[TowerTalk] How to fix crooked Rohn 45G short base?

[Les Kalmus]

A better approach might be to use a pier pin. Cut the existing base 
flush with the concrete. Get a Rohn bottom plate made for a pier pin and 
a pin. Then drill a hole in the center of the concrete and epoxy in the 
pin.  You're ready to go. See this link for an example:

https://www.dxengineering.com/search/part-type/tower-base-plates/product-line/rohn-pier-pin-tower-base-plates?autoview=SKU&sortby=Default&sortorder=Ascending

You'll probably have to replace the section you had embedded and cut but 
this will give you a "by the book" tower base.

Les W2LK


On 7/4/2020 10:55 AM, Grant Saviers wrote:
> I've made joiners and bottom plates for different tower sections for 
> Field Day, R25 to aluminum etc.
>
> The Rohn leg bolts hold in shear so larger holes are not a good answer.
>
> Getting two plates made with welded on pin and socket, that can be 
> shimmed to correct the angle makes sense as a solution, but needs a 
> lot of strength as you noted.  I would go with the shimmed plates.  
> Have them galvanized.
>
> For starting over, there are expanding grouts (Dexpan) that break up 
> concrete.  Drill deep holes, mix and pour.  Removing concrete with 
> rebar/tower section will be a PITA.  A big excavator might pull it 
> straight out whole.  I'd try that first.  Or Dexpan to break off the 
> exterior then pull.
>
> Grant KZ1W
>
>
>
> On 7/4/2020 06:46, Blake Sobiloff via TowerTalk wrote:
>> Hi guys,
>>
>> Due to the property lines and terrain I don’t have room to pour 
>> another one next to the existing one, so jackhammering out the 
>> current one may be the only option.
>>
>> Some others have suggested drilling new bolt holes to make the first 
>> section plumb. That seems like the easiest option, but I worry that 
>> (depending on how close the new holes are to the existing holes) that 
>> will weaken the tower right where the majority of the bending stress 
>> is focused. I admit I’m naive about these things, though.
>>
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