self supporting TV towers

[Garrett Wollman]

<<On Sun, 27 Sep 2009 22:16:31 -0500, Kevin Vahey <kvahey@comcast.net> said:

> Now the question I have is - given what happened to WBZ-TV in Allston
> in 1954, why would WNAC-TV go self supporting in Newton when they
> moved from Malden.

Why would you think there would be a connection?  The fact that the
WBZ-TV tower failed in Hurricane Carol says nothing about the design
requirements for the WNAC-TV tower in Newton.  You might as well ask,
given that Eiffel Tower in Paris hasn't fallen down yet, why would
anyone build guyed towers?

Historically, far more guyed towers than self-supporters have failed,
although I can't speak for the relative frequency, and there are a lot
more guyed towers than self-supporters.  (Speaking only of steel
lattice towers here -- I've never heard of a monopole failing.)

Like any engineering problem, the design of lattice towers involves a
set of design requirements, including the probability of component
failure, plus some additional margin for error, and a budget.  It's
the responsibility of professional licensing boards to ensure that
structural engineers are appropriately qualified, and that the design
assumptions are reasonable and appropriate given past experience.
When they get it wrong, there's a whole branch of the legal profession
to find someone to pay for the consequences.

-GAWollman