Moss,
This is interesting but, I may be getting confused by terminology. The term I was seeing that I thought met ANSI standards was auto-locking. That's what my Jake is; it locks automatically but it only takes a twist to open it.

I assume double locking means you have to do two things to release the gate lock, like push up and twist. Omega makes the Jake in a screw-lock, a Quik-Lok, and a 3 stage Quik-Lok.

So do auto locks meet ANSI standards or do they require double-lock or triple lock biners and auto-locking?

I've been using screw-lock Petzl OKs and have yet to find a lock loose, but now I'm wondering if I may need to replace them with double locks.

Edit:
I think I've found the answer to my question. The WesSpur site says that to meet ANSI standards for Tree Care Operations and Arborists, the carabiner must be auto-locking, auto-closing, and require two actions to unlock them and another to open. The also have to have a minimum breaking strength 5,000 lbs (23kn).

I think the standard is (or should be if it's not) triple action, double locking. Meaning three moves to open or close. Two of those steps are locking so there is double redundancy on the locking and triple redundancy on the motion required to open the gate.

The easiest way to explain is to hold one in your hand and put it through the paces.
-moss

Ron,

I agree with you that autolocking biners are way more dangerous than screw locks. I choose triple action biners over screw locks, though.

Don't give up on that Omega Jake yet. Try out the 3-stage quiklock, which isn't near as prone to accidental opening. It's one of the smoothest opening triact biners on the market (in my opinion). I love 'em!

Guys, thanks so much for your responses. I went by On Rope 1 on my way in today and bought a Petzl Am'D Triact-Lock and a Kong HMS Auto-Block. They both are listed in the Sherrill catalog as devices that meet ANSI standards. Well I double checked that and Sherrill states that the Kong does NOT meet the ANSI standard, yet the Kong unlocks exactly like the Am'D - push up and twist. WesSpur says both meet the ANSI standard - no wonder this is confusing.

I'm sitting here playing with the Kong right now and with a 9mm rope through it and a half turn around the gate, and the slightess resistance on the end of the rope, I can pull the rope briskly and it immediately comes out of the biner. I can do it at will, time after time. And I'm not talking about extremes here, it's a half turn around the gate - that could easily happen and since I only have an 8 foot length of rope I put just a slight amount of friction with my finger to simulate the weight of a longer heavier rope. It's simply scary how easy it is to do.

I just tried the same thing with the Petzl Am'D and got the same results - it's easy to make the carabiner unlock, open, and release the rope. Not only is it easy, it represents a very simple configuration that could easily happen while climbing.

I have tried the same thing with my Petzl Oval screw locks and have yet to open one. In fact, commonly I have to use both hands to open a screw gate that I tightened snugly with one hand.

But let's be sure I am testing carabiners that meet ANSI standards. Each of these require you to push up the lock and then twist. Thats two actions. Then after doing that a 3rd action is required to open the gate. That's the ANSI requirement, right?

Lots and LOTS of confusion here about the ANSI Z133 standard. Let's see if I can clear up some of the confusion...

The Z requires that biners/life support hardware have greater than 5k# breaking strength. When a biner is rated 22kN it comes up about fifty pounds short. That's why the Kong biners don't make the cut...no matter what some vendors say...UNLESS the Kong biners are labeled 5k#, and some were for a while.

The gate opening definition is:

...requires two separate and distinct motions to prepare the gate to open.

The actual spring loaded gate is NOT counted as a motion. Twist lock biners and screwgate biners don't comply with the the Z standard.

For too many years arbos have used biners that snap shut. The use of screwgate biners has never been common in pro tree climbing in the US. Since that's the case I feel VERY strongly that screwgate biners not be used. Considering the few documented accidents from having autolockers open I believe we're on the right path.

Tree climbing is a bit different than other rope access disciplines. We routinely go up, down and sideways. Our ropes move across bits and pieces that could cause screwgate biners to open.

