[TowerTalk] Falling a tower

[Barry]

I downloaded the file from the W5LL site and it won't open in 
Quicktime or WMV? Quicktime says format not supported and WMV goes 
looking for the codec and can't find it.  Other mpg's play.  Ideas?
Tnx,
Barry W2UP

On 29 Sep 2005 Terry Gerdes wrote:

> Hi all,
> 
> I was recently given a 150 foot Rohn 25 tower.  It was a old surplus
> Loran transmitter tower.  The tower is actually the transmit antenna
> and sets on a big Lapp insulator.   The lower set of guys were
> Phyllistran (old potted style) and the upper guys were EHS steel
> connected to the tower and part of the antenna.  The last 21 feet of
> the upper guys were Phyllistran.  The whole tower formed a large
> vertical with the four of the guys serving a top loading.  There were
> five sets of guys and nine other guy wires off the top servings as
> additional top hat loading.
> 
> When I got there, I inspected the guy anchors and everything looked
> fine. One problem noted was that all of the tower sections were tack
> welded together.  That was a bit of a issue as I would have to come
> back with a generator and surface grinder to grind off the tack welds.
>  I suspect the tack welded legs were probably a effort to improve the
> conductivity of the vertical.
> 
> I started up the tower inspecting sections as I climbed.  Some light
> surface rust was present but everything looked fine.  The lower set of
> guys also looked fine.  The fifth tower section had some suspicious
> rust.  I took the hook on the pulley and stated poking around and
> pretty soon had a hole in the tower leg big enough to put my thumb
> into.  There were other areas in that section that also failed when
> poked at with the hook on the pulley. Either time for a crane or time
> to let her fall.   See picture at:
> http://www.ab5k.net/images/LoranTowerLeg.jpg
> 
> The contact point who gave me the tower came up a bit later.  I told
> him I would do a "controlled fall".  He was just happy that the tower
> would soon be gone and did not really care.  So now I had to determine
> what a controlled fall was it there was such a thing.  The tower was
> in a fenced area and if it fell flat, it would take out the fence
> which was not desirable.  I decided to take off the second set of guys
> and pull the tower over at that point.  My reasoning was that the pull
> point would be close to the rusted section which would be a failure
> point.  The tower would bend at that point and the rest would
> accordion under the influence of the guys.
> 
> Besides safety, the two goals were try and save the Lapp insulator and
> keep the tower with in the fenced area.   The second set of guys were
> removed and one of the guys was extended and ran over to the truck
> where it was attached to a come-a-long.  After a lot of pulling there
> was a significant dog-leg in the tower, but it was still up.  I was
> surprised by the amount of side force it took to bring it down.  The
> tower broke up in four sections the longest being the top section. 
> Most of the sections are ruined but the Lap insulator was saved.  A
> few of the sections can be cut off and be used a concrete base
> sections.  The Phyllistran survived as well as the turnbuckles and
> equalizer plates.
> 
> Bob, NX5M, took video of the tower coming down.   The DVD was
> converted to MPG and can be downloaded from either of the two sites
> listed below.  Thanks to Matt, W5LL and Jim, K5LAD for hosting the
> file.
> 
> Jim - K5LAD:
> http://www.hayseed.net/~jpk5lad/download/Rohn25fall.mpg    (77.9 meg)
>   or a slightly smaller zipped version
> http://www.hayseed.net/~jpk5lad/download/Rohn25fall.zip    (71.7 meg)
> 
> Matt, W5LL:
> http://w5ll.com/mpg/Rohn25Fall.mpg
> 
> 
> I'm sure there will be comments especially after seeing the video.  It
> was a really interesting project.  By the way, the bad rusted section
> did not buckle.   If I had it to do over again I would probably drop
> the first and second set of guys.
> 
> Thoughts?
> 
> 
> 73 Terry - AB5K
> 
> 
> 
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> 
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--
Barry Kutner, W2UP              Internet: w2up at mindspring.com
Newtown, PA                     Frankford Radio Club