Adjustable rope bridge

[phatkaw]

All this talk about safety lately it surprises me that I haven't seen anything about using dynamic rope for a bridge..

 

[Fl Canopy Stalker]

I tied a Blake’s Hitch for my DIY waist belt on my Method.
It works good! Kinda leaves a big knob there though...

The HTP I used is awfully stiff for such tight curves in the knot. It makes me a tiny bit sketchy.

Htp is too stiff. You’d have to go to a smaller diameter for a Blake’s to grab as reliably on htp or of course a traditional prusik works good. Even then that htp is much larger than that amsteel is, even when it’s double braided through itself

 

[Fl Canopy Stalker]

All this talk about safety lately it surprises me that I haven't seen anything about using dynamic rope for a bridge..

I thought about it. I guess for me it is more of a dynamic rope is stretchy so even if you use a dynamic bridge, a dynamic tether and a dynamic prusik, it’s still somewhat of a false security because saddles are not meant to be fall arrest. We can lower impact forces but regardless all of that fall will be completely absorbed by your back, hips and pelvic area. In doesn’t take a ton of force to injure you when all that force is centralized. So to me, it’s a false sense of security to some extent. I stand by the keep your system tight, use it properly, and then a fall won’t happen or if it did, the distance and fall factor would be so small that dynamic wouldn’t make the difference.

 

[Brocky]

I am running a Blake’s hitch. You had to go to smaller diameter to get your hitch to bite, the Blake’s hitch is the only friction hitch that allows you to use rope of the same diameter! Since the bridge is doubled rope, I use the Blake’s. It is essentially the exact same set up as an arborist climbing ddrt with an open
system configuration

A few more single eye hitches

 

[Fl Canopy Stalker]

A few more single eye hitches
View attachment 51230

I prefer a 4 or 5 wrap Blake’s. Cornell college of climbing has done extensive testing and it’s safe to say, our bodies will give before that hitch does. I have a few hitch books and I’ve toyed with a few others but nothing slips and grips as well as a Blake’s hitch.

 

[Fl Canopy Stalker]

A few more single eye hitches
View attachment 51230

I read somewhere that Blake created his hitch because the taut line was too unreliable. I am not a huge fan of it and the Bellunese is a 5 wrap Blake’s with one extra wrap on top lol that extra wrap is useless and only adds bulk. Do you use any of these @Brocky? I’m sure if you are involved in arborist industry, you’ve used a tautline but have you tried any of these others?

 

[Brocky]

The Tautline was the first I learned and one of the worst friction hitches, almost got out of tree work from the frustrations. The Helical, Bob Thrun’s variation, Prohaska, and the Knut H are the ones I have used, the last being one of the better. But many double eye hitch work so much easier.

 

[Fl Canopy Stalker]

The Tautline was the first I learned and one of the worst friction hitches, almost got out of tree work from the frustrations. The Helical, Bob Thrun’s variation, Prohaska, and the Knut H are the ones I have used, the last being one of the better. But many double eye hitch work so much easier.

I agree to some extent on double eye hitches but a bridge is usually only lengthened or shortened a couple times a hunt, and the smaller cord on one side of the bridge doesn’t allow perfectly equal positioning (the exception being if you have “comfort channels”. By using the Blake’s hitch, both sides are exactly the same diameter and it has easier adjustments with similar holding capabilities. Also since the adjustment is from one side, the bridge also allows the saddle to be pulled tighter for the walk in. Try as I might, I haven’t found a down side to this bridge

 

[FrankNess14]

[mention]Fl Canopy Stalker [/mention] is that amsteel Blake’s a full bury? Locked Brummell for girth or prusik lite or prusik and full length bury? How long is it? This looks promising and I may have to try it out!


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[Fl Canopy Stalker]

[mention]Fl Canopy Stalker [/mention] is that amsteel Blake’s a full bury? Locked Brummell for girth or prusik lite or prusik and full length bury? How long is it? This looks promising and I may have to try it out!


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Both sides of the bridge have the tag end spliced all the way back through itself stopping about 3” short of the end of the amsteel. That will make the stopper knot a little smaller upon the exit. It helps make the amsteel a little stiffer while also giving it a core for the friction hitch to bite. And yes I do use a locked Brummell to keep it from sliding back while I am tying everything. The locked Brummell isn’t really necessary because the tag end is ran all the way through into the stopper knot tied at the end however, I use the locked Brummell because it makes it easier to milk the slack out of the top (cover). I’ll message you with the length details if you’d like

 

[GetHomeSafe]

See my problem with oplux is that it’s not as strong as I would like. And it requires such small hitch cord for the friction hitch. No one can shorten their bridge without removing their weight from it, but with my amsteel bridge, I can lengthen it while loaded if I want. I can also adjust it with the use of one hand. But I also don’t use the traditional set ups of the utilibridge or the triad. So with oplux, I get a rope that isn’t near as strong, is more susceptible to bend radius and ultraviolet degradation. The only benefit is that it has a high melting point (900 degrees) but if your friction knot bites down as hard as amsteel does, friction will never be produced enough to cause the amsteel to fail. So all those knots in oplux would reduce its strength to below 3000 lbs however since a bridge is in doubled rope configuration I am sure it’s plenty strong enough. Just not my favorite for a bridge I’d use old fashion 11mm predator rope before I’d use oplux. I’m weird like that

There are no knots in the oplux other than a stopper knot. So I have no idea why your talking about knots in oplux? The knots are in the TRC. 5463 pounds is the rating for 8mm oplux. The TRC is higher as it doubles. 5463 / 210 = 26+ safety factor. I weigh 185, but used 210 to account for cold weather gear weight. Arborists shoot for 20. As always with all our gear. Inspect, if there is excess wear... Replace. Adjustment is extremely easy even post load. But I am glad your pleased with your rig, I am as well.

