Thinking about using a cherry-picker on a job in the near future?.
You may like to have a read of this:
Cherry- Picker PDF
{File size is just over 1MB, but is well worth a read.}

Nasty.

Good report, but it looks like they may have been "shotgunning" a little at the end. They mentioned fiberglass degradation at the end, but it was never mentioned as a mitigating factor. (personally, I think that it still would have snapped even if it were brand new). I don't know if I would have added that if it wasn't a cause.

I use these types of lifts quite a bit, and it makes me nervous every time. (I don't like hights to start). It reminds me of one of my favorite cliches : Never trust an interlock (guard) to save your life.

All of the lifts we use are rentals, and I just assume that none of the safety features are going to work. It makes me pay alot more attention to what I am doing.

Ed

Ed,
I agree with the majority of your post.
I use bucket trucks as a matter of course in my line of work (PoCo Line-Mechanic).
Our gear is stripped totally every 6 months and inspected.
Having said that, the only fibre-glass part of the truck is the actual bucket.
The rest of it is insulated with multiple layers of neoprene and PVC.
Even the stabilising legs.
Mind you when fibre-glass "goes" is does so in a hurry!.

I have seen a number of bucket lifts that were also designed to be used as cranes....rotate the basket aside, and there is a a hook & pulley ready for use.

I am amazed that there is no relief valve, regulator, ir other device in the hydraulic system that would not limit the force applied to within limits safe for the boom.

Or- is what I'm asking impossible for some reason?

My thoughts exactly. Almost every hydraulic system I have ever come across has a bypass valve or something similar to limit oil pressure in case a cylinder gets jammed or something like that.

John,Kenny,
I think you guys are thinking of the older single redundancy system.
Double redundancy offers a better degree of control under fault conditions.
Double redundancy also offers the chance that a line burst won't send you to the ground as quick.
This is Hydraulics we are talking about here, low pressure one end, high pressure the other mean anything?.

[This message has been edited by Trumpy (edited 03-12-2006).]