[TowerTalk] Fwd: screw anchors (was Welding Rebar)

Tue Jan 7 09:05:04 EST 2014

I put up a 50ft Rohn 25G tower in 1971 using used 25G sections.  I bought Rohn screw in anchors and used no concrete, but a Rohn BP25 baseplate (no longer sold).  Took
this tower down in1987 everything looked FB, no rust.  It
had held a light TA33 with 40 meter conversion kit without any problems.  I then moved to Ohio and reused the tower and anchors until 2010.  Again, the anchors look just fine.  Recently put the same 25G back up but added a few sections and put 5 feet in a 4 X 4 X 5 hole with concrete.  Top is now at 73 feet and guyed at  34 and 64 feet using the same anchors.  Again no sign of rust.  Do you ever see anchors put in by cable, electric or telephone companies using concrete, or see them replacing anchors routinely?

73
Dave -N4DB-

On Tuesday, January 7, 2014 8:04 AM, Hans Hammarquist <hanslg at aol.com> wrote:

If I understand you right, the screw anchors should be replaced at about ten years interval. Needless to say, if something fails due to corrosion or what-have-you it will break, that's what maintenance is for. The pull-out force is what it is for a intact screw anchor. It will be less for an anchor damaged by corrosion. That's there the maintenance come in.

If you check my album:
https://www.facebook.com/media/set/?set=a.10150198503693539.328964.579753538&type=1&l=b4a8463457
there is one picture of some bolt that were holding the tower together when I received it. They were, obviously not fit for service any longer.

Hans - N2JFS

-----Original Message-----
From: K0DAN <k0dan at comcast.net>
To: Hans Hammarquist <hanslg at aol.com>
Sent: Mon, Jan 6, 2014 4:20 pm
Subject: Re: [TowerTalk] screw anchors (was  Welding Rebar)

I have had a screw anchor fail, resulting in the destruction of a 70' tower 
plus all antennas and hardline.

This was about 16 years ago, and the tower had been up 15+ years with no 
problems. Over time, galvanic action between the soil (thick clay below 
about 2' of black dirt) and the steel caused one anchor rod to stretch out 
like taffy and eventually snap. This caused a chain reaction of the other 
guywires. It was ugly and costly.

Except for a temporary installation, I'd encourage anyone considering use of 
screw anchors to install them into concrete and not in direct contact with 
soil. YMMV.

73
dan
k0dan

-----Original Message----- 
From: Hans Hammarquist
Sent: January 06, 2014 15:00
To: towertalk at contesting.com
Subject: [TowerTalk] screw anchors (was Welding Rebar)

I don't see any problems with screw anchors. Anyone what havae had any 
problems with them The one I use are, according to the manufacturer's spec., 
good for a pulll force of 14,400 # in undisturbed,dry sand.

Hans - N2JFS

-----Original Message-----
From: Wayne Kline <w3ea at hotmail.com>
To: Roger (K8RI) on TT <k8ri-on-towertalk at tm.net>; towertalk 
<towertalk at contesting.com>
Sent: Mon, Jan 6, 2014 1:51 pm
Subject: Re: [TowerTalk] Fwd:  Welding Rebar

I think we all have a  few OMG or WTF regarding tower/antenna   installation 
and
upkeep

Field  Day.  are a prime example of  Elmer's rule ( If it did not fall down 
it
was not big enough or high enough )

I personally know of a statin that had 5 towers 4 100' & 1 80'  guyed with 
3/16
ehs three levels on the 100' and two levels on the 80
all with mono band beams  one being a full size 40 meter beam and there 
were
screw in anchor's and NO  I repeat NO concrete
anywhere . the bases being Rohn 25 hinge  plates   bolted to 2' X 3' steel 
plate
and a three or four rebar's 1/2 dia pounded in the soft wet ground.. last 
for
many many many years

  YMMV

Wayne W3EA

Date: Mon, 6 Jan 2014 03:26:43 -0500
> From: K8RI-on-TowerTalk at tm.net
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] Fwd:  Welding Rebar
>
> On 1/6/2014 12:58 AM, Hans Hammarquist wrote:
> > I believe K2TTT put one tower up using nothing as a base, just the tower
standing on a small plate, resting directly on ground. Yes, it is (was) 
guyed.
> Over the years (since 61) I've had 7 towers up using dirt bases. They
> were only 40-50' with one 60 footer, and one 90 footer, all guyed.  I
> had a 5L 20M KLM, 6L 15M KLM,(42' booms) and a 7L Wilson 10M Yagi on a
> 39' boom. One was 90' with a Cushcraft ATB34  It's a rather rugged dirt
> base and in solid soil, I'd not hesitate to go 90 feet with 25G, but
> avoid those towers that only have the horizontal bracing.
> http://www.rogerhalstead.com/ham_files/Dirt_Base.htm  I'd consult an
> engineer for higher or different soil.  I over guyed the 90 footer which
> was a mistake.  The extra weight and proper tension of the larger steel
> guys put an excessive vertical load on the tower causing the bottom 3
> sections to bell out where they join, requiring a hydraulic jack to get
> them apart.
>
> 73
>
> Roger (K8RI)
>
> >
> > Dave, am I correct?
> >
> >
> > Hans - N2JFS
> >
> >
>
>
> ---
> This email is free from viruses and malware because avast! Antivirus
protection is active.
> 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 

_______________________________________________

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