 

[tmattson]

Question since this thread is related. I have a Flatbranch Solitude2.0 on the way, with webbing bridge.
For a backup bridge (I will use webbing as primary and leave a few inches of slack in the backup), is beal jammy or some othe 5-6mm cord a good choice? Want something simple and not bulky. Maybe some Bealjammy from DanO. Just looking for opinions.

 

[Fl Canopy Stalker]

There are no knots in the oplux other than a stopper knot. So I have no idea why your talking about knots in oplux? The knots are in the TRC. 5463 pounds is the rating for 8mm oplux. The TRC is higher as it doubles. 5463 / 210 = 26+ safety factor. I weigh 185, but used 210 to account for cold weather gear weight. Arborists shoot for 20. As always with all our gear. Inspect, if there is excess wear... Replace. Adjustment is extremely easy even post load. But I am glad your pleased with your rig, I am as well.

Man trc shows a 3500 or so break strength and I also know the leg is doubled so it’s approximately 1.5 times stronger than the weakest spot. Again I am not saying that oplux isn’t strong enough. In fact I said it is plenty strong for a bridge due to it being doubled. I am stating it isn’t as strong as 1/4 amsteel which is around 7700 lbs break strength. And the osha standard for fall restraining equipment is typically 10 times your suggest load or 3000 lbs, whichever is higher. For climbing ropes it’s not 20 times for safety factor, it’s minimum of 5000 lbs and arborists also require at least 10 mm climbing line and at least 8mm friction cord. Unless you had special training to use ropes below that size. So if we are spouting “arborist standards” then oplux would have to be your hitch cord and your rope would be even larger. Again not splitting hairs with you since we aren’t arborist and it doesn’t matter. Not everyone wants their bridge to adjust from each side because with double friction hitches, the bridge usually won’t shorten as much as one side adjustments. And it’s also more fiddle factor. That’s not everyone because we are all different. I simply stated I don’t like oplux because it has many of the hang ups of amsteel without the strength. That is my opinion, it wasn’t meant as an attack you your bridge or to somehow insult you and I am sorry if it was taken that way. Lots of people love oplux and rescue tech because they are not effected by heat. I’m just not one of those people.

 

[GetHomeSafe]

The TRC cord strength doubles not 1.5x. But you want to argue and have the last word so you win. Happy now?

 

[Fl Canopy Stalker]

The TRC cord strength doubles not 1.5x. But you want to argue and have the last word so you win. Happy now?

Wasn’t arguing dude. I definitely don’t want to offend you or argue. You forgot to subtract the loss of strength for the knot to make the continuous loop or the knots for the eye to eye end. Even if you use sewn eyes on rope that small it usually weakens the rope by 10 to 15%. So 1.5 is usually a safe estimate, for some continuous loops it’s even less. Remember we are tying hitches, not using it in basket configuration so the strength isn’t doubled. It is still way stronger than most likely needed for a bridge. Again not arguing sir. You asked me what I meant and gave me some stats, I only offered my response. Sorry again if I some how rubbed you wrong. I didn’t mean to good sir.

 

[Fl Canopy Stalker]

Question since this thread is related. I have a Flatbranch Solitude2.0 on the way, with webbing bridge.
For a backup bridge (I will use webbing as primary and leave a few inches of slack in the backup), is beal jammy or some othe 5-6mm cord a good choice? Want something simple and not bulky. Maybe some Bealjammy from DanO. Just looking for opinions.

Beal Jammy on rescue tech or oplux will be plenty strong enough for a bridge, amsteel will also be plenty strong enough. Are you planning on the back up bridge being adjustable or would a fixed length work for your application

 

[tmattson]

Adjustible until I get it dialed in. Then likely fixed.

 

[Islandshooter]

Adjustible until I get it dialed in. Then likely fixed.

That’s what i did. Until i started cinching it smaller while climbing sticks or one-sticking. Just makes my life less aggravating to be able to adjust it. But thats just me

 

[Fl Canopy Stalker]

Adjustible until I get it dialed in. Then likely fixed.

Then 5.5 Beal cord on 8mm rescue tech or oplux works great. Another fantastic option sometimes over looked is 9mm pro tac from Bluewater. Although I will say oplux ties down a little tighter than rescue tech or pro tac. Which is good if you tie a figure 8 for your eye. I believe @phatkaw posted a fantastic picture of his set up. Or creating an amsteel bridge would work just as well. There’s a video of the triad on page one of this. On you tube I believe there’s a video of how to create a utilibridge, or the bridge I posted would all work too. When it comes time that you make a fixed bridge then oplux with 2 figure 8’s would work great: or you can splice amsteel with two eyes, girth hitch one side and use a carabiner to attach the other. Since it’s fixed. That way you can remove the back up if you want. There are a whole bunch of ways it can be done.

 

[John RB]

I like 2 separate bridges on my saddle. My Factory bridge is longer and that's the one that I spend my time on. My short one is used for redundancy other specialty maneuvers. Its also my rappel device, given that it has a carabiner locked on it and I use that to form my munter friction hitch. This is how I rig my redundant Bridge.

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