For Mrtree and Hammy

[Stephen Blair]

more roots for Antoine:biggrin:

[mrtree]

You are obviously a very intelligent chap, but that is a rather ridiculous analogy!

 

What is ridiculous about comparing a tree to a building. They are both structures that must withstand the same rules of physics.

 

The point is the Eiffel Tower is not only hollow but has holes all over the shell; thus why does a hollow tree, or one with a hole in the outer wood, immediately get called hazardous, dangerous, defective, etc. The Eiffel Tower stands, thus I think trees can stand when they are less than "entire".

 

The job of an arborist or evaluator is to take training, experience, knowledge and technique and determine if the structure of a tree warrents its removal or some mitigation technique.

[Tony Croft aka hamadryad]

the errosion around the root crown will alter what the las cut will appear as. the last image doesnt look a worry at all.

[Tony Croft aka hamadryad]

so now all we need is photos of this "union" you where worried about.

[skyhuck]

What is ridiculous about comparing a tree to a building. They are both structures that must withstand the same rules of physics.

 

The point is the Eiffel Tower is not only hollow but has holes all over the shell; thus why does a hollow tree, or one with a hole in the outer wood, immediately get called hazardous, dangerous, defective, etc. The Eiffel Tower stands, thus I think trees can stand when they are less than "entire".

 

The job of an arborist or evaluator is to take training, experience, knowledge and technique and determine if the structure of a tree warrents its removal or some mitigation technique.

 

I've not come across any steel trees

 

If the Eiffel Tower corroded to 50% of its original dimensions, it would be dismantled.

[mrtree]

Hama asked "what do you mean by 250%?". This is a measure of the structural safety of an object. When an engineer designs a structure s/he must design it for the loads intended. Thus 100% indicates the design is safe (will not fail) under the current design when you consider the architecture, load, and material.

 

The same idea can be applied to trees. Wessoly (and others) have done engineering work on trees to understand how "safe' they are and how to measure that. Tree pulling tests are the result. For those that can pull trees there are on-line calculators that give us an indication of the safety of the tree you input data for.

 

When using these calculators I don't want to see 100%, I want to see something in the 200% plus range, meaning that the tree is twice as strong as needed for the intended load (generally 117kph winds I believe). That gives us some leeway beyond "just strong enough"

 

Steven has stated he would like to learn about VTA etc. look at Mattheck's books and articles about tree pulling etc. Search Erk Brudi's site and look up papers by Brudi and van Wassenaer and a very general paper by van Wassenaer and Richardson (check out Urban Forest Innovations website, maybe the PDF's are there).

[Johny Walker]

iv come a cross a few reinforced with steel girdles

[mrtree]

I've not come across any steel trees

 

If the Eiffel Tower corroded to 50% of its original dimensions, it would be dismantled.

 

Steel and wood are both materials that show strength properties, thus structures of wood and steel may need different amounts and arrangements of materials to achieve the same strength.

 

While steel may corrode, and wood may decay, the great thing about trees is they actually continue to add strucutre as they grow and large trees are actually more stable (ie. resistance to toppling and stem breakage) than smaller trees.

[Tony Croft aka hamadryad]

Hama asked "what do you mean by 250%?". This is a measure of the structural safety of an object. When an engineer designs a structure s/he must design it for the loads intended. Thus 100% indicates the design is safe (will not fail) under the current design when you consider the architecture, load, and material.

 

The same idea can be applied to trees. Wessoly (and others) have done engineering work on trees to understand how "safe' they are and how to measure that. Tree pulling tests are the result. For those that can pull trees there are on-line calculators that give us an indication of the safety of the tree you input data for.

 

When using these calculators I don't want to see 100%, I want to see something in the 200% plus range, meaning that the tree is twice as strong as needed for the intended load (generally 117kph winds I believe). That gives us some leeway beyond "just strong enough"

 

Steven has stated he would like to learn about VTA etc. look at Mattheck's books and articles about tree pulling etc. Search Erk Brudi's site and look up papers by Brudi and van Wassenaer and a very general paper by van Wassenaer and Richardson (check out Urban Forest Innovations website, maybe the PDF's are there).

 

so your a tree statics man! SIA for short, noit a fan myself, but I wont say too much till ive done the training and have a valid opinion.

[Stephen Blair]

so now all we need is photos of this "union" you where worried about.

 

on it Hammy!