- Location
- Lexington, Kentucky
Haha nope. Neighbor was there next door working on some stuff and the dog kept looking at something under the shed. Never found out what it was.
CMI Twin Expedition
- Thread starter TreeStuff
- Start date
- Location
- Vancouver BC
I'm confused now too. Now it IS ok to use mechanical ascenders without backing them up? First of all ya the issue of debris, second they aren't even rated for life support, third haven't toothed cams been know to shear the cover off of ropes when heavily loaded? The petzl hand ascenders are also only rated to 5KN which is WAY below life support. Deffinately surprised to hear that comment from Tom D.
- Location
- Vancouver BC
And fourth, mechanical ascenders have the ability to fail or malfunction and generally much harder to inspect (internal mechanisms)than a hitch. So long as a hitch is tied, set and dressed properly it is generally bomb proof, no? Anyways no chance in hell I'm hanging my a$$ off of an ascender...
- Location
- Retired in Minneapolis
Ascenders have been used to move on MILES of ropes. Overall, I would trust a mechanical more than a hitch..but...this is a VERY broad brush statement, don't nitpick or we'll get distracted.
Sure, ascenders can destroy ropes. But, that isn't likely to happen unless there is slack in the system.
I've read test results from drop/pull tests on hitches. Some slip to failure at pretty low loads. the prusik tends to perform the worst in the tests. Most hitches will slip/grab though. There are some cord materials that have such low melting points that they shouldn't, in my opinion, be used for friction hitches. Tenex-type materials concern me.
Used correctly ascenders have a good performance history. Like anything, used wrong, they will fail.
Sure, ascenders can destroy ropes. But, that isn't likely to happen unless there is slack in the system.
I've read test results from drop/pull tests on hitches. Some slip to failure at pretty low loads. the prusik tends to perform the worst in the tests. Most hitches will slip/grab though. There are some cord materials that have such low melting points that they shouldn't, in my opinion, be used for friction hitches. Tenex-type materials concern me.
Used correctly ascenders have a good performance history. Like anything, used wrong, they will fail.
Waldo
Participating member
- Location
- Portland, OR
even a friction hitch will get jammed up with debris and fail.
- Location
- Central Hardwood Belt, USA
[ QUOTE ]
But the topic of debris becoming jammed in the cam somehow has popped up. Wondering if Tree Machine has found a fix for this on his Petzl's.
[/ QUOTE ]
Yes, quite simply, don't bash through brush like a frickin gorilla.
The control allows you to advance mere centimeters at a time.
You may hang, fully suspended, all your weight, for as long as you want before advancing. You advance at your speed. Stop, go, you just do it at your pace, whatever that moment calls for. There is no penalty,.
While hanging, if you sink a flipline, you can trim stuff out of your path.
Work on the way up is OK. Whatever is efficient and safe. Tie in twice, relax, cut safely, do your work in excellence.
Don't <u>allow</u> debris to jam in your ascenders. YOU are in control of the climb. The ascent part of your climbing world just became easier. Utilize the advantage, clear brush deliberately or just watch carefully as you slowly push the ascender through a cruxxy area. Yes, I did say slowly. You don't need to 'jam' an ascender through a brushy zone. Stand on your footlock, advance the ascender. You may some day, like myself, enjoy negotiating the more complicated parts.
If you can totally trust the ascender to do what it does, you can best do what it is you do, which is safely ascend, work-position, and perform arboricultural duties while aloft.
Great conversation, thank you for inviting me in.
But the topic of debris becoming jammed in the cam somehow has popped up. Wondering if Tree Machine has found a fix for this on his Petzl's.
[/ QUOTE ]
Yes, quite simply, don't bash through brush like a frickin gorilla.
The control allows you to advance mere centimeters at a time.
You may hang, fully suspended, all your weight, for as long as you want before advancing. You advance at your speed. Stop, go, you just do it at your pace, whatever that moment calls for. There is no penalty,.
While hanging, if you sink a flipline, you can trim stuff out of your path.
Work on the way up is OK. Whatever is efficient and safe. Tie in twice, relax, cut safely, do your work in excellence.
