Communications Tower•
•
•
Proposed Action.
Overview.
Issues to Consider.
Supporting Documents.
o Background
o Location Map
o Tower Specifications
Nancy fl-fl Anderson
Community Development
Analyst
0
February 16, 1988 Planning Commission Report: CUP88 -3
CITY OF HOPKINS
Communications Tower
Staff recommends adoption of the following motion: The request by the
City of Hopkins for a Conditional Use Permit to construct a 120 foot
communications tower is approved.
The City of Hopkins is upgrading its' communications system. The new
system involves primary transmitting and receiving equipment located
at various existing structures throughout the City and a back -up
antenna at City Hall. For an effective system the back -up antenna
needs to be 120 feet high. This tower will be used by all City
departments. Without a Conditional Use Permit the tower could be 105
feet high.
o Is the tower necessary for the safety and welfare of the
citizens?
o What is the impact on surrounding properties of a 120 foot
tower?
•
• CUP88 -3
Page 2
DETAILED BACKGROUND.
Name of Applicant: City of Hopkins
Address of Property: 1010 First Street South
Present Zoning: B -2
Reason for Request: Ordinance requires a Conditional Use
Permit for heights over the maximum allowed
Nature of Request: To erect a 120 foot tower
The proposed communications system involves having several primary
remote sites throughout the City. Existing sites such as the Hopkins
House and Hopkins Village Apartments will be some of the primary
sites. The primary sites do not have a back -up power system, so if
there is a power failure or if they are hit by lightning a back -up
system is needed. City Hall was chosen for a back -up site because of
the availability of a back -up generator and to eliminate reliance on
leased telephone circuits.
The Communications Engineer working on this project has indicated that
the proposed tower will have to be 120 feet in height to be effective.
1111 The Police Department is proposing to locate the tower just north of
the police garage on the east side of the building. This location
will provide a secure location because the tower would be surrounded
by the City Hall on two sides. A fence will be built on the other two
sides for security. At this time the Police Department has not
decided what type of fence will be built.
It has been recommended that the tower be free standing. A guyed
tower would not be aesthetically pleasing and requires a loss of
several parking spaces.
The existing communications equipment on the City Hall boiler stack
will be removed.
This tower will provide the City with flexibility to add additional
systems for the City as well as some other functions for the County,
like Civil Defense. This tower will be the best for a long term
communications system.
City Hall is surrounded by the Auto Mall to the south, the Post Office
to the east, apartments to the west and Norwest Bank to the north.
•
•
• CUP88 -3
Page 3
ANALYSIS.
The proposed tower will be put on the City Hall site for the welfare
and safety of all the citizens of Hopkins. Unfortunately no tower of
this type is aesthetically pleasing. The placement of the tower will
minimize the impact of the City Hall site as well as the surrounding
residential area. The residential neighborhood to the west and the
new townhomes on First Street will be approximately 95 feet. The
tower will take only the parking space which was used by the utility
trailer for the barricades.
This type of tower will provide the City a flexible system for the
future. Additions can be made from future expansion of the
communications systems in Hopkins.
Edina recently built a communication tower. This tower is a single
pole, which may be more aesthetically pleasing, but the tower is not
flexible for adding or deleting equipment.
ALTERNATIVES.
1. Approve the communication tower. This alternative will
provide the City with the most flexible and effective
standby and coordination communications.
2. Deny the communication tower. This alternative will
jeopardize the safety and welfare of the citizens.
3. Approve a single pole tower. This alternative will
provide an adequate system, but the system can never be
changed.
4. Continue for further information. If the Commission
feels that more information is needed or there might be a
better site, then this item should be continued.
•
•
•
CITY OF HOPKINS
Hennepin County, Minnesota
RESOLUTION NO: 88 -
RESOLUTION MAKING FINDINGS OF FACT AND APPROVING
APPLICATION FOR CONDITIONAL USE PERMIT CUP88 -3
WHEREAS, an application for a Conditional Use Permit
entitled CUP88 - has been made to allow a 120 foot high
communications tower at the Hopkins City Hall, 1010 First
Street South.
WHEREAS, the procedural history of the application is
as follows:
1. That an application for Conditional Use Permit
CUP88 - was filed with the City of Hopkins on
January 28, 1988.
