Advice on survey with some odd findings

[Chris at eden]

Steel cable bracing is not out dated, it has it uses and has a completely different installation reason that cobra.

Cobra generally allows the tree to move and breath.

Steel bar and bracing is used more for static bracing.

 

I went to a seminar a few weeks back. They were pretty adamant that steel bracing is a thing of the past. Didn't even have any in the lecture or the demo.

 

Also the most recent findings are that even cobra bracing has a significant impact on mass damping and does not allow for the formation of adaptive growth in forks. It actually increases the risk of cupboard door failure if used to secure compression forks. If used on horizontal over-extended limbs it kind of waggles the fork in the opposite direction to the tip if that makes sense. They suggest bracing horizontal limbs closer in to the trunk to counter the effect.

 

The speaker (for this part) was Mac who runs the TRAQ qualification for CAS and the ISA. Mostly based on Mattheck's work I believe.

 

Bracing is a bit of a dark art if you ask me.

[daltontrees]

Just been trying to find a source of info that might support the "initiate veteranisation" concept.

 

Nothing really in Ancient & other veteran trees: further guidance on management, or Ancient Tree Guide no.7: Ancient Trees for the Future, but a quick google kicked up this -

 

https://www.cityoflondon.gov.uk/things-to-do/green-spaces/city-commons/ashtead-common/wildlife-and-nature/Documents/City-commons-veteranisation-information.pdf

 

and this -

 

http://www.pro-natura.net/publikat-filer/Veteranisation%20of%20oak_paper_Bengtsson%20et%20al_Sheffield.pdf

 

another school day!

 

I was going to say, veteranisation does have its place. I am involved in a local community woodland, and unfortunately every time the schools organise a bug hunt they find just about nothing as there's hrdly any deadwood. The trees are mostly about 40 years old plantation. There are bats in the area but they are commuting there from a nearby older park. I spent about 2 days looking at about 2,000 trees in the woodland, and I don't think I saw a single potential roost feature. The plan is to deliberately trash a few of the trees, and the Bengtsson et al paper is the sort of planned damage I had in mind plus the creation of a few poles. And some thinning for small clearings to encourage a range of tree ages to develop. I've already built some bat boxes and put them up.

 

Just trying to speed up the process and get this artificial woodland behaving as it will in 100 years' time if left to its own devices.

[Andymacp]

I went to a seminar a few weeks back. They were pretty adamant that steel bracing is a thing of the past. Didn't even have any in the lecture or the demo.

 

 

 

Also the most recent findings are that even cobra bracing has a significant impact on mass damping and does not allow for the formation of adaptive growth in forks. It actually increases the risk of cupboard door failure if used to secure compression forks. If used on horizontal over-extended limbs it kind of waggles the fork in the opposite direction to the tip if that makes sense. They suggest bracing horizontal limbs closer in to the trunk to counter the effect.

 

 

 

The speaker (for this part) was Mac who runs the TRAQ qualification for CAS and the ISA. Mostly based on Mattheck's work I believe.

 

 

 

Bracing is a bit of a dark art if you ask me.

 

 

It's interesting stuff and certainly not fully researched yet.

I can see what you mean about horizontal limbs.

Did they have examples of failed cobra?

[kevinjohnsonmbe]

I was going to say, veteranisation does have its place. I am involved in a local community woodland, and unfortunately every time the schools organise a bug hunt they find just about nothing as there's hrdly any deadwood. The trees are mostly about 40 years old plantation. There are bats in the area but they are commuting there from a nearby older park. I spent about 2 days looking at about 2,000 trees in the woodland, and I don't think I saw a single potential roost feature. The plan is to deliberately trash a few of the trees, and the Bengtsson et al paper is the sort of planned damage I had in mind plus the creation of a few poles. And some thinning for small clearings to encourage a range of tree ages to develop. I've already built some bat boxes and put them up.

 

 

 

Just trying to speed up the process and get this artificial woodland behaving as it will in 100 years' time if left to its own devices.

 

 

I hadn't encountered it before, interesting concept! I like it.

 

In the OPs context though, impossible to price a job against such a vague spec.

 

Good learning and thanks for sharing OP.

[Chris at eden]

It's interesting stuff and certainly not fully researched yet.

I can see what you mean about horizontal limbs.

Did they have examples of failed cobra?

 

No mate, no examples of failed systems but they were massively plugging the product as a fall arrest system. I.e. if the tree does fail it doesn't hit the floor. I see so many of these things fitted incorrectly, too low usually, or massive horizontal subsiding limbs braced to a 200mm leader. Bonkers really.

 

It wasn't cobra though, it was the other one that looks similar, I forget the name. They had a solicitor there also talking about the legal implications and dismissing the myth that if you brace you are leaving yourself wide open. Like many things its about what is reasonable.

 

They briefly touched on the fact that Kew are now taking out all their old bracing systems. Apparently they had some strong winds through and they broke quite a few of the old steel braces but the trees stayed up. Did say though that some of the braces were very old which would obviously contribute.

 

Cheers

[David Humphries]

.....They briefly touched on the fact that Kew are now taking out all their old bracing systems. Apparently they had some strong winds through and they broke quite a few of the old steel braces but the trees stayed up. Did say though that some of the braces were very old which would obviously contribute.

 

Cheers

 

Some removals, but certainly not all.

 

I've been to Kew a few times since the fatality and have been looking at the work they are carrying out to mitigate risk of further branch/tree failures since the incident and have specifically been looking out for bracing removal.

 

I was there on a seminar last week and there are still braces (old and more recent) in a number of trees close to and above footpaths.

 

Not sure where the 'fact' that you mention came from.

 

 

 

.

[Chris at eden]

Some removals, but certainly not all.

 

I've been to Kew a few times since the fatality and have been looking at the work they are carrying out to mitigate risk of further branch/tree failures since the incident and have specifically been looking out for bracing removal.

 

I was there on a seminar last week and there are still braces (old and more recent) in a number of trees close to and above footpaths.

 

Not sure where the 'fact' that you mention came from.

 

 

 

.

 

 

Not sure David just relaying what the trainer said. You will note though that I said they are taking out all their old bracing systems, not they have taken them out. I took this as it is an on going system of checks with the old steel ones going and replaced if required. Part of the focus of the seminar was that bracing was overused and in many cases did not need installing at all. Also that quite often it gets installed and then just left with no appropriate checks. They were using Kew as a good example in how they were going back a re-examining what they have done previously and changing if need be. In my experience that doesn't happen on other sites.

 

Apologies if that didn't come across properly in the first instance.

 

Do you do much bracing at your place? What do you use?

[David Humphries]

Not sure David just relaying what the trainer said. You will note though that I said they are taking out all their old bracing systems, not they have taken them out. I took this as it is an on going system of checks with the old steel ones going and replaced if required. Part of the focus of the seminar was that bracing was overused and in many cases did not need installing at all. Also that quite often it gets installed and then just left with no appropriate checks. They were using Kew as a good example in how they were going back a re-examining what they have done previously and changing if need be. In my experience that doesn't happen on other sites.

 

Apologies if that didn't come across properly in the first instance.

 

Do you do much bracing at your place? What do you use?

 

 

we use a similar version to Gefa that Treeworker have developed, more often to be used as tethering system at work, but conventionally as well

 

as you say, checking and replacing when necessary is key

 

[ame]

[/ame]

 

.

[Beardie]

I'm intrigued by the notion of spraying for leaf miner. Since they are living within the leaf, wouldn't spraying be totally ineffective?