[TowerTalk] [Boatanchors] Base for tower

[Run]

I did essentially the same thing you are trying putting up my "Dover " 
tower.
Dover is also no longer in business.

When you pull a permit , you should be required to meet tower location 
and engineering design requirements.
If you are a homeowner , the planner will look at your initial plans and 
make recomendations about the tower engineering.  If you are a 
contractor , forget getting any help.


I first had to assume that Dover designed the tower to meet structural 
design and followed Rhon suggestions for section width and height.   My 
tower is self supporting and 65 feet heigh with the first sections 18 
inches , then 14 inches then finally 11 inches.
I used information from Rhon for the base and looked over some Civil 
engineering books to identify the required base for my soil conditions.  
I also used Rhon for the steel type and then went through the mechanical 
engineering calculations to figure the yeild strength of the one leg by 
measuring the leg diameter and thickness.  Stress was calculated with 
the tower linearly loaded with 1/2 inch of ice in an 80 MPH wind.  Eash 
sq foot applys 20 pounds force in an 80 MPH wind.  Whatever force was 
left over allowed for antenna loading or antenna area so you know what 
you can safely put up without exceeding the design.  I just wrote in the 
drawings that the antenna area was not to exceed this limit.

The planner accepted it all except he required me to place a 10 inch 
weld on the 1 inch rod that would attach to the tower legs where I 
calculated 8 inches.  Hi comment was that the force is applied through 
the center of the rod and therefore the weld was offset by half of the 
bar diameter and created a torsional load on the weld that was not 
accounted.  We change the 8 to a 10 and it all passed....tower is up and 
most importantly, my house insurance covers any tower liability because 
I have a valid permit!,

Yes , it's possible for a laymen to research and do these type of things 
and the planner who passed the engineering prints is a P.E.
I am just a dumb E.E. who took a strength of materials course along the way.
---
Ron

WØQFC wrote:

>Jim:
>You said:
>"It would seem to me that these questions are better answered by a local
>engineer in consultation with the tower manufacturer".
>That would be great except the manufacturer went out of business 40 years 
>ago!
>I am trying to use the collective experience of the Ham community, who has 
>"Been there, done that".
>Also, the specs for the tower mounting -even though they might be 40+ years 
>old - were most likely written by a PE in the first place.
>Gene, WØQFC
>Spring Hill, Florida
>WEB SITE:
>http://www.w0qfc.com
>
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