rookie question

T

TJinSC

Well after two years of part time climbing I have the first spar I'm going to have to use negative blocking to bring down. Equipment: porty on 3/4 tenex, block on 3/4 tenex, 5/8 polydyne, 1/2 arborplex (guide line). All in near new condition. Tree is a souther yellow pine about 28" at base but only about 12" to 16" where it will have to blocked.

Question has to do with shock loads and position of porty. First, with above equipment and only planning on taking 3-5 foot pieces does anyone see any concerns after adding shock load values? Second, the tree takes several little change in directions and I was thinking about cutting each piece with its natural lean. Doing that should the porty be moved each time to keep a straigt line with block, or is it ok if say the porty is at the 6 oclock position on the tree and the block is back around the 12 oclock position (worst case)?

I lied, another question. For all my other rigging I've used a steel clevis to cinch the rope around branches. All the pics of negative blocking I've seen use a half-hitch with a timber hitch. Does anyone see a problem with using a half hitch and clevis the rope around the spar instead of the timber hitch?

Thanks in advance,

TJ
 
You'll be fine on WLL, and offsetting the porty is fine, keeps the pieces from mashing the rope against the stem.

I would recommend tying pieces off with a half hitch and running bowline,id imagine its actually faster than continually screwing and unscrewing a clevis, plus a clevis is gonna hurt if its dropped and clocks someone in the back or shoulder....I've never had a running bowline fall out of the tree. :-)
 
1. Make sure to do a thorough 'tree risk assessment'. Negative rigging applies the most forces to a spar.
2. Without pics, it's hard to say where to place the porty. If the rigging line is gonna get some abrasion from rubbing against the spar, I'd say move the porty so the rigging line doesn't get abraded. Your call.
3. Notch & back cut. Be sure to cut the proper size notch opening, with NO bypass. Leave enough hingewood so you can shut off the chainsaw, clip it to your harness and push the log over. Use your handsaw to cut more hingewood. Two hands on the chainsaw at all times.
4. Why do you want to use a clevis (screw pin shackle?) I always tie knots. A half hitch, followed by a runnin bow.

Best of skill!!
 
Yep loads are fine, especially if the groundie runs'em. No shackle.
If the leans are slight I would use a wedge, felling bar or pull line to put them all into the same hole.

What spar escape system are using?
 
My friend that got me started with tree work got me started with the shackles. That's what he used so naturally that's what I picked up. I'll use the bowline on this job, who knows might like tying knots better. Whatsoever use as a stopper so the rope doesn't rum back they the block if you lose grip?

Tree appears to be very healthy, reason for removal is homeowner has had to repair roof several times from branches falling out in storms. I limped the tree yesterday and did not see anything to indicate any flaws in the tree.

Spar escape, good question. Usually when I'm just blocking the tree I run my climb line around as a second tie in, then if I need to I can hook in a fig 8 and rappell down. Are there better ideas?
 
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Spar escape, good question. Usually when I'm just blocking the tree I run my climb line around as a second tie in, then if I need to I can hook in a fig 8 and rappell down. Are there better ideas?

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There are several options. Use one you are most comfortable with. If you climb Ddrt, an adjustable FS is a great option.
 
Never seen that last one, Singlejack. Pretty slick. One question, though. Not trying to pick on anyone and I may be wrong, but I was always told not to choke a biner around a spar like that. Danger of sideloading and what not. I think the one in your pic was a monster of a steel one. Is that what makes it ok? I would really like to know, I've longed to be able to use one for a long while now, since I use SRT for just about every ascent and some work too, especially spars.
 
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Never seen that last one, Singlejack. Pretty slick. One question, though. Not trying to pick on anyone and I may be wrong, but I was always told not to choke a biner around a spar like that. Danger of sideloading and what not. I think the one in your pic was a monster of a steel one. Is that what makes it ok? I would really like to know, I've longed to be able to use one for a long while now, since I use SRT for just about every ascent and some work too, especially spars.

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You're right - as a rule, choking with a 'biner is generally considered unsafe. Good of you to point that out so it can be openly discussed. However, <u>IF the spar is big enough</u>, side loading is trivial -- especially with "a monster of a steel one" like that 'biner.

Notice on the cover of WesSpur's 2011 catalog the life line appears to be choked with an aluminum 'biner. That's certainly no recommendation -- nor is my pic a recommendation -- just an option. As Norm said: "Use one you are most comfortable with." If you can set (choke) a 'biner, up close and personal, on a large stem, so it's NOT side loaded, is it safe ... comfortable? There's a great thread here on the 'Buzz about a <font color="blue">choking carabiner</font>. It discusses ways to choke even small diameters with a 'biner.
 
Thank you everyone for your input. SingleJack, the first and third example require some sort of decender (grigri,i'd), yes? I think I'm going to use the second example as it is closest to what I already use, only better as it is offers imediate escape.