2. That the Hopkins Planning Commission reviewed
such application on February 24, 1988.
3. That the Hopkins Planning Commission, pursuant
to published and mailed notices, held a public
hearing on February 24, 1988; all persons
present at the hearing were given an
opportunity to be heard.
4. That the written comments and analysis of the
City Staff and the Planning Commission were
considered.
NOW THEREFORE BE IT RESOLVED, that the Hopkins City
Council makes the following Findings of Fact in respect to
Conditional Use Permit CUP88 -3:
(1) That the communications tower is needed for the
safety and welfare of the residents.
That the proposed tower will provide the needed
standby and coordination radio equipment to
serve the citizens of Hopkins.
Adopted this 1st day of March, 1988.
Donald Milbert, Mayor
•
Conditional Use Permit Application
R. Reason for request:
The City of Hopkins has undertaken a radio communications en-
hancement oroject which will affect virtually all City departments
which use either police, fire or local government radio communica-
tion. Primary transmitting and receiving equipment for the system
will be located remotely, at a number of locations in and near the
City of Hopkins. In all cases, antennas at the remote sites will
be installed on existing structures, eliminating individual site
tower construction.
In order to maintain communications continuity in the event of
disruption of primary sites, either due to weather conditions,
commercial power outages, and /or telephone network interruptions,
it is necessary to maintain a standby communications site for
maintenance of critical communications at all times.
In the case of Hopkins, it is desired to locate the standby
equipment, as well as coordination equipment, at the City Hall to
eliminate reliance on leased telephone circuits for control of
equipment and to ensure the availability of electrical power
through the use of the emergency generator which is installed at
City Hall.
In order for the standby and coordination radio equipment to be
effective, it will be necessary to place antennas at higher
elevations than the building structure would allow. The radio
communications engineer who has been retained for this project has
indicated that this need would be best satisfied through the
construction of a radio tower of 120 feet in height. The use of a
guyed tower in this application is not recommended due to aesthetic
and parking space impact. A freestanding tower of this height
would require spacing of the three legs at the base of 14 feet,
7 1/8 inches. Each leg would, of course, be attached to a concrete
pad. The tower would taper, with the spacing between legs at the
top narrowing to two feet, six inches. The EIA standard for radio
towers in this geographical area of the country requires the
ability of the tower to withstand a sustained 80- mile - per -hour wind
with one -half inch of ice on the tower surface. This standard is
what dictates the size and spacing of the tower base.
City staff analysis of the proposed tower has resulted in a
suggested placement in the east City Hall parking lot adjacent to
the commercial power transformer near the police department
entrance. It is believed that this location will offer the highest
degree of security, as well as the least aesthetic impact to the
area. It should be noted that construction of this tower will
allow for removal of the unsightly set of antennas presently
installed on the City Hall boiler stack. It will also be necessary
to protect the tower from trespassers through the use of a fence as
well as some posts to prevent contact from vehicular traffic. This
site will also minimize impact on parking space, with a net loss of
approximately one and one -half spaces. This space is normally
occupied by a utility trailer which is used seasonally by the
police department for barricade placement and stored at the
municipal garage the majority of the time.
I . -
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•
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.
D
ile Name: DWG101
K 14'7 7/8"
_ +120'
— +100'
_ +60'
— +40'
- +20'
920' AMSL
REV. DATE
CHANGE
FILE NAME:
ANTENNA MOUNTING LEG
A C
B A
C B
D A
E C
F B
G C
H A
ANTENNA MOUNTING
CONSULTING ENGINEER
LEONARD J.KOEHNEN ASSOC. INC.
POST OFFICE BOX 851103
RICHARDSON,TX 75085 214/680 -9033
CITY OF HOPKINS MINNESOTA PROJECT
LEONARD J.KOEHNEN,PE
MOUNT HT USE
120 FT PD RPTR STAND BY
100 FT FD CHAN /MUT AID STBY
100 FT PW RPTR STAND BY
78 FT HENN F3 EMCCY
70 FT MONITOR RECEIVERS
S0 FT POINT TO POINT
45 FT HENN INTERSYST
60 FT METRO EMCCY
NOTE: THE TOWER HAS 3 LEGS. THE LEFT LEG SHOWN IS NOTED AS LEG A
THE RIGHT LEG SHOWN IS LEG B. THE HIDDEN LEG IS LEG C.
