Help with Pulley System

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17 years 2 months ago - 17 years 2 months ago #129838 by oldtimer
Replied by oldtimer on topic Testing, Testing.......
Well, it was fun testing this or any system rather than me trying to argue every point and counter point back and forth. So, this gave me an excuse to try something (old) and new . Since I have done this before a long time ago and came up with the same results and that is
why I do not use it anyways.

There are some pictures on my flikr.com site that I posted in 2002.
http://www.flickr.com/photos/83574643@N00/484197295/in/photostream/
I made one more test tying a fixed rope
holding the top pulley and removed all the extra unneed figure 8 knots and Friction Saver and that way the pulley stays up next to the TIP branch and you can climb w/o the creeping down problem described on the other post. Still a very slow system and requires a lot of rope since I used a tanden dual pulley at the top and 4 ropes up and down between the top and bottom pulleys about 100 ft of rope total to reach about 30 ft high TIP.
It was fun to test it anyhow. Now we can move on to the next invention by another new rec climber.

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17 years 2 months ago - 17 years 2 months ago #129840 by wildbill
Replied by wildbill on topic Help with Pulley System
I experimented with Mark F's design of May 10-11, and it worked very well. I went up just a few feet several times just to make sure and then rigged it about 50 feet up and made four ascents. There were no problems that I could find.

I also tried replacing the lower pulley with a Grigri, which turned it into an elongated version of the Yo-yo or RAD system. This was not such a good idea because even my least stretchy rope, New England Safety Blue, had a little too much stretch and too much bounce to it. It took a long, long time to climb just a few feet.

On the plus side, this system is a little simpler to set up than the Super System and it has the added safety feature of being able to lower an injured or frightened climber to the ground.

On the negative side, it requires two ropes and a split-tail, while the Super System needs only one rope and a split-tail.

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17 years 2 months ago - 17 years 2 months ago #129841 by geofk12
Replied by geofk12 on topic Help with Pulley System

On the negative side, it requires two ropes and a split-tail, while the Super System needs only one rope and a split-tail.


I was able to set up Mark's system with only one rope & a spit tail - worked great.

Geof

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17 years 2 months ago - 17 years 2 months ago #129842 by john e routon
Replied by john e routon on topic " Geof K --You are the winner"
This post /book has been a thrill,observing all the interaction and concern by everyone.Now I realize why I selected the tree name of Trailwatcher. Geof --you are the man!!!!!!!!

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17 years 2 months ago - 17 years 2 months ago #129847 by TreeTramp
Replied by TreeTramp on topic One Rope + two rope sleeves + one biner = 4:1 MA
You all by know I like to swing. Really big swings made by rigging an 8 foot diameter trampoline with a six leg spider.




So to make the most use out of my rope I always use a simple lifting system made of the above items. And it is very easy to rig.

Set your rope over your anchor point by pulling the center of your rope over the limb with a sleeve on each rope. This gives your two bitter ends on one side and a loop on the other side of the limb. On the two better ends: Bend a 8 on one end and stopper knot on the other. Clip a biner in the 8 and add the loop from the other side in the same biner. Pull down on the stopper end and it pulls rope thru the biner and back over the limb and down to the end with the 8.

On the bottom side of the biner you can hook yourself or a Buick if you need to lift one.

Add a friction hitch on the down rope or sercure to a neighboring trunk and you are ready to 1,000's of pounds.

See you at the top and Rendezous.
Dan

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17 years 2 months ago - 17 years 2 months ago #129848 by moss
Replied by moss on topic Help with Pulley System

Originally posted by TreeTramp

Set your rope over your anchor point by pulling the center of your rope over the limb with a sleeve on each rope. This gives your two bitter ends on one side and a loop on the other side of the limb. On the two better ends: Bend a 8 on one end and stopper knot on the other. Clip a biner in the 8 and add the loop from the other side in the same biner. Pull down on the stopper end and it pulls rope thru the biner and back over the limb and down to the end with the 8.


After the second read I got it. Nice rig, I could have used it to pick up the car that was blocking me into my driveway on Sunday. Would have been fun to have the person return to find their car hanging in a tree.
-moss

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17 years 2 months ago - 17 years 2 months ago #129852 by geofk12
Replied by geofk12 on topic Help with Pulley System
I tried your suggestion and did not find it easy to move. Perhaps I had it rigged wrong. I tried it again, but this time with two biners at the top. It moved much easier. Saturday I'll try it again with two biners at the top and one at the bottom.

Thanks for the suggestion!
Geof

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17 years 2 months ago - 17 years 2 months ago #129855 by wildrice
Replied by wildrice on topic Help with Pulley System
We use this system all the time. Our site has used this for the past 2 years. We have never had it creep down. Also, we use a delta link at the top and run the the down rope through it. This allows it to be choked off, which may prevent the creep.
We only need one rope for this .As a member of search and rescue and other time mebmers that use MA for the past 30 plus years have never seen a flaw with this methode.

