Accepted Climbing Practices (ACP)

Since we're looking at this as an international guideline and we're not writing arborist guidelines it would make sense to go with the 22kn minimum strength threshhold for all equipment used for life support (I think Leon is also recommending this).
-moss

This subject will now be broken down into smaller pieces in topics by themselves to keep focused. From here on out when we talk of Accepted Climbing Practices we will head it under ACP. Like: ACP- Carabiners, ACP- Saddles, etc. I will start with what I see as topic threads as proposed by our subject facilitator, Leon.

Ethics will be handled in a similar manor. They will look like; Ethics- Noise, Ethics- Ground Impact, etc.

Thanks Leon for your review of Z133 subjects. You’ve given us a place to start, subject wise.

I encourage others to take part too. This is a discussion after all.

Originally posted by Leon
Well this appears to be going a little slow. I'm going to take Peter's advice and start with some ideas on one subject (climbing equipment) and see if I get any responses.

Here is what the Z133 has to say about arborist climbing gear. Some of this is quoted, some is my paraphrasing. In a few places I have added my own opinions, which are in parentheses:

Saddles: "Type II saddle belts and lanyards as specified in ANSI A10.14 shall be worn when above ground level". (Seems to me like rock climbing harness would be okay as long as the climber doesn't mind being incredibly uncomfortable. Also I would have no problem with a homemade harness, for instance one made out of tubular webbing as long as the parts all meet the safe weight requirements)

Ropes: ANSI says that arborist ropes should be 1/2 inch, have a MBS of 24kn when new, and should be designated as arborist climbing lines by the manufacturer. Split tails should meet the same strength requirement. The new edition will probably include the newer 11mm lines as OK. It does not mention static entry lines.

Lanyards: (Lanyards should have the same MBS as ropes. Other than that it doesn't really matter what you use.)

Carabiners and Snaps: These should be double locking and at least 5,000 lbs MBS. (I don't know where they came up with the 5,000 lbs. It makes much more sense to me to use 22kn, which is the standard in every other industry I'm aware of, and is only 50 pounds less than 5,000.)

Other climbing devices: The only other device the Z133 currently as far as I can see mentions is the false crotch, which it says should be rated to 5,000 lbs MBS. (My opinion is that ascenders, descenders, false crotchs, etc. are all OK as long as they are rated to 22kn and used properly.)

Splicing: "Splicing shall be done in accordance with manufacturer's specifications."

Here's a few more quotes from the current Z133:

"Equipment used to secure an arborist in the tree or from an aerial lift shall not be used for anything other than its intended purpose. EXCEPTION: The arborist climbing line may be used to raise and lower tools."

"Ropes and climbing equipment shall be stored an dtransported in such a manner to prevent damage through contact with sharp tools, cutting edges, gas, oil, or chemicals."

"Arborists shall inspect all compnents of their climbing system for damage, cuts, abrasion and/or deterioration before each use. Excessively worn of damaged compnents shall be removed from service"

"Arborist climbing lines shall never be left in trees unattended".


Well there you have it, folks. A crash course in what the Z133 currently has to say about arborist climbing equipment. Obviously this does not cover everything that could be mentioned (tree hammocks, for example), and there is no reason that we cannot change what it does cover. My fingers are tired so I'm going to let this go for some responses.

What do you guys and gals think? What needs to be added? What needs to be taken away? What needs to be changed? What is the average wing speed velocity of an unladen swallow?

If this does take off, and a real discussion begins about this we should probably give it it's own thread.

what about friction saver rings? whats the boards desire for WL and material? some of us use stainless steel anchor shackles (3000 - 10,000 lb WL) for our friction saver straps....

There is no specific spec for friction savers in ANSI. As long as all components are rated to 5,000lbs you're good to go. As always, use common sense.

what are the rings rated for on the friction savers that many companys sell??? anybody have any idea?

(this is what i'm refering to:

Originally posted by SRT-Tech
what are the rings rated for on the friction savers that many companys sell??? anybody have any idea?

I'd check with Buckingham, they seem to have the corner on the market in the U.S. on this type of false crotch. They come in steel or aluminum, the steel rings are out of sight strong. The aluminum would have to be 5000 lbs or better as Leon mentioned. I have never heard any report of a ring failing on these for arborist work. This type of saver is not as commonly used in the rec climbing world. I have a Buckingham with steel rings and used to climb on it a lot but rarely use it now. It's heavy and I like my conduit pipes, they're very easy to install and wear well. The ring savers are not bad to install but when you take them out it's best to lower them with a throwline so as not to damage the rings on ground impact and that invites problems in some situations.
-moss

Hi Moss,

I'm an engineer with a heavy construction background, and I think I can shed light on the 22kN/5,000lb requirement.

The OSHA standard for the capacity for an anchor for fall protection is 5,400lb. At my old job, we would always get crews wanting to tie off to a jersey barrier as fall protection, but try as we might, we could never get them to work at 5,400lb. Even a big piece of concrete like that would fall over with that force applied.

My co-worker decided to check the 5,400lb thing to see if it made any sense. Turns out a standard "worker with his tools" (250ish lbs) that OHSA uses for fall protection standards will generate very close to 5,000lbs if they fall 7/8 feet and get stopped by a harness. The peak force can really get that high.

My guess is that the climbing standards use similar assumptions. So yes, if you're a decent sized climber and you fall a short distance before being stopped by your gear, your stuff really can see that kind of force and needs to be rated near 5,000lbs/22kN SWL.

Hope that sheds some light.

That's good information. In tree climbing it is said "we don't fall". There is zero or very little shock absorption in the rope or gear. A 6-8' fall on an arborist semi-static rope will develop dynamic forces that can kill or seriously injure the climber. That's why the most common phrase you'll hear from a tree climbing instructor teaching a student is "Push up the hitch, take out the slack!". For the purposes of professional (arborist) rope and harness tree climbing standards, my understanding is the rope strength rating system is based on a rescue scenario. A rope, carabiner or any stand-alone piece of life support gear should hold two 250 lb climbers x10 (or x15, I've heard both figures mentioned) to cover dynamic loading etc., the end value is close to the OSHA value you described.
-AJ