[TowerTalk] [Bulk] Rohn 25G tower permitting

[Roger (K8RI) on TT]

On 2/3/2015 10:56 PM, Brian Carling wrote:

If the 25G is short enough to only need one set of guys, then it will 
work fine with a "dirt base". ROHN used to sell them.  The only 
requirement for a 50 - 60' 25G even with a big tribander is the soil 
must be firm enough to keep the base from sinking, or moving sideways.

The base of a guyed tower need only to stabilize the tower, keep it from 
sinking, or moving sideways.

73

Roger (K8RI)

> Thank you Jack,
>
> It is similar to where I was heading, but I am planing to use one set of guy wires and a slightly smaller base. If you have guy wires the size of the base is not that critical.
>
> I have someone working with me now on the engineering and drawings based on information from the Rohn 25G catalog and the TI 222 document.
>
> Best regards - Brian Carling
> AF4K
> 117 Sterling Pine St.
> Sanford, FL 32773
>
> Tel: +USA 321-262-5471
>
>
>
>
>> On Jan 30, 2015, at 1:56 AM, Jack Brindle <jackbrindle at me.com> wrote:
>>
>> Rohn has a section in their catalog for unguided towers which includes Rohn 25. They call for something like 2.5’ x 2.5’ x 4’ of concrete for the base. I’m not sure I really want to be up 35 feet on that, but it has been in their literature for as long as I can remember. I am sure many folks have built one of these, and would love to hear opinions on ways to make it safe. I suspect this is what the original poster was referring to. Not all of us can have tall towers - sometimes 35 feet will have to do, and extensive guy systems can be problematic on small city lots. So, the question really is how do we put this stuff up and make it safe? Is this where you were heading, bcarling?
>>
>> 73,
>>
>> Jack B, W6FB
>>
>>
>>> On Jan 29, 2015, at 8:19 PM, Roger (K8RI) on TT <K8RI-on-TowerTalk at tm.net> wrote:
>>>
>>> On 1/29/2015 6:57 PM, Grant Saviers wrote:
>>>> My 140' Rohn 65 base is 4x4x2 ft. PE engineered.  So 3' of concrete is a bit much, check the Rohn catalog.  The most important thing with a base in concrete is the legs go through it and into some gravel for drainage.  I've seen many legs split by water freezing in them.
>>> Or use a pier pin base with solid lefs. Easy to make and not expensive.
>>>
>>> 73
>>>
>>> Roger (K8RI)
>>>
>>>> I wouldn't go as far as "3/4 ply and broomsticks" but the loads from 30' won't need much of a base for 2000psi soils.  It's all in the catalog.
>>>>
>>>> Grant KZ1W
>>>>
>>>>
>>>>> On 1/29/2015 10:10 AM, Wilson wrote:
>>>>> I think you are being led around by the short hairs.
>>>>> How did you decide a 27’ tower needed to be in 3’ of concrete?
>>>>> For practical purposes there is no bending and no horizontal load at the base of this tower, assuming it is guyed, of course, which –25 must be.
>>>>> You could stand 30’ of 25 on a piece of 3/4” plywood and three broomsticks and have a fine installation!
>>>>> The guywire and anchors are your real design hotspots, so a reasonable estimate of overturning moment is necessary.
>>>>> With it, you figure the worst guyline load and that gives you an anchor capacity requirement.
>>>>> You may have the perfect place for some screw in anchors, or an ideal place to display some heavy yard art!
>>>>> Yes, you’ll have a little horizontal load due to drag on the tower itself, if it’s in the clear, so maybe use rebar or pipe instead of the broomsticks.
>>>>> I have a 2’ square pad and a tilt plate for mine (40’) and it’s overkill.  The tilt plate is great for antenna maintenance.
>>>>>
>>>>> And are you required to tell them all about the antennae to be installed?
>>>>> The less you tell them, the better, since you’ll be changing eventually anyway.
>>>>>
>>>>> WL
>>>>> _______________________________________________
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> TowerTalk mailing list
>>>>> TowerTalk at contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>> _______________________________________________
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> TowerTalk mailing list
>>>> TowerTalk at contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>
>>> -- 
>>>
>>> 73
>>>
>>> Roger (K8RI)
>>>
>>>
>>> ---
>>> This email has been checked for viruses by Avast antivirus software.
>>> http://www.avast.com
>>>
>>>
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk


-- 

73

Roger (K8RI)


---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com