EIA TIA 222 F Structural Standards for Steel Antenna Towers and Antenna Supporting Structures

ANSl/TIA/ElA-222-f-1QQ6 Approved: March 29, 1996

TIdEIA ” STANDARD

Structural Standards for Steel Antenna Towers and Antenna Supporting Structures

.

TIAIFJA-222-F (Revision of ELUTLbZZf-E)

JUNE 1996

TELECOMMUNICATIONS

&WUSlRYASWCUllON

INDUSTRY ASSOCIATION

.

i -= = m= ws

.

Reproduced By GLORAL ENGINEERING DOCUMENTS WlthlhePetrniuion01EiA

Under Roy&y A~mement

June 10, 1996 TO:

Recipients of new TIA Standards and Engineering Publications

Enclosed please find one copy of the following TINEIA Standard:

TINEIA-222-F

Structural Supporting

Standards Structures

for Steel Antenna

Towers

and Antenna

Additional copies of this Standard may be obtained from the Global Engineering Documents, ’ I.S.A. and Canada (l-800-854-7179) International (303)-397-7956 at a price of $80.00 each.

Sincerely,

Cecilia tie&g Engineering Department

enclosure

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NOTICE

TIALEIA Engineering Standardsand Publications are designed to serve the public interest through eliminating misunderstandingsbetween manufacturers and purchase& facilitating interchmgeabihy and improvement of products, and assistingthe purchaserin selectingand obtaining with minimum delay the proper product for his particular need. Existence of such Standards and Publications shall not in any respect preclude any member or nonmember of TIA/EIA from manufacturing or selling products not conforming to such Standards and Publications, nor &al! the existence of such Standards and Publications preclude their voluntary use by those other than TIAKIA members, whether the standard is to be used either domestically or internationally. Standards and Publications are adopted by TIA/EIA in accordance with the American National Standards Institute (ANSI) patent policy. By such action, TIA/EIA does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the Standard or Publication. This Standard does not purport to addressall safety problems associated with its use or all applicable regulatory requirements. It is the responsibility of the user of this Standard to establishappropriate safety and kahh practices and to determine the applicability of reguIatory limitations before its use. (From Standards Proposal No. 3278, formulated under the cognizance of the TR-14.7 Structural Standards for Steel Antenna Towers and Antenna Supporting Structures Subcommittee . Published by QTELECOMMUNICATIONS INDUSTRY ASSOCIATION 1996 Standards and Technology Department 2500 Wilson Boulevard Arlington, VA 22201

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STRUCTURAL STANDARDS FOR STEEL ANTENNA TOWERS AND ANTENNA SUPPORTING STRUCTURES

!O

CONTENTS Section

Page Number OBJEC’TWE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

SCOPE...............................................................

1

MATERIAL ........................................................ 1.1 Standard .......................................................

1

LOADING

2

1

.........................................................

2.1 Definitions ........................................... 2.2 Nomenclature for Section 2 Loading ................................ 2.3 Standard ....................................................... 3 a

4

4 11

3.1 Standard .......................................................

11

MANUFACTURE

18

5 FACTORYFINISH

AND WORKMANSHIP

11

.............................. .........................

...................................................

5.1 Standard ....................................................... 6 PLANS, ASSEMBLY TOLERANCE& AND MARKING

18 18 18

...................

6.1 Standard ........................................................ 7 FOUNDATIONS AND ANCHORS ..................................... 7.1 Definitions.. ...................................................

18 18 19 19

7.2 Standard .......................................................

19

7.3 Special Conditions ............................................... 7.4 FoundationDrawings ............................................

i0

8 SAFE‘TY FACTOR OF GUYS ......................................... 8.1 Defmition ...................................................... 8.2 Standard..........................~ ”

3

2.4 References ..................................................... STRESSES .........................................................

4.1 Standard.............................~

*

2

..........

............................

9 PRESTRESSING AND PROOF LOADING OF GUYS ..................... 9.1 Definitions.. ................................................... 9.2 Standard .......................................................

21 21 21 21 21 21 22

TIAEIA-222-F

CONTENTS (Continued)

c ,

a

Page Number 10 INITIAL GUY TENSION , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 22 10.1 Definition ...................................................... 22 10.2 Standard .......................................................

Section

10.3 Method Of Measurement .......................................... 11 OPERATIONAL REQ IJ-mMmTs .................................... 11.1 Definitions ...... ............................................... 11.2 Standard ....................................................... 12 PROTECTIVE GROUNDING ......................................... 12.1 Definitions ..................................................... 12.2 Standard ....................................................... 13 ~JMJXPG AND WOlSKING FACILITIES .............................. 13.1 Definitions ...... ............................................... 13.2 standard ....................................................... 14 -PWI’KE

AND INSPECTION

..................................

14.1 Standard ....................................................... 15 ~A.LxIS OF EXKI’ING TOWERS AND STRUCTURES ................. 15.1 Standard.............................\ ......................... 16 COUNTY LISTINGS OF MINMLJMBASIC WIND SPEEDS ...............

22 22 22 22 23 23 23 23 23 23 24 24 24 24 25

ANNEXES Annex A: Annex B:

Annex C: Annex D: Annex Annex Annex Annex

E: F: G: H:

Annex I: Annex J:

PU-KI-WER CHECKLIST .................................. DESIGN WIND LOAD ON TYFICAL MICROWAVE ANTENNAS/REFLECTORS ................................. TABLE OF ALLOWABLE TWIST AND SWAY VALUES FOR PARABOLIC ANTENNAS, PASSIVE REFLECTORS, AND PERISCOPE SYSTEM REFLECTORS . . . . . . . . . . . . . . . . . . . . . . . . .