One of your tree monitors who is OSHA certified has thoughly inspected our climbing program and MA systems (including the PACK system) and has not found any flaws or concerns with it.

Personally, I can understand that the extra rope to support the Super System is nice incase of a rescue, but that is the only reason I find to use the extra rope.

Please note when you have your split tail tied in that you are putting weight on three ropes(one the down rope and the other two are supporting the lower pullie which the climber is attached to).

Mother Earth- Our Most Sacred Heirloom

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17 years 2 months ago - 17 years 2 months ago #129886 by treeman
Replied by treeman on topic My Super System test
Preamble comment to test:
I have had the top pulley creep on occasions too. I have never seen or heard of this system dropping a climber.

My test:
Setup-
No cambium saver used.
Anchor branch on white oak- 14 inches in diameter.
Running delta screw link set hard against anchor branch by hard pull from the ground.
No figure eight knots used on left side or anywhere on system except in running noose and bridge on split tail.
Distance to top pulley about 15 feet.

Two tests were applied:
Test 1: stand on ground and slack/pull, slack/pull with no load on standing part (down rope) of rope other than my arm weight. Result- top pulley descended gradually. Applied 20 jerks and achieved a 36 inch descent of top pulley. I then loaded up system with my body weight and shock loaded system and waited for my butt to hit ground. Butt stayed above ground and pulley did not move down further. I then stood up and hand jerked rope again with slack/pull tensioning. Pulley started to descend again by increments.
Test 2:
I then decided to load the system (pulley a bit down over 3 feet from anchor branch) up with an unusual weight. I had the Good Harken (GRCS) winch set up below the system and tied a 9/16 braid on braid load line and locked down the winch for a self tailed load. A pull test was applied. The load was applied to the figure eight on a bight- where a climber would be suspended. A dynometer was not used so quantification can not be accurately reported here. A hard load was applied. There was no movement of system. The load was taken off and I looked at the Blake’s hitch for fusion of knots. The Blake’s knot moved normally and was not jammed.

In my opinion it is the jerking of slack/load, slack/ load that makes the top pulley descend gradually. This is often done by inexperienced climbers that lack a more fluid movement of the Blake’s hitch. Possible solution is to eliminate the slack/load jerking by installing a pulley beneath the Blake’s hitch to automatically advance the knot.

A counter balance cord on the left side with a ground tie off is interesting. Certainly merits a test. A dynometer should be used for pull testing too I think.

Waving from a treetop,
Peter Treeman Jenkins

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17 years 2 months ago - 17 years 2 months ago #129893 by oldtimer
Replied by oldtimer on topic Let those Pulleys alone!
No Further kicking this dead horse!
I am "out" to try my new Rope I just got from Master Nick . It is bright BLAZE!!!!!

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17 years 2 months ago - 17 years 2 months ago #129896 by moss
Replied by moss on topic Help with Pulley System

Originally posted by Oldtimer
No Further kicking this dead horse!
I am one to try my new Rope I just got from Master Nick . It is bright BLAZE!!!!!


I am glad to see Treeman do such a thorough test. Putting a GRCS load on it adds a useful dimension to the testing.

I think putting a pulley/hitch advancer under the Blake's (as Treeman suggested) is the only way to travel if only to reduce the number of arm movements per pull and to reduce pulley creep.

I'll be using the system for a climb tomorrow.

Congrats on your nifty new and spliced (I assume) Blaze Oldtimer!
-moss

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17 years 2 months ago - 17 years 2 months ago #129902 by Tom Dunlap
Replied by Tom Dunlap on topic Help with Pulley System
I was with Peter when the trials were performed. We could jiggle the 2 rope line and make the choked line up top come down a little. But...it took a lot of effort and the climber would lower such a little bit that I can't see how a safety issue is involved.

Higher in the thread someone referred to a mythical "OSHA Guy" It is very unlikely that any OSHA employee would sanction something like this. This is way beyond their job description and likely their skill/knowledge base. I am going to guess that the person who looked at it was just another arbo/tree climber who might be involved in some safety capacity.

Climb on!

Strong limbs and single ropes!
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17 years 1 month ago - 17 years 1 month ago #129915 by jimw
Replied by jimw on topic Help with Pulley System
Oldtimer
posted on 14-5-2007 at 02:41 AM

I made one more test tying a fixed rope holding the top pulley . . . and that way the pulley stays up next to the TIP branch and you can climb w/o the creeping down problem described on the other post.


Wild Bill
posted on 14-5-2007 at 06:44 PM

I experimented with Mark F's design of May 10-11, and it worked very well.


Geof_K
posted on 14-5-2007 at 06:55 PM

I was able to set up Mark's system with only one rope & a spit tail - worked great.


