List readers:
I am currently involved in assisting one of my clients in permitting a
70' guyed/bracketed tower on a 70' by 100' residential lot. The
planning board has approved the tower and the building department is
in the loop as to actual building permit requirements.
The layout and foundations for both the tower base and elevated guy
posts were engineered and designed by myself. The building
department's issues with the installation revolve around Chapter 17 of
the UBC concerning special inspection of the installation and
components.
Concrete
I have eliminated the need for special inspection of the concrete
placement and the requirement of taking test cylinders by designing
with and specifying 2500 psi concrete. Any greater strength
specification and you risk having to take test cylinders. I also
alleviated the rebar special inspection by making that part of my
required structural observation program.
Excavation
This special inspection requirement was alleviated by being part of my
structural observation program.
Fabricated Steel components (non tower)
There are 3 W6 steel beams embedded in concrete and projecting 7 feet
out of the ground acting as guy anchor posts. This was done to clear
the guys from the single story house roof and frame. The special
inspection for these is waived as they are just cut beams.
There is a steel angle house bracket system that connects to the house
eave line. This was designed by myself and was necessary to get tower
through the zoning requirements. There is some minor 3/16 fillet
welding that may have to be either special inspected or done by an
building department approved fabricator. It seems that my 30 years of
experience in designing and building heavy steel framed industrial
plants and my PE license are not adequate to visually inspect 6 inches
of fillet weld.
Manufactured Tower components
It seems that in order to satisfy the building department's
requirements the tower sections must be fabricated by an approved
fabricator (At this time Rohn doesn't meet their requirements) or be
continuously inspected at time of fabrication by an approved inspector
(their approval requirements). The building department seems
determined to impose this particular special inspection requirement on
my client. I have had discussions with the BD concerning the fact that
the tower sections are manufactured to shelve and not to order. That
they are designed and manufactured in accordance to EIA/TIA 222-2e or
later, which by the way is recognized by the UBC as an "recognized
standard" is complies with the UBC requirements of life safety. I also
have been in contact with Rohn and they are quite helpful within the
limits of their responsibility and have provided me with data as to
their pre qualified weld procedures and certification cards of their
welders as well as information on the Engineer responsible for their
welding procedures and QA for the welding.
I have not ever come across this requirement before especially with a
pre-manufactured component that conforms to some recognized standard
of design and manufacture.
I'm sorry about the rambling but I needed to set the stage for my
request from the assembled group.
I would like to gather information from you tower owners concerning
your permit endeavors and requirements. I would like to know the
jurisdiction (city or county), date and permit number of your tower
permit. I only want info on permitted towers from 1995 on. I would
also like to know the applicable code, UBC, SBC or BOCA and what
special inspection requirements were made part of the permit for your
installation. Especially if the permit required that the tower
sections be from an approved fabricator and/or an special inspector
had to be involved in the manufacture of your permitted tower.
I would like to thank all of you for your input now,and wish to
apologize for my asking for your help when I should be assisting all
of you with your questions.
73 and all the best
Hank Lonberg PE
KR7X
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