Just like cars, never buy one built on a Monday, Tuesday after Monday Night
Football or Friday or other days that follow holiday weekends < ;-) UR
experience may vary!
----- Original Message -----
From: "W5LT" <W5LT@verizon.net>
Sent: Friday, August 15, 2008 8:55 PM
Subject: [TowerTalk] Fwd: Heights Towers Aluminum??
> The lower strength of welded aluminum is recognized in the Aluminum
> Association Specifications standard, and the new Heights series used the
> lower value in the design and analysis of the tower sections. That
> makes no mention of 'baking' a weld to regain the lost strength.
> Keep in mind that the 'allowable' strength of any material is the limit
> value used in any design. It is arrived at by discounting, with a safety
> factor for the material in question, the minimum specified limits of the
> yield & ultimate stress for the various types of stress (tensile, shear, &
> bearing). Generally the discounted yield strength is the value used for
> design purposes. Thus the design has an inherent 'safety factor against
> failure, the main purpose of which is to have some margin against
> imperfections in the manufacturing process or other variables.
> Of course, if the welding is defective, all bets are off.
> I do know that Heights is using the TIG welding process in the new series,
> but that still leaves operator skill & technique as a significant
> I do not know the methods used to manufacture the 'old' series.
> Bob, W5LT
> -----Original Message-----
> From: David H Craig [mailto:email@example.com]
> Sent: Friday, August 15, 2008 1:16 PM
> To: HansLG@aol.com; firstname.lastname@example.org
> Subject: Re: [TowerTalk] Fwd: Heights Towers Aluminum??
> 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
> a center-sleeve of 1 1/2" OD 1/4" wall aluminim tube into a 2" OD 1/4"
> tube so I could have a travel mast with two 8 foot sections that would
> 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
> 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: <HansLG@aol.com>
> To: <email@example.com>
> 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
>> to fix that before I put the tower up. Now I may get all the welds
>> before I put it up. I looked at the welds before and wondered if they
>> 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: firstname.lastname@example.org
>> To: email@example.com
>> 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
>> 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
>> 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
>> slight cutting away of material right at the weld. This is the point
>> 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
>> 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
>> only a 31 mph gust. The top section failed right where it went inside
>> section. A leg buckeled in and it was all down hill from there. Once
>> 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
>> collasping, didn't. I did not see the Z bracing buckle, the welds just
>> 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
>> between the way the load is distributed down the tower.
>> At K8GP, we use a lot of Univeral self-supporting towers that pivot up
>> atop our school buses. Our towers take a lot of abuse from being
>> (it's only 5 days twice a year!) and riding around on bumpy roads on top
>> school buses. Our towers have survived 80+ mph winds and when we have a
>> it's usually a fatigued Z brace and NOT at a weld and we only go up 30
>> I'm not passing judgement on Heights towers or aluminum towers in
>> just adding to the discussion of what I saw. For most of us, a tower is
>> 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!
>> -------------- Original message --------------
>> From: <firstname.lastname@example.org>
>>> Hi Dick,
>>> Unlike K3CB's recent experiences with the catastrophic failure ofboth
>>> Heights crank-up towers (one in dead calm weather and the other in
>> 30 MPH
>>> winds), the collapse of the Heights tilt-over tower was the direct
>> of an
>>> inexperienced tower owner significantly exceeding the maximum dead
>>> I suspect he isn't alone in failing to appreciate the importance of not
>>> exceeding the dead weight specification for tilt-over towers.
>>> ---- Original message ----
>>> >Date: Thu, 14 Aug 2008 16:40:33 -0600
>>> >From: "Dick Williams"
>>> >Subject: Re: [TowerTalk] Heights Towers Aluminum??
>>> >I have seen several interesting comments on the reflector concerning
>>> >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
>>> >over in the center (80 ft towers with the fold over at the 40 ft
>>> >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
>>> >sitting on the ground that I am not using right now (150 bucks picked
>>> >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
>>> >to the ground (elements vertical). If the elements are too long, I
>>> >start removing element sections as I lower it down until the boom is
>>> >enough to work on.
>>> >It is too bad that Glenn Martin Engineering does not produce the
>>> >more. It is the similiar to the Hazer except it is on a external track
>>> >the side of the tower. I have one on a 120 ft Rohn tower. Have a Force
>>> >Mag 620/340N on it with a M2 R2800 rotor. Works great; brings the
>>> >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
>>> >"ground level" antenna work.
>>> >Dick K8ZTT
>>> >TowerTalk mailing list
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