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Re: [TowerTalk] Calculations

To: Jim Lux <jimlux@earthlink.net>
Subject: Re: [TowerTalk] Calculations
From: "Alan C. Zack" <k7acz@cox.net>
Date: Mon, 13 Sep 2004 20:24:01 -0700
List-post: <mailto:towertalk@contesting.com>
Having had just gone through this process I have the following comments:
I agree the $250.00 charge seems reasonable as the P.E. has to take the manufacturer's drawings and calculate the wind loads, etc, from them. What I received was two sets of nine pages of very complicated calculations. I have a E.E. degree and an I.E. degree but don't fully understand what is contained in the calcs. They are based on the IBC-2000 Bldg code using UBC 1618 wind loads. The first and last pages have the wet stamp by the P.E. I had thought the Bldg Inspector might have kept them for awhile and looked them over before approving them but the first guy who I had been dealing with said they looked good, called over his supervisor who had previously explained to me what I needed, who also approved them. They kept one of the two sets and gave me the other set with a stamp on each page showing approved for construction. I have to have this set available for the field inspector when he comes out to see the hole and rebar before the concrete is poured and again for the final approval.
I would disagree on the cost of the shipping of the drawings. It was included in the price of the calcs and were sent in one of those USPO Priority Mail flat rate envelopes for $3.25 that I received in about two days.
I agree that the P.E. should be paid a reasonable fee for his services but what is wrong with the tower manufacturer paying for it and getting the rights to be able to provide the drawings to customers when required? There is a copyright notice on the drawings but it is held by the tower manufacturer, not the P.E., so it seems the drawings are the property of the manufacturer.


Jim Lux wrote:

I'm sure you meant "recurring costs should be minimal"...

It depends on how the company getting the calculations contracted with the
engineer.

Most building departments want a "wet-stamped" set of calculations, which
implies that the engineer has reviewed the calculations for that specific
installation and so forth.  This "individual review" would be both legally
and ethically required. The engineer is responsible for also knowing the
local peculiarities of the code, etc. Just to put $250 into perspective,
that's probably around 2-3 hours of the engineer's time, plus all the
incidental costs involved. (does the $250 include shipping the drawings, for
instance.. that's $25 right there)

Indeed, the incremental cost for an engineer to "review" the calculations
might be less than the first time, but bear in mind that's probably what the
engineer is doing the first time.  That is, the $250 pays for the licensed
engineer to review the calculations provided by the manufacturer. I'm not a
tower designer, so if someone just brought me all the drawings for the
tower, it would cost a lot more than $250 to do all the calculations from
scratch.  You'd have to look up the material properties of the parts the mfr
used, check the drawings for the kinds of welds and bolts, etc.  Someone who
designs towers and similar structures for a living would have all this
information at their fingertips, and would know at a glance if the mfr is
using a "generally accepted industry practice" so the strutctural analysis
they'd be reviewing would be fairly cookbook.A "skilled practitioner" would
know where the trouble points might be and home in on those.


All in all, $250 is very reasonable for this kind of professional review.



----- Original Message ----- From: <WarrenWolff@aol.com> To: <towertalk@contesting.com> Sent: Sunday, September 12, 2004 12:58 AM Subject: [TowerTalk] Calculations



And once a fellow gets a set of 90 MPH calculations for $250 or so, why,

o'


why should any future sales of the same calculations cost the next fellow

the


same $250? The non-recurring cost should be minimal; right?

Warren
W5KKW
_______________________________________________

--
__________________________________________________________________________


Alan Zack
Amateur Radio Station K7ACZ
Las Vegas, Nevada, USA
Quality Engineer, The Boeing Company, Retired
Aviation Chief Warrant Officer, U.S. Coast Guard, Retired
U.S. Coast Guard, Always Ready, Always There
Every hour, Every day, Around the Clock and Around the World
SEMPER PARATUS
http://gocoastguard.com


_______________________________________________


See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.

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