CCP 01-22-2002 - Laserfiche WebLink

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ARDEN TOWERS1 INC. 3440 BAYSIDE ROAD ORONO,IIN 55356 952-473-3660 FAX 952-473-3880 December 19, 2001 Mr. Dave Scherbel City Building Official City of Arden Hills Arden Hills, MN 55112 Dear Mr. Scherbel: Enclosed is the Ehresmann Engineering Report with attachments dated December 14, 2001 which we have so long awaited. In addition I am enclosing a copy of a letter from the manufacturer, Rohn Industries and also from Tom Pucci of Motorola. Tom is now a V.P. at Motorola but in 1981 he was the salesman that sold me on the idea of erecting a tower for their use. If you have been following the business news, Motorola is being sued by one of their former employees for about a billion dollars. Due to restrictions placed on him by his legal department, Tom could not address the original antenna arrangement for fear of getting sued again. You can underntand that they are extremely cautious in light of their past experiences. The letters are intended to address the question mised concerning the number of antennas on the tower. The original illustration on the plan approved back in 1981 showed 15 antennas for purposes of illustration. They were all at the highest levels possible, allowing for frequency separation, since that was required of the technology at that time. David Brinker, V. P. of Engineering at Rohn Industries indicates in his letter that the loading shown indicates the minimum strength requirements, meaning that the tower, as originally designed, could possibly accommodate more antennas if a structural analysis determines that to be possible. He also told me verbally that antennas at the higher level place more stress on the tower than the same antennas spread more evenly down the tower. Some of those factors are the weight of the longer coaxial cables and also the wind velocity at higher levels. The structma1 analysis attached hereto indicates that the tower with the present loading meets TIAlEIA-222-F with y," ice loading hased upon reducing the height by 80 feet and making a minor modification to one guy wire. It doesn't appear that it is necessary to do anything further regarding that matter if it can be agreed that the antenna array originally shown was for illustration and an indication of the tower's minimum strength requested at point of design. We have scheduled all modifications identified in the Ehresmann report to be completed by Dietz Brothers Tower Company of Spicer/New London as soon as possible. Alan Dietz advised me that weather permitting they would do it as soon as possible after January I since they are booked until that time. They will require five to six days of good weather, meaning temperatures above 20 degrees and very low wind. I trust that this meets with your approval. If there are any unanswered questions or if you need additional information please contact me and I will do my best to provide it. Thank you for all of your effort concerning this matter. With your help, I believe we have come to a reasonable conclusion. Sin'!7ly, / ".' / j/ .::'/ / /' (.,/ ,,?'}\. . Dan Vaughan President y -- -- --