Thanks, Oldtimer, Bill, and Geof. Making those kinds of safety/security modifications is one of the things that a few of us are hoping that anyone who chooses to use this system will make.

Peace.

Jim

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17 years 1 month ago - 17 years 1 month ago #129918 by jimw
Replied by jimw on topic Help with Pulley System
Wildrice
posted on 17-5-2007 at 12:32 AM

Our site has used this for the past 2 years. We have never had it creep down. Also, we use a delta link at the top and run the the [sic] down rope through it.

Interesting. I wonder what you’re doing that no one else is doing; everyone else reports creep. Others also report choking with the delta link.

As a member of search and rescue and other time mebmers [sic] that use MA for the past 30 plus years have never seen a flaw with this methode [sic].

I’m rather confused by that sentence. Surely you aren’t suggesting the use of this system by SAR teams, are you?! Your comment:

. . . I can understand that the extra rope to support the Super System is nice incase [sic] of a rescue . . . .

implies that you are. Why on earth would a competent SAR team use such a system?! There certainly are many more-appropriate and proven techniques.

I’m not an expert in vertical rescue, but it just doesn’t make any sense to me that someone would use this Superflaw System to do a rescue. In thinking about some rescue scenarios, it seems there is always a better system to use (even if Superflaw were without flaw).

Wildrice: Please provide one rescue scenario where the SS would be the preferred rescue system.

As for your having never seen a flaw with the system, certainly now that you have read this thread, you are aware that it does have a serious flaw, aren’t you?

One of your [is this an error? --- do you mean “our”?] tree monitors who is OSHA certified has thoughly [sic] inspected our climbing program . . . has not found any flaws or concerns with it.

Well, if s/he “has not found any flaws or concerns with it,” that only shows that s/he doesn’t understand it. That then shows that s/he did not inspect it thoroughly.

As for “OSHA certified,” I’ve addressed that before. Tom commented on it, too:
Tom Dunlap
posted on 21-5-2007 at 12:44 AM

Higher in the thread someone referred to a mythical "OSHA Guy" It is very unlikely that any OSHA employee would sanction something like this. This is way beyond their job description and likely their skill/knowledge base.

I’m glad you said that, Tom. Yes, twice before, it was said that an OSHA-certified person had approved the system.

So where are those alleged “OSHA certified” people who will state publicly that the Superflaw System is without flaw? Will those of you who know such a person ask him/her to join us in this discussion?

By the way, what does an OSHA “certification” indicate, anyway? Does it mean that they are certified to understand---truly *understand*---such things as rigging systems? Do they have the credentials to approve a design, as a Professional Engineer does? Or does it mean that they can read the rule book and state that a certain size rope is required?

I don’t know. I just now did a Google search for “OSHA certification” and did not see anything promising. I’m beginning to believe Tom was accurate when he used the word “mythical.” Does anyone out there know?

Peace.

Jim

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17 years 1 month ago - 17 years 1 month ago #129931 by jimw
Replied by jimw on topic Nice work, Treeman
Treeman, I really like your detailed report of your well-thought-out tests. Thanks for that!

Treeman posted on 19-5-2007 at 03:25 AM:

In my opinion it is the jerking of slack/load, slack/ load that makes the top pulley descend gradually.

That should be correct; moss and a few others have said the same thing.

Actually, “jerk” is the correct word from the world of physics: Just as “acceleration” addresses how a body’s velocity is changing, “jerk” addresses how the body’s acceleration is changing (simplistic explanation). Yes, “jerk” is a legitimate scientific term.

What is causing the system to creep is the extra force “felt” by the system when the climber moves upward: The velocity of the climber’s body changes from zero to some upward velocity; thus it has to accelerate. Mr. Newton told us that a force must be applied to cause a mass to accelerate. That force, added to the existing force (the weight of the climber), apparently is enough to cause the system to creep.

You say:

Possible solution is to eliminate the slack/load jerking by installing a pulley beneath the Blake’s hitch to automatically advance the knot.

I must be missing something here; I don’t see how the PMP would do that. The jerk (or even a smooth acceleration) is caused by the pull on the down rope, not by the advancing of the climbing knot.

I had hoped to run tests Sunday, but by the time I completed my obligatory yard work, rain was imminent. Maybe next weekend.

Treeman, I would like to suggest two additional tests for you (and moss, Bill, and any others):

1 --- Replace the top pulley with just a carabiner. This will simulate a pulley with significant friction. I realize that one would implement the system this way only if one did not have a pulley available. I’d just like for you to see how the system reacts when this is done. The result probably will be more pronounced if you use a cambium saver rather than having the rope directly on the branch.

2 --- Instead of passing the rope over a branch, run it through a pulley (in other words, use three pulleys). This will simulate what Mark and I have been talking about when we express concern about a slippery branch (e.g., as Mark mentioned, wet lichen). Warning: Approach with caution!

Thanks again, Treeman. Nice work.

Peace.

Jim

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