[TowerTalk] Mobile Tri-ex 70 tower

[Michael Tope]

Some folks I work with had to place some 225-450 MHz corner reflectors 
on a dry lake bed and anchor them firmly in place. That is when I 
learned about the existence of the Industrial Fabrics Association 
International (IFAI), Tent Rental Division (TRD) Procedural Handbook. 
Chapter 3 addresses anchoring:

http://www.snicc.org/wp-content/uploads/2017/11/TRD17_TentSafe_Handbook.pdf

FWIW, I guy my AB-577 military mast with those 7ft steel T-posts (the 
ones that are typically painted green) that they sell at Tractor Supply. 
They have held up well for a number of years in a windy location with no 
problems in sandy soil and a modest wind load (Spiderbeam antenna). For 
heavier winds loads (like a crank-up tower with bigger antennas), I am 
not sure that I would trust them without doing some real engineering (I 
just winged it with the AB-577 installation).

73, Mike W4EF.................

On 7/13/2018 11:53 AM, jimlux wrote:
> On 7/13/18 11:35 AM, Richard (Rick) Karlquist wrote:
>>
>>
>> On 7/13/2018 7:14 AM, jimlux wrote:
>>> On 7/13/18 6:11 AM, W0MU Mike Fatchett wrote:
>> They drive rebar in the ground with
>>>> a washer welded at the end for the tie offs.
>>>>
>>> > I doubt they have any signifcant pull-out strength, so if the wind 
>>> comes up, the stake will bend, pull out, and over the tower goes.
>>
>> Probably true, although they are analogous to the big "tent stakes" used
>> to put up large temporary tents, and those have a successful track 
>> record. 
>
> Those stakes are typically some fairly stiff steel and larger in 
> diameter (1"), known as "bull pricks" in the entertainment industry 
> (traditionally, they were rear axles, the gear providing a convenient 
> "head" upon which to hammer).
>
> https://www.versalestore.com/p1959/30amp;quot;-Tie-Down-Ground-Anchor-(Bull-Prick).htm 
>
>
>
>
>  A trick I use with guy stakes is to pound two of them
>> in about 3 feet apart.  The stakes are long enough to allow them to
>> stick up 2 or 3 feet.  A rope/cable is attached to the rear stake right
>> at ground level.  The other end goes to the top of the front stake.
>> The guy goes to the bottom of the front stake.  This gives tremendous
>> leverage and insurance against bending, pulling out, etc.
>
> yeah, something like fence T-posts would work.
> They too, are typically a stiffer steel than "rebar"
>
>>
>> At my QTH, we have 100% clay, and as long as it is dry (which it always
>> is the 4th weekend in June) it is like concrete.  I hired a D10 CAT to
>> try to rip this stuff up with a single 7 foot "knife" and the D10
>> (with 600 HP) actually stalled.  The driver complained that he had
>> "only" 100 tons of weight to pull with.  OTOH, during the winter 
>> rains the clay has the consistency of peanut butter.
>>
>>>
>>> *real* temporary installations designed to withstand significant 
>>> wind (or seismic) loads will use auger screw anchors, or these days, 
>>> I've seen a lot of use of "big blocks of concrete" or K-rail/jersey 
>>> barrier. 
>>
>> Before jumping to that solution, an intermediate solution is to use
>> a big pickup truck with a heavy duty trailer hitch parked at the
>> guy point.  (The truck owner has to turn over the keys to the
>> field day captain for the weekend, to prevent one of "Murphy's
>> helpers" from driving the truck away.  Hi.)
>
>
> That works.. 5000# truck is the same as 5000# lump o' concrete.
>
>
> i guess the net-net on all this is that guying a temporary tower 
> requires some amount of thought.
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