Blocking Down a Big One

[rwilk]

Ok guys need a little help.

I put in a bid today on my largest tree. Approx 85' "bull" pine. It has alot of large canopy limbs, which should not be any problem, except my Vermeer 935 won't chip everything . My biggest concern is getting the spar to the ground. It is about 38"-42" dbh and it looks that big all the way to the top. I only have a landing zone of 15' square. I have done some smaller blocking down with rigging, but I'm usually able to bomb 20" sections by cutting and pushing off the spar. My biggest concern is how long of sections can I rig down at a time using 12 strand 5/8" rigging line with a 2ton steel pulley and port-a-wrap as the lowing device. I'm confident with the techniques, but worried about the lengths.

I don't have enough in the job to rent a crane and operator. Any help would be greatly appreciated.

I guesse you must always do your first big, big one.

thanks
rwilk

 

[NeTree]

With wood that size, and taking shock loading into consideration, I would take it easy and go with no more than 3' pieces.

 

[tjk]

I would recomend investing in a 5/8" double braid rope. You will increase your SWL considerably

 

[Stumper]

.Like netree said. Keep 'em short. Depending on how that small landing zone is configured and what borders it you may be able to bomb firewood blocks once you get the top and upper spar roped out.

 

[Kneejerk Bombas]

What size sling are you going to hang your pulley with?

Good advise so far, all I can add is when I chunk down a spar, go by firewood lengths, because that's most likely what the wood will be turned into. If you keep this in mind, there's not a bunch of extra cutting and left over sniglets.
So I would cut the wood into 2 or 3 firewood lengths, which is a good size to deal with at that diameter.

 

[ORclimber]

You might keep a couple wedges close by and a long handled crow bar to help encourage the big ones.

 

[Greg]

No one I know would keep a pine like that for fire wood, and you are going to have to cut it up too small to interest a saw or pulp mill. I think the 3ft lengths are a good size, but do yourself a favor and get and adj whoopie or loopie sling to take up to use in blocking it down. you are going to have to move your block about 23 times (70ft tall / 3ft chunks) and you are going to be one worn out climber tieing and untieing a timber, cow, or what ever kind of hitch you normally hang your block from. The whoopie will allow you to just slide it down and start cutting again. Not to mention you are going to have a heavy saw weighting you down that whole time.
I'd also start thinking about how you are getting your wood out of there, that is a lot of wood, I'd think about a bobcat, or about 3 guys working 3 dollys.
I hope you already have a Porta Wrap, this job requires it (half a wrap and LET IT RUN!!). This kind of job really gets a ground guy good at running the ropes. We just did one and my goundie had it running smoothe as butter, no shocking the spar and slinging me all over the place like he sometimes likes to do. Around here that job would go for $750 - $1200 in a back yard. I'd bid about $950.
Have fun!
Greg

 

[NeTree]

I keep a wood grenage and a sledge on hand to (sometimes) split big chunks in 2 or more pieces. Much easier to handle, especially towards the end of the day.

 

[heartland]

rwilk,

I think the idea of bringing wedges and/or a crow bar is good. I had trouble with my hinges during my training and think that would have helped a lot.

Here is a good link that you might want to run thru. Seems that everybody had good input.

From personal experience, I think it is paramount to have a groundie skilled in letting it run. If not, you (the climber) will suffer in more than one way:

1. lots of spar shake
2. risk of spar failure due to stress

Obviously, there are many factors that contribute to spar failure ranging from general health of the tree to the type of ground it is in... not saying any of this to scare you. Just be safe and use your noggin.

Be conscientious about how you tie yourself in with both lifeline (most likely SRT) and your lanyard. I like keeping these above the block - others prefer below.

 

[WillClimb]

I just took down a dead red oak in about the exact same conditions. 36+" DBH, and that was at least 30-40' up the trunk. 10' from the house, 20' from power lines with huge, tree sized limbs hanging over house and wires. I bid the job for $1800 and beat out a large reputable company who bid it @ 3K. I cant believe how low the prices were quoted earlier in this thread. All I know is that I felt like I under-bid it.

Anyway, I had to rope everything down! I would definitely get the whoopie sling. I cow hitched everything and my body was cramping at the end of each day. Unfortunately I used my whoopie for the porta wrap. I used a 3/4" line with a 13,000 tensile so I took down a little larger pieces than 3' and my groundie ran them beautifully.

Better inform the client that there will be at least some minimal lawn damage, if not by the final trunk dropping, then from the Bobcat, which I do suggest.

Next time I'll rent a man-lift for a tree like that, but I do enjoy being able to say that I did it, pure climbing.

Oh, and not to mention, it rained off an on everyday, with lightning! I had to take oh so many trips up and down that tree...

 

[oldugly]

sounds like alot of fun. Also sounds like you got plenty of advice, the main point, and I think all agree, is use your head, it is the best work saving device known to man. Really though with a landing area of that size, and a tree of that size, you shouldn't have much of a problem. Just alot of work involved.

 

[rbtree]

rwilk,

A 15 foot square lz is pretty big. (Unless you meant 15 sq feet, lol!) Why not ring the edges with some brush and wood, (even plywood and tires if needed) and maybe the exact lz also, and free drop it all. Then line the edges with the chunks as they come down. Much faster, and relatively safe if you can control the bounce. I've chunked out many a tree in super tight spots.....

