Trebuchet wrote:
moss and oldtimer: Many thanks. Great recommendations! Let's see: Be consist, i.e. "no flip flops in trees" (good tree-climber wardrobe decision, too?); tailor your climbing _style_ to accommodate when you're tired; commit to safety and be responsible for maintaining safe habits and systems. Please correct me if I've misinterpreted either of you.

Having said all that, I believe that climb-rated (23kN+) screwgate carabiners, double-auto-locking carabiners, and stainless "screw_link_s" are secure.

I believe that still unanswered question is, "Can a screwgate carabiner be "properly closed" to adequately prevent un-threading and inadvertent opening?". No, say the pros.

Vibration, friction, shock. I believe all these types of forces should be considered as potential methods for thwarting a gate lock.

I think that something like the Tory Red Cap Finger Tips (http://www.toryinc.com/) might be adapted to reduce the tendency for the screwgate lock to un-thread. In fact, I'd say there might be a size that would be adequate to similarly reduce the ease with which some have said that they can thwart the double-auto-lock gate. I'll probably buy a handful, strictly for the ground-_base_d laboratory environment, and see what they'll do. OK, here's the disclaimer: This mere speculation on usefulness of a specific technology is in no way a recommendation to any climber to use any product referenced.

Thanks again.

You got it. If you're fatigued, stressed or in a crisis (rescue) situation you may accidentally attach to a screwgate and treat it like an autolocker. Imagine using your climbing system if you were sleep deprived for one night. Can you still use it smoothly and safely? Give yourself room for mental mistakes in your setup.

I don't like the idea of trying to "improve" the security of a screw gate. Added security may make it difficult to undo when you need to get off it fast (change over to SRT rappel during stinging insect attack). Using a screw gate means that you're aware that rope movement or branch contact could potentially unscrew the gate. Therefore you accept it and climb with that awareness to protect yourself.

It's well known that autlockers can also be opened by rope movement and branch contact. Again, the climber using an autolocker must be aware of this and pay attention during the climb.

A versatile climber can make use of either when they need to but why undermine yourself by mixing gate technology on purpose?
-moss

On the subject of redirects, I don't like a doubled rope running through either type of gate. Redirects are more a technique of work climbers. For a rec climber it makes more sense to simply double crotch with the other end of your rope rather than redirect. The advantage being that you don't have to climb up to take it out like you do with a redirect. It takes a little longer to set up a double crotch (not much longer)but you eliminate the problem of rope running though a biner. It's also much easier to come back to the tree from an outer branch tie-in on a double crotch than it is on a redirect.

Rec climbers can learn a lot by paying attention to how pro arborists climb but there's a point where some work climber technique makes less sense for rec climbers. Secured footlock ascent is a good example, makes no sense for rec climbing. Cool skill to master but otherwise not useful for rec climbing.
-moss

I have used redirects while working in a tree by wrapping a small dynema sling around the branch thru a binner holding a small pulley. The rope follows along the pulley and it moves fairly easy. It works well in some instances but like Moss mentioned you will have to go back and remove it before being able to get down from the tree. It works but it is not that practical in general. In this set up I used screw _link_ biners or self locking it does not matter because the rope never touches the binner but instead moves along the mini-pulley.

Edited: rapping vs wrapping

oldtimer wrote:
I have used redirects while working in a tree by rapping a small dynema sling around the branch thru a binner holding a small pulley. The rope follows along the pulley and it moves fairly easy. It works well in some instances but like Moss mentioned you will have to go back and remove it before being able to get down from the tree. It works but it is not that practical in general. In this set up I used screw _link_ biners or self locking it does not matter because the rope never touches the binner but instead moves along the mini-pulley.

I was thinking that a redirect would be safer if you ran the rope through a pulley or a screw_link_. You'd need a double pulley though, right? Screw_link_ might be a happy medium, you can crank it down tight (carry a little wrench), or tighten it with grippy gloves. Even if it did somehow become unscrewed it would difficult for two ropes to jump out of the narrow gap on an open screw_link_.
-moss

You'd need a double pulley though,

I have a Fixe pulley like this one=>(http://www.rei.com/product/635119?vcat=REI_SEARCH )that is wide enough to fit both ropes at the same time. Since you are not moving long distances away from the redirect point the amount of friction is very minimum and the main benefit is to allow the rope to follow you along in a different direction without dragging over several rough branches and in the case you loose control the distance from the redirected TIP to the climber is shorter and the potential for a mayor tree trunk hit is significantly reduced or eliminated. Using a Screw_link_ is definitely overkill in this scenario because even if the redirect where to fail completely you are still tied to the main TIP way up higher from where you are currently working. IMO.
This set up technique I used many times in a couple of large take downs I did on three dead trees in from of my house. I tied as high as possible and worked along large limbs way out and this gave me a lot of extra balance while making the cuts with both hands on the chainsaw.

Rock climbers have been hanging in non-locking biners for many years. Would I? Prob. not.

I have some biners made by Black Diamond that ARE positive lockers and automtic at the same time. To open, just twist and open, but as they close, they automatically lock. Once closed, slide the sleeve up turn in the opposite direction and the sleeve snaps down into the lock slot. Gate can not be twisted or opened unless you lift, twist, drop, twist again and finally open the gate. Sounds very complicated, but they are VERY, VERY secure. Rated at 25 Kn. I don't think they make these any more, but I would never part with them. Pear shape is good for hitches too. All of a sudden I feel warm inside!

I need a hobby - oh wait...never mind.