59 61

71

DETERMINATION OF ALLOWABLE BEAM TWJST Am SWAY FOR CROSS-POLARIZATION LIMITED SYSTEMS . . . . . . . . . . . . . 77 TOWER MAINTENANCE AND INSPECTION PROCEDURES . . . . 83 CRITERIA FOR THE ANALYSIS OF EXISTING STRUCTURES . . . 101 SI CONVERSION FACTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 COwmY ON ICE DESIGN CRITERIA FOR CO-CATION STRUCTURES.. . . . . . . . . . . . . . . . . . . . . . . . . . 105 GEOTECHNICAL JJqVESTIGAnONS FOR TOWERS . . . . . . . . . . . . ,109 CORROSION CONTROL OPTIONS FOR GUY ANCHORS IN DIRECT CONTACT WITH SOIL . . . . . . . . . . . . . . . . . . . . . . . . . . 111

STRUCTURAL STANDARDS FOR STEEL ANTENNA TOWERS AND ANTENNA SUPPORTING STRUCTURES OBJECTIVE The objective of these standards is to provide I&,&= uitezia for specifying and designing steel antenna towers and antenna supporting structures. These standardsare not intended to replace or supersede applicable codes. me information contained in these standards was obtained from sources as referenced and noted herein and represents, in the judgement of the subcommittee, the accepted industry practices for minimum standardsfa the design of steel antenna suppohg structures. It is for general information only. while it ia believed to be accurate, this information should not be relied upon for any specific application without competent professional examination and verification of its accuracy, suitability, and applicability by a licensed professional engineer These standards utilize wind loading criteria baaedon an annual probability and are not intended to cover d environmental conditions which could exist at a particular location. These standards apply to steel antenna towers and antenna supporting structures for all classesof cmmmications service, such as AM, CATS, FM, Microwave, Cellular, TV, VHF, etc. These standards may be adapted for international use; however, it is necessary to determine the appropriate basic wind speed (fastest-mile) and ice load at the site location in the specific co~npy based on local meteorological data. Equivalent International System of Units (SI) are given iu brackets [ ] throughout these standards. SI conversion factors have been provided in Annex G. It is the responsibility of the purchaser to provide site-specific data and requirements differing from those contained in these standards. Annex A provides a checklist for assisting the purchaseri.nspecifying the requirements for a specific structure when using these standards..The user is cautioned that local conditions of wind and ice, if known, have precedence over the minimum standardsdescribed herein.

SCOPE These standards describe the requirements for steel antenna towers and antenna supporting stnmures. 1

MAIERIAJd

1.1

Standard 1.1.1 Material shall conform to one of the following standards except as provided in 1.1.2. 1.1.1.1 Structural steel, cast steel, steel forgings, and bolts shall confom~ to the material specifications listed in the June 1, 1989, American Institute of Steel Constmction, “Specification for Structural Steel Buildings - Allowable Stress Design and Plastic Design”, hereinafter referred to as the AISC specification. 1.1.1.2 Light gauge steel stmctural members shall be structural quality as defined by the August 19, 1986, American Iron and Steel Institute, “Specification for the Design of Cold-Formed Steel Stmctural Members”, hereinafter referred to as the AISI spe@fication. 1.1.1.3 Material for tubular steel pole structures and components shall conform to section 7.0 of A.NSI/NEhtA TTl- 1983, “Tapered Tubular Steel Structures”.

-

--

-

-1.

l

----I

1.1.2 When materials other than hose specified herein are used, the supplier must Provide certified data concerning mechanical and chemical properties. 1-1-3

Bolts and nut locking devices (excluding guy hardware).

Sl.@xitical coM&o~ md ~nnections subjected to tension where the application of externally applied load results in prying action produced by deformation of the connected parts sha.Ube m& v&h b&h-strength bolts tightened to the miuimum bolt tensions specified in the November 13, 1985, AISC, “Specification for Structural Joints using ASTM A325 or A490 Bolts”. 1.1.3.1

EepbOn: where it can be shown that the stiffness of the connected parts is sufficient to rtth= prying forces to ittsignifrcauce, tension connections may be made with high-strength bolts tightened to a snug-tight condition as defined in the AISC specification refened to in 1.1.3.1.

(Note: Contact surfacesfor slip-critical connectionsshall not be oiled or painted and for galvanized material, the contact surfaces shall be prepared in accordance with the DISC specification referred to in 1.1.3.1.) 1.1.3.2 Bearing-type connections may be made with high-strength bolts tightened to a snug-tight condition as defined in the AIsC specification referred to in 1.1.3.1. 1.1.3.3 Where high-strength bolts are used and tensioned in accordance with the mc specification referred to in 1.1.3.1, a nut-locking device is not required. 1.1.3.4 Bolts not covered in 1.1.3.3 require a nut-locking device.

-

1.1.3.5 Hot-dip galvan&& A490 bolts shall not be used. 1.1.4 Materials other than steel are not within the &ope of this section. 2

LOADING

2.1

Definitions 2.1.1

Dead Load - The weight of the structure, guys. and appurtenances.

2.1.2 Ice Load - The radial thickness of ice applied uniformly around the exposed surfacesof the structure, guys, and appurtenances. 2.1.2.1 Unless otherwise indicated, a specified radial ice thickness shall be considered as solid ice. 2.1.2.2 The density of solid ice shall be considered to be 56 lb/f9 18.8 kN/m3]. 2.1.2.3 The density of rime ice shall be considered to be 30 lb/@ [4.7 kN/m3]. 2.1.3

Wind Load - The wind loading requ&ments specified in 2.3 (see Annex A).

2.1.3.1 Basic Wind Speed - Fastest-de wind speed at 33 ft [lo m] above ground corresponding to an annual probability of 0.02 @O-yearnmrrence interval). 2.1.4 Appurtenances - Items attached to the structure such as m*MaS, transmission lines, conduits, lighting equipment, climbing devices, platforms, signs, anti-climbing devices, etc. 2.1.4.1 Discrete Appurtenance concentrated at a point.