Don't know if I'll be able to get pics tommorow, but will be sure to share how everything went. Time to practice my running bowline a few more times before bed. I think I might like this better than the shackle already.
 
It may have been answered already but it looked like you asked what knot to use to keep your rigging lines from unthreading from your block(s). A simple slipknot but it must spill in your favor and be set at the correct point within the line. ie if your next limb or log is 30' away from your final rigging block, the stopper knot should be about 40' into the rigging line because a half hitch with a running bowline hogs up SO much line. If I'm a little winded I can often give hand signals as to where I want the stopper knot placed. I might also shout "20 feet in, greenies!"
I have a bad habit of working too hard when setting my HH &amp; RB against the bights. It's really easy to simply rotate them then clean them up against the bights.
Make good decisions
Communicate constantly
Don't cut at jugular level
Know and understand your escape route(s)
Maybe do a dry run first
Take as much of the guesswork out of it as possible
Share your findings with us brah.
Just a few things. Be so careful...
 
Well everyone, what a day! The first piece slung me around like a fly on the end of a 8 foot rod. After that my groundie (aka wife) understood letting the line run. The job went painfully slow, but everything went smooth, nothing was damaged, and nobody hurt. I had a close call with my fingers when holding the spar. The sling rolled down and almost pinned my lil finger, luckily moved just fast enough only the glove got pinched.

I ended up figuring the slip knot on my own, just didn't guess how far to tie it in the line, so the first time or two I had to pull rope and tie another knot. I have a few more questions, but will have to post when I get home.

TJ
 
What I do is choke onto the spar with either a running bowline or a biner and a split tail and use a lanyard as well..done above the sling for the block

For blocking down large pieces I use a half hitch with a running bowline on top..

Be sure to cut the notch on the face before you place the ropes.. then make the back cut, shut the saw off and push the piece and be sure to tell the ground workers to let her run ( this reduces shock loading).

Take your time and don't be in a hurry ....
 
Once you work the bugs out and nail down the ergonomics of it all you'll be able to set up your next move in preparation for your back cut in about 8 minutes but like surfarmer said, don't be in a hurry. What kind of sling and hitch are you using? Tell your wife to think of your porty like ABS on a heavy truck and to sllllooooowww the load down. I'm excited for you man!
 
Sling and hitch. I was using 3/4 tenex with a bowline for the block. I used a cow hitch on the upper end of the tree, then a timber hitch farther down when the wood got to thick for the amout of sling I had. It was the timber hitch that rolled onto my glove.

Would a whoopie or loopie have made things considerably easier than tying cow and timber hitches every 6-8 feet down the tree? Anyone use the $90 cmi block from wesspur? Are the more expensive ones easier to open and lock? I had to really work at making the bolt line up when my lowering line was weighting it down.
 
The loopie has good points and bad. On rough bark trees moving down 6-8ft can be a fight. I used timber knot for years before loopie arived. Easy to use for me. Get the timber mostly tight to spare before loading. Will keep from rolling down. (Eating fingers). Far as leaving line in pulley when moving down. That a pain. Just remove from pulley and hang from saddle. Move pulley to new location and install. Cut your face cut. Pull up 10-15ft of rope make a slip knot to hang from saddle. Weight of rope hangs there. Or feed 10-15ft through pulley and make slip knot. Weight of rope hangs on pulley. Ty your end of rope to spare. Pull out slip knot. Moving on..
 
When you said your glove got eaten I almost knew you were using a timber hitch. Awsome hitch but it must be loaded against the bight and like Sawdust said, choked tight. Draw an imaginary line at the vertical plane of the finished product and try to never load the TH away from the bight. As you've learned, even loading it vertically has its risks but when you load it away from the bight there is a rotating hazard that can make things go VERY badly. It must be tied, dressed, set and USED correctly and it may not be as forgiving as a cow hitch. There is still a rotating hazard with a cow hitch and less with a loopie sling but again...tradeoffs. A loopie, when used correctly is almost idiot and bombproof and they're easy to learn and teach but situationally they can be VERY difficult to relocate.
I know it's spendy but longer slings will let you use a cow hitch and it's variations and that will open up new doors.
That CMI block, if it's the one I'm thinking of, is an awsome piece of equipment. Of course there's higher quality stuff out there man but used within its limitations, it has dollar signs and artistic expression written all over it. Even the more expensive blocks can be a challenge to thread when loaded so I'm clear with ground support that I'm rigging and don't want them to start grabbing at lines when I've got loose hardware. I'll sorta hold the cheek plates in line with a taco grip from the UNDER side of the block with my left hand and screw the upper spindle home with my right while sweatting bullets of course cuz it's just hard and I know you don't want to drop that thing. lol Keep going brah and keep sharing. Wz
 
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