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Re: [TowerTalk] Fwd: Heights Towers Aluminum??

To: <>, <>
Subject: Re: [TowerTalk] Fwd: Heights Towers Aluminum??
From: "David H Craig" <>
Date: Fri, 15 Aug 2008 14:15:41 -0400
List-post: <">>
    I have no first-hand knowledge of these towers, but I am currently 
working with an experienced aluminum welder (military aircraft) on a tower 
project.  Presuming arguendo this is not a "buttering" problem (cold weld 
with no penetration) it sounds as if the completed units are not 
heat-treated to bring them back to the original tensile strength.
    An example- I asked my welder friend about the practicability of welding 
a center-sleeve of 1 1/2" OD 1/4" wall aluminim tube into a 2" OD 1/4" wall 
tube so I could have a travel mast with two 8 foot sections that would silde 
together & bolt on just one side.  He told me the tube stength would be 
compromised unless the welded portion was "baked" at the appropriate temp 
for 24-36 hours, and that in his shop (a gov't facility with top of the line 
gear) the "oven" can only fit 3ft long objects.  To wit:  "In some 
applications it is better to just use hardware and this is one of them".

    Why do I get the impression that the critical welded areas of these 
towers are not re-heat-treated?


----- Original Message ----- 
From: <>
To: <>
Sent: Friday, August 15, 2008 1:33 PM
Subject: [TowerTalk] Fwd: Heights Towers Aluminum??

>I am glad to get this information. The Height tower I have in my yard just
> now is old. I noticed that some of the weld or the Z have opened and was 
> going
> to fix that before I put the tower up. Now I may get all the welds 
> inspected
> before I put it up. I looked at the welds before and wondered if they were
> OK,  but as I am not an expert I thought they were OK. The welds that 
> brook were
> under high tention after the Z itself bent at these places.
> Hans N2JFS
> ____________________________________
> From:
> To:
> Sent: 8/15/2008  2:00:39 A.M. Eastern Daylight Time
> Subj: Re: [TowerTalk] Heights Towers  Aluminum??
> Hi all,
> As being the lucky person to clean up the  mess left by Owen's tower
> failures, I can tell you first hand that all antenna  weights, wind load 
> specs,
> lengths, etc. were passed on to Heights before Owen  put them up, anyone 
> who knows
> Owen knows he goes by the book and documents!!  He was told that his 
> loading
> was within spec.
> I am no expert on  aluminum welding but I do a fair amount about steel
> welding and what I have  seen is a failure of welds on his towers. 
> Normally, a weld
> is stronger than  the surrounding material. If there is a failure, the 
> weld is
> intact but metal  is ripped away around the weld. A sign of a good weld is 
> a
> slight cutting away  of material right at the weld. This is the point 
> where
> the material starts to  melt and becomes one with the welding rod 
> material. Some
> of the failed welds  on his HF tower that came over first look like they 
> just
> poped off, like a  cold solder joint.
> His second failure, just a couple of weeks ago,  occured at 36 mph as
> measured by his Davis wx station and verified by the  local airport which 
> reported
> only a 31 mph gust. The top section failed right  where it went inside the 
> next
> section. A leg buckeled in and it was all down  hill from there. Once 
> again,
> as the leg that was receiving all the downward  pressure (opposite the 
> legs in
> the wind) pushed inward and the Z bracing which  is supposed to keep it 
> from
> collasping, didn't. I did not see the Z bracing  buckle, the welds just 
> broke.
> All the discussions thus far seems to be  centered around just self
> supporting foldovers, not crank ups as Owen's was.  I'm sure there is a 
> difference
> between the way the load is distributed down  the tower.
> At K8GP, we use a lot of Univeral self-supporting towers that  pivot up 
> from
> atop our school buses. Our towers take a lot of abuse from being 
> overloaded
> (it's only 5 days twice a year!) and riding around on bumpy roads  on top 
> of
> school buses. Our towers have survived 80+ mph winds and when we  have a 
> break,
> it's usually a fatigued Z brace and NOT at a weld and we only go  up 30 to 
> 40
> feet.
> I'm not passing judgement on Heights towers or  aluminum towers in 
> general,
> just adding to the discussion of what I saw. For  most of us, a tower is a
> pretty good size investment in time and money, and  since my tired, old, 
> fat butt
> is climbing up, I want nice heavy, thick,  galvanized STEEL under me!
> Terry
> -------------- Original message  -------------- 
> From: <>
>> Hi Dick,
>> Unlike K3CB's recent experiences with the catastrophic  failure ofboth of
> his
>> Heights crank-up towers (one in dead calm  weather and the other in light
> 30 MPH
>> winds), the collapse of the  Heights tilt-over tower was the direct 
>> result
> of an
>> inexperienced  tower owner significantly exceeding the maximum dead 
>> weight
>>  specification.
>> I suspect he isn't alone in failing to  appreciate the importance of not
>> exceeding the dead weight  specification for tilt-over towers.
>> 73
>> Frank
>> W3LPL
>> ---- Original message ---- 
>> >Date:  Thu, 14 Aug 2008 16:40:33 -0600
>> >From: "Dick Williams"
>>  >Subject: Re: [TowerTalk] Heights Towers Aluminum??
>> >To:
>> >
>> >I have seen several interesting comments on the  reflector concerning
> Heights
>> >Alum towers; and in fact, I posted a  couple myself.
>> >
>> >As I mentioned in a previous post, I  have three of them and they all 
>> >tilt
>> >over in the center (80 ft  towers with the fold over at the 40 ft 
>> >level).
>> >
>>  >Obviously, weight is a concern, you can't put 400 lbs of antenna and
>> >acessories on the top and expect it to work.
>> >Alum  masts certainly help; in fact I have a nice 20 ft, 1/2 inch wall 
>> >one
>>  >sitting on the ground that I am not using right now (150 bucks picked
> up).
>> >
>> >As far as size, I have not found that to be a  problem (just weight). I
>> >put the antenna together (or take it  down to work on with the boom
> parallel
>> >to the ground (elements  vertical). If the elements are too long, I just
>> >start removing  element sections as I lower it down until the boom is 
>> >low
>> >enough  to work on.
>> >
>> >It is too bad that Glenn Martin  Engineering does not produce the 
>> >Voyager
> any
>> >more. It is the  similiar to the Hazer except it is on a external track 
>> >on
>> >the  side of the tower. I have one on a 120 ft Rohn tower. Have a Force 
>> >12
>>  >Mag 620/340N on it with a M2 R2800 rotor. Works great; brings the 
>> antenna
>> >right down to the ground ready to be worked on when needed. And  all it
>> >takes is a 1/2 inch electric drill to raise and lower it.
>> >
>> >All said and done, I like the Heights towers and  the Voyager system for
>> >"ground level" antenna work.
>> >
>> >Dick K8ZTT
>> >
>> >
>> >
>>  >_______________________________________________
>> >
>>  >
>> >
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>> >
>>  >
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