Don't <u>allow</u> debris to jam in your ascenders. YOU are in control of the climb. The ascent part of your climbing world just became easier. Utilize the advantage, clear brush deliberately or just watch carefully as you slowly push the ascender through a cruxxy area. Yes, I did say slowly. You don't need to 'jam' an ascender through a brushy zone. Stand on your footlock, advance the ascender. You may some day, like myself, enjoy negotiating the more complicated parts.
If you can totally trust the ascender to do what it does, you can best do what it is you do, which is safely ascend, work-position, and perform arboricultural duties while aloft.
Great conversation, thank you for inviting me in.
- Location
- Retired in Minneapolis
[ QUOTE ]
And fourth, mechanical ascenders have the ability to fail or malfunction and generally much harder to inspect (internal mechanisms)than a hitch. So long as a hitch is tied, set and dressed properly it is generally bomb proof, no? Anyways no chance in hell I'm hanging my a$$ off of an ascender...
[/ QUOTE ]
Zacn,
Here's another way to look at this...
We have many more complicated life support systems that we use daily that NEVER get inspected. Cars, airplanes, the electrical system in our houses.
Hitches and cord are not as simple as most people think. Look back on the cord that was used to make a bridge for a climbing harness. It turns out that high density cordage is NOT the best for that application.
If we looked at the amount of time that arbos spend on rope compared with the rope time in the whole world it would be a small sliver. Sure, we have unique surroundings but take a look at industrial rope access. Painting, welding, repairs using toxic materials all are done routinely on rope and mechanicals with success.
Mechanicals can be inspected easier than cordage I think.
And fourth, mechanical ascenders have the ability to fail or malfunction and generally much harder to inspect (internal mechanisms)than a hitch. So long as a hitch is tied, set and dressed properly it is generally bomb proof, no? Anyways no chance in hell I'm hanging my a$$ off of an ascender...
[/ QUOTE ]
Zacn,
Here's another way to look at this...
We have many more complicated life support systems that we use daily that NEVER get inspected. Cars, airplanes, the electrical system in our houses.
Hitches and cord are not as simple as most people think. Look back on the cord that was used to make a bridge for a climbing harness. It turns out that high density cordage is NOT the best for that application.
If we looked at the amount of time that arbos spend on rope compared with the rope time in the whole world it would be a small sliver. Sure, we have unique surroundings but take a look at industrial rope access. Painting, welding, repairs using toxic materials all are done routinely on rope and mechanicals with success.
Mechanicals can be inspected easier than cordage I think.
- Location
- Chapel Hill, NC
I don't think industrial rope access is comparable to tree work. They don't work with the unknowns arborists do. Everything is engineered and rated including the tie-ins. Roped access is ridiculously safe compared to tree work, they're climbing on stuff that was designed to be climbed with rope. It's the 'sport climbing' of professional roped disciplines. Tree work is Trad.
EVERY tree is different, I've seen a live 5" white oak limb fail right at the crotch under a 200# load. IRA is not the same and when you set the tie-in from the ground, entering on doubled ropes is considerably safer than a trunk tied single rope. And to me, that's when the climber is most vulnerable.
I'm all for SRT when it's ready and I appreciate you guys on the leading edge, making it happen... but it ain't here yet... soon hopefully, but not yet. You're having to force it. SRT won't be ready until it's naturally the best way to work a tree. Right now, that's DdRT. It's safer and there's not really much of a reason to switch, other than you just wanna climb SRT. The not having to isolate is cool but that ain't enough to make me want to change.
Consider this a friendly argument... I'd hate to have to drive all the way to Tejas just to whip up on you.
EVERY tree is different, I've seen a live 5" white oak limb fail right at the crotch under a 200# load. IRA is not the same and when you set the tie-in from the ground, entering on doubled ropes is considerably safer than a trunk tied single rope. And to me, that's when the climber is most vulnerable.
I'm all for SRT when it's ready and I appreciate you guys on the leading edge, making it happen... but it ain't here yet... soon hopefully, but not yet. You're having to force it. SRT won't be ready until it's naturally the best way to work a tree. Right now, that's DdRT. It's safer and there's not really much of a reason to switch, other than you just wanna climb SRT. The not having to isolate is cool but that ain't enough to make me want to change.