An appurtenance whose load can be assumed to be

I)

2.1.4.2 Linear Appurtenance - An appurtenance whose load can be assumed to be distributed over a section of the structure. Nomenclature for Section 2 Loading

2.2

0

0

AA

Projected area of a &near appurteuance

AC

Projected area of a &Crete appurtenance

42

Effective projected area of structural components in me face

AF

Projected area of fit structural componeuts in one face

AC

Gross area of one tower face as if the face were solid

AR

Projected area of round structural components in one face

C

Velocity coefficient for tubular pole structure force coefficients

CA

Linear or discrete appurtenance force coeffkient

CD

Guy hag force coeffkient

CF

Structure force coefficient

CL

GUY lift force coefficient

D

Dead weight of the structure, guys, and appurtenances

.?F

Wind direction factor for flat structural components

DP

Average diameter or averageleast width of a tubular pole stmctm

DR

Wind direction factor for round structural co&ponents

F

Horizontal force applied to a section of the structure

FC

Design wind load on a discrete appurtenance

FD

Total drag force on a guy

FL

Total lift force on a guy

@I

Gust response factor for fastest-mile basic wind speed

I

Weight of ice

Kz

Exposure coefficient

Lc

Chord length of guy

RR

Reduction factor for round structural components

V

Basic wind speed for the structure location

WI

Design wind load on the structure, appurte~ccs,

WO

Design wind load on the structure, appurtenmccs, gUY%e% without ice

d

Diameter of guy strand

e

Solidity ratio

@Ys, etc.9with radial ice

2.3

h

Total height of structure

92

Velocity pressure

r

Ratio of comer diameter to diameter of inscribed circle of a tubular pole structure

t

Radii thickness of ice

Z

Height above average ground level to midpoint of section, appurtenance or gUY

8

Clockwise angle from guy chord to wind direction vector Standard

2.3.1

Wind and Ice Loads

2.3.1.1 The total design wind load shall include the sum of the horizontal forces applied to the structure in the direction of the wind and the design wind load on guys and discrete appurtenances. 231.2 This standard does not specifically state an ice requirement. Ice loading, depending on tower height, elevation, and exposure, may be a significant load on the stnmure in most parts of the United States. If the structure is to be located where ice accumulation is expected, consideration shall be given to an ice load when specify& the requirements for the structure. (Refer to Annexes A and H.)

2.3.2 The horizontal force (F) applied to each section of the structure shall be calculated from the equation: F=qzGHCCFAE+~(CAAP31(lb>N

;

Not to exceed 2 QZG & where AC = Gross area of one tower face (ft2) [m2] (Note: All appurtenances, including antennas,mounts and lines, shall be assumedto remain intact and attached to the stmcture regardless of their wind load capacities.) 2.3.3 The velocity pressure (Q) and the exposure coeffkient (K3;) shall be calculated from the equations (see Annex A): Q = -00%

Kz V2 (lb/ft2) for V in mi/h or

qz=.613KzV2PJforVinm/s Kz = M3312” for 2 in ft or Kz = Cx/1012nfor 2 in meters 1.00 2 Kz < 2.58 V = Basic wid speed for the structure location (mi/h) Cm/s1 z = Height above average ground level to midpoint of the section (ft) [ml 2.3.3.1 Unless otherwise specified, the basic wind speed W) for the structure location shall be determined from section 16.

2.3.4

Gust Response Factors

2.3.4.1 For latticed structures, the gust response factor (GH) shall be calculated from the equation: &I = .65 + .6O/(h/33)’ I7 for h in ft or %I = .65 + .60&h/10)’ I7 for h iu meters 1.00 2 G-JJ< 1.25 2.3.4.2 For tubular pole structures, the gustresponse factor (GH) shall be 1.69. 2.3.4.3 One gust response factor shall apply for the entire structure. 2.344 When cantilevered tubular or latticed pole structures are mounted on latticed structures, the gust responsefactor for the pole and the latticed structure shall be basedon the height of the latticed structure without the pole. The stressescalculated for pole structures and their connections to latticed structures shall be multiplied by 1.25 to compensatefor the greater gust response for mounted pole structures. 23.5

Structure Force Coefficients 2.3.5.1 For latticed structures, the structure force coefficient (CF) for each section of the mct~e shai.i be calculated from the equations: CF = 4.0e2 - 5.9e + 4.0 (Square cross sections)

CF = 3.4e2- 4.7e + 3.4 (Triangular cross sections) e = Sdidity Ratio = (AF + AR)/&

: AF = Projected area (ft2) [rnz] of flat structural components in one face of the section. AR = Projected area (ft2) [m2] of round structural components in one face of the section and the projected area of ice when specified on flat and round structural components. (Refer to Figure 1). (Note: The projected area of structural components shall include the projected area of connection plates.)

I 1A1tl.b222-F

t \ 1Ly I/\\0’-2 t = Specified radial thickness of ice Figure 1 (Note: Ice, when specified,shall be assumed to accumulate uniformly on all surfacesas illustrated. The additional projected area caused by the ice accumulation may be considered cylindrical even though the bare projected area is flat. Consideration shall be given to the change in shapefrom round to flat for closely spaced linear appurtenances with ice accumulations.) 2.3.5.2 For cantilevered tubular steel pole structures, the structure force coefficient (CF) shall be determined from Table 1. 2.3.6 The effective projected area of structural components (AE) for a section shail be calculated from the equation: AE = DF AF + DR AR RR (f$) Cm*] (Note: For tubular steel pole structures, AE shall be the actual projected area basedon pole diameter or overall width.) 2.3.6.1 The wind direction factors, & and &, shall be determined from Table 2. 2.3.6.2 The reduction factor (RR) for round structural components shall be calculated from the equation: RR = .51e2 + .57

RR < 1.0

2.3.6.3 Linear appurtenances attached to a face and not extending in width beyond the normal projected area of the face may be considered as structural components when calculating the solidity ratio and wind forces.

