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C&RT get the go-ahead to cut back trees.


Alan de Enfield

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THE Canal and River Trust has been given the go-ahead to carry out work to several trees in a conservation area at the Farnhill embankment next to the Leeds and Liverpool Canal.

Some of the trees, which include oak, cherry and hawthorn, will be crown lifted and retained, while others will be cut down, and the area of the embankment returned to a grassed area.

The trust's senior ecologist says in his submission to the council that the long term aim is to create scattered and informal tree development at the site with grass between the tree, which will allow safe and easy access.

After viewing the plans, Craven District Council said it would not be putting a Tree Preservation Order on the trees and so the work could take place.

 

Work to trees along canal embankment can go ahead | Craven Herald

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2 hours ago, Alan de Enfield said:

THE Canal and River Trust has been given the go-ahead to carry out work to several trees in a conservation area at the Farnhill embankment next to the Leeds and Liverpool Canal.

Some of the trees, which include oak, cherry and hawthorn, will be crown lifted and retained, while others will be cut down, and the area of the embankment returned to a grassed area.

The trust's senior ecologist says in his submission to the council that the long term aim is to create scattered and informal tree development at the site with grass between the tree, which will allow safe and easy access.

After viewing the plans, Craven District Council said it would not be putting a Tree Preservation Order on the trees and so the work could take place.

 

Work to trees along canal embankment can go ahead | Craven Herald

 

What does 'crown lifted' mean - cutting off the lower branches?  Tree Monkey will know.

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5 hours ago, Mac of Cygnet said:

 

What does 'crown lifted' mean - cutting off the lower branches?  Tree Monkey will know.

Yes, removing the lower branches to achieve your desired aim

8 hours ago, Alway Swilby said:

I believe the thinking nowadays is that trees are not good for embankments, the roots de-stabalise them apparently. Network Rail certainly feel that way now.

It depends on the embankment and the size of the trees

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22 minutes ago, Murflynn said:

next thing will be the electricity distribution companies will seek to cull all trees that could bring down overhead cables during storms.  

it's a pity the use of buried cables is not mandated in many areas where it would be relatively cost-efficient.

It's been tried, unsurprisingly there was a fair amount of blowback, the idea was quickly pulled, mostly It's a more risk based approach now

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9 hours ago, Mac of Cygnet said:

 

What does 'crown lifted' mean - cutting off the lower branches?  Tree Monkey will know.

 

I found some very nice explanations of basic tree-monkery terms on this firm's website. Neither over-simplified nor over-complicated.

 

Here is their page explaining crown lift, with a nice diagram:

 

https://www.pjchaffin.com/tree-surgery-explained/crown-lift/

 

 

 

 

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1 hour ago, Murflynn said:

it's a pity the use of buried cables is not mandated in many areas where it would be relatively cost-efficient.

And what areas are those? My understanding is that underground groups cables is hugely expensive compared with overhead. One of the problems is that cables get hot when carrying current. For overhead wires this heat is easily dispersed to the surrounding air; not so underground. So the individual wires have to be widely separated underground, and that means a very wide swathe of land is needed to accommodate an underground high voltage line.  And, apart from the cost, that amount of disruption is not acceptable to landowners.

Edited by David Mack
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13 hours ago, Alway Swilby said:

I believe the thinking nowadays is that trees are not good for embankments, the roots de-stabalise them apparently. Network Rail certainly feel that way now.

You wouldn't say that if you saw the number of railway bridges which have trees growing out of them. Moulsford Bridge is a good example

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30 minutes ago, David Mack said:

And what areas are those? My understanding is that underground groups cables is hugely expensive compared with overhead. One of the problems is that cables get hot when carrying current. For overhead wires this heat is easily dispersed to the surrounding air; not so underground. So the individual wires have to be widely separated underground, and that means a very wide swathe of land is needed to accommodate an underground high voltage line.  And, apart from the cost, that amount of disruption is not acceptable to landowners.

The terrain would also make this prohibitively expensive and/or impossible in some upland areas.

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I suggest that the lines that should be buried are the local distribution cables, AFAIK these are generally 3.3kV. 

 

I am fully aware that HV transmission cables (e.g. 240kV and higher) cannot be buried in a cost efficient manner, but in my experience those are not the cables that may be affected by falling trees because they are raised well out of danger.

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8 minutes ago, Murflynn said:

I suggest that the lines that should be buried are the local distribution cables, AFAIK these are generally 3.3kV. 

 

I am fully aware that HV transmission cables (e.g. 240kV and higher) cannot be buried in a cost efficient manner, but in my experience those are not the cables that may be affected by falling trees because they are raised well out of danger.

Local networks, not Nat Grid, use 132kv 66kv 33kv to distribute to sub stations the 11kv network is then used from the sub stations to feed 240v transformers via pole mount or ground mount, most of this network will be wooden pole mounted apart from the 132kv which tend to use metal towers.

 

I care remembered the specs for pole height but there is not a massive difference between 11kv and 66kv.

 

All of the overhead network is managed to try to protect from falling trees, including Nat Grid network in fact Nat Grid was and still is very pro active in how they risk manage their tree works, which is not surprising really when the consequences of a Nat Grid failure is considered 

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6 hours ago, tree monkey said:

It depends on the embankment and the size of the trees

 

We've been through this before and agreed that trees are fine on slopes constructed in well graded homogenous soils but that those aren't the slopes at risk anyway. On the types of slopes that are at risk, typically those with a thin soil layer overlying rock, trees are a problem and therefore de-vegetation is a principal activity in earthwork risk management. It also has the effect of enabling access, controlled drainage and reliable inspection so it's about quite a bit more than whether trees are directly detrimental to the earthwork.

