[TowerTalk] how much rust is too much?

[Matthew Kaufman]

On 10/13/2014 8:37 PM, Tim Duffy wrote:
> Hello Matthew:
>
> What is the center to center distance of the legs? It could be Rohn 25 - not
> model 45 from the photos.

If my notes are right, I measured it at about 17 inches, and the joints 
are like Rohn 45 joints, not swaged joints.

>
> It looks like the dirt trapped lots of moisture around the base. That might
> be a problem.

That is exactly what happened. Not sure what percentage of its life was 
spent like that, but long enough to eat through the galvanizing and get 
rust going.

>
> A close inspection of the entire installation by a trained and certified
> tower professional is defiantly in order. Do not take any chances.

Point taken. But still want to get a rough idea of the right level of 
professional. Most "tower professionals" aren't structural engineers, 
and most structural engineers want to defer to the manufacturer of the 
structure. If we're looking at "yeah, that's more than enough good metal 
remaining for sure", I'll go with a tower professional. If we're looking 
at "definitely way too much metal is missing and the bottom section and 
plate must be replaced" (or "just replace the whole tower") then I'll 
find a tower professional who likes cranes, I suppose.

Matthew