TIAEIA-222-F

Table 1

Force Coefficients (CF) for Cantilevered ‘Ihbular Pole Structures Round

1.20

32 to 64

16 Sided r > 0.26

12 Sided

8 Sided

1.20

1.20

1.20

1.20

125

1.20

.72

1.03

1.20

I

1

~32

16 Sided r < 0.26

130 013

w 22.9

915 1.78 + 1.4Or-cm

J2+(64-C)

am&

. 44.8

t

1.08 - 1.4Or

59

>64

SI Units

< 4.4 4.4 to 8.7

Round

16 Sided r < 0.26

16 Sided r > 0.26

12 Sided

8 Sided

1.20

1.20

1.20

1.20

1.20

3.78

1.20

9.74

1.78+ 1.4Or

(Cl I3

VDp

3% .

.72 +(8k7;ooc) .

.72

1.08 - l&r

59

> 8.7 C = &

-+5

-

Q.6 1.03

1.20

forDpinft[m]

Notes: 1. The above force coefficients apply only to cantilevered tubular pole structures which stand alone or are mounted OIIthe top of a latticed strwture. 2. The force coeffkients indicated account for wind load reductions under supercritica.l flow conditions and therefore do not apply to appurtenances attached to the structure. Use Table 3 for appropriate force Coeffkients for appurtenances. 3. For ail CTOSS sectional shapes, Cf need not exceed 1.2 for any value of C. 4. V 1sthe basic wind speed for the loading condition under investigation.

Table 2

Wind Direction Factors Tower Cross Section

DR

Square

1.0

1+.75e (1.2 max)

* Measured from a line normal to the face of the structure

1.0

1.0

1.0

TWEIA-222-F

The force coefficient (CA) appkd to the projected area (ft2) [m21of a hxr app~enance (AA) not considered as a ~~~ctural component shall be determined from Table 3. 0 The force coefficient for cyli&$c~ members may be applied to the additional projected area of radial i= when specified. (Refer to Figure 1.) 2.3.7

Table 3

Appurtenance Force CoeffkieMs AspectRatio 5 7 Member Type Flat

cylindrical

I

AspectRatio> 25

CA 1.4 *

2.0

0.8

1.2

CA

Aspect Ratio = Overti length/width ratio in plane normal to wind direction. (Aspect rstio is not a function of the spacing between support points of a linear appurtenance, nor the section length force.) ccmidered to have a uniformly distributed Note: Linear interpolation may be used for aspect ratios other than shown.

2.3-g Regardless of location, linear appurtenancesnot considered as structuraI components in accordance with 2.3.6.3 shall be included in the term C CA AA. 2.3.9 The horizontal force (F) applied to a section of the structure may be assumed to be mi.f~nnly distributed based on the wind pressure at the mid-height of the section. 2.3.9-l For guyed masts, the section considered to have a uniformly distributed force shall not exeed the span between guy levels. 2.3.9.2 For free-standing structures, the section considered to have auniformly distributed for= shad not exceed 60 ft [ 18 m]. 2.3.9.3 For tubular steel pole structures, the section considered to have a uniformly deputed force shall not exceed 30 ft [9.1 m]. 2.3.10 In the absence of more accurate data, the design wind load (Fc> on a discrete appurtenance such as an ice shield, platform, etc. (excluding microwave antennas/passive reflectors) shall be calculated from the equation:

where x CA AC considers all elements of the discrete appurtenance including any feed lines, brackets, etc., related to the appurtenance. Components of a discrete appurtenance attached directly to a tower face and not projecting away from the face may be considered as structural components when c&dating the solidity ratio and wind forces. 2.3.10.1 The velocity pressure (9z> shall be c&ulated based on the centerline height of the appurtenance.

0

TWEIA-222-F

2.3.10.2 The gust response factor (GH) shall be calculated based on the total height of the stmtm for latticed structures (see 2.3.4.4) and shall be equal to 1.69 for tubular Pole smctures.

2.3.10.3 The design wind load (Fc) shall be applied in a horizontal direction in the direction of the wind. 2.3.10.4 The force coefficient (CA) applied to the projected area (fP) Cm21of a discrete appurtenance (AC) shah be determjncd f&r Table 3. The farCe coefficient for Cysts members may be applied to the cylindrical portions of the appurtenanceand to the additional projected area of ice when qecifred. (Refer to Figure 1). 2.3.10.5 When an equivalent flat-plate area based on Revision C of this standard (AF + 2/3 AR) is provided by a manufacturer of an appurtenance, a force coefficient of 2.0 must be applied to the equivalent flat-plate area when determiktg design wind loads. When the appurtenance is made up ofround members only, a force coeSzient of 1.8 may be applied. 2.3.11 In the absence of more accurate data, the design wind load on microwave antennas/passive reflectors shall be determined using Annex B. 2.3.12 When the azimuth orientations of antennaslocated at the samerelative elevation on the stmctu.re are not specified, the antennas shall be assumed to radiate symmetrically about the structure. 23.13

shielding of antennas shall not be considered.

