Adjustable harness bridge

[Tom Dunlap]

At the Texas TCC a competitor had an adjustable bridge on his harness that caught my eye. He had used New England Ropes Tech Cord to tie a distal as an adjuster.

When I made up the first iteration that's what I used. But, after having the distal bumped by the ring on the bridge I realized that I wanted a different setup.

The bridge is made from some 11mm Yale static line. It's soft so that a double overhand stopper is easy to use at the end for a stopper.

This is on my TreeFlex using the factory, rattle proof, shackles with the inserts.

Here, the bridge is adjusted about as short as possible.

In this configuration I would attach the elastic cord to the top of the Unicender to keep it upright. During ascent the Unicender acts like a chest ascender. It is low so it's out of the way of my hands.

The twisted shackle keeps the Uni fair. You may be able to see the stainless steel ring on my left. That has a breaking strength of 8k# and would be used for a double tie in.

 

[Tom Dunlap]

Pic 2

Adjusting the bridge shorter.

I do have to unweight the bridge with a little hip pop to let the rope slip through the Micro-cender. Sometimes the Micro will invert and get balled up by slipping under the webbing of the harness. That happens when I get sloppy instead of deliberate.

 

[Tom Dunlap]

Pic 3

Slacking out to extend the bridge.

Again, unweight the Micro-cender.

 

[Tom Dunlap]

Pic 4

View from the side. The extra rope for the bridge tails out to my right. It's tied off with a double overhand stopper knot and then secured to a little ring on my harness.

The extra bridge rope is daisy chained until I figure out how much I need. When that is dialed-in I'll cut the rope and secure it again.

 

[Zac]

pretty slick.

Where did you get the 8k steel ring?

Pretend you're a gear inspector at a TCC. Do you have a problem with the microcender having the spring-loaded pin as opposed to a nut and bolt?

 

[Tr33Climb3r]

[ QUOTE ]
pretty slick.

Where did you get the 8k steel ring?

Pretend you're a gear inspector at a TCC. Do you have a problem with the microcender having the spring-loaded pin as opposed to a nut and bolt?

[/ QUOTE ]

same exact question I was going to ask...

 

[Tom Dunlap]

The ring came from West Marine.

If I was going to a comp I would print out the catalog description and bring my sales receipt. In a pinch an ISC Gator if I had to.

Personally, I don't have an issue with the spring pin. It takes several very deliberate and complex motions to get the pin to slide out. Under a load the pin is very unlikely to be able to be slid out.

But...if I was going to a TCC I would have a second Micro with a grade eight bolt and brand new Nylock jam nut.

Good question Zac! See, the thing with using bolts is that I've see some mild steel, low grade bolts used which have MUCH less strength than the original factory approved spring pin. Then, I know that a Nylock nut looses holding power every time it's reused. I doubt that Nylock would approve of more than a single use in a life support situation...if they even approve of their jam nut being used in a life support system to begin with.

 

[Zac]

I don't put the bolt on. Sometimes that spring pin is hard to get out when it's unloaded.

 

[Colin]

doesn't that setup get the boys and the stomach in different positions?

 

[Tom Dunlap]

Nope...it has the least crotch-bite of any harness that I have climbed in during 35 years of treework.

Stomach??? I have a 5.5 pack tummy! Not bad for being 55

The way that the harness is configured the bridge supports pull away and the load is transferred down to the hips and then around back to the hip bones. Not onto the soft tissues if it's adjusted right.

 

[Treeswinger]

Looks awesome Tom Do you think it will work on my sequoia?

 

[Tom Dunlap]

TS,

I'm sure there is a way to adapt the concept to your harness. Since the TreeFlex has small shackles it is an easy setup.

Post some pictures if you put one together.

 

[Treeswinger]

I will Tom Gonna play with the idea after the conference

 

[richhoffman]

Tom,


I take it the purpose of this is to slack out the bridge so you can have a self belay while hip thrusting???

 

[Tom Dunlap]

Hip thrusting??? What's that?

I haven't done that for years

Actually, by shortening the bridge for the ascent the Uni is down tight like a chest ascender. Then, when it's time to work I can extend the bridge to keep the Uni where I want it...either below my chin or above my head but never out of reach. When I dial in the longest distance I'll cut and resecure the lanyard and do away with the extra length.

 

[richhoffman]

Self-belay would be nice on limb walks!

 

[Waldo]

Treeswinger, there is a very slick way to set it up on your sequoia. instead of the micro-ascender that Mr. Dunlap has on his put a little ropeman ascender right onto your gold ring, it will fit. Be sure to tie the other end of your bridge onto the rated ring, because the ropeman isnt ansi friendly.

link:
http://www.wildcountry.co.uk/Products/AscentDecentBelay/RopemanMK1/

 

[Treeswinger]

Thats a great idea Waldo thx!

 

[Tom Dunlap]

HOld on a second before you use a Ropeman!

Go and read the instructions and make VERY sure that the cross sectional dimensions and shape that are required are met by using the ring on the harness.

When I used a Ropeman years ago I didn't read the instructions and used too small a biner. What I saw was that the wear was concentrated on a few teeth. That was a warning that sent me back to the instruction sheet. The biner I used was too small which could have lead to less than optimal grab.

When I did my prototype setup I couldn't find my MicroGrab so I used the Ropeman knowing that the pin in the shackle was too small. I only used it for walking around on the ground but the action wasn't right. The Ropeman would invert and flip 'inside out'. The Micro doesn't do that as much.

 

[Treeswinger]

There are 3 webbing loops on each side to attatch the bridge rings to the sequoia i use the center ones. I was thinking of attatching the microcender to the outside webbing loop on one side and the rope to the ring on the other side that should wok right?