Blocking Down a Big One

[rwilk]

Unfortunately there is no ajoining tree, so speed line won't be an option. I will try to get some pictures to post. I am going to the customers house to turn in a formal written quote. I'll post them if I get them. If I get the job I will post some action shots

see ya

rwilk

 

[rbtree]

Ram,

You bet. An old timer told me about removing a huge doug fir on Mercer Island, Seattle area. It took him five days!!!

I've never split rounds while aloft, but have had to resort to ripping a few times to get to a manageable size chunk.


Photo is of a 5 foot dbh fir that we had just removed 15 feet of dead top. Tree was still some 125 feet tall. It was very dead, so I set a couple slings, and had a belay as I moved above...like rock climbing on lead. I had to rip each piece into 2 to 4 pieces to get to a size that I could toss the required 15 feet out to miss the wrought iron fence and landscape. While the job was delicate, it was probably the least amount of noticable work for $1000 we've done.

 

[rbtree]

Dave climbing the same tree.

 

[ramanujan]

wow, that's a big one. got that really thickly furrowed back that only the old ones do. Doug-firs and big leaf maples, looks like home

there are a few firs of that size around here in residential areas, but haven't climbed one yet. someday likey.

 

[lync]

wedges

I blocked down a 48 dbh oak last year, and without wedges it wouldn,t have gone as well as it did. Go buy 3 small plastic 5 inch wedges. Drill a 1/8 hole lenthwise thru the wedge about 1/2 inch fro where you hit it with the hammer, thread an old piece of pullstarter cord thru it an knot it. leave a 2 ft lenth hangingoff the wedge. Buy some large allegator clip electricalclips home depot, like the kind you use for clamping test wires to a car battery. Tie the cord to them. They can be clipped to the bark or to your flip line so that whenthe slab drops you still have the wedges with you in the tree. Make sur you have enough bar that your cuts overlap. Good luck.

Corey

 

[rbtree]

That saw looked lonely, so :

 

[NickfromWI]

rope point...

Everything sounds good, but I do have one complaint. I few people mentioned upgrading to a double-braid rope so that you have more strength/increase your SWL. This doesn't ring true with what I know about ropes. For example, a 3/4" Samson Stable Braid (a very popular arborist rigging line) has an ABS of 20,400lbs. Tenex, which is also a polyester line, of the same size has an ABS of 22,400. Single/Hollow braid is usually stronger than a double braid of same material and diameter.

Stick with what you've got for a rigging line!

love
nick

 

[NickfromWI]

i almost forgot....

As a side note for comparison. Yale Cordage's Yalex (their single-braid polyester) at 3/4" has an ABS of 24,000lbs!

love
nick

 

[John Paul Sanborn]

Re: rope point...

Originally posted by NickfromWI
[B Single/Hollow braid is usually stronger than a double braid of same material and diameter.
[/B]

Is this because the fibers can straighten out more when loaded, giving more flexability?

Is the core of the dbl braid just to keep it rounder when bending around a pulley or break?

 

[TheTreeSpyder]

Ummmmmmmmm lost,



So, if i stuffed smaller Tenex inside another Tenex; i would weaken it?

 

[Stumper]

No Spydy but it probably would test lower than the sum of the 2 individual ropes. Cordage theory is heady stuff.

 

[TheTreeSpyder]

i am seeing in Thee Catalouge 2003, a small quote i have probably missed before, though trust it was offered.....

"Super Braid Plus........ is woven tightly for increased durability, but friction between the closer fibers reduces tensile strength....... "

WOW!

Fascinating Captain!
Absoulutely Fascinating!
:alien:

 

[John Paul Sanborn]

That is a new cord designed to work better with bollards. It does not deform as much when wrapped.

The harder the weave the less strech which lowers the tensile.

If I could get Sean G. to do more the lurk here, he could explain it. I have just a vuage understanding.

Another thing that occured to me is that the sheath of single braid is not the same as the hollow braid. So stouter yarns may be used in the manufacture of the single.