2.3.14 The design wind load on guy& shall be determined in accordance with Figure 2. The design wind load may be assumed to be uniform based on the velocity pressure (sz> at the . midheight of each guy. 2.3.15 The maximum member s&sses and structure reactions shall be detexmined considering the wind directions resulting in maximum wind forces and twisting moments. Each of the wind directions indicated in Table 2 shall be considered for latticed structures. . 2.3.16 Each of the following load combinations shall be investigated when calculating the maximum member stressesand smcture reactions (see Annex A): D+Wo D+.75W1+1 (Note: When the basic wind speed is specified as ocmning simultaneously with an ice load by the purchaser or local authority, no reduction factor shall be applied to WI.)

Wind Forceson Guys

FD = 9~ GH CD d Lc = Total drag force (lb) [NJ FL=qzGHCLdLc=Totalliftforce(lb) N Q = Velocity pressure at mid-height of guy (lb/ft2) PAJ (see 2.3.3) k = Gust response factor based on total height of structure (see 2.3.4) d = Diameter of guy strand (ft) [m] Lc = Chord length of guy (ft) [m] 0 = Clockwise angle from guy chord to wind direction vector (0 5 180’) CD = 1.2 sin3 8 CL = 1.2 sin28 cos 8

Figure 2

2.4

References

AAsH”lQ “Standard Specifications for Structural Supports for Highway Signs, LumGres atid Traffic Signals”, Ar~~erican Asso&~on of State Highway and %UlSpOrdOn Offici& wash.@ton, DC., 1985 with 1988 interim ~pecitication~. ma, “‘Minirn~m Design Loads for &&iiugs and Other SUUCUIXS”, Ace 7-93, An&can Society of Civil Engineers, New York, NY, 1993. DieU W.S., “Engineering Aerodynamics”, Revised Edition, Ronald Rress Co., New York, NY, 1936. IAs% “Recomnendatio~ for Guy& ~ast$‘, ~temati~nal Association for Shell and Spatial S~c~eS, working Group Nr 4,1981. LOU, T., ‘Force coefficients for ‘hnanission Towers”, A Master Research Report in Civil &&=-i.ng, Department of Civil Engineering, Texas Tech University, Lubbock, TX, 1983. sfiu, E., changery, MJ., and Fil,liben, J.J., ‘Exueme Wmd Speeds at 129 Stations in the Contiguous United States”, Building Science Series Report 118, National Bureau of Standards, Washington, D.C., 1979. 3 STRESSES Standard 3.1 3.1-l Unless otherwise noted, structural members shall be designed iu accordance with the appropriate AISC or AISI specification. 3.1.1.1 For structures under 700 ft 1213m] iu height, allowable stressesmay be increased l/3 for both load combinations defined in 2.3.16. 3.1.1.2 For structures 1200 ft [366 m] or greater in height, allowable stressesshall not be increased. 3.1.1.3 For structures between 700 ft 1213 m] and 1200 ft [366 m] in height, allowable stressesmay be increased by linear interpolation between l/3 and 0. (Note: For structures 1200 ft [366 m] or greater in height, increasesin allowable stressesdo not apply due to the uncertainties of the wind effects above this height.) 3.1.1.4 Stnxture height, for purposes of determimn g allowable stresses,shall be based on the total structure height including tubular or latticed poles mounted on the structure. 3.1-l .5 Refer to 2.3.4.4 for stressincreasesrequired for cantilevered tubular pole structures mounted on latticed strucme~. 3.1.2 For guyed structures, the displacement of the mast at each guy level shall be considered wilen computing stresses. 3.1.3 The end connection and intermittent filler mqrimments of section E4 of the AI!K specification for double angle members need not be satisfied when the slendernessratio for the buckling mode involving relative deformation between the angles is modified as follows when determining allowable stresses:

.

. .

.

_..

-

em-

.

where KL (To 1

= column slenderness of built-up member acting as a unit about the axis evolving relative deformation

a RI

= largest column slenderness of individual components

(F,)

= modified column slenderness of built-up member

a

= distance between connectors

4

= minimum radius of gyration of individual component

3.1.4 A reduction coefficient equalto .75 shall be used when calculating effective net areasin accordance with section B3 of the AISC specification for angle members and other similar members connected by one leg with one or two fasteners. 3.1.5 The reduction factor of 3.1.4 does not apply to the required investigation of block shear in accordance with section J4 of the AISC specification. Net shear and tension areas shall be based on hole diameters l/16 inch [1.6 mm] larger than bolt hole diameters. 3.16 Bolt holes shall not be considered pin holes, as referred to in section D3 of the AISC specification. 3.1.7 Deformation around bolt holes shall be a design consideration for the purposes of calculating allowable bearing stressesin accordancewith section J3.7 of the AISC specification. 3.1-g Table J3.5 of the AISC specification shall ‘apply except at sheared edges where the minimum edge distance shall be 1.5 times the bolt diameter. 3.1.9 The measured unsupported length of a compression member shall be determined considering the rigidity of the connected parts and tbe direction of buckling about the axis under consideration. 3.1.10 Jn computing allowable stresses,when effective length factors are considered less than 1.00 for leg members or members whose ends are attached by a single bolt, justification of each factor must be shown by test or computation. 3.1.11 For a guyed structure, the stability of the structure between guy levels shall be considered when calculating allowable member stresses. 3.1.12 Limiting values of effective slenderness ratios for compression members shah preferably be 150 for legs, 200 for bracing, and 250 for redundants (members used solely to reduce slenderness of other members). 3.1.13 Bracing and redundants utilized to reduce the slendernessratio of compression members shall be capable of supporting a force normal to the supported member equal to 1.5 percent of the supported member’s calculated axial load. This force is not to be applied simultaneously with the forces resulting from loads applied directly to the StruCttKe.

3.1.14 Structural Steel Single Angle Compression Members 3.1.14.1 Allowable compression stressesshall be calculated in mce with the ABC “Specification for Allowable Stress Design of Single Angle Members” except that the flexurahorsional buckling provisions do not apply. 3.1.14.2 Members subjected to lateral loads, which induce bending, shall meet the PrO~SiOnsof section 6 of the AISC specification referred to in 3.1.14.1.

