[TowerTalk] [MWA] OH8X 80-160 monster tower collapses

[GEORGE BETHEA]

Very true and the author referenced an Engineering study that is being taken. We may find out the cause when they complete it.

73,
George K5JZ

Happy Holidays




________________________________
 From: Kelly Taylor <ve4xt at mymts.net>
To: K5JZ <k5jz at bellsouth.net>; Minnesota Wireless Association <mwa at w0aa.org>; TCDXA <TCDXA-list at tcdxa.org>; Tower Talk <towertalk at contesting.com> 
Sent: Tuesday, December 10, 2013 10:29 AM
Subject: Re: [TowerTalk] [MWA] OH8X 80-160 monster tower collapses
 

Hi George,

We know that from the explanation on the Arcala website.

Doesn't answer the question, however. You shouldn't design a tower system
such that the difference between maximum and minimum windload is the
difference between survival and failure.

If anything, the system should have, and probably was, built to withstand a
multiple of the maximum windload, with the windload-mitigation system merely
an added layer of headroom.

If the failure mode was the system kept turning and turning and turning the
array, it seems to me a failsafe mode that recognizes that failure and
defeats the system is easily designed. The need for such a failsafe should
have been readily apparent, given the engineering brainpower that obviously
went into this array.

Glad nobody was hurt and the tower only damaged itself on the way down.

73, kelly
ve4xt


On 12/10/13 7:11 AM, "K5JZ" <k5jz at bellsouth.net> wrote:

> As I understand it, the system that was engineered to point the array in the
> direction of the least amount of wind drag failed and the system corkscrewed
> and collapsed the array upon itself.
> 
> 73,
> George K5JZ
> 
> ----- Original Message -----
> From: "Kelly Taylor" <ve4xt at mymts.net>
> To: "Minnesota Wireless Association" <mwa at w0aa.org>; "TCDXA"
> <TCDXA-list at tcdxa.org>; "Tower Talk" <towertalk at contesting.com>
> Sent: Monday, December 09, 2013 12:30 PM
> Subject: Re: [TowerTalk] [MWA] OH8X 80-160 monster tower collapses
> 
> 
>> I offer my condolences to Radio Arcala, but I have a question about that
>> explanation: shouldn't the engineering of the tower system have accounted
>> for the possible failure of a windload-mitigation system?
>> 
>> Does anyone know: was it insured?
>> 
>> 
>> 
>> 73, kelly
>> ve4xt
>> 
>> 
>> On 12/9/13 11:43 AM, "Larry Menzel" <pensionguy at gmail.com> wrote:
>> 
>>> A sad day in Finland, the fantastic, now doomed, 330ft monster tower for
>>> 80
>>> and 160 had a catastrophic failure during a high wind storm in September.
>>> Apparently the engineering spec called for an automated feature to turn
>>> the
>>> massive array for minimum windload failed, allowing the whole structure
>>> to
>>> "corkscrew" and collapse on itself.
>>> 
>>> Here's a link: http://dx-world.net/2013/oh8x-tower-collapse/
>>> 
>>> Larry, W0PR
>>> _______________________________________________
>>> Minnesota Wireless Association mailing list
>>> To post a message: MWA at w0aa.org
>>> List Help: http://mail.w0aa.org/mailman/listinfo/mwa_w0aa.org
>>> MWA Official Web Site:  http://www.w0aa.org
>>> 
>> 
>> 
>> _______________________________________________
>> 
>> 
>> 
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