I cut the 'bloody stub' off flush with the base, grouted the old legs shut
and bought the Rohn 25GSSB base. Drilled 4 holes and installed 'L' bolts as
large as would fit the holes in the plate. Think they were the size Rohn
sells for the 45G plate but they filled the holes nicely. Used the special
epoxy cement (can't remember the actual name but believe it is no-expansion
stuff) to secure the new bolts and used a nut and washer above and below the
plate so it would be leveled when everything set up. Use some wood shims and
the base plate to keep the bolts in place while the epoxy cures. The bulk of
the installation info came from right here on Tower Talk. Thanks again guys.
Mike / W8DN
----- Original Message -----
From: "Chuck O'Neal" <cdoneal@comcast.net>
To: "Tower (K8RI)" <tower@rogerhalstead.com>; <kr7x@comcast.net>; "Melvin
Brafford" <roadrulz@isp.com>
Cc: <towertalk@contesting.com>
Sent: Wednesday, July 07, 2004 4:39 PM
Subject: Re: [TowerTalk] Broken Rohn 25G Base Section
> My suggestion would be to flush cut the remaining legs with
> the surface of the concrete base. Then drill a hole in the
> center of the concrete base for a pier pin instead, provided
> they make a pier pin base plate for the Rohn 25.
>
> A pier pin for the bottom section is a much better way to go
> anyway. I use them an all my towers. No worries about
> getting that first section straight and the resulting stress
> you place on the tower when it isn't perfectly vertical.
>
> 73
> Chuck...K1KW
>
>
>
> ----- Original Message -----
> From: "Tower (K8RI)" <tower@rogerhalstead.com>
> To: <kr7x@comcast.net>; "Melvin Brafford" <roadrulz@isp.com>
> Cc: <towertalk@contesting.com>
> Sent: Wednesday, July 07, 2004 3:31 PM
> Subject: Re: [TowerTalk] Broken Rohn 25G Base Section
>
>
> > WARNING: Welding on tower legs is welding on galvanized
> material. This
> > gives off a very poisonous gas. Make sure the wind blows
> the smoke away
> > from whoever does the welding.
> >
> > I'd do it the way they do on the 45 G and solid leg
> towers. Use a sleeve
> > similar to the construction of a 45G. They are straight
> with no reduction is
> > size at the joint.
> >
> > First, make certain that the portion of the base section
> is straight.
> > Neither twisted or bent with no welds broken.
> >
> > Make up sleeves/adapters to fit the bottom of next section
> slip an insert
> > inside that just nicely fits into the base of the next
> section. 25G legs
> > are reduced in diameter at the top and enlarged at the
> bottom. Your cut off
> > section is going to be full diameter at the top. I'd just
> use a steel pipe
> > to create an adapter that would fit inside, or preferably
> outside the base
> > legs and a slip fit *inside* the next section. It'd take
> two different
> > sizes to do this.
> >
> > An adapter that fits over the base and inside the next
> section helps prevent
> > water from running down into the inside of the base legs.
> >
> > There is also the option of making it into a hinged base.
> Just look at the
> > catalog diagrams of the hinged base. They are just two
> steel tabs welded
> > onto each base leg with holes to fit the next section.
> >
> > Roger Halstead (K8RI, EN73 & ARRL Life Member)
> > N833R, World's Oldest Debonair (S# CD-2)
> > www.rogerhalstead.com
> >
> > > Mick:
> > >
> > > A possible fix depending on how you are at welding or
> know someone who is
> > a certified welder is to trim the legs down to say 12"
> long vertically.
> > Weld some channel legs to the stub legs say 8" overlap and
> have the channel
> > legs end about 8" above the stub legs. Weld the legs to
> the back of the
> > channel sections with the channel flanges pointing to the
> outside..... (weld
> > on both sides of the leg to channel lap. You can use stich
> welding to
> > minimize warpage.
> > >
> > > O[ <------ outside
> > >
> > > Take a normal tower section and set on top of the stub
> rohn legs and drill
> > out the channel web to match the bolt holes in the tower
> legs. Bolt up and
> > you have created a reinforced splice in the leg. The
> channel can be C4 or so
> > does not have to be real big just a bit larger than the
> area of the leg in
> > cross section.
> > >
> > > This is a suggestion and other splice mechanisms would
> also work. The load
> > in the legs at the base for a guyed tower, even those
> embedded in concrete
> > is mostly axial not in bending.
> > >
> > > Your milage may vary but this should work.
> > >
> > > 73
> > >
> > > Lonberg Design Group, Ltd.
> > >
> > > Hank Lonberg, P.E.,S.E. / KR7X
> > > President
> > >
> > >
> > >
> > >
> > > > On May 21 a storm took down my 100' Rohn 25G. All the
> "big grip"
> > connections,
> > > > EHS cable, etc held up ok. When an 80' tall tree fell
> on the SE guy
> > wires, the
> > > > NW guy anchor pulled up out of the ground, and the
> tower folded like a
> > hair-pin
> > > > at the 30' level, and fell toward the direction of the
> tree(SE). The
> > force
> > > > exerted on the tower as the tree hit it also, broke
> one of the tower
> > legs at
> > > > just above the 2' level. The 25G was pushed and pulled
> at the same time.
> > I'm
> > > > left with around 2 feet of tower sticking out of the
> concrete base. The
> > swaged
> > > > ends are gone, and all I have left is the 3 legs which
> appear to be ok,
> > and the
> > > > 2 remaining cross and Z brace sets seem ok. I wonder
> if anyone would
> > trust using
> > > > the remaining base section stub, and if so how would
> you attach the next
> > section
> > > > above it? Thanks, and direct dialogue will be fine, so
> as not to clutter
> > up the
> > > > reflector.
> > > >
> > > > 73, Mick W4YV
> > > > _______________________________________________
> > > >
> > > > See: http://www.mscomputer.com for "Self Supporting
> Towers", "Wireless
> > Weather
> > > > Stations", and lot's more. Call Toll Free,
> 1-800-333-9041 with any
> > questions
> > > > and ask for Sherman, W2FLA.
> > > >
> > > > _______________________________________________
> > > > TowerTalk mailing list
> > > > TowerTalk@contesting.com
> > > > http://lists.contesting.com/mailman/listinfo/towertalk
> > > _______________________________________________
> > >
> > > See: http://www.mscomputer.com for "Self Supporting
> Towers", "Wireless
> > Weather Stations", and lot's more. Call Toll Free,
> 1-800-333-9041 with any
> > questions and ask for Sherman, W2FLA.
> > >
> > > _______________________________________________
> > > TowerTalk mailing list
> > > TowerTalk@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/towertalk
> > >
> >
> >
> > _______________________________________________
> >
> > See: http://www.mscomputer.com for "Self Supporting
> Towers", "Wireless Weather Stations", and lot's more. Call
> Toll Free, 1-800-333-9041 with any questions and ask for
> Sherman, W2FLA.
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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