This one was in horrible shape. I'm surprised it last as long as it
did. The ham's QTH was next to a creek and his home flooded several
times, so I'm sure that didn't help things. The steel and rust just
sloughed off in sheets until we got to bare uncorroded metal. Wasn't
enough good metal to worry about regalvanizing, we just threw it in the
trash since the ham that bought the tower had a Rohn 25 base he was
going to use anyway.
> WOW, Ive removed and reused many base plates including a few that were
> within 100-200 yards of the ocean and never saw one that bad even after
> 20-25 years. Id suspect a concrete that has a higher concentration of
> salts than normal leaching out over the years.
> Ive also had many sections regalvanized that were covered in surface
> rust from being in very exposed locations and also subject to acid rain.
> The interiors were still perfect.
> ----- Original Message ----- From: "Tom Anderson" <WW5L@gte.net>
> To: "jeremy-ca" <email@example.com>
> Cc: <firstname.lastname@example.org>; "Jim Lux" <email@example.com>
> Sent: Thursday, June 28, 2007 1:06 PM
> Subject: Re: [TowerTalk] Tower ACCIDENT
>> A word about using Rohn's flat plate mounts.
>> Several years ago I helped the XYL of an SK dispose of her OM's ham
>> equipment. One of the last things sold was his 60 feet of Rohn 25
>> tower. It was attached to the concrete slab which was like 4x4x6 by
>> one of Rohn's flat plates and bolts at each corner.
>> She didn't want the mounting plate left, but would be ok with the
>> slab, so we used a sledge to knock off the thoroughly corroded bolts
>> and once we removed the mounting plate we saw that it had nearly
>> corroded through on the bottom side to the top, although from the top
>> the corrosion wasn't visible. Apparently the slab wasn't flat or
>> crested to allow water to flow away from the plate. It pooled
>> underneath and the years of water being present had corroded the plate
>> to the point where within a few months it might have failed and the
>> whole 60 ft guyed tower had come down when the base slipped.
>> Tom, WW5L
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