If you must lower everything: Wood that size is pretty heavy, at around 300 lb per foot of more. So double braid or even 7/8th would be much better...and a groundie who lets the pieces run.

 

[ramanujan]

i'm with rb on this one.

as long as you have some dirt under you and not all nice lawn or paving, cut firewood pieces and bomb it all down on the same spot.

with a sharp saw i can make three straight firewood cuts a lot faster than i can rig the block, make the undercut, tie the half hitch and running bowline, make the back cut, make sure the groundie is a-okay to go, push the block, wait for block to be united and the rope to come back up...

not to mention that if lengths are rigged then they will likely need to be bucked up again on the ground before they can be moved or split.

imho square rigging blocks is unnecessarily time consuming unless truly needed.

 

[Greg]

On a spar like that I just make one cut and push the peice off, no hinge. I think in Bareneks book he calls it a Salami cut where you cut down at an angle so the chunck just slides off when you get through it. You stay on the high side of the cut and it is a very effective method. The only time I'll hinge it is when the peice is 4-5ft+, Wood that big you need to know for sure where it is going to go. Good advise from RB you could just free drop it, but don't drop chuncks on top of other chuncks that are on the ground, from a height you can't predict if that peice is going to shoot off in the wrong direction.
Greg

 

[John Paul Sanborn]

Rog beat me to it, I think that chunking the peices out may be better.

Felling bar to assist in getting the chunks moving always a good thing, you can tie a throwline lanyard on one and clip it to your saddle.

I'm guesstimating 400# per liner foot with your max diameter of 3.5 ft. I found a weight for green yellow pine at 37 lbs per cu.ft.

So each 10 ft section is around 2 ton. (Pi r squared * h * w)

20 inch wood around 200# So blocking out long sections up to that diamerte is not a big thing.

Have Nick Araya make you a heavy loopie sling fot the blocking, they are much better then a whoopie. Remeber the block sling should be twice the rating of the rope, and using a loopie gives give you around 4x rating of a deadeye sling when used in a basckett. If 2 bights can fit in the block, then of course you have a 2x on a choker. But where I'm going is that you don't need 3/4 or 1 inch slings for the block to get a good SWL in the system.

How long to clean the spar and blow the top? Could you afford the minimum fee of a crane to get the spar out? find out what the travel time and setup would be to your site and see if there would be enought time for several pics stacked roadside in the minimum fee.

 

[rwilk]

Thanks for all the advise;

1. Both my port-a-wrap and block slings are 3/4" double braid. The idea of the whoopie or loopie is good. I do really hate tying and re-tying.
2. As for my bid price, $1750 and I am better than a much larger company, (have not got it yet, but customer says should get it in 2 wks.)
3. The landing zone does have a few azalea bushes right at the base to the tree. Shouldn't be a problem telling the customer he may loose a few. I do have and will use a bobcat, but I must roll the chunks down a hill (4' hill with hard slope) out of the LZ.
4. One thought i had about bombing chunks (3-4') was to hinge the spar, but instead of roping them down, use a pull line and have the groundies pull the chunks off / over. Will the downward single cut work ok without binding back on the saw. (Makita 7300 with 28" bar.)
5. As for the let it run, I'm having trouble getting both of my regular groundies to understand this. They constantly shake the sh&* out of me. I told them I was going to hoist them to the top and tie them in and shake them (lol). We have two trees to work this coming week that are much smaller, but must be roped out, we'll practice the running, stuff.

Thanks guys keep it coming

rwilk

 

[Tom Dunlap]

A consideration that I came across while reading an article about wind loads in trees in Arborist News was to leave limbs on the tree. This dampens the movement in a tree. The more mass the tree has the more energy it takes to put it in motion. If you can clear a vertical pie column up the tree, you will reduce the slamming that is uncomfortable.

Is there another tree anywhere in the vacinity to use as an anchor for a speedline? There are some really interesting speedline configurations with haul back/lowering lines anchored in another tree. This might allow you to take bigger pieces and not shock load the spar.

Tom

 

[ORclimber]

Originally posted by rwilk
4. One thought i had about bombing chunks (3-4') was to hinge the spar, but instead of roping them down, use a pull line and have the groundies pull the chunks off / over. Will the downward single cut work ok without binding back on the saw. (Makita 7300 with 28" bar.)

rwilk

You could place a wedge or 2 in your cut to keep the chunk from sitting down on your saw bar.

Wedges are under rated. One of these days I'm going to heat up/or predrill some eye screws and sink them into the side of a few wedges so they can be hung from a saddle.

Ira Miller, a retired climber in Portland tells a story about bombing huge fir chunks in a parking island. He had to wedge the pieces up and slide metal rods under the chunks to get them to roll off the spar and land flat.

 

[ramanujan]

while on the subject of huge firs, an old fellow i work with (mostly done with climbing, on occasion he still does) tells of taking a dead section out of the top of a large old douglas-fir. had to cut slabs, then split the slabs with an axe while still in the tree and then toss the chunks out over whatever was under the tree.

anyone ever heard of splitting blocks on top of the spar?

 

[John Paul Sanborn]

All I've ever done is cut up hollw trunks and throw the chunks. Lota slice and dice jokes after that happens.

On the pine in question, is there another tree that a load transfer system could be set with another pulley.

Set a lowering line as usualy with the block under the chunk and top tie another rope tha comes out of an adjacent tree to ease the load down.