ALL ANTENNAS ARE SHOWN FOR CLARITY ON LEGS A AND B.
THE TABLE ABOVE SHOWS THE CORRECT MOUNTING LOCATIONS.
PRELIMINARY SIZE AND ANTENNA PLACEMENT
OF PROPOSED CITY HALL RADIO TOWER.
SCALE NONE
DATE 2 -9 -88
DRAWING NO.
87332 -101
TOWER SCHEDULE
SECTION JSPREAD
NO.
DMENSION
TOWER LEGS
60651 YELD STN,
TOWER BRACES
FLANGF
TOP
P1 ATFS
I BOTTOM
FLANGE
BOLTS
BRACE
BOLTS
NONE
UPPER
LOWER
aax13K51 T2LD 3411.
1 W
I-2
1 -2
9 , 6 - 0 SOLID
3; $ SOLID
3,A,3,::/-
3 44 2 3 X4d
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1 -2
1
3, A SOLID
5 0 SOLID
6
3 22IX 3yex4'
L
3 2'21,3, RC X 36
'
12 -p X1:2
NONE
3 WN
1-6
1 -10
.V0 SOLID
M 0 SOLID
1 /1, SOLID
3 x 3 X4q
1`1".`62
4 x a),(:414.11,;5:-''2
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12- x2%2
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L 14 x I4 x 1 1,
8
L 1 1 4 x l,4 0;
L I 134x'4
L 2 x 2x1 /6
L 2 x 2 X3,
L 3 x 3 x ',6
L 3 x 3 x 3'
6 N
2
4
2 0 PIPE
7 N
4-61
43-6;
2 - 0 PIPE
8 N -
6-63;
6-61
2 1, 2 d PIPE
9 N
6
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2'r O PIPE
ION
10-6
1
t2 -7.
1 246 PIPE
11 N
12 -7
14 -73
3 0 PIPE
12N
14-7
16-83
3ij PIPE
13 N
16 -83
18-6
4 •0 PIPE
1414
16 •
20 - 93 8
4• d PIPE
13'4 X3'4 x'4;
L 4 6 4 x '
L 4 x 4 x 1/4' J
FLANGE 1,E
77 % 975%1a,XI+ 12 -1 X4'■
912X92 5 9;2 S'29C 3942X1{' 4 ;2- 1 X.4'',4
va e C
9 2 X9,2X
',,"'g'' 7 824. 1-: 5,� s',t9C 1W 2 1 X4'4
OF THAT SECTION IS OFFSET.
54 -30
S4 - %X1'4
54 '1X1
15 N
20 -9
22 -03
5 PIPE
16N
22
24
5 ' t PIPE
* ASTERISK INDICATES THAT THE BOTTOM
A
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--
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_ • 21
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- ftt 5
_ 5 •
"85 ,'
-85 ,
—.5 M
-145 2,
316 1
14 2
66 3
- 146 •
1 .6 3
N7 1
N7 2
M7 3
-N7 4
-N7 5
Ne 1
- N 2
- N e 3
- 146 A
14 9 1
69 2
- 149 3
- N10 3
-1411 2
- NIL 3
-N12 1
- 1412 2
- 1113 1
- •13 2
- N14 1A
1414 1•
- 1414 24
- 1114 26
— 1115 IA
1 1 ;
AT MERNIEOIATE CLPS
USE TOP l a SE C'S 611129
ITYPIOLI FOR SECS sN -/Sro I
- 1113 2A
- 1415 26
- N16 10
- 4416 2A
- 1116 26
320 TOWER ELEVATION
BRACING DETAILS
Pole SECTIONS 4N & 5N
'
AT EYO CLIPS. USE 11014. I NEAREST FLANGE PLATE
BRACING DETAIL FOR SECTIONS 6N -I3N
AT WTERMEDURE CUPS, 1,
TOPE 6007014 HOLES �4
i Z\
OUTSTANDING LEGS Cr
ANGLES ARE IPM
SPLICE CONNECTION
AT 060 CL663. use HOLE NEAREST FLANGE PLATE
BRAONG DETAIL FOR SECTIONS 14N -16N
SEC NO LEGS BRACES TOTAL
IW
2W
3 WN
4N
51
6N
71
6N
9N
I0N
II N
12 N
13N
1414
1514
18 N
WEIGHTS
260
345
290
300
426
420
430
570
690
790
845
1,155
1,155
175
1 95
190
245
274
300
400
840
825
910
1,625
2, 000
2,15 0
116
160
230
435
540
480
545
700
720
830
1410
1515
1,700
2,470
3,155
3,305
GENERAL NOTES:
1 , . - 4f •7 w /.!%!CC /JLGYOffAU
w /!'v. %! //L J : ^.'moo.•. Jf! /N 4S, J7w4
2. ALL PART NO METAL SWPED WOE 0A4W114L6'
3 PAL NUTS P80Y10E0 FOR ALL LOWER 6017$
4. STEP 60135 PRCY® ON ONE LEG FOR SECTIONS 4N
TRRU 1111, ANO STEP 60173 ON 3 LEGS FOR SECTIONS
UN 71RU 16N.