3.1.14.3 Effective length factors shall be calculate&n accordancewith ANSYASCE 10-90, ‘Design of Latticed Steel Transmission Towers”, hereinafter referred to as AXE 10, (See Table 4). (Note: The effective length factors established in ASCE 10 have been adopted to adjust the ABC allowable compression stressesfor the effects of eccentric axial loading and partial end restraint.) 3.1.14.4 Effective length factors, other than those specified herein, shalI be substantiated by kStS.

3.1.14.5 Slenderness ratios (L/R) shown in Figures 3 and 4 shall be uti.Iized as a guide to cWmine measured and effective slendernessratios. 3.1.14.6 Members shall be considered fully effective when the ratio of width to thickness (w/t) is not greater than the limiting value specified in A!XE 10. 3.1.14.6.1 When width-thickness ratios exceed the limiting value, allowable stresses shall be reduced in accordance with section 4 of the AISC specification referred to in 3.1.14.1 with Q equal to the value calculated for Fcr in AXE 10 divided by the yield . stress of the member. 3.1.14.6.2 The width w for cold-formed angles shall equal the distance from the inside bend radius to the extreme fiber but not less than the angle width minus three times the angle thickness. 3.1.14.6.3 Width-thickness ratios (w/t) shall not exceed 25. 3.1.14.7 ASCE 10 effective slenderness curves 5 and 6 of Table 4 shall be restricted to bracing and redundant members with multiple bolt or properly detailed welded connections. In addition, connections must be to membefi having adequate flexural strength to resist rotation of the joint including the effects of gussets. 3.1.14.8 Where eccentricity at a joint cannot be avoided, due consideration shall be given to the additional stressesintroduced in the members. 3.1.15 For tubular pole structures, the secondary bending moments caused by vertical loads shall be considered when computing stresses. 3.1.15.1 Allowable combined bending and axial stresses for polygonal tubular steel pole structures shall be determined from Table 5.

TIAEIA-‘22-F

Table 4

lo-90

ANSI/ASCE EFFECTIVE

SLENDERNESS

CURVES l-3 4 I

CURVES

CURVES 4-6 k>

120

CURVE 4

CURVE 1 KL=L R

KL -=R

R

(CONCENTRIC BOTH ENDS)

R

30 + .75k

(ECCENTRIC ONE W>

CURVE

KL R

60

+ SO:

(ECCENTRIC BOTH ENDS)

5

-I-.762 i (PARTIAL RESTRAINT ONE END) KL -= R

,28.6

CURVE6

CURVE 3 -=

L R

\ (NO END RESTRAINT)

CURVE 2 KL -=

120

KL -= R

46.2 + A15 k

(PARTIAL RESTRAINT BOTH ENDS)

TIAXIA-Z-F

SINGLEANGLECOMPRESSION MEMBERS SLENDERNESSRATZOSFORLEGBRACING SYMMETRICAL BRACING CRlTICAL

MEASURED SLENDERNESS RATIO: 4

EF’FEC’IWE SLENDERNESS RATIOS:

L

I

120

L

RZ CURVE 1

> 120

RZ CURVE 4

STAGGEREDBRACING . Y

x CRITICAL

MEASURED SLENDERNESS RATIOS:

L R,

, &

,‘OR

(’ :‘,),,

EFFECTIVE SLENDERNESS RATIOS:

i

MAX I CURVE 1

120

k MAX > 120 CURVE 4

NOTE: FOR LEG MEMBERS, MEASURED EQUAL TO THE PANEL SPACING AXIS OF THE LEG.

Figure 3

LENGTH (L) SHALL BE MEASURED ALONG THE

TIAEIA-222-F

SINGLE ANGLE COMPRESSIONMEMBERS SLENDERNESS RATIOS FOR BRACING MEMBERS REFER TO SECTION 3.1.9 FOR DETERMINAnON OF MEASURED LENGTHL

Lu=L1+5U a

7

CURVE2

* 1

CRrIIcALMEAsuRED SLENDERNESS RATIO:

%

EFFEm

CURVE4 L,

RX

ORe

sLEyRNEss Iwtios: i MAX 5 120 g > 120 u > 120 RZ cLJRvE2 CLiRVE6 CURVE5

Ll > L2 Lx=L1+5U

Note: For bracing members with welded or two or more bolt cxmections, measured length (L) Shall not be less than the distme between the cemroids Of the ~nnectiolls at each end. Properly detailed welded c.onnectiom may be considered as providing partial restraint.

Figure

4

3.1.16 The design of reinforced concrete for foundations and guy anchors shall Conform to me “Building Code Requirements for Reinforced Concrete” (AC1 318-89) issued by the American Concrete Institute. 3.1.16.1 For structures under 700 ft [213 m] in height, the required reinforced concrete strength shall equal 1.3 times the full structure reactions produced by each load combination defmed in 2.3.16. 3.1 J6.2 For structures 1200 ft 1366m] or greater in height, the required reinforced concrete strength shall equal 1.7 times the full structure reactions produced by each load combination defined in 2.3.16. 3.1.16.3 For structures between 700 ft [213 m] and 1200 ft 1366m] in height, the required reinforced concrete strength shall be determined by linear interpolation between 1.3 and 1.7 times the structure reactions.

