Towertalk
[Top] [All Lists]

Re: [TowerTalk] how much rust is too much?

To: towertalk@contesting.com
Subject: Re: [TowerTalk] how much rust is too much?
From: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
Date: Tue, 14 Oct 2014 04:40:12 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
On 10/13/2014 11:45 PM, Matthew Kaufman wrote:
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.

I installed 100' of 45GT. It used swedged joints, just like the 25G only larger. The solid leg 45Gs use a circular flat plate joint. It's about 3" in diameter IIRC, but it's been a long time since I saw one.

Look for pits after removing the rust. Be extra cautious if there are any pits large enough to notice. There are ultrasonic thickness gauges for measuring the tube thickness. I used to measure a lot of pipes and tanks, even with epoxy paint on them. If there are ANY pin holes in the tube or welds, you will need an auxiliary base to hold the tower, or a big crane.. A job for professionals.

 73 and good luck,

Roger (K8RI)



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
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk


--

73

Roger (K8RI)


_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>