As a lawyer in a previous life, I have had direct experience with
litigation over tower safety.
Personally based upon what I know, and I that knowledge I am
no expert... but still, I would never erect a tower in any manner
that was not specified by the manufacturer.
Yeah... Yeah... I know there are plenty of towers which has been
up for a long time without conforming to specifications -- but I
would not bet my farm on it. All that needs to occur is have it
fall on someone, and, ...well, ... I predict you will be writing a check
to the widow.
Now this is just my personal take, and I know it is not a popular
take, but I marvel at all the ways some ham operators try to
out-think, out-engineer, the manufacturer, and stray from original
manufacturer specifications and installation technique. This is not
a matter where I would cut any corners, and when I erect my
tower later this year, you can be assured I will do it to the letter
of the instruction manual, just to keep all liability where it
belongs -- on the manufacturer and the installer. In fact, you
can bet I'll be out of town when my tower goes up, but that
installation shall be exactly as specified. Once you deviate
from that, liability tends to follow you, instead.
Just my take.
Happy trails and 73. ---- Richards - K8JHR ----
==============================================================
Derek Cohn/WB0TUA wrote:
> Hi Everyone,
>
> This year, our Field Day group put up two Rohn 25G towers. Towers were
> erected in the middle of a full size football field and separated by enough
> distance that if either one fell, it would not contact the other. Our
> stations were located about 200' from the towers to provide an extra measure
> of safety.
>
> My concern that I'd like to discuss is less about the tower and antennas and
> more about safety. While I hope the towers don't come down, my sole focus is
> making sure no one gets hurt/killed.
>
> Tower No. 1:
>
> 40' with 15' of mast sticking out the top with a 135' all band doublet hung
> from it. Tower base was a Rohn BPH25G bolted to an 8' automotive ramp made
> of angle iron (weighed about 150lbs.). Tower was pulled vertical with a
> truck mounted crane with truck sitting on the 8' automotive ramp and
> temporary guys made of nylon rope were attached and terminated in 2" pipe
> hammered into the ground at 120 degrees around the tower. Once guys were
> fixed, truck with crane was backed off the automotive ramp and headed for
> tower no. 2
>
> Tower No. 2:
>
> 40' and had a TA-33 tribander on it. Tower base was a Rohn BPH25G bolted to
> an identical 8' automotive ramp made of angle iron (weighed about 150lbs.).
> Tower was pulled vertical with a truck mounted crane and temporary guys made
> of manila rope were attached and terminated in 2" pipe hammered two feet into
> the ground at 120 degrees around the tower. Truck remained parked on the
> automotive ramp with crane attached to rigging on tower.
>
> We had no issues with this installation. HOWEVER, I'm thinking we
> under-engineered the guy lines. My prime concern is with tower no. 1 that
> had only the guys for support (the second tower had the crane attached to the
> rigging the entire time). Eventhough this installation was designed to only
> be up for approximately 24 hours, I wonder if we should have used more
> substantial material for the guys. I'm concerned that if someone wandered
> into the tower area and tripped on a rope guy, the force might provide enough
> "pull" to start the tower crashing down. In addition, the guys were "hand
> tightened" with unknown tension. We used a level to make sure the tower was
> vertical as the crane pulled it into position and then snugged up the guys so
> that the tower remained vertical as the crane was removed from the rigging.
>
> In retrospect, I think this was a risky installation but I'm no engineer.
> Should I have bought a spool of 1/4" EHS and a LOOS tensioner and installed
> these for this temporary installation or am I being paranoid? I want to be
> sure that the fact we had no issue doesn't give me a false sense of security.
>
> What would be appropriate guy material for a Field Day installation such as
> I've described above?
>
> Thank you for your input & 73,
>
> Derek Cohn
> Morse Telegraph Club - Alton Chapter
> Office UD, Sine DJ
> Amateur Radio Station - WBØTUA
> 1969 Brunswick M274A5 Mechanical Mule
> _______________________________________________
>
>
>
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