3.1.16.4 Structure height, for purposes of detennhing required reinforced concrete sue@& shall be based on the total structure height including tubular or latticed poles mounted on the structure. Table 5 Allowable Combined Bending and Axial Stresses for Polygonal ‘lobular Steel Pole Structurt!s

Compact Sections F~=.60Fy Noncompact Sections

FB = Fy= t = w =

16 Sided

‘Fyin ksi 215 c &w/t c 365 565 < & w/t : 958 FyinMPa FB -852 Fy (CO - 0.00137 ,& w/t) ksi FB = .852 Fy (1 .O - 0.000522 ,&w/t) MPa

12 Sided

240

< &w/t 630 < &w/t FB -870 Fy FB = .870 Fy

Fyin ksi < 365 2 958 FyinMPa (TO - 0.00129& w/t) ksi (1.0 - 0.000491 ,/&w/t) MPa

8 Sided

260 c &w/t 683 7 &w/t FB =.852 Fy FB = .852 Fy

Fyinksi < 365 2 958 FyinMPa (TO - 0.00114,/& w/t) ksi (1.0 - 0.000434 & w/t) MPa

Allowable combined bending and axial stress Yield strength Wall thickness Actual flat side dimension, but not less than dimension calculated using a bend radius equal to 4t

Note: Equations obtained from EPRI report TLMRC-87-R3, “Local Buckling Strength of Polygonal Tubular Poles”, April 1987.

IIA/klA-122-F

4

MANUFACTURE

4.1

Standard

AND WORKMANSHIP

Manufacturing and worha&ip shall be in accordance with CO-@ accept& standards of the structural steel fabricating industry. 4.1.2 Welding procedures shall be in accordance with the requirements of the aPProPfiate AISC or AISI specifications. 4.1.1

5

FACTORY FINISH

5.1

Standard 51.1 In the absence of other specific requirements, all materials shall be galvanized (see Annex A). 5.1.1.1 SUUCtUra.lMate~~ - S~I-UC~~ ~taials shall be galvanized in accordancewith ASTM A123 (hot-dip). Exceptions may be made when galvanizing in accordance with ASTM A123 would be potentially detrimental to the structure or its components. Examples include applications utilizing certain high-sue@ and/or proprietary steels and weldments. In these cases, an alternative method of corrosion control shall be specsed. 5.1.1.2 Hardware - Hardware shall be galvanized in accordance with ASTM Al53 (hot-dip) or ASTM B695 Class 50 (mechanical). 5.1.1.3 Guy Strand - Zinc-coated guy strand shall be galvanized in accordance with ASTM A475 or ASTM A5S6.

6 6.1

a

PLANS, ASSEMBLY TOLERANCES, AND MARKING . Standard 6.1-l Complete p1a.r~ assembly drawings, or other documentation shall be supplied showing the necessary marking and details for the proper assembly and installation of the material, including the design yield strength of the spuctural members and the grade of structural bolts required. 6.1.2 Tolerances for the proper layout anchors shall be shown on the plans.

and installation of the material; and the foundations and

6.1.2.1 Plumb - The horizontal distance between the vertical centerlines at any two elevations shall not exceed 25 percent of the vertical distance between the two elevations. 6.1.2.2 Twist - The twist (angular’ rotation in the horizontal plane) between any two elevations shall not exceed 0.5Oin 10 feet [3 m] and the total twist in the structure shall not exceed 5’. 6.1.2.3 Length - For tubular steel pole structures with telescoping joint, butt welded or flanged shaft connections, the overall length of the assembled structure shall be within plus 1 percent or minus l/2 percent of the specified height. (Note: Horn reflectors and other types of offset-feed antennas have polarization performance requirements, which are sensitive to ar+@ar displacement from boresight direction. Special consideration must be given to the mount, attachment hardware, installation practice, as well as the support structure, to minimize all contributing factors to initial skew or offset.)

e

6.1.3 All structural members or welded structural assemblies, except for hardware, shall have a part number. The part numbers shall correspond with the assembly drawings. The Part number is to be permanently attached (stamped, welded lettering, stamped on a plate that is welded to the member, etc.>to the member before all protective coatings (galvanizing, paint, etc.1are aPPhed. The part number shall have a minimum character height of l/2 in. [13 mm], be legible and clearly visible to an inspector after erection. 7

FOUN-DAnONS AND ANCHORS

7.1

Definitions 7.1.1 Standard Foundations and Anchors - Structures designed to support the specified loads defined in Section 2 for normal sod conditions as defined in 7.1.3. Pile construction, roof msmations, foundations or anchors designed for submerged soil conditions, etc., are not to be considered as standard. 7.1.2 NonS tandard Foundations and Anchors - Structures designed to support the specified loads defined in Section 2 in accordance with site specific conditions. 7.1.3 Normal Soil - A cohesive soil with an allowable net vertical bearing capacity of 4000 pounds per square foot Cl92 kPa] and an allowable net horizontal pressure of 400 pounds Per square foot per lineal foot of depth [63 kPa per lineal meter of depth] to a maximum of 4~00 pounds per square foot 1192 pa].

(Note: Rock noncohesive soils, saturated or submerged soils are not to be considered normal soil.) a

7.2

Standard 7.21 Stanchi foundations and anchors may be used for bidding purposes and for construction when actual soil pa&meters equal or exceed normal soil parameters. 7.22 When standard foundations and anchors are utilized for final designs, it shaU be the responsibility of the purchaser to verify by geotechnicai investigation that actual site soil parameters equal or exceed normal soil parameters. (See Annex A.) 7.2.3 Foundations and anchors shah be designed for the maximum structure reactions resulting from the specified loads defined in Section 2 using the following criteria: 7.2.3.1 When standard foundations and anchors are to be used for constnrction, “normal soil” parameters from 7.1.3 shall be used for design. 7.2.3.2 When nonstandard foundations and anchors are to be used for construction, the soil parameters recommended by the geotechnicai engineer should incorporate a minimum factor of safety of 2.0 against &imate soil strength (see Annexes A and I). 7.2.4

Uplift

7.2.4.1 Standardf oundati ons, anchors, or drilled and belled piers shall be assumedto resist uplift forces by their own weight plus the weight of earth enclosed within an inverted pyramid or cone whose sides form an angle of 30’ with the vertical. The base of the cone shall be the baseof the foundation if an undercut or toe is present or the top of the foundation base in the absence of the foundation undercut. Earth shall be considered to weigh 100 pounds per cubic foot [16 kN/n$] and concrete 150 pounds per cubic foot [24 kN/m3].

