Very clever idea John, and there are spots on this island where it would
be very workable. Not from my lot, though - would have to get the barge
several hundred meters from the nearest water deep enough to float it,
and the lot is probably too small.
Thanks for a unique idea, though!
> Hello Jeff,
>
> Reading through your notes, it occurred to me, that perhaps if you have
> the access, you might consider placing the tower on a flat bottomed
> river barge, which would obviously cope with the water/sea/land
> variables of your site.
>
> The pirate sea going radio stations that have been set up around EU and
> the UK seem to cope with the extremes of weather, and yet do not
> overturn due to the wind pressure applied to their lattice towers on
> their floating structures.
>
> Obviously I cannot provide the detail on how this might be done, but if
> I were faced with a similar problem, I would look into acquiring an old
> Thames coal barge, they are like huge sardine cans, people convert them
> into fixed house boats. I would mount a crank up, tilt over 60ft tower
> in the centre of the barge. Stone ballast could be placed inside the
> barge for stability when the barge was high and dry, but not enough to
> sink the barge when the waters rose, the structure could then ride out
> the storm. I would also sink anchors/chains to keep the barge secured to
> the site during high water and fold over the tower so that the structure
> could ride out the worst weather extremes.....
>
> Just a few thoughts.......
>
>
> Sincerely, John. G3JVC/GM3JVC.
>
>
>
>
> On 23.10.2013 17:38, Your Name wrote:
> > I am trying to determine if it would be practical to safely install a
> > 40
> > to 50 foot free-standing or bracketed (not guyed) tower in my
> > location.
> > I would like to hear from anyone who has erected a tower in a similar
> > area.
> >
> > My location is Chincoteague Island, Virginia, Zip Code 23336. If I am
> > reading the â??three second gust speedâ?? maps correctly, this location
> > is
> > in a 120 mph area on the Exposure â??Câ?? maps. However, the location is
> > also about a quarter-mile from open water (an inlet off the
> > Chesapeake
> > Bay), so it is possible that it should be considered Exposure â??Dâ??.
> > The
> > location is flat and barely above sea level, with no significant
> > features to obstruct wind.
> >
> > The soil quality is about as poor as possible from a support
> > standpoint.
> > It is silty sand, and during the course of a year varies from
> > dry/loose
> > to completely waterlogged. It is also mildly salt-contaminated(from
> > seawater flooding in 2012), and so rather corrosive. The ground water
> > table is high - holes deeper than 3-4 feet tend to fill with
> > saltwater.
> >
> > One good thing: winters are relatively mild, frost depths never
> > exceed
> > an inch or so. Ice storms are rare. Icing would not be expected to
> > exceed 1/4 - 1/2 inch at most, and ice storms have not been known to
> > occur at the same time as high winds.
> >
> > One final feature of the site: it is subject to tidal flooding during
> > severe tropical storms and norâ??easters. Every 2 or 3 years, the base
> > of
> > any tower at this site will be immersed for several hours in
> > seawater,
> > to a height of up to 4 feet. (Most houses here, if you are wondering,
> > are elevated on pilings or perimeter walls.)
> >
> > Guying of the tower is absolutely not possible. Bracketing to my
> > residence (modern construction, concrete walls from the ground to
> > four
> > feet, frame above four feet) may be possible.
> >
> > The total wind load of all equipment would be about 10 square feet.
> > I would install either a K4KIO Hex-Beam, a 2-element Steppir Yagi, or
> > a
> > small tribander (Force 12 C-3S or similar) on the shortest practical
> > mast at the top of the tower. All of these have rated wind loads
> > below
> > 6 square feet. A medium-sized rotator (Yaesu G-800 SA or equivalent)
> > would be used. I would probably also attach 1-2 fixed,
> > omnidirectional
> > VHF/UHF antennas to the tower.
> >
> > My initial idea is to simply overengineer - select a tower rated for
> > 120
> > mph at *double* my planned windload, and go up a step or two on the
> > usual foundation size. I'm also inclining toward an aluminium, rather
> > than steel, tower due to the saltwater corrosion issue.
> >
> > Any thoughts would be much appreciated. I might end up turning to a
> > Professional Engineer for final planning, but I'd like to check to
> > see
> > if this is even remotely feasible before I incur that expense.
> >
> > Thanks,
> >
> > Jeff / KS4TL
> >
> > _______________________________________________
> >
> >
> >
> > _______________________________________________
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> > TowerTalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
>
>
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