It wasn’t long ago when carabiners were not recognized by ANSI for tree climbing use. Now they are. Praise the Lord!

So what is a standard for life support carabiners? Locking, yes? How many actions? We have single action (screw down or screw up!), double action, and triple action varieties. Ball lock, barrel lock, and maybe other types of which I do not know about.

What about non-locking carabiners? Would you ever choose to hang with one? What standard would you go by?

What about snaps? Do recreational climbers use snaps? What kind should be used? Should the only guide for snap use be in its strength rating?

Peter, I believe that double locking and triple action mean essentially the same thing. The Sherrill catalog clarifies (or does it confuse it?) by calling these positive locking. These carabiners make two motions when automatically locking, for example the barrell slides down and twists clockwise. It takes three "actions" to open one of these (push up, twist counterclockwise, pull back the gate). The ball lock and barrell locks both fall into this category, as well as other more obscure mechanisms.


There are only two types of snap mechanism that I am aware of: locking and non-locking.


My personal opinion is that when used for life support, carabiners should be double locking, snaps should be locking, and both should be rated to a minimum of 22kn.

Double or auto locking are good terms. Why even consider using screw gate biners?

Screw gates can and are being used safely by some tree climbers and I know of at least one camp that uses some screw gate biners for its tree climbing program. They have a rigorous policy of doing a "gate check" with ALL climbers, whether they are using screw gates or double locking. They do the "gate check" before and during a program, and it ends up being part of the mindset of the climbing participants.
When I purchased my own equipment, I chose to buy double locking biners, primarily because they are faster. But I certainly would have felt OK about buying screw gate biners from a safety standpoint. I have to do a gate check with my double locking biners, anyway.

Patrick

I have had a couple occurrences (years ago when double action carabiners were state of the art) when a branch rubbed against the barrel and the gate opened. It was a shocking experience to look down and see the gate open with a branch inside. This was during my tree working days, when contorted positions were common.

So should a triple action carabiner be advised for main life support? What should be said about manual screw locks? Gate Check! We still use a “gate check” at the TCI school so new students will look at their main tie ins from time to time.

Checking gates should always be a normal thing. No question.

Unless I can read a study that shows that screw gate biners are better than double acting I'm not going to even consider screw gates for any climber support. I have used them occasionally for hanging my portaledge. In this application the biner is hung, checked and things don't change. Much different application than in a climbing system.