I rA~!zlA-222-F

Straight shaft drilled pien for st&ad foundations shall have an ultimate skin friction of 200 pounds per square f00t pa lineal foot of depth [31 kPa per Iineal meter of d@l to amaximumof 1000 pounds per square foot of shaft surface area 148kpal for upllfr or download resistance. 7.2.4.2

7.2.4.3 Nonstandard foundations, anchors, ami &i.lkd piers shall be designed in awodance with the recommendations of a geotechnid report (see Annex I). 7.2.4.4 Foundations, the following:

anchors, and drilled

shah be proportioned in accordance with

piers

(WR /2-o) + (WC D-25) 2 Up and (wR+wc)/l.5 where:

1 up

WR = soil resistance from 7.2.4.1.7.2.4.2 or 7.2.4.3 WC = weight of concrete Up = maximum uplift reaction

7.2.4.5 A mat or slab foundation for a seif-supporting structure shall have a minimum safety factor againstoverturning of 1.5. 7.2.5

The depth of standard drilled foundations subjected to lateral or overturning loads shall

be proportioned in accordancewith the following: LD 2 2.0 + S/(3d) + 2 [S2/(18d2)+ S/2 + M/(3d)]ln (ft) LD > .61 + S/(143d) + 2 [S2/(41333d2) + S/96 + M/(143d)11R [ml where: LD = Depth of drilled foundation

. below

grounilevel (ft) [ml

d

= Diameter of dri.Uedfoundation (ft) [ml

S

= Shear reaction at ground level (kips) &NJ

M

= Ovemuning moment at ground level (ft-hips) [m-w

Reference: Broms, B., “Design of Laterally Loaded Piles”, Journal of the Soil Mechanics and Foundation Division Proceedings of the American Society of Civil Engineers, May, 1965. 7.3

Special Conditions 7.3.1 When a support is to be designed by other than the manufacturer,themanufacturerwill be responsible for furnishing the reactions, weights, and interface details for the purchaser’s engineer to provide the necessary attachment. 7.3.2 The effects of the presence of water shall be accounted for in the design of nonstandard foundations. Reduction in the weight of materials due to buoyancy and the effect on soil properties under submerged conditions shall be considered.

7.4

Foundation Drawings 7.4.1 Foundation drawings shd indicate structure reactions, material strengths, dimensions, reinforcing steel, and embedded anchorage material type, size, and location. Foundations desiped for nomA soil conditions shall be so noted. (Note: Normal soil design parameters and methods are presented to obtain uniform standard foundation and anchor designs for bid&g purposes. Design methods for other COnd~OnSand 0t.k foundation types must be consistent with accepted engineering practices.)

8 8.1

SAFETY FACTOR OF GUYS Definition 8.1.1 Guy Connection - The guy connection is defmed as the hardware or mechanism by which a length of guy strand is connected to the tower, insulator, or guy anchor. The connection may include, but is not limited to, the following: shackles, in-line insulators, thimbles, turnbuckles, twin base clips, u-bolt cable dips, poured socket fittings, and grip- type dead-end connections. ‘l%vin base and u-bolt chps used on guy strand through 7/8-in. diameter shall be considered to have a maximum efficiency factor of 90 percent. In all other cases,clips on strand shall be considered to have a maximum efficiency factor of 80 percent. For all other types of end connections, manufacturer’s recommendations should be followed when determining the connection efficiency factor, 8.1.2 Safety Factor of Guys - The safety factor of guys shall be calculated by dividing the published breaking strength of the guy or guy connection strength, whichever is lower, by the maximum calculated tension design load.

8.2

Standard 8.21 For structures under 700 ft [213 m] in height, the safety factor of guys and their connections shall not be less than 2.0. 8.2.2 For structures 1200 ft [366 m] or greater in height, the safety factor of guys and their connections shall not be less than 2.5. 8.2.3 For structures between 700 ft [213 m] and 1200 II [366 m] in height, the minimum safety factor of guys and their connections shall be determined by linear interpolation between 2.0 and 2.5. (Note: A l/3 increase in stress for wind-loading conditions does not apply to the published breaking strength of guys and their connections.) 8.2.4 Structure height, for purposes of determinin g the required safety factor of all guys and their connections, shall be based on total structure height including tubular or latticed poles mounted on the structure.

9

PRESTRESSINGAND PROOF LOADING OF GUYS

9.1

Definitions 9.1.1 Prestressing of Guys - The removal of inherent constructional looseness of the guy under a sustained load. 9.1.2 Proof Loading connections.

The assurance of mechanical strength of factory assembled end

-

-..

_

_--

a

Standard

9.2

9.2.1 &stressing and proof loading are not normaLly required. When specified. Presnessing and proof loading shall be performed in accordance with the recornmendati~~ of the gUY manufacturer. (Note: For tall, guyed structures, consideration should be given to prestressing and Proof loading.) 10 10.1

INITIAL GUY TENSION Definition

10.1-l Initial Guy Tension - The specifieci guy tension in pounds [newtons] under no wind load conditions, at the guy anchor at the specified temperature (see 10.2). 10.2

Standard

10.2.1 Initial tension in the guys, for design purposes, is normally 10 percent of the published breaking strength of the strand with upper and lower limits of 15 and 8 percent respectively. Values of initial tension beyond these limits may be used provided consideration has been given to the sensