In a message dated 7/14/2009 4:57:25 P.M. Pacific Daylight Time,
towertalk-request@contesting.com writes:
> Last winter, I had a stack of a 40m full size beam and a tribander
wiped out
by a storm. The point of failure was the steel tube that I was using which
bent over and caused a knock on affect which destroyed the beams. We have
learn the difference between pipe and tube the hard way.
> There are several steel stockists here in Ireland, but they only carry
standard galvanised piping. I have checked the towertalk archives and there
is a lot of discussion there on the merits of Chrome-moly tubing and the
different grades that would be suitable for this type of installation.
> However, these seem to be US standards and the steel merchants here are
not
familiar with them.
> Can anyone point me in the right direction ? If someone has purchased
tubing
for a similar project, I would be very grateful if you could send on
details
of what tubing you have used.
What you want to do is to ask your steel supplier what the yield
strength of the material is. I have attached the Masts chapter from my
upcoming
tower book in a separate email. My Up The Tower book will be out next
month.
Unfortunately it's all in US units but converting it should be easy
enough. I also offer the MARC (Mast, Antenna and Rotator Calculator) Program
for running the numbers. The book and the program are both available from
_www.championradio.com_ (http://www.championradio.com) .
BTW you probably don't need chromoly material. You might if you have
big, aggressive antennas on the mast and big winds but for most applications
it's way overkill.
Cheers,
Steve K7LXC
TOWER TECH
and
Champion Radio Products
Cell: 206-890-4818
**************Can love help you live longer? Find out now.
(http://personals.aol.com/articles/2009/02/18/longer-lives-through-relationships/?ncid=emlweu
slove00000001)
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