 

Edited by Captain Pegg
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1 minute ago, Captain Pegg said:

 

We've been through this before and agreed that trees are fine on slopes constructed in well graded homogenous soils but that those aren't the slopes at risk anyway. On the types of slopes that are at risk, typically those with a thin soil layer overlying rock, trees are a problem and therefore de-vegetation is principal activity in earthwork risk management. It also has the effect of making access easier, enabling controlled drainage and enabling reliable inspection.

I agree, which is why I said depends on the embankment, in the right place trees can help reduce erosion and stabilise slopes but it's not a universal panacea and as you have highlighted can make things worse, woodsheaves cutting is a classic example

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2 hours ago, Tonka said:

You wouldn't say that if you saw the number of railway bridges which have trees growing out of them. Moulsford Bridge is a good example

These trees are almost invariably buddlea which is an invasive species.  The use of sodium chlorate weedkiller has been banned and the current crop of ineffective weedkillers that are permitted seem unable to touch it.

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14 minutes ago, furnessvale said:

These trees are almost invariably buddlea which is an invasive species.  The use of sodium chlorate weedkiller has been banned and the current crop of ineffective weedkillers that are permitted seem unable to touch it.

There's plenty of available treatments, if these aren't killing the plant the application method or timing is wrong 

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7 hours ago, David Mack said:

And what areas are those? My understanding is that underground groups cables is hugely expensive compared with overhead. One of the problems is that cables get hot when carrying current. For overhead wires this heat is easily dispersed to the surrounding air; not so underground. So the individual wires have to be widely separated underground, and that means a very wide swathe of land is needed to accommodate an underground high voltage line.  And, apart from the cost, that amount of disruption is not acceptable to landowners.

Yes, those buried in a trench under the Regents Canal towpath in London are cooled by the cut water

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Burying cables takes me back to my first ever site inspection in the summer of 1987.

BICC (Erith Kent) were supplying 400kV national grid lines as part of Didcot power station expansion, to be buried under Goring golf course.

Hugely expensive but the land owner simply wouldn't let the cables go overhead, a certain HRH if I recall correctly.

A good decision in my opinion but I can only conject as to who paid the cost hike.

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On 03/01/2022 at 15:00, tree monkey said:

There's plenty of available treatments, if these aren't killing the plant the application method or timing is wrong 

Thanks for that.  It is probably the case that the previously available chemical, sprayed from the weedkilling train, was able to do the job, whereas nowadays a more personal, and hence more expensive, touch is required.

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On 04/01/2022 at 19:25, furnessvale said:

Thanks for that.  It is probably the case that the previously available chemical, sprayed from the weedkilling train, was able to do the job, whereas nowadays a more personal, and hence more expensive, touch is required.

 

Structures were never sprayed from the weedkilling train and that's what the initial comment was about. Vegetation on structures is annoying. I was able to pull a branch off a buddleia bush growing from the middle of the arch crown to well above the parapet as I walked the dog across the bridge over the north end of Droitwich station the other day.

 

Back when I was important I oversaw the creation of two gangs to remove vegetation from structures which we planned to run ahead of the inspection programme. It was getting so bad that it was impeding inspection and I routinely see places where that is still the case. I think structures maintenance has suffered more than other areas from industry change in recent years. Things are done very differently from when you may have been involved, that's certainly the case for me as I started in that field.

 

As for trainborne weedspraying there are more restrictions on spraying in close proximity to public areas than there once were and stations do tend to suffer as a result although I suspect they always did to some degree, plus the fact that there isn't the capability/capacity to plan (and replan) it all around when it isn't raining.

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The main summit level embankment on Ludwig's Canal in Bavaria had its slopes planted with fruit trees, while the Canal du Midi may have had trees planted along its banks about 100 years after it first opened, but does not seem to have any planted on embankment slopes.

Ludwigs Kanal summit level embankment 077.jpg

1995 Canal du Midi 527.jpg

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17 hours ago, Captain Pegg said:

 

Structures were never sprayed from the weedkilling train and that's what the initial comment was about. Vegetation on structures is annoying. I was able to pull a branch off a buddleia bush growing from the middle of the arch crown to well above the parapet as I walked the dog across the bridge over the north end of Droitwich station the other day.

 

Back when I was important I oversaw the creation of two gangs to remove vegetation from structures which we planned to run ahead of the inspection programme. It was getting so bad that it was impeding inspection and I routinely see places where that is still the case. I think structures maintenance has suffered more than other areas from industry change in recent years. Things are done very differently from when you may have been involved, that's certainly the case for me as I started in that field.

 

As for trainborne weedspraying there are more restrictions on spraying in close proximity to public areas than there once were and stations do tend to suffer as a result although I suspect they always did to some degree, plus the fact that there isn't the capability/capacity to plan (and replan) it all around when it isn't raining.

I am aware of that, being a former railway engineer.  However, the weedkiller must have soaked through the ballast on viaducts as the problem of buddliea sprouting from below rail level masonry was not a problem (when I was important)! 😄

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7 minutes ago, furnessvale said:

I am aware of that, being a former railway engineer.  However, the weedkiller must have soaked through the ballast on viaducts as the problem of buddliea sprouting from below rail level masonry was not a problem (when I was important)! 😄

 

The weedkiller works by application to the leaves which it wouldn't achieve even if it did percolate through ballast, and then there's the issue of all the overbridges and retaining walls. It wasn't a problem because it was manually cleared by directly employed structures maintenance gangs, something that largely ceased to exist in the 1990s as such activities weren't deemed critical in performance led contracts.

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