thoughts on high bracing

[Mitchell]

hey folks

I was hoping for any experienced thoughts on cabling bracing. The tree = just over 100' high 3' dbh healthy codominate spruce, trunks split at about 6', 3 feet of possible included bark, both stems show rubbing for 6' above that.

What i did: I went up to about 70 feet with my cabling gear and ultimatly decided to just run a 1/2" 4' treated rod through both stems. As both stems, [one 12' and another 18"] were only 2' apart, I dispenced with cable between. I bolted both ends of the rod [but not each stem seperatly] so there can be movement.

I have not heard of bracing that high any thoughts on what I did.

scott

 

[lees trees]

never put a rod so far up but the only concern I have shock loading causing the nuts to back off

 

[Mitchell]

no high rod; why so?

never put a rod so far up but the only concern I have shock loading causing the nuts to back off

Thanks for the feedback; I realized I deviated from the text book and that is why I asked for feedback. It seemed redundent to run a 12' cable between. I double nutted the bar ends and preened the threads so it should not back of.

Well I type this I thought of a potential problem; the through wound may never fully heal with the stems moving on the rod. Would it have been better to nut both sides of each stem lock them together. perhaps the 12" cable was not so redundent...

 

[jomoco]

Stick with the text book

Thanks for the feedback; I realized I deviated from the text book and that is why I asked for feedback. It seemed redundent to run a 12' cable between. I double nutted the bar ends and preened the threads so it should not back of.

Well I type this I thought of a potential problem; the through wound may never fully heal with the stems moving on the rod. Would it have been better to nut both sides of each stem lock them together. perhaps the 12" cable was not so redundent...

I believe a cable with drop forged through bolts would have been your best bet at that height, primarily because the cable can bend to accomodate any side loading or sheer that is bound to occur.

I believe what you've done with a rod at that height may may do more damage than good.

But that's just my opinion as a proffessional cabler, take it for what it's worth.

Best of luck,

jomoco

 

[Mitchell]

more damage

I believe a cable with drop forged through bolts would have been your best bet at that height, primarily because the cable can bend to accomodate any side loading or sheer that is bound to occur.

I believe what you've done with a rod at that height may may do more damage than good.

But that's just my opinion as a proffessional cabler, take it for what it's worth.

Best of luck,

jomoco

thanks for the thoughts. In a nut shell, why would you say it could be more detrimental;from sheer issues or less chance of the wound healing.
AHhh I should have known better to deviate from the texts. I made a spontanious decision in the tree. Depnding on what you folks say I'll swap it out next time im out there. The tree was healthy sheltered and not splitting so it should not be a problem for some time.

 

[jomoco]

Answer

thanks for the thoughts. In a nut shell, why would you say it could be more detrimental;from sheer issues or less chance of the wound healing.
AHhh I should have known better to deviate from the texts. I made a spontanious decision in the tree. Depnding on what you folks say I'll swap it out next time im out there. The tree was healthy sheltered and not splitting so it should not be a problem for some time.

To answer your question, both.

Best to stick with the book.

Work safe,

jomoco

 

[rbtree]

In storms, winds gust, back off, change direction, etc etc. Just look at a tree during wind. Individual parts will be moving around differently. IMO, there will be some very high side loads applied to that bolt.

I simply use Cobra for codom's....allows movement...avoid steel unless there's an open crack.

 

[RedlineIt]

Mitchell,

I think you've gotten the responses you need already but I will just add that I would be most concerned with metal fatigue in the rod. There's going to be movement up there and over time it will take its toll. Then when that big North wind comes through that rod is not going to be in condition to take the stress you originally installed it for.

Use the threaded rod just at the top of the included bark area. Cable it 2/3 of total height above that. If the stems are just 2' away at that height you'll be overlapping your cable splices.

Good Luck!


RedlineIt

 

[Mitchell]

cobra for codom and support:couple questions

In storms, winds gust, back off, change direction, etc etc. Just look at a tree during wind. Individual parts will be moving around differently. IMO, there will be some very high side loads applied to that bolt.

I simply use Cobra for codom's....allows movement...avoid steel unless there's an open crack.

I spent time looking at old cobra threads, seems to be the real deal. I like the idea of encouraging reaction wood; thats why in my ill fated attempt above I decided to let the trunks move free. However, can you set up the cobra system with such small distances 18 to 24 inches between the stems?

the cobra literature suggests that their system [with out absorbers] can be used to support heavy branches growing at right angles [horizontal] to leaders. Any one done this? I have a large sound gary oak 4' dbh with a heavy 24" 40' long branch jutting out. I was going to through bolt [or lag] then cable it with 3/8 ehs to a central leader. The branch leans over a house. Would this be an appropriate application for cobra?

thanks

 

[Mitchell]

Mitchell,

I think you've gotten the responses you need already but I will just add that I would be most concerned with metal fatigue in the rod. There's going to be movement up there and over time it will take its toll. Then when that big North wind comes through that rod is not going to be in condition to take the stress you originally installed it for.

Use the threaded rod just at the top of the included bark area. Cable it 2/3 of total height above that. If the stems are just 2' away at that height you'll be overlapping your cable splices.

Good Luck!


RedlineIt

Yes your right about the wind, this property north of Sooke is right on a bluff over the ocean. They lost several 4' and 5' dbh trees in the hurricane this winter. Next time Im up I will cut the rod and throw a cable in; might not be for awhile however as it is 50 miles away. the tree is sheltered behind a large maple so it should be ok for awhile. I'll report what happened to the rod hopefully this spontanious attempt might be instructional, if nothing else

 

[jrparbor04]

from what i have seen and read,,,,the cobra system is great,,,but many have said that the squirrels love to eat at it,,,and,,,why use a rod so high up? shouldnt there be a cable at 2/3 the hight with a brace closer to the point of origin of the codom's?