Consider this a friendly argument... I'd hate to have to drive all the way to Tejas just to whip up on you.
- Location
- Retired in Minneapolis
Hahaha...the trip would be worth it..not for the whipping though! We've never argued so why would I start
I'm not making a 1:1 comparison, just look at rope access overall. Mechanicals get a bad rap when cordage gets off easy until the same factors are considered.
Until I, or someone, sits down and does the +/- chart comparing DdRT and SRT this will continue to spin. There won't be a best or worst like in any part of life. It depends...
When I think of comparing I go back to my first exposure to SRT when I read the first edition of On Rope. The chart in there that compares the various rope ascent systems tells a lot. There are many factors to consider, ease of setup is only one. Safety is another.
Back to the thread...I'm delighted to see this new tool in the market. It solves safety issues that had been hard to fix previously.
It is such a nice tool I almost...ALMOST...would go back to DdRT in order to justify buying it
I'm not making a 1:1 comparison, just look at rope access overall. Mechanicals get a bad rap when cordage gets off easy until the same factors are considered.
Until I, or someone, sits down and does the +/- chart comparing DdRT and SRT this will continue to spin. There won't be a best or worst like in any part of life. It depends...
When I think of comparing I go back to my first exposure to SRT when I read the first edition of On Rope. The chart in there that compares the various rope ascent systems tells a lot. There are many factors to consider, ease of setup is only one. Safety is another.
Back to the thread...I'm delighted to see this new tool in the market. It solves safety issues that had been hard to fix previously.
It is such a nice tool I almost...ALMOST...would go back to DdRT in order to justify buying it
- Location
- Chapel Hill, NC
OH, and I just got my CMI EXPTWIN ascender, haven't roped up with it yet but it looks pretty solid.
No way the rope can escape the frame with the redundent safeties.
The only failure modes I can see are pin failure, cam failure or frame failure... and frame failure seem veeerrrryyyy unlikely, it's a solid hunk of metal. The pins appear to be 1/8" diameter so, also unlikely to fail. The cams appear to be investment cast and very substantial. CMI says they took all parts off their price list because no one will ever have to buy one, they warrant them 100%.
All that adds up to high initial trust in this device. I'll probably try it without a cord backup for working the lower canopy on the way up. It's a nice adaptation of the Expedition specifically for arborists.
In that same order I got some All Gear High Tenacity Loop Line and it seems pretty useful. It's stupidly easy to splice with a locked Brummel. It's flat laid hollow braid... looks like maybe 32 strand...Dyneema.
It will be great for making tethers and slings... lot's of potential. Good thing to have on the truck just in case... but have a fid with you, I wouldn't use it with knots without really testing it first, slippery stuff.
No way the rope can escape the frame with the redundent safeties.
The only failure modes I can see are pin failure, cam failure or frame failure... and frame failure seem veeerrrryyyy unlikely, it's a solid hunk of metal. The pins appear to be 1/8" diameter so, also unlikely to fail. The cams appear to be investment cast and very substantial. CMI says they took all parts off their price list because no one will ever have to buy one, they warrant them 100%.
All that adds up to high initial trust in this device. I'll probably try it without a cord backup for working the lower canopy on the way up. It's a nice adaptation of the Expedition specifically for arborists.
In that same order I got some All Gear High Tenacity Loop Line and it seems pretty useful. It's stupidly easy to splice with a locked Brummel. It's flat laid hollow braid... looks like maybe 32 strand...Dyneema.