People need to be taught to do gear checks routinely no matter if they use screwgates or autolockers. Almost every time that I reposition I'm giving my whole system a once-over. This takes absolutely no time.. It becomes as routine as breathing if the climber is taught to do that from the beginning. Too often climbers are not being taught with a strict regimen...too much loosey goosey _style_ actions.

Since autolocking biners came on the market I have never had one fail during use. No one who's worked for me ever had a failure either. The autolockers that I have in my 'Dead Climbing Gear Collection' have come from other climbers. The ones in the collection that are mine are all Kongs. They fail when a small plastic piece inside the gate sleeve breaks. This has always happened when a gate snap shuts, never during use. In those cases another biner was taken and the Kong junked.

The most that I have ever had an MR screw _link_ open, after being hand tightened, is three flats or about 1/2 a turn. The threads are finer on MRs than screw gate biners. When screw/nut threads are made there are several tolerance or slop, specifications. The MRs are tight, screw _link_s loose. Look at the thread pitch too. Oh, when I use MR or screw_link_ I mean the ones made only by Maillon-Rapide that are commonly found in climbing catalogs. Along with these plain steel ones I use stainless steel screw_link_s made by Wichard or other known marine quality manufacturers. It the company name and rating aren't on the _link_ or hangtag, I don't buy them.


Ron,

How do you get the wrapped rope to push in the button on the Petzl biners and release? Are you using the new _meta_l sleeve biners or the plastic sleeves?

Wow! Right you are! I didn't realize that until you posted - the Kong is rated at 22kN; that is shy of the ANSI standard by about 54 pounds. However, while that is a concern, it's only shy by a bit over 1%; I'm not too concerned about that.

What really, really bothers me is whether they will unlock in use. I can "drop" a rope much easier with a PAT (Push And Twist) than I can using the exact same procedure on a screw lock. OTOH, I have to respect the collective expertise that went into setting the ANSI standard.

While I am really new at tree climbing, I am widely experienced in antecdotal "evidence". The problem with antecdotal evidence is the absence of detailed accounts and numbers required for statistical accuracy.

That is, do we know for sure how many total climbs have been performed using screw locks and out of those climbs how many times a screw lock biner openned and caused an accident?

Also, it is not surprising at all that certain types of equipment are used and other types aren't. If most of the tree climbing instructors use a certain piece of gear, that's what they teach and that's what their students use.

You asked how I hold the biner:
I hold the biner vertically with the gate to the right and the spine to the left. The gate opens at the top.

I pass the rope from the bottom over the bottom end of the biner, through the biner and under the top end of the biner.

I hold the bottom end of the biner in my right index finger as if the biner had been attached to a loop. I bring the rope at the top of the biner back over the gate; it clearly makes a half turn around the gate. I apply a very slight amount of friction to the rope at the bottom of the carabiner to simulate a little weight or drag a rope would naturally have. I briskly pull the rope upwards and it pulls the gate up and twists it around and opens it and the rope drops free. It's easier with the Kong than the Petzl, but I can do it pretty easily with either.

I even tied a figure 9 with a bight for a little mass and did not apply any friction to the rope and could still open the gate and release the rope.

Please understand, I consider this a serious concern; this is not just something I wish to banter back and forth about. I'm new to this and even though I have over $100 invested in screw lock biners (Petzl OK) I won't hesitate to buy safer biners if I see reasonable evidence that I what I'm using is a significant risk.

But I also need to be sure that stories about screw locks openning are not propogated by circular cirulation. I also want to be sure that a few incidents have not been made to seem like many more.

As for ANSI, did they have data that they analyzed and came to a conclusion that screw lock biners were in fact X% more likely to open than double locks or was it because the experts on the committee had always used double locks and heard a story or two about screw locks and decided from that?

I guess the issue is on what data or evidence was it decided that screw locks were less safe than double locks?

And P.S.
Can somebody tell me the configuration of a 5-3 Blake's hitch. I asked this in another thread and got no responses. I know the 5 means five wraps, but are the 3 wraps at the bottom or top?