[TowerTalk] A near imminent TX-455 failure

[D. Scott MacKenzie]

Welding may work - it would be much better if the tower were down to repair
it.  However, I would try to brace the legs together with some sort of stout
brace, then pin them.  Weld them too.  Once that is complete, then you could
weld the legs.  Pray for no wind.

-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com]On Behalf Of K4SAV
Sent: Sunday, November 13, 2005 10:30 PM
To: towertalk at contesting.com
Subject: Re: [TowerTalk] A near imminent TX-455 failure


Man, that is a scarry looking situation.  Looks like one little twist of
the tower, and down it comes, and there seems to be a house close by.
Does someone have any suggestions as how to stabilize this thing before
it all comes down?

It looks like two legs have broken all the way through, just above the
weld point. KB0FPH said he thought the welds had failed. I know this is
somewhat difficult to see, but it appears to not be the weld that has
failed, but the main support legs just above the welds. I had to save
the web page, recover the jpg files, then blow them up with a viewer to
get a closer look.  Scott, would welding still be appropriate if the
welds have not have failed?

Wish I could offer some good suggestions, but I don't have enought
experience in this kind of problem. I would probably be trying to drop
some steel rods down the tower legs, and then guy the thing to keep it
from falling, but what do I know?  Maybe someone else can help.  He
really needs it, guys.

Jerry, K4SAV


D. Scott MacKenzie wrote:

>>From the photographs, it appears that failure originated from the edge of
>the weld beads. Usually this indicates lack of fusion on the weldments.
>Failure should occur in the base metal.  It also appears that the tower is
>either painted or galvanized (I can't tell because I can't see well enough
>at the fracture.  Since the welds appear to have failed at the weld bead,
>grinding the weld bead off, then rewelding would be appropriate.  I would
>also suggest some sort of backing plate to reduce the loads on the weld may
>be utilized to reduce the stresses on the weldment.  The hard part will be
>getting the  joints lined up for welding.
>
>In my former life doing failure analysis on structures and components,
>unfortunately, this is a common mode of failure, most often associated with
>inadequate penetration of the weld.
>
>IMHO
>
>Scott aka KBOFHP
>
>
>-----Original Message-----
>From: towertalk-bounces at contesting.com
>[mailto:towertalk-bounces at contesting.com]On Behalf Of Nick - VE3EY
>Sent: Sunday, November 13, 2005 8:26 PM
>To: towertalk at contesting.com
>Subject: [TowerTalk] A near iminent TX-455 failure
>
>
>I am posting this note on behalf of a friend of mine.
>
>His 55 foot TX-455 US Tower is on the verge of collapsing down.  The
>owner just noticed that two out of three legs of his tower just broke
>down.   The legs snapped just above the mounting ears where the tower is
>fastened to the "T" mounting plate.   We suspect that some 90 km/h wind
>gusts we have had here in Toronto last week may have been a contributing
>factor.
>
>The tower is currently nested and the antennas are still on top of it.
>It is basically holding on only one of the remaining legs and a few
>cross braces.   It was installed brand new in 1990 and it had a 2 el GEM
>Qubical Quad installed ever since.   In 2003, owner replaced the short
>mast with a 22" cromoly nested about 3" inside the tower and added a
>home made rotary dipole for 30/40 m at about 10 feet above the Gem
>Quad.   The dipole is a modified Cushcraft D3W warc dipole.
>
>The pictures of the damage can be seen here.
http://dx.fireroute.com/TX455
>
>We are looking for some advice how to remedy this problem.   Would there
>be any way to fix this tower short of buying a new one?
>
>
>73,  Nick
>ve3ey
>
>
>_______________________________________________
>
>See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
>Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
>questions and ask for Sherman, W2FLA.
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk at contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
>
>_______________________________________________
>
>See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk at contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>
_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.

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