Help me understand Carabiners a little better

J

jwp

I can't remember all the terms that I have seen but here are a few:

Twist lock
Screw lock
Ball lock
Pin lock (not sure about this one)
Auto lock
Bi lock
triple lock
Pear shape
D shape
Oval shape
Steel
Alum

I am sure that I have missed some.

Which carabiner is an example of a triple lock, ball lock, auto lock, oval, alum carabiner?

Is the petzl williams ball lock a triple lock carabiner? On this carabiner I push a button, then twist the barrel, and then push the gate open. So is this considered a triple lock, auto lock and a ball lock carabiner?

I have some screw lock carabiners that I really hardly ever use. I have heard the phrase don't screw up. I assume that this has something to do with the orientation of the carabiner in the system. Will someone in the know enlighten me to why the orientation of the carabiner or the term don't screw up is important.
 
It's probably easier to divide acceptable life support attachment devices into categories first, then ask questions per category. Mileage varies on terms, there are regional and industry differences on how people describe these attachment devices.

Here are the two major categories for tree climber life support attachments (not including rope snaps used on lanyards):

1. Locking carabiner
An aluminum alloy or steel carabiner with a locking gate mechanism. Carabiners are not safe to load on the short axis across the gate, they should be loaded on the long axis, there is dramatic strength difference. Carabiners come in many different shapes, D, Oval, Pear (more often called HMS) etc. Locking gates on carabiners can be autolockers or manual lockers (twist gates). There are many kinds of autolocking gate designs. Twist locking manual gates are not recommended for tree climbing for a variety of reasons. They require a mininmal number of turns to open or close, this can be a problem in an arboreal environment where there is a high possibilty of unobserved contact between the gate and tree parts or climber gear. Autolockers are effective but must be inspected regularly to verify that the mechanism is working properly. An autolocking gate carabiner must be checked to verify it has locked whenever you clip in to one.

2. Screwlink
A mild steel, stainless steel or aluminum alloy screwlink (I don't use aluminum screwlinks). Screwlinks do not have a pivoting gate like a carabiner. They can generally be loaded from any direction. A delta shape is stronger for all load directions, pear and oval screwlinks have good strength loading on the shorter axis but are strongest on the long axis. Screwlinks can be hand tightened or wrench tightened, they require many turns to lock or unlock. They are usually double threaded and are closed with a long hex profile nut. They come in many different shapes (pear, oval, delta etc.) stock diameter and rated strength. Use reputable manufacturers for life support use. For example do not use a hardware store screwlink for life support use. A screwlink used for life support should have the manufacturers name and rating values stamped on it.

That's all I got on the subject ;-)
-AJ
 
Well maybe I have more...

There is no "triple lock" carabiner that I know of. The current standard of safety for an autolocking gate requires three actions to open. Two of those actions are locking (or unlocking). To be accurate this type of autolocker is called a triple action/double locking gate carabiner.

Confused yet? The best way to understand is get one in your hands and play with the locking gate, slow it down and examine each gesture required to open or close the locking gate.

-AJ
 
[ QUOTE ]
I have some screw lock carabiners that I really hardly ever use. I have heard the phrase don't screw up. I assume that this has something to do with the orientation of the carabiner in the system. Will someone in the know enlighten me to why the orientation of the carabiner or the term don't screw up is important.

[/ QUOTE ]

"Don't screw up" refers to orienting a twist lock carabiner with the gate opening down. If you're "screwing up" that means that gate is opening is up not down. This is not applicable in tree climbing, at least for autolockers, tree climbers orient the gate up or down depending on their system configuration. I'd stay away from using twist gate manual lockers for tree climbing, they are too problematic.
-AJ
 
[ QUOTE ]


Is the petzl williams ball lock a triple lock carabiner? On this carabiner I push a button, then twist the barrel, and then push the gate open. So is this considered a triple lock, auto lock and a ball lock carabiner?

[/ QUOTE ]

The Petzl William is a triple action double locking gate. Ball lock just refers to the particular design of the autolocking gate. You can get a Petzl William autlocker in a "normal" autolocking gate design or a ball locking gate design. They are both autolockers and are both triple action. I hate button lockers, what a pain! Haha, had to get that editorial comment in there ;-)
-AJ
 
JWP...get out your copy of Z133 and read these sections.

You do have a copy of Z133 don't you?

8.1.10 Carabiners used as part of a climber’s work-positioning (suspension) system shall be selfclosing
and self-double-locking and shall have a gate-locking mechanism that requires
at least two consecutive, deliberate actions to unlock. Carabiners shall be capable of
withstanding a 5,000-pound (22.24-kN) load along its major axis with the gate closed
without breaking or distortion sufficient to release the gate.
8.1.11 Carabiners and snap hooks used as part of a climber’s fall protection (work-positioning/
suspension/fall-arrest system) shall not be linked together unless designed to do so and
accepted by the manufacturer.
8.1.12 Load-rated screw links used as part of a climber’s work-positioning (suspension) system
shall have a minimum tensile strength of 5,000 pounds (22.24kN) and shall be securely
tightened to ensure that they will not unintentionally open during use.


If you want to learn more about carabiners take some time and paste those words into Google. By doing your homework you'll acquire a LOT more in-depth knowledge than you might hope for from posting such a wide ranging question here.

The Sherrill catalog is a great source of information too.

There are SOOOO many good books available now that should be on every arbo's bookshelf.
 
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