtually all breaks in non lockout situations.

drachenjoe - 2014/09/12 18:32:30 UTC
Germany

Hi guys,

in a v-bridle, tensions can vary much more than calculated,

Bullshit. If you know the apex angle you can calculate EXACTLY how towline tension translates to bridle tension.

Thats why we only use weaklinks in front.

You only use weak links up front because you're too fuckin' stupid to be able to understand high school geometry/trig and put it into practice.

- 180 lbs
- 200 lbs (Standard)
- 220 lbs

From light weight to Tandem. 260 lbs after the Trike..

So a two hundred pound glider gets to fly at 0.9 Gs, a three hundred pounder at two thirds of a G, and a tandem glider at half a G. You guys are total morons.

BTw: we dont use those appalachian style knotted fishing lines

Of course not. You're not smart enough to tie them.

[Tad Eareckson]

http://www.hanggliding.org/viewtopic.php?t=31811
Weak link material

Karl Allmendinger - 2014/09/13 16:01:55 UTC
Silicon Valley

Has anyone tested any of these weak links?
Made some and broken them?
Broken some more after they have been used?

TESTED weak links?

http://ozreport.com/forum/viewtopic.php?t=24846
Is this a joke ?

Davis Straub - 2011/08/28 15:26:28 UTC

Then again, Russell Brown had us double up behind him after six breaks in a row at Zapata. We couldn't figure out why we had so many breaks so quickly. Maybe just coincidence.

Dr. Trisa Tilletti - 2012/06

We could get into details of lab testing weak links and bridles, but this article is already getting long. That would be a good topic for an article in the future. Besides, with our backgrounds in formal research, you and I both know that lab tests may produce results with good internal validity, but are often weak in regard to external validity--meaning lab conditions cannot completely include all the factors and variability that exists in the big, real world.

http://ozreport.com/forum/viewtopic.php?t=31052
Poll on weaklinks

Jim Rooney - 2013/03/04 19:31:36 UTC

No it is not.
It's a 260lb weak link.

Davis Straub - 2013/03/06 18:29:05 UTC

You know, after all this discussion I'm now convinced that it is a very good idea to treat the weaklink as a release, that that is exactly what we do when we have a weaklink on one side of a pro tow bridle. That that is exactly what has happened to me in a number of situations and that the whole business about a weaklink only for the glider not breaking isn't really the case nor a good idea for hang gliding.

I'm happy to have a relatively weak weaklink, and have never had a serious problem with the Greenspot 130, just an inconvenience now and then.

I'm thinking about doing a bit more testing as there seemed to be some disagreement around here about what the average breaking strength of a loop of Greenspot (or orange) weaklink was.

We don't TEST weak link strengths. We just assign arbitrary values to them and alter the figures for the convenience of the discussion of the moment.

You talking 'bout what those German twats are using? Probably Tost weak links with custom inserts. Yeah, they've been tested to make sure everybody stays safely way the fuck below the bottom of the US legal range.

[Tad Eareckson]

http://www.wallaby.com/aerotow_primer.php
Aerotow Primer for Experienced Pilots

The Wallaby Ranch Aerotowing Primer for Experienced Pilots - 2014/09/16

A weak link connects the V-pull to the release, providing a safe limit on the tow force. If you fail to maintain the correct tow position (centered, with the wheels of the tug on the horizon), the weak link will break before you can get into too much trouble.

34-03715
http://farm6.staticflickr.com/5594/14877659539_4d1333c6a3_o.png