TV Tower collapse

[Lou W9LRS]

A big one goes down 
Other Broadcasters help get them back on the air

http://www.weau.com/home/headlines/WEAU_13_tower_collapses_in_Fairchild.html

[K5UJ]

this is pretty surprising because I did not hear of any severe icing up that way.  I wonder how the wx was with respect to wind and ice.  It will be real interesting to find out the failure point.   I thought all the bad wx last night was over in N.D. and Iowa.  Maybe someone on the Classic Radio Net from up that way will have wx info for the night it came down.   The TV towers I have heard of that came down previously were either due to an extreme amount of icing or Hurricane Andrew.

Rob

p.s. happy birthday Lou

[W2PFY]

Too bad it came down. It didn't look like it used very heavy duty steel but I am not an engineer so take that with a grain of acid.

We had one go down in Plattsburgh, NY a couple years ago and another went down on Mt Graylock, Ma years ago both due to icing.

[KM1H]

The same storm dumped 4" of ice on parts of Michigan and 18" of snow further North.

Id guess maintenance was ignored and the owner had expected it to happen some day. Metal fatigue, and rusted guy wires that were likely original all contributed.

In many parts of the country (and Wisconsin) the airheads would be out celebrating and doing all they could to block reconstruction. It looks like the folks in that area of WI are quite normal however.

Carl

[k4kyv]

So it was a combination of ice and wind?  I would think they would use a lot of overkill on any kind of tower in ice-storm country. If I were erecting such a tower myself, I would check past wx reports for the known record ice accumulation, add about 50% to that figure, and then have the tower designed for even that figure with plenty of safety margin. It would be more expensive, but perhaps in a 50 year span, lower insurance premiums would recoup the cost, and certainly avoiding a fall would recoup the cost of replacing the tower.

Were rusty guys known to be a factor in that one?

[K5UJ]

The thing is that with a 2000 foot tower the wx on the top 500 to 1000 feet can be completely different from the ground.  There could have been 100,,150 mph wind at 2000 feet, much lower temp, heavy ice but dramatically different wx on the ground.  When you think about it, it is amazing they stay up as long as they do.

[W2PFY]

Id guess maintenance was ignored and the owner had expected it to happen some day. Metal fatigue, and rusted guy wires that were likely original all contributed.

I can't speak for that tower or others for the most part, but I know of a place that has six towers on it and the insurance companies have a guy go up there and check the general tower conditions.

They have a gauge of some sort to check the tension on the guy wires every couple months. It seems to me if they were insured, someone would be doing the same thing there. I was there on at least one occasion when they did their testing. I'm sorry that I didn't tag along to see what they do. 

[Lou W9LRS]

Another thought to ponder, the tower also held an Fm antenna and if they had not yet removed it, the analog TV antenna as well as the DTV antenna and maybe a back up for the Analog, DTV and FM . I say this because I know of some stations that left the old tv antennas in place for a period after the DTV conversion. This would present a huge wind load at the top of the tower. Who knows what other space was rented on that aged tower. I'm sure that the tower was checked when they did the DTV antennas, but they may not have recalculated the wind load under Ice conditions. Thanks for the Birthday wishes Steve.

Lou

[K5UJ]

Fybush has something about it in this week's tower site:

http://www.fybush.com/featuredsite.html