Hollow stump question

[pantheraba]

I took down an oak yesterday, a "cavitized leaner" I described in another thread.

I set my two TIPs to other trees because I was concerned about the lead being sound where it branched off at a 45 degree angle at the 30 foot mark...there was a cavity from a limb rotting out about 75% of the diameter...that limb was vertical, must have been the main trunk at one time.

Once I got in the tree and on the leaning part, I bounced around a bit and could not make it fail (had already tried by puling from the ground with a rope). I roped out the limbs as I ascended, took out the top and chunks in pieces and finally got it all down.

The surprise was when I took down the spar...it was very hollow from the ground up to about 6 feet (it was about 15 inch diameter where I cut it at 3 feet above ground). I discovered the hollowness when I made my face cut...it had me concerned about having enough hinge wood. There were not any signs of any disease or weakness at the base or anywhere external. The rot stopped at about 6 feet above ground and the tree was solid from there on up (except for the limb cavity at 30 feet...and it was localized).

Looking back now, I should have taken a sledge (or something heavy), I suppose, and "sounded" the stump before going up.

The tree held up well and I did not suspect any structural integrity deficiencies until I saw the hollow stump.

So here is the question: if you strike a stump and it sounds hollow, how do you decide whether it is safe to climb or not?

Or do you just use independent TIPS so you don't have to depend on the tree for support?

Or do you drill a hole through the tree to see what you do (or do not) encounter?

I have not had formal "hazard assessment training" and am looking for some suggestions.

Thanks.

 

[pantheraba]

Here is a shot of going up the secondary (now main) lead.

I did this without spurs. Due to the small diameter up in the top, maintaining good alignment on the tree was sometimes tough. I used some homemade rope loops to girth hitch and form foot holds.

For those of you that do spurless takedowns, is that how you get a purchase with your feet?

Do you carry several different lengths of loops to work with different trunk diameters?

 

[pantheraba]

There are some more pictures posted at

http://layton.smugmug.com/gallery/749203

OK..I did use spurs the first day to set a load belay line in a nearby tree (a high crotch in another tree that let me swing pieces over and outside the roof line) and do a little trimming.

The second day, I did not use spurs...I used foot loops (with a Klemheist) to help ascend my DdRT entry (I used a pulley on a floating false crotch...I guess that is the proper description...I set up the Ddrt on my pulley and then lifted it about 40 feet to just below a crotch and then climbed up to the pulley)

And then I used footloops on the trunk (girth hitched)to help stablize when making cuts.

 

[Norm_Hall]

For a tree to be safe to climb, a rule of thumb is to have 1" of sound wood for each 6" of diameter. This is for climbing only, not climbing and rigging off of the tree. If the tree is leaning more than 15 degrees, you add more sound wood into the formula. This will depend on species, time of year and soil conditions. An 1/8" X 12" drill bit is what we use on the jobsite to check for sound wood.

 

[davespencer]

To do a quick check for tree soundness, plunge (bore) cut the trunk with the bar vertical (see what is ma thread for over definition of vertical). You will only damage holding fibers the width of the chain unlike a horizontal plunge, just watch the chips coming out.

Dave

 

[pantheraba]

<font color="red">1" of sound wood for each 6" of diameter...for climbing only, not climbing and rigging off of the tree.

leaning more than 15 degrees add more sound wood into the formula.

1/8" X 12" drill bit to check wood </font>

Got it...

And the plunge cut (vertical) would have told me a lot, too. Thanks for the info.

 

[pantheraba]

stump shot - one inch rule?

Here is a picture of the stump at felling cut...it was a little smaller than I thought...actually 13" x 11" at 30 inches above ground. There was about 2 inches of sound wood all around the tree, for a total of 4 inches diameter solid wood...that doesn't seem like much to me...I am glad I used a wedge to nudge it over (it had about a 5 degree lean the wrong way)

My first inkling of a problem was my hinge cut...the angled face cut and base cut intersected at almost nothing..only hinge wood was in the sides.

In the picture, I have already cut off the hinge cut...customer wanted it left flat.

I am going back to study the two "intrusions" through the good wood at the 8:00 and 8:30 positions on the stump...looks like some of the rot may have been working its way to the outside.

If I understood an earlier reply correctly, I was at the minimum acceptable amount for safe work in the tree?? (1" good wood per 6" diameter).

Does 2 inches on each side equal a total of 4 inches support wood? How does the 1" per 6" rule apply to this tree?

Cutting it open to find only a one inch thick circle of wood would be a sobering situation. /forum/images/graemlins/shocked.gif

 

[Norm_Hall]

Re: stump shot - one inch rule?

1" of sound wood for each 6" diameter means a 6" tree can have a 4" hole in it.
1" of sound wood all the way around.
This depends on the species and if the tree is dead or alive. A 6" linden with 1" of sound wood would be a little suspect. A 6" oak with 1" of sound wood is OK.