Replacement Bridge for Sequoia

rfwoodvt

rfwoodvt

New member
Location
This side of eternity.
Looking at replacing the web bridge on my sequoia with a spliced rope bridge.

Looking for your thots on what type of rope you would use and how you would address the necessary shortness of the buries.

Since I have a lot on hand, I was thinking of tenex covered with a polyester cover from some left over double braid. But that is just because I have some on hand.

What would you use, and why?

ThanX!
 
Rick, I don't have time to post them now but I have pics of a jacketed bridge I made about 20 months ago. It had 2 separate spliced Vectran elements and a jacket from a kernmantle rope. Both elements severed from wear and compression that was so severe, you won't even recognize the material as Vectran. This happened last week, a couple of pics are on my FB page; it looks a LOT like the bridge failure Jeremy had with jacketed Technora.

Even though I love the design, I think you should be cautious with jacketed bridges. I think you need to be able to watch your bridge wear. I was stunned at how much abuse that thing was absorbing.

We've discussed that Technora and other Aramid fibers are self abrasive but the literature states that Vectran has no such problem. I'm sure self abrasion was a factor with my bridge but I think bending fatigue and fiber compression are the main factors.

Nick had a bridge with simple polyester, a hollow braid element but it wasn't Tenex, some kind of yacht rope I think.
Hey Nick, wanna give us the details on that bridge?
 
18M? Wow, that's a long way. I'm sorry to hear that, I'm assuming he died. I think it's the first time I've heard of a bridge failing and resulting in a fall.

Yep, the bridge is such a crucial part of the system. Failure in the absence of really good luck is catastrophic.
 
[ QUOTE ]
A climber here in Victoria recently fell 18m due to a failed spliced rope replacement bridge on a sequoia.

Dont take any chances on this.

[/ QUOTE ]

I've been splicing 3 strand since 1967, hollow braids since 1987, DB's shortly thereafter, 16 strand since it was introduced. I still don't splice my own bridge. Go with a manufacturer's replacement.
 
I became uncomfortable with the rope bridge in general after climbing on it a few times. I have a cougar and always felt a little at risk. I climbed with an old buckinham with steel rings for years and always felt secure. I got the idea on this site to ad a second bridge as a back up. I tied a length of tachyon with buntline hitches to the rings and now clip into both bridges at once. It's not bulky or awkward at all and I feel much safer. I inspect them every climb and they are holding up well. You have to trust your gear or how can you focus on your job.
 
[ QUOTE ]
18M? Wow, that's a long way. I'm sorry to hear that, I'm assuming he died. I think it's the first time I've heard of a bridge failing and resulting in a fall.

Yep, the bridge is such a crucial part of the system. Failure in the absence of really good luck is catastrophic.

[/ QUOTE ]

Unbelievably, he did not die, or even really get as messed up as you would expect. He was in a wheelchair, but not permanent, but i think both legs badly broken.

From what i know, the outer jacket of the rope looked fine, the inner core or splice failed. It was not yet established whether it is a splice failure or a rope failure. I think its still being investigated.
 
I make rope bridges from all-polyester 1/2" rope. They break at over 5,400 pounds and I can get them down to 9 (or maybe 8) inches. I'm really happy with them. I triple-dip them in Yale Maxijacket coating just to stiffen them up a bit.

Rope bridges can be super safe. You just have to select the right fiber, rope construction, and splice for the application.

love
nick
 
Yes I can, as a matter of fact. There are some very old threads on here, some dating as far back as 2002 or 2003 where I first showed my bridge. I will merely spend a few minutes searching the archives of this forum and I shall return with a couple pictures and links to whole threads on the topic- rather than having to recreate the whole conversation...
 
I still vote for nylon webbing bridges like the one on my TreeFlex, or the original one on the Petzl's.

it is strong, easy to check for wear, and mine , even though I climb hard, shows no signs of wear.
 
I don't like the way my BFII OEM bridge wore so fast, that's why I replaced it. I agree webbing is better suited as a material for repeated bending under compression. I really don't care for the BFII webbing bridge design though.

I'm not sure what I'm gonna do yet, I'm riding a temporary made with Tech Cord and a dyneema runner but I've got some ideas. I used to use a two element bridge like williamd, usually clipping into both but it was kinda handy to use them individually when on two tie-ins. I used that at least a year and never had any real complaint, I just wanted a simpler setup so I made the one that turned to mush.

