Ascender ratings

S

Sawdust

Location
Bucks Co. P.A.
I have been using SRT for 9 years now. Dont beleive I ever used DRT to acces a tree. Only used for comp. My main tool is the PETZL handled ascender. NEVER had any problems with it. I have used many other tools for this. I always find my way back to PETZL(handeled). I have seen the JUMAR used wrong and fail twice. Both at a comp., but that was 5 or so years ago. Cmi just doesnt feel right and look right. The thing I'm not comfortable with, now I'm getting older and...well maybe not wiser :), but the teeth on the PETZL are starting to bother me. I've noticed more cover fraying recently that makes my rope seem less desirable to use.

The point is I like the PETZL. But the ratings listed on the notice dont match the 5k rule. Downward force is rated at 20kn, upward force is 18kn. Could I get an explanation on this.Is it the total of the numbers that make it safe for use or is it being overlooked.
I'm still looking for a cammed ascender with a handle. If only petzl would make their BASIC with a cam instead of teeth or a toothless cam.
Later
 
What's Rob? I too been using the Petzl and really liked it. I loaned it out once and the guy I loaned it to said it slipped on him a few times. I have noticed that if you do not slide it up parallel with the rope it will jam up or slip a bit. I normally don't have a problem but once in awhile when in a hurry I do. I bought a Kong double ascender a few months ago and use it all the time now for single and double. I like the two handles and has about the same feel as the Petzl. I feel it's a better and sturdier design. I've noticed I can move much faster with the Kong and if you are going to use it one handed you just have to use the handle on the camming side. The only problem I see is that there is no rating stamped on it just the CE stamp and number.

BigJon
 
Tim Walsh wrote a couple of articles on ascenders last year in TCI. You could write to him C/O of the NAA or look up his email in the Users section. He might email the article to you.

Take a look at GAry Storrick's page for the definitive answer to all ascenders and descenders:

http://storrick.cnchost.com/VerticalDevicesPage/VerticalHome.shtml



The rating numbers, I believe, are the loads that the frame will fail not the grip rating. In order to have a number for a grip load every rope has to be tested in the same way. Any numbers taht you will find are for rock climbing rope, either static or dynamic. No one has ever done any laod tests on arbo rope. Since arbo rope is bigger than rock rope, the numbers will be way different.

This is an interesting issue for arboriculture rope work. On one hand, people are freaked out about climbers replacing the webbing on B'fly saddles and tieing KNOTS for cripes sake! Then on the other hand, ascenders are allowed even though they're labled for ropes up to 11/12mm and have breaking strengths less than 22kN. Some inconsistencies that need to be ironed out.

Take a look at the ISC ascenders: http://iscwales.com/
These beauties are stout! Milled out of a solid piece of aluminum not stamped. The teeth have blunt points and a really good cam design. Denny Moorhouse knows how to make gear. On a rock climbing forum one person wrote that an ISC could be used as a hammer if needed and still would be the best ascender on the market.

Hearing about occasional slipping gives more creedence to using a back up of some sort. Take a look at the Rocker while you're in the ISC page. Yates sells them in the US.

Tom
 
A couple of weeks back there was a very serious accident in southern Germany involving the Kong ascenders. A young climber ascended on a double line into a conifer, 8m up, in the first branches, one of the cams opened up, he fell to the ground and snapped his spine. Amazingly- and very fortunately- the nerves remained undamaged, but still a very serious incident. Let's hope he gets better soon. What probably happened, was that the lower branches flicked first the safety open, then pulled the cam into it's open postion. Then the rope came out, ran through, and that was that! Apparently, after the police came to investigate the accident and saw how the cam had opened, they banned the use of Kong ascenders in the police force. The climber is sueing Kong.

The basic problem with using the ascenders the way we do, is that despite having two camming mechanisms, this doesn't constitute a second safety. If one cam opens, the line'll run through & you'll take a fall- unlike on two isolated lines, where it would be a second safety, or in SRT, when you back up the ascender. It's really the worst of both worlds. Also, on the Kong ascenders, there's that "open" position, where the cam is jammed behind the body- if you look at the "Patin", for instance, it doesn't have that. What it means, is that if, as was the case in this accident, a branch does jam up against the pins- that stick out well beyond the body- it'll remain open, instead of snapping back into place.

I'm just back from France, they do a lot with ascenders, like climbing off them (admittedly some people do back them up with two prusiks & release them before climbing off them). I think cross loading the ascenders is a sure-fire receipe for disaster. This wasn't supposed to end up as a Kong rant- I'll willingly admit that Ascenders are comfortable, but I do feel for our application they're not the right tool and potentially dangerous!

The sollution? I reckon the easiest alternatives are either using a backed-up SRT set-up or a foot-lock strop.
 
Simple ascender safety addition

If you are using this sort of ascender, a carabiner with a circular cross section can be placed in the uppermost attachment point closest to the cam and it will ensure the rope stay in place. Its the same hole in the illustrations used for having the ascender "pull along" with you. Make sure you put the carabiner around the rope rather than in front of the rope.

