Walnut, old cable in it, what to do?

[Matt Follett]

I have come across a dilema of sorts...

a Client has serveral large walnuts on their property which we did a deadwood clean-up on. the largest of the bunch, probably 50" DBH or so and some 80' of spread is in the slow process of decline, but has lots yet to go... Anyway several years ago, 15 or more (before the client purchased property) some one installed several cables. One in particular is attached to part of the now dead top, but the wood there is still relatively solid (it's lagged in)
the limb extends quite far out from the tree and is perhaps 8" at attachment. It is relatively sound, and a once solid attachment for it's size, but the cable did the mechanical change and the limb is now far longer then it should be without the cable.

We don't install steel anymore, only cobra were necessary.

I can't decide whether we should remove this large limb and open up more decay to the top, replace the cable with steel to a different attachment point, replace with cobra to a different attachment point or run away screaming (there is not a lot left up there that I would consider solid enough to attach to either??)

I am certainly concerned about future failure of this cable and then the limbs impending failure (there is quite a bit of tension on the rusty old cable)

see my lousy diagram for limited clarification

 

[Menchhofer]

My first thought would be for you to thin the limb in question to reduce some of the weight and then install the cobra farther out on the limb as it should be.

Since the entire tree is in decline though, you mentioned removing the entire limb , but you are concerned about decay from the cut. Eight inch dia branch is about the limit to consider removing while maintaining proper codit. It remains a viable alternative.

I would probably lean toward the limb removal as the tree is in decline anyway and due to the fact there could be potential targets in the vicinity.

Sounds as if the tree will need to be removed in the future.

Will you also need to deadwood remaining parts of the tree?

 

[Matt Follett]

Yeah the tree will be removed, but I would like to think long after I can't climb anymore

in some ways I would remove the limb but it is large, and I'm afraid of increasing the rate of decline of this not so healthy top, ( I should clarify that there is good bud development and plenty of vigor left in the tree as a whole) My concern in cabling is that I may be putting myself at liable risk if the attachment fails in the near future (let's say 10 years) we do check our cables ever 2 years, and are increasing that to each year for cobra stuff untill I have more experiance and confidence in it's longevity.

I think for piece of mind, tree health wise we will recable it with the cobra, but I might install it under SLIGHT tension, has anyone done this???

BTW yes the tree has been cleaned up, I did not notice this untill I was in the tree, and left it for future work/consultation

This is one MASSIVE tree, which I would guesstimate at well over 200 years, the house dates to 1820's and the trees were there (and large) when it was built! the first limbs are at about 20 feet and the have to be close to 2 feet or more in dia.

 

[Kneejerk Bombas]

Originally posted by TreeCo
In one of the FACE reports I remember reading where a climber died when he cut a cable and the part of the tree he was in failed and fell to the ground.

Never cut a cable under tension.

Originally posted by Menchhofer
Eight inch dia branch is about the limit to consider removing while maintaining proper codit. It remains a viable alternative.

I'm not sure what you are getting at here. Any time you are cutting into heartwood, you comprimise the trees ability to compartmentalize, don't you?

I think at this point the work is about hazard reduction. The tree doesn't have a good long term prognosis. If it was necessary to cable the limb years ago, the limb will need even more support now that the top is decaying.

 

[treeist]

I implore you to leave cable, prune branch back, clean out dead.

 

[John Paul Sanborn]

Inform the client of the risks involved. You have noticed the problem, it is your responcability to let the client know.

The client must always be the desision maker, we just give options, and the possible consequances.

1. do nothing
2. reduce end load more
3. add a cable
4. 2&3
5. remove the limb
   [/list=1]
   
   My preferance would be #4 done in dormancy so the tree can add dynamic mass farther back on the limb.
   
   1 & 5 do not apeal to me for the obviouse reasnons
   
   I would not remove the current cable because the tree has grown with it, I would just add Cobra to augment the current one and maybe to catch a flailure.

 

[Kneejerk Bombas]

You guys are assuming there is a good way to cable the tree. Look at the drawing and show me where you would run the cable.
Treeist suggested leaving the cable and removing the deadwood, but the cable is secured to deadwood.
Are you suggesting the cable be added like a saftey chain on a trailer, just there to catch it if it falls?

 

[Matt Follett]

Thanks guys

I think I am headed towards adding the cobra cable, and leaving the limb while doing some slight reducing too.

Even when informed this is a client who says 'you guys know best, do what you want.' so it's hard to get them to decide, ultimately this will be on my shoulders.

JPS, you say I should leave the old cable? my only concern with this is the upper lag is into this dead stub (see that poor drawing of mine ) Would you think to repace it (the cable is in poor condition as well) or just leave it and add on??

Thanks again

 

[Matt Follett]

Mike

I just got yours after writing mine above, that's sort of my concern, the drawing is not to scale of course, but I'm concerned about attacing this thing to something above it with the intent of that attachment holding, should the branch fail under ice load, storm type conditions

 

[Tom Dunlap]

Giving advice is the same as arm chair quarter backing. We would need to know a lot more about the tree in order to give advice.

Anyone doing cabling should consider subscribing to the follow up service that Sherrill has implemented. I think that it's a good value and gives the installer some level of protection. By shifting inspection responsibility to the client, the installer might be able to dodge a bit of the responsibility.

With the information you've been able to give, I'll lay out a couple of different plans. There are already some good ideas here. John laid out a good option plan.

the way that I would consider the top anchor point is to consider what I might have found in other similar trees. The walnut in our area aren't that large so I can't even think about the species. If it was a white/burr oak in the Twin Cities, I'd be pretty confident. Silver maple, watch out. you know the drill.

After seeing your drawing, I would consider a cable to be a safety net. Keep a broken limb from creating a disaster. Reduce the extent of the damage not eliminate.

Could you replace the lag in the dead top with a through bolt? If you can support the limb on the trunk, below the anchor. Remove the lag and install a through bolt with a large plate on the back side then reinstall the cable on the new through bolt. You could add an eye nut on the end of the bolt and then connect a cable to the other end, in effect, supporting the right limb on the left.

The 2/3 height factor is the ideal placement. Reducing the ratio means that a higher load is placed on the anchors and cable. Take the time to calculate the trade-offs.

Could you add a cable around the trunk, parallel to the limb? Maybe add some lateral cables to limit the limb from swinging like a gate.

Once you decide on a plan, be sure to let us know what came up.

Tom

 

[John Paul Sanborn]

If you are concerned with the soundness of the holding wood, then I would go with Tom's description. Sue a comealong, unload the cabel, install the newone before cutting the old.

Maybe combine steel and synthetic.

Don't try to talk the client out of removing the limb. Let them understand the risks and make their own decisions.