From now on I intend to replace my bridges every year... with what? I'm not sure but I'm thinking I'll incorporate a redundant part somehow, one that doesn't get much wear and can save my butt if the primary fails. I think the 5mm NE Tech Cord will work. We're using it now to backup Jared's Hi-Vee bridge with stopper knots... cuz we found out if you work at it, you can pull double overhand and stevedore knots through a bow shackle once they set and get wet and shrink up.

I think bridges/shackles need to be checked every climb. That's the only reason I didn't get pasted. I know exactly when those bridge elements parted... granted I'd just gone 70' on them so my check was out of sequence but I'd checked the day before and the bridge felt solid. It obviously wasn't, I've been climbing on an understrength bridge for a while now I guess. That's why I also think the bearing elements need to be visible and easy to check.

Of all the life support components we use, I think the harness bridge is THE most critical because of the wear it gets. You guys should see this Vectran, pictures don't do it justice... the stuff is like compressed paper pulp, you can't even tell it was braided cord except for the eyes.
The bending and compression forces on a bridge are pretty major, then think about the angles and how much extra tension is on the attachment points... the thing has concentrated forces working on it day in day out and it gets wet and sweaty and bloody... bridges have to be really tough.
 
yeah, being able to inspect it every climb is important Chip.

For my life, I'm staying with folded, sewn nylon webbing :)


I have seen what type of force and abuse tubular web slings can absorb, and that is just double thickness.

web bridges are folded then folded then doubled tripled or quadrupled and sewn, damn things would probably tow a train when basket-hitched ;)

make mine webbing when my a$$ is on the line buddy .
 
Thats a good point, I've dropped some good sized wood into those daisy chain webbing slings, and those are just single thickness held together with bar tacks. Those sequoia bridges are hell, 4 or 6 times thick?
 
[ QUOTE ]
...Dyneema, vectran, technora, kevlar don't belong on a bridge. Polyester does...

[/ QUOTE ]

Why not Dyneema, Nick?
 
I've not seen a dyneema woven into a rope that is tight enough to work on something so small.

Also, when I've experiemented with a dyneema bridge, it didn't handle the friction from the biners very well. It didn't abrade as quickly as technora, kevlar, and vectran- but it didn't do nearly as well as polyester.

I've had polyester bridges last a loooooong time. I've seen nothing else that can handle this particular application as well as polyester.

love
nick
 
[ QUOTE ]
I've not seen a dyneema woven into a rope that is tight enough to work on something so small.

Also, when I've experiemented with a dyneema bridge, it didn't handle the friction from the biners very well...

[/ QUOTE ]

This is interesting. I haven't tried using Dyneema in a friction situation. Evidently, from your experience, there is more resistance to abrasion when the weave is tighter. I would have guessed, since the rope is rubbing against a smooth biner, that the weave would make no difference. Maybe I'll have to make one and see how it works for me.
 
[ QUOTE ]
[ QUOTE ]
I've not seen a dyneema woven into a rope that is tight enough to work on something so small.

Also, when I've experiemented with a dyneema bridge, it didn't handle the friction from the biners very well...

[/ QUOTE ]

This is interesting. I haven't tried using Dyneema in a friction situation. Evidently, from your experience, there is more resistance to abrasion when the weave is tighter. I would have guessed, since the rope is rubbing against a smooth biner, that the weave would make no difference. Maybe I'll have to make one and see how it works for me.

[/ QUOTE ]



I think he's saying that it has more to do with the material than the weave. Also, keep in mind that professional climbers are using their stuff for about 6-10 hours per day 5-7 days a week. That kind of wear is hard to replicate without being tested in work situations.

Nick is brilliant, I'm going to stick to what he says.
 
[ QUOTE ]
Evidently, from your experience, there is more resistance to abrasion when the weave is tighter. I would have guessed, since the rope is rubbing against a smooth biner, that the weave would make no difference. Maybe I'll have to make one and see how it works for me.

[/ QUOTE ]

Not just my experience- this is one of the major factors of rope construction. A more tightly woven rope will be weaker, heavier, and more abrasion resistant than a loosely woven rope. Rope construction is all about matching the weave of the rope to get the most out of the fibers in those 3 categories (weight/cost, strength, abrasion resistance) and just a few other things.

That is why webbing makes a great bridge. It is woven very tightly (compared to rope) and can handle direct friction a lot better than, say, Yalex/Tenex.

There are things I like better than webbing. Some of my harnesses have webbing bridges, some have rope.

love
nick
 
You must log in or register to reply here.

New threads New posts

Back
Top Bottom