Heres a link with an example- a simple kong oval carabiner through the upper hole of a SRT (australia) handled ascender...on the way up into the crown of a 90meter euc viminalis.
By the way, I try to avoid that girth hitch into the bottom handle...even though its strong as the ascender teeth it still wierds me out.

http://www.geog.utas.edu.au/yoav/yopho/archive/evercreech/index/15EvercreechViminalisTree9NOV02wwhiteknightgoingup.htm
 
Re: Simple ascender safety addition

Mark,

I appreciate that you took the time to share that story. A prayer goes out to the climber.

Yoav,

I don't think that both of the top holes can be clipped with the doubled Kong ascenders. I could be wrong. Would someone who owns them check? If a biner can't be used as a lock a pin could be used like the spring pins on Gibbs ascenders.

I forgot about those SRT ascenders. They make a wide variety of ascenders. If I ever visit you, I know taht I'm bringing some of them home with me.

http://www.srte.com.au/default.asp


Tom
 
Re: Simple ascender safety addition

Your right about the biners. I don't own one biner that will fit through both holes at the top of the Kong double ascender. I tried petzl william the oval petzl, DM Whales, Faders, Black Diamond, Mongoose, petzl attache. Anyone else have a biner that fits?

BigJon
 
Re: Simple ascender safety addition

You can push down on the cam and it won't remain open but if you push down on the lock out latch it could conceivably get pushed far enough into the locked (open) position.
You could disable the latch or just use your head like you do with your hitch and keep it clear of branches.
I always use a back up hitch but not a prusik.
The only problem is with a doubled rope when one is locked into the ascender and the other rope passes freely through the hitch, will it stop your descent?
I doubt it.
I think you would have to secure both ends at the bottom but then there would be no way to retrieve it from up in the tree.
 

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Re: Simple ascender safety addition

Tom, what am I supposed to do with that link(Gary Storricks Page)?? Also I just bought brand new Petzl, stamped rating is for 8-13mm now.
As far as slipping on a Petzl..?? Just cant picture it. I havent even come close to even seeing a sign of slippage. I have always used a biner to lock the rope. Yes, it says it in the "directions". People usually laugh when I read the inserts and stuff. If anything they give you a couple of ideas to use it for.
So based on the numbers in the insert, we shouldnt be able to use them. But I'll fight to use them. As long as it's used right. Theres no need to side load. Not made for that.
Set your line right and ya shouldnt have to worry bout that.
Yoav, that looks like a nice ascender. any more info on that?
Later
 
Re: Simple ascender safety addition

Sawdust,

I fixed the link to Storricks page. Once you get there, look for the link to his collection. A couple of clicks later and you'll be reading about some amazing tools.

Glad to hear that the Petzl's are rated for 13mm rope. As you know, I'm an advocate of backing up ascenders. The Rocker is my current fav.

Tom
 
Re: Simple ascender safety addition

Kevin, I find your attitude somewhat surprising, to say the least. Are you implying that if something happens to a climber using ascenders, that he wasn't "useing his head"?

I'd say the risk on the scenders is higher, because a hitch can't open up on you completely. And there is the odd branch on a tree that could do so. It all boils down to the old "what can happen, will happen, at the most awkward moment" thing.

The way ascenders are frequently used in tree-care there is indeed cross-loading: consider aerial-rescue, with the climbing-line running of a pulley below the ascender. For this case, TCC rules only demand a back-up knot below the ascenders. Fact is there is/ can be considerable force applied across the body of the ascenders.

Just to clarify my position on this issue: I'm not trying to make ascenders worse than they are, it just irks me when people imply that ascenders are the only, best & most efficient way to access the tree, witout also mentioning potetial risks, especially versus arborist with less experience.
 
Re: Simple ascender safety addition

Mark;
It shouldn't surprise you.
What I'm saying is you shouldn't rip and tear up through the limbs, be careful, cautious and aware of what you are doing at all times.
Keep your mind on what you and your equipment is doing at all times, that's using your head.
It's accident prevention.
We even take care in watching that our hitches don't become contaminated with debris which will cause it to fail.
That has been drilled into us since day one.
 
Re: Simple ascender safety addition

So does anyone know about these ratings on the ascender. Seems like we gettin away from the topic.
I have been searching and leads me back to what I already know. If these numbers dont match, some of the "back-ups" could be worse if it needed to be used.
 
Re: Simple ascender safety addition

Sawdust said:

>Yoav, that looks like a nice ascender. any more info on >that?

Actually, I don't know too much about them except that they make high quality stuff. That SRTE (sydney) ascender is the first I've used a cast ascender rather than a stamped ascender. It feels more solid and somehow seems to run up the rope easier. Another very nice feature is that it has a little flat ring placed in the main tie in hole rather than the squarish edges you find on stamped ascenders.
Here's their site:
http://www.srte.com.au/
The only unique item appears to be the "No worries belay device" and the minitraxionesque riggers mate.
enjoy
 
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