[TowerTalk] Tower ACCIDENT

[Roger (K8RI)]

I can only tell you what I've done in the past.
I'm not a professional, but I've been climbing for many years and had to do 
so at work as well.


> This information is all well and good ... it rings with a bell of
> caution ... BUT , how do you know .. ????

First you do a thourough visual inspection of the tower, tower bolts, guys, 
and guy anchors looking for any damage, irregularities (is it straight, 
bent, twisted, or dented. How about cross braces no longer attached.), and 
*signs* of rust. Rusty bolts, or signs of rust around the bolt holes. I'd 
even go so far as to remove at least one bolt from the bottom of each tower 
leg. Is the bolt rusty or is the bolt good but has signs of rust being 
deposited on it, particularly as a stain. (pull the top bolt of the pair and 
use a light to inspect the lower bolt in place if possible)

Guy wires may or may not rust from the inside. I've taken down towers where 
the guy wires were completly coated with rust, but proved to be plenty 
strong.  Be wary of small guy wires. Wire rope showing rust is likely to be 
bad or at least seriously compromised and particularly the smaller diameter 
stuff. It can be tensioned to near it's working strength as a test using a 
Loos gage. If it passes back off to the normal 10% of the rated strength.

I *always* use temporary guys on any older tower. Even use extra temporary 
guys if there is any doubt.

I shold note that the tensioning of the guy wires doesn't necessiarily prove 
the tower is good. It's only a test of the guys and the atach points. 
Remember a tower can have some serious damage and still have sufficient 
strength in the vertical plane while having very little in the horizontal at 
spots.

Internal rust may be completely invisible from the outside, hence the reason 
for checking the bolts for signs of rust. It may be stains which are a 
warning sign, but not necessiarily and indication the tower is ready to 
fail. OTOH if there is loose, granular rust laying on the bolts or visible 
at  the base of the tower it's time to call a crane in. I'd definately not 
climb in that case.

At one time I had an electronic thickness gage that worked on steel and 
aluminum. It only needed to be calibrated for the material to be tested. We 
used it on pressure vessels. How well that would have worked on tower legs, 
I don't know.

BUT even after a thourough inspection there is still a fair amount of 
intuition involved because as I said above, some serious damage may be 
completely invisible and with no outward signs elsewhere.   I've put up and 
taken down a lot of towers, but when it comes to older towers I become very 
picky. As I said earlier, I also use temporary guys so even if a guy broke 
or a secion buckled it'd not fall far unless it broke off completely.

> In this case the climber felt all was well until the tower came down
> with him on it .. but now how in the world do you test and determine
> all is OK before you climb.?? Or what steps do you use to protect
> your self ...
> Certainly the professional tower people who partake in this forum
> will have a degree of in site for us .. but it needs to be
> discussed.!!! We've got guys here with 5-10-20 plus years old towers

http://www.rogerhalstead.com/ham_files/tower9.htm  The tower shown is well 
over 30 years old and had been up at 3 different locations. It showed no 
signs of rust and was climbed regularly. However it was reaching the point 
where there were many small irregularities in it. IE it was no longer 
straight. Not bad, but not straight either and that was when I decided it 
was time to replace it.  After it was taken down there were no signs of rust 
damage inside.

> ....What is the answer??

As a personal opinion, climbing is risky even with the proper equipment. 
Climbing old towers can be down right dangerous and I'd not recomend it for 
a casual climber unless they can get some one "in the know" to do a good 
apraisal of the tower. Even then there are no gurantees.

Roger (K8RI)