S ALL 'TOWER YORRERi AAE 143T -0PP1D 64L66NRE0
AFTER /A9RICATION
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2.
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1' -10
f - 74
1 -01
12 -3x24
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3
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3.8
4N
2' -2'
1' -107
1 -3"
12 -e 030
4*
3i
6=61 6.
511
2 - 6
2 - 2
1 -5
12 -x30
4+
34
7= -6 8.5
61
4 -`6-
S-11"
2'-7-,1
I2 -'•30
4
33-
9'0 12.Z
7N
25,300
2,000
6' -6'}
8'- 6 R '
5- 8a
7'- 5"
3-91
4
12-1(30
41
41
31
31
6' -"
8' -0
4'-G'
5 -6
I' - 6'
2 -0
69 G
89' 7
96
9 6
5.0
8.4
5_3
9.1
10 -0 15.0
13 16" 27.3
8 -6'
9' -6
4-O
5 - O .
2'O"
2' - 0 -
69 8
89 7
4. 5
6.5
8 11
39,400
5,000
9N
32,700
5,500
10 -6 I
9 -1
6L 1
12 -F30
4
34
8 -0 '
5 =
2 - 0 .
897
M6
8.4
9.1
14 -0
23.
9' -O
5-0"
20'
897
6,3
ION
32,700
5,500
12 -7 +"
Id -II"
2 - -314
I2 -i(36
5
4
8' - 0'
5 -6"
2-0'
897
96
8.4
9.1
17 -0
43.2
4-0'
5'
2'
897
G.3
1 1 N
48,700
4,500
14 -74
12! 8,}
8- 5 1 }'
12 -1x42
7 17
5
9' -3'
5 -6'
2-0'
897
9 6
8.9
9_ 6
10'
5
2 - 0'
891
6,8
1214
47,700
4,500
16 -
14-53-
9' -7 "
12 -3-x42
7
5
2-3'
5'-6'
2-0"
897
96
8.3
9-6
10-6
6'-0'
2 -0'
897
6.8
1314
62,200
6,000
18'- 81I-'
16'- 2 b"
10-9
124x42
7T
5
9L3'
6' -o'
2-0 '
8 89 8
9 6
10.1
10.8
I I' - c,'"
6' -0'
2-6"
109 8
11.0
I4N
62,200
5000
20' -93'
17' -11
12 -0"
12- 1x48
91
54
8 6 -0"
2 -0'
898
96
10.1
10.8
11' -0
6' -0'
2 -0"
1098
11.0
I5 N
97,000
10,000
22 - 9'
5- 8 7
L- IK II"
12 - 1848
94
54
11b 5 -0'
2-6'
1298
96
12.6
14.0
13'-0"
6' -0
2 -6
1298
12.1
161'
97000
' 0000
24 -98"
2I'- 5,
14- 3}e
12- 1 x48
9-i
53-
11L0' 6 - 0"
2 - 6'
129 8
9 6
12.6
le -
13'0
6' -0
2-6"
129 8
12.1
ILES LOAO ANO SMEAR VALUES ARE FOR ONE
LEG. ♦CONCRETE
•
QUANTITIES SHORN 45E 103 THREE MESS.
2_401, FOR EO'6JNOLT TOLERANCES SEE
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FOUNDATION LAYOUT
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BOIT ORIENTATIONS
ANCHOR
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