My understanding of the dynamics of the Dbl braid construction is that the core is only a small percentage of the MBS. So the reduction in sheath size would reduce the overall strength of the cordage.

 

[Joe]

.

 

[ramanujan]

from what i understand, the the highest strength of a fiber is achieved when it perfectly straight, no bends or curves at all. so the tighter the weave of rope, the more bends that are included, as well as each of those bends being sharper.

another factor in break strength is stress caused by curvature of the rope. on a hard braided rope such as our climbing line, at a point where the rope runs over a biner or pulley, the fibers on the outside of the curve are taking much more of a strain than those on the inside.

a softer rope that flattens around curves has the ability to more evenly distribute strain. this is also one reason for the impressive strength to size/weight ratio of webbing.

there are so many trade-offs from one type of weave or fiber to another that there is no perfect rope for any one application, a large part of rope selection is our own preference.

 

[TheTreeSpyder]

To quote Ken Palmer as i watch buddy watch my tapes for first time in background:

"The hollow braid (used for anchor slings) isn't as strong as the double braid....." in AM's early "Ropes Care and Construction".


Don't know which is right,
jes fascinated!

Perhaps wee caught'em here;
they say ya can't always be write!

 

[rwilk]

hey guys been alittle too busy to post much , but a little update.

I have not got the bid on the pine in questions as of yet, but I'm still trying, but I'm not going down on price.

I did do a dying white oak last week and it went well. I roped out some of the branches over the driveway and bombed the rest since the yard has not been established yet (new construction house. New driveway killed the tree or helped finish it off.) I was going to try and cut the spar down in firewood chunks, but by the time I got to it and the 95 degree heat with 105 heat index told me put a rope at the top, wedge it at the bottom and let it go. I did learn that investing in a few plastic wedges will help be cause the last cut I made aloft, kicked my a$$ trying to get my bar out. Anyway I'll keep you posted and thanks for all the help.

rwilk

 

[TheTreeSpyder]

Before i knew there were tree books (and as there were lots less) i raaided shipman's books and army manuals for knots and other unchanging, basic rudiments of procedures of handling like events; in those disciplines; feeding my hunger to know and grow. Finally got bright idea, to go to library find something i know i heard of called NAA; wrote, got annual magazine filled with listing of dealers etc. Called about 20, asked for over a dozen different catalogs and got'em. Wow! A new light, peopel doing what i been trying to learn!

Worst thing is i got lazy, lost number or other humaning; and missed freaking Sherrill on that round! Took a few more years to fumble home that way.

Finding ISA board years later blew me away, as others wanted to talk of this stuff too. Was gonna say felt like i wandered in and found my own peoples; a seperate kind, but kind they was, their really nice guys and thus-don't' wanna putt them down!

Save perhaps MaasWhole@..... he's all ways been a cranky ol'cuss (guess we'll see now for sure! )

1 strategy i came up with on bar pinch is to try not to end up with the weight on the bar to finish, at least i always though it might werk. Might suffer same principles in trees or on ground. used sticks and bark to keep kerf open a lil'while longer on ground; and it made changeover up and in tact. Once used wallet in tree(has to be at least nearly as thick as kerf though), so don't pay attention to me! i think Daniel of DNA (Natl. Dyslexic Association); tries to pass it off as counter intuitive; jest to give me hope!

Diagram might be blurry, perhaps 4th printing.

-:alien:

 

[John Paul Sanborn]

Sean called me a few days ago, let's see if i can remember what hea said. (still can't get him to post, even anonomusly )

As the Donzelli paper states it is material and construction that alters the tensil fro rope to rope.

Double brades dont load 50/50 for the most part, be cause of the differance in weave, friction and bend radius.... the cores usualy take more of the load.

So with a single braid, double carrier cord you have more loading in a straighter fashion, thus allowing higher loading.

in theory, perfectly straight fibers will load the best, but in practice, they are not straight and this chaos reduces the tensil, so a slight twist or weave will increase the load bearing capasity of the same fibers. After that, the more bend/twist the greater the reduction in tensil.

Do i make sence?