It will be great for making tethers and slings... lot's of potential. Good thing to have on the truck just in case... but have a fid with you, I wouldn't use it with knots without really testing it first, slippery stuff.
i think the srt vs Ddrt is basically what kind of trees do you climb 90% of the time. are the tree suitable for srt? or are the trees more suited for Ddrt? i think excurrent trees are more suited to srt it is easier to set an srt line in a conifer or sweet gum or hickory. but in a large very decurrent water oak or live oak? humm i don't think so especially if you have to change tips alot. where, what, what type of work am i performing 100% of the time determines my access method, climbing system, gaffs or no gaffs. so if i climbed redwoods and doug firs i'd be a srt junkie, but i don't so i Ddrt and use twin tips a lot. i think the proper question is what works best for me. i've said this before and i'll say it again i know guys that climb with out gaffs throw knotting their way around the tree tying a sui-slide that ROLL out some quality work. personally i like rope guides, hitch climber pulleys, access lines, removable retrievable redirects, saddles that don't squeeze my boys and my hips, and mar bars. with all that said one week a year i get out the old stuff and old school only to remind myself where i came from. and yes i rope walk on a rare occasion
- Location
- Chapel Hill, NC
Agreed about excurrent vs decurrent and suitability. That's kinda the thing with me and SRT. It's better on the vertical but not so much the side to side, especially with lots of scaffolding branches.
When climb a tall pine or a sweetgum, I go up on a doubled 10mm, to me it's easier and safer.
I know it sounds like I'm anti-SRT but really I'm not. I want it to work and I've tried, but I keep going back to DdRT.
With a ring/ring friction saver and tuned hitch it works better than I can. The only time my rope slows me down is when I have too much of it to manage.
When climb a tall pine or a sweetgum, I go up on a doubled 10mm, to me it's easier and safer.
I know it sounds like I'm anti-SRT but really I'm not. I want it to work and I've tried, but I keep going back to DdRT.
With a ring/ring friction saver and tuned hitch it works better than I can. The only time my rope slows me down is when I have too much of it to manage.
- Location
- Oakland, CA
[ QUOTE ]
Back to the thread...I'm delighted to see this new tool in the market. It solves safety issues that had been hard to fix previously.
It is such a nice tool I almost...ALMOST...would go back to DdRT in order to justify buying it
[/ QUOTE ]
Tom,
as an SRT climber, would you use a tool like this (i mean specifically the safety backups) to use if it were available in a single line version? Would it displace whatever other ascender you are using currently?
thanks for letting me pick your brain!
Pete
Back to the thread...I'm delighted to see this new tool in the market. It solves safety issues that had been hard to fix previously.
It is such a nice tool I almost...ALMOST...would go back to DdRT in order to justify buying it
[/ QUOTE ]
Tom,
as an SRT climber, would you use a tool like this (i mean specifically the safety backups) to use if it were available in a single line version? Would it displace whatever other ascender you are using currently?
thanks for letting me pick your brain!
Pete
- Location
- Retired in Minneapolis
I resist derailing the thread to talk about how SRT can work in spreading crowns because any branch union becomes a new redirect...so I'll leave that for another thread....hehehhehe!
Pete,
Is that a bristlecone pine in your avie? Or...???
don't pick too much, I'm not feeling too brainy right now.
Hmmm...if those features were in a single handle AND I needed another handled ascender...then I might get one. As it is I have too many single handled ascenders now. If I was starting out without gear or giving advice to a new SRT climber, yeah, I'd LOVE to see the same features in single.
I don't use a handled ascender very often though. If I did long ascents and used a treefrog more I might get one. The Uni can be my upper or chest ascender depending on the situation. If I use the Uni as my chest ascender then I'll use a handled for the upper. I'm not so concerned about ropes coming out in any case. I NEVER let ascenders be jammed through brush or to roll them past limbs when they are weighted. I'm VERY careful to not let them brush against anything when I'm climbing the tree instead of the rope. If they ever do brush the tree I feel the vibration and stop to look and do a sit test before going back on rope.
Pete,
Is that a bristlecone pine in your avie? Or...???
don't pick too much, I'm not feeling too brainy right now.
Hmmm...if those features were in a single handle AND I needed another handled ascender...then I might get one. As it is I have too many single handled ascenders now. If I was starting out without gear or giving advice to a new SRT climber, yeah, I'd LOVE to see the same features in single.
I don't use a handled ascender very often though. If I did long ascents and used a treefrog more I might get one. The Uni can be my upper or chest ascender depending on the situation. If I use the Uni as my chest ascender then I'll use a handled for the upper. I'm not so concerned about ropes coming out in any case. I NEVER let ascenders be jammed through brush or to roll them past limbs when they are weighted. I'm VERY careful to not let them brush against anything when I'm climbing the tree instead of the rope. If they ever do brush the tree I feel the vibration and stop to look and do a sit test before going back on rope.
