Cobra Bracing - should it be replaced if taut?

[AllTrees]

Ive just carried out an aerial inspection of Cobra Bracing I installed in 2019. At the the time it was installed the required slack and loops were built in. 6 years on and and it is stretched taut with no give. Therefore the loops that were installed can't be adjusted to reintroduce a little slack. Should the whole system be replaced or left as is?

[Joe Newton]

If you can use mechanical advantage or a ratchet to tighten the stems together you might be able to introduce enough slack into the bracing to adjust it. 

[Steve Bullman]

3 hours ago, AllTrees said:

Ive just carried out an aerial inspection of Cobra Bracing I installed in 2019. At the the time it was installed the required slack and loops were built in. 6 years on and and it is stretched taut with no give. Therefore the loops that were installed can't be adjusted to reintroduce a little slack. Should the whole system be replaced or left as is?

Is a light thin an option?

[openspaceman]

1 hour ago, Joe Newton said:

If you can use mechanical advantage or a ratchet to tighten the stems together you might be able to introduce enough slack into the bracing to adjust it. 

 

I was thinking the brace is doing its job and restraining some of the weight, I'd be looking at the union below it.

 

Mind I am not a fan of bracing, last I did was around 1976 with 1/2" galvanised wire rope.

[Joe Newton]

26 minutes ago, openspaceman said:

 

I was thinking the brace is doing its job and restraining some of the weight, I'd be looking at the union below it.

 

Mind I am not a fan of bracing, last I did was around 1976 with 1/2" galvanised wire rope.

Depending on the type of brace used you'd effort it to be taut in full leaf but not to the point where you couldn't adjust it.

 

The problem being when the brace becomes a structural part of the tree. COBRA has a service life of around 10 years. You wouldn't want it to be fully supporting a part of the tree at that point.

 

As Bullman pointed out, a light weight reducing could help mitigate this.

[AllTrees]

2 hours ago, Joe Newton said:

Depending on the type of brace used you'd effort it to be taut in full leaf but not to the point where you couldn't adjust it.

 

The problem being when the brace becomes a structural part of the tree. COBRA has a service life of around 10 years. You wouldn't want it to be fully supporting a part of the tree at that point.

 

As Bullman pointed out, a light weight reducing could help mitigate this.

Thanks for the replies. Its a large, multi_stemed and layered Western Red Cedar, badly topped many years ago but has since recovered an almost natural shape in a managed estate setting. I've copied this from Arb Report. 

 

"Tree previously heavily reduced/topped. Large bark wounds to ‘topped’ main stems – long standing with good wound-wood formation. Hazard beam formation to lateral limbs – occluded. ‘Cobra’ brace installed since previous inspection – unknown date." 

 

I installed the Cobra brace as recommended 6 years ago. I'll try MA to pull the stems together and put some slack in the brace. If unsuccessful is replacing recommended?

[Steve Bullman]

Was the brace installed shortly after the reduction?

[openspaceman]

18 hours ago, AllTrees said:

If unsuccessful is replacing recommended?

From what @Joe Newton says that brace is 2/3 through its design life and from the look of those forks I expect it would fall apart if removed.

[AllTrees]

Again thanks for the replies. There was no give in the trunks. Customer agreed to replace it and monitor it every couple of years for adjustment rather than 6 years