Aerial rigging in trees

[adam2]

Other points to consider, are what are the consequences of failure.

 

There is a lot of difference between a few cheap PAR cans falling into A RELIABLY cordoned off area, and the same par cans falling onto persons with possibly fatal consequences.

 

Likewise when considering the potential damage to the tree, there is a lot of difference between a unique and valuable tree that may be the subject of a preservation order, and one out of a large area of pines that are soon to be cut for timber anyway.

 

As an example I once rigged several rather heavy HID floods from a branch of an old oak tree. Doubts had been expressed about the reliability of the branch and the risk was managed by preventing access in the potential fall zone. And as for the tree, the owner took the view that if the branch fell off, then that proved it was already on the way out and would soon have fallen anyway. I attached the lights to scaf tube at ground level and hoisted it to the desired height from a distance.

 

 

 

[top-cat]

 

As an example I once rigged several rather heavy HID floods from a branch of an old oak tree. Doubts had been expressed about the reliability of the branch and the risk was managed by preventing access in the potential fall zone. And as for the tree, the owner took the view that if the branch fell off, then that proved it was already on the way out and would soon have fallen anyway. I attached the lights to scaf tube at ground level and hoisted it to the desired height from a distance.

 

Whilst mitigating the risk of falling objects striking people by cordoning off the fall area is admirable and no doubt the right thing to do, I am still not sure that your approach to the situation was legal, as far as LOLER is concerned.

 

Regulation 6 says:

 

 

 

Positioning and installation

 

6. (1) Every employer shall ensure that lifting equipment is positioned or installed in such a way as to reduce to as low as is reasonably practicable the risk—

 

(a)of the lifting equipment or a load striking a person;

 

So you've likely fulfilled your obligations there; however it then says

....(b) from a load—

(I) drifting;

(ii) falling freely; or

(iii) being released unintentionally; and it is otherwise safe.

 

My point is that LOLER says that it must be prevented from falling in the first place... simply ensuring nobody is hit if it does fall is not considered enough.

 

Additionally' date=' Regulations 4

 

Strength and stability

 

4. Every employer shall ensure that—

 

(a)lifting equipment is of adequate strength and stability for each load, having regard in particular to the stress induced at its mounting or fixing point;

(b)every part of a load and anything attached to it and used in lifting it is of adequate strength.

 

So simply saying "that looks strong enough, but if it's not and it does break, well it would have done anyway" is not considered adequate either. If you suspend a load from something which you are not 100% convinced is good for the load you are applying (which, as BR often points out, may need to be the opinion of somebody higher qualified - a structural engineer in the case of buildings, or perhaps an arborist in the case of trees) then it would seem you are in breach of the regulation and therefore acting illegally - regardless of what other steps you have taken to mitigate the risk to people in the event of it failing.

[adam2]

I agree that my actions might not have been fully legal, but I am also satisfied that the risk of failure was very low, and that the risk of serious consequences from any failure was effectively zero.

 

Trees are unpredictable unlike say modern buildings. The safe load on say a roof beam can be determined by a suitably qualified architect or structural engineer, the safe load on a tree cant be much more than an informed guess since the internal condition of the tree is large unknown. The rules regarding safe working loads etc are fine for man made structures, but of limited use for trees.

 

The safe working load of some trees is zero, a number of lives have been lost by apparently sound trees or parts thereof falling onto persons below.

 

 

 

[top-cat]

I agree that my actions might not have been fully legal, but I am also satisfied that the risk of failure was very low, and that the risk of serious consequences from any failure was effectively zero.

 

In case it wasn't obvious, that was exactly what I was saying. The precautions you took were good in minimising the risk and anyone would applaud that... however in this instance because you're talking about a lifting application, it could well be interpreted that you broke the law, regardless of the actual danger presented. Of course the chances of a prosecution being brought against you (normally breaches of LOLER are brought about in court as breaches of the HASAWA) in an incident where nobody is hurt are low. But the point is still there... and you should try to be legally compliant all the time. Regardless of how much use you believe the regulations to actually be, they are the word and the law and you have a responsibility to do all you can to comply with them.

 

As a side note, I have some friends who are arborists and actually they are often able to give a pretty good indication of what kind of loading trees can take. After all a part of their job is deciding whether trees are safe standing as they are or whether there is a safety need to cut them down or at least chop bits off. To say that it's nothing more than 'an informed guess' might not be exactly how a good tree surgeon would describe it... being that it is after all their profession.

[Seano]

it could well be interpreted that you broke the law

 

Then again, maybe he didn't. "Reasonably practicable".

 

Of course the chances of a prosecution being brought against you [...] are low.

 

Zero. So no need to bang on about it ad nauseam.

[top-cat]

it could well be interpreted that you broke the law

 

Then again, maybe he didn't. "Reasonably practicable".

 

Reasonably practicable indeed. In an instance where it is not 'reasonably practicable' to obtain approval from a field expert that the supporting structure you are hanging from is fit for the weights involved... is the answer "don't hang it at all" or "hang it anyway"... because I'd bet on the former.

 

Of course the chances of a prosecution being brought against you [...] are low.

 

Zero. So no need to bang on about it ad nauseam.

 

Well... I disagree. I am not from the camp that says breaking the law is OK as long as you won't get caught.

[dashroom66]

I have never rigged anything using a tree, and don't consider myself competent to do so, but just to satisfy my curiosity; how do you rig off a tree without damaging it?

[kerry davies]

Just spotted this topic and just to add that I spent 30 years hanging serious loads off trees.

 

By the time I climbed up there they were called telephone poles but the principles were the same. They also have the advantage of being in the world of work so HASAWA applied and they have a hundred years more experience than anyone in the leisure field.

 

It might be a good idea for research purposes to get hold of the manuals of aerial rigging and pole work from telephone and power suppliers. The GPO is where much of the safety groundwork for riggers was developed in the UK anyway and they had it all formalised on paper. All wooden utility poles are subject to regular non-invasive testing for rot and decay and those procedures are also formalised.

 

One thing that is crucial is geometry because, just like trees, poles bend and stay wires and the alignment of loads are vital elements. The other most crucial element is stability and, just like trees, poles had a "root system". It takes a hell of a lot more effort to snap a pole or a tree than to drag it out of the ground. Choose your tree well.

 

As for protecting the tree then temporary work can be done with strops and the like but anything that is rigged around a living tree long-term will end up grown into the bark and eventually the timber of the tree.

[abbotsmike]

Not quite on topic (mods feel free to split or zap) but on a trip to Go Ape a few years back, we were somewhat bemused to see that each participant's harness safety line was terminated with an alloy carabiner. This clipped onto the zip wire and was dragged behind the user. All of our carabiners had nicely worn grooves in the metal, that you suspected would send a Loler inspector crazy. We queried it and were told it was just fine...

 

OTOH, if they used steel carabiners, the wear would be as much on the cable as the carabiner. I bet I know which is cheaper to replace periodically!

 

Several of my climbing carabiners have some grooves in them from ropes. It's not considered to be an issue, as long as it's not too deep! 'Too deep' is generally up to the judgement of the owner though....

 

http://www.ukclimbing.com/news/item.php?id=67607