- Location
- Vancouver BC
Tom, you are using rope access to compare to tree work which is apples to oranges. I'm working with a fellow who comes from a rope access background. He says there is a reason there are very few deaths in rope access. It is redundant. There is at least 2 points of attachment at ALL time, and some times as many as 6. In Canada at least. Why? Because in case that POS mechanical device fails, you won't fall and die. You were suggesting that it is fine to use it with no back-up which is what this whole argument is about right? One more point that I already mentioned, its not rated for life support. Doesn't that mean it can't be used for life support? So it's not ok to use a loopie rated to 22KN (4,950 lbs) but its ok the use a mechanical device, not backed up and rated to 3300lbs? This sounds kinda crazy to me..... Anyways to each his own I guess. Do whatever you are comfortable with and stay safe.
- Location
- Oakland, CA
Thanks Tom,
You'll love it - that is actually a big sierra mountain juniper (40' maybe?) - i think that juniperus occidentalis var.australis (which they are changing to juniperus grandis, looks like) is what is meant by that. In any case, a tree instead of a shrub, this one is at 9000 feet or so in the northern hinterlands of Yosemite. My lady and I saw a lot of these on our hike last summer, some *way* bigger than this but i couldnt' get far enough away from those ones to get a good photo!.
As to thread:
Yeah, I am just getting into SRT when I feel it'll help me, so I am coming at this question from that perspective. I am looking for something to use as the top of a tree frog ascent system for access, or at least I think I am. The EXPTWIN is cool, but perhaps not worth double the weight of an Ascension if it is mostly used on single rope. I would get the EXPTWIN as a single with certainty, but am not sure if I'd use it tons in a doubled ascent situation. Besides, at $150, one could save an extra $200 and get into a Uni, which is a whole new can of worms.
I know what you are saying about moving through brush and rope popping out - just know when you are in a funny spot and keep an eye out, just the same as always.
hmmm. thinkin'. time to take that thinkin' to sleep.
Pete
You'll love it - that is actually a big sierra mountain juniper (40' maybe?) - i think that juniperus occidentalis var.australis (which they are changing to juniperus grandis, looks like) is what is meant by that. In any case, a tree instead of a shrub, this one is at 9000 feet or so in the northern hinterlands of Yosemite. My lady and I saw a lot of these on our hike last summer, some *way* bigger than this but i couldnt' get far enough away from those ones to get a good photo!.
As to thread:
Yeah, I am just getting into SRT when I feel it'll help me, so I am coming at this question from that perspective. I am looking for something to use as the top of a tree frog ascent system for access, or at least I think I am. The EXPTWIN is cool, but perhaps not worth double the weight of an Ascension if it is mostly used on single rope. I would get the EXPTWIN as a single with certainty, but am not sure if I'd use it tons in a doubled ascent situation. Besides, at $150, one could save an extra $200 and get into a Uni, which is a whole new can of worms.
I know what you are saying about moving through brush and rope popping out - just know when you are in a funny spot and keep an eye out, just the same as always.
hmmm. thinkin'. time to take that thinkin' to sleep.
Pete
treebing
Been here much more than a while
- Location
- Detroit, Mi.
SRT is way better for spreading trees than tall skinny ones IMO. You dont have to ever change tips you just climb through the crotch and keep going! I mean to say the true advantage of SRT come through when you have a broad spreading tree that you need to work the tips of. DDRT is best for me when I am on a straight up and down situation with no redirects and I have to carry a big saw.
- Location
- Central Hardwood Belt, USA
Everybody,
On this SRT / DdRT 'debate' please realize we are in a Dual Ascender thread.
The dual ascender allows handling of a pair of lines (twin) identically. This is neither DdRT nor SRT.
I don't think the readership may quite fully realize. It's not about DdRT or SRT anymore. DdRT and SRT have now become options.
If you are all about SRT, use a single ascender, you don't need the dual. To fully realize advantage from the dual, you need to <u>use it</u> as a dual. This is 1:1 ascent, footlocking the twin line (and all the meat that a paired rope provides). It is the easiest ascent mode out there. Again, you are neither in DdRT or SRT.
Once you experience the ease that footlocking can be, you'll want to work and work position off of them. The backup safety, dual-redundancy allows this. No ascender prior has been so inviting as to allow....
gulp.....
manipulating the cams as needed throughout your climb.
There. It has been said. Old taboo broken. New technology, new era. New rope technique. DbRT or twin-line. I suppose you could call it dual line, goes along with the dual ascender. I need the community, collectively, to wrap your heads around this. This is very, very new to probably most all of you, I would think,
So it is neither DdRT nor SRT. It is identical to SRT in almost all respects, except no anchoring one end and no doubling effect at the tie-in point.
DbRT is as simple as cracking open a cam on one side while leaving the other side untouched, you use your second hand to belay any short drops, capitalizing on the friction over the tie-in, as well as the fine-control friction with your hand.. Slow and precise positioning while under full weight. Anti-panic mode? Just let go.
But for the most part, downward adjusting of the dual ascender is by cracking open both cams simultaneously (with one hand) and drop the ascender down to where you want. THIS, TOO, IS DIFFERENT, you no longer have to weight your rope to adjust down. You just move your piece up or down as needed, it's very liberating.
And you will never have to advance a frickin knot and tend slack. That slavery is over. The physics don't lie. Ascent has come of age.
On this SRT / DdRT 'debate' please realize we are in a Dual Ascender thread.
The dual ascender allows handling of a pair of lines (twin) identically. This is neither DdRT nor SRT.
I don't think the readership may quite fully realize. It's not about DdRT or SRT anymore. DdRT and SRT have now become options.
If you are all about SRT, use a single ascender, you don't need the dual. To fully realize advantage from the dual, you need to <u>use it</u> as a dual. This is 1:1 ascent, footlocking the twin line (and all the meat that a paired rope provides). It is the easiest ascent mode out there. Again, you are neither in DdRT or SRT.
Once you experience the ease that footlocking can be, you'll want to work and work position off of them. The backup safety, dual-redundancy allows this. No ascender prior has been so inviting as to allow....
gulp.....
manipulating the cams as needed throughout your climb.
There. It has been said. Old taboo broken. New technology, new era. New rope technique. DbRT or twin-line. I suppose you could call it dual line, goes along with the dual ascender. I need the community, collectively, to wrap your heads around this. This is very, very new to probably most all of you, I would think,
So it is neither DdRT nor SRT. It is identical to SRT in almost all respects, except no anchoring one end and no doubling effect at the tie-in point.
DbRT is as simple as cracking open a cam on one side while leaving the other side untouched, you use your second hand to belay any short drops, capitalizing on the friction over the tie-in, as well as the fine-control friction with your hand.. Slow and precise positioning while under full weight. Anti-panic mode? Just let go.
But for the most part, downward adjusting of the dual ascender is by cracking open both cams simultaneously (with one hand) and drop the ascender down to where you want. THIS, TOO, IS DIFFERENT, you no longer have to weight your rope to adjust down. You just move your piece up or down as needed, it's very liberating.
And you will never have to advance a frickin knot and tend slack. That slavery is over. The physics don't lie. Ascent has come of age.
- Location
- Central Hardwood Belt, USA
treebing
Been here much more than a while
- Location
- Detroit, Mi.
Tyler was describing to me how you climbed like that. I am very intrigued. I would like to see it in action. Isn't it a pain to manipulate both tails? do you have to have both hands on the ascender to descend? I am picturing you thumbing each cam through out the climb or when you limb walk can you just sort of manipulate one cam. I think really seeing is understanding. It sounds crazy. Working the tree off of dual ascenders.
What are other advantages of double line other than retrievabilty and bigger purchase area for footlock. I like the retrievability, but i really dont think footlocking a single line is very difficult.
What are other advantages of double line other than retrievabilty and bigger purchase area for footlock. I like the retrievability, but i really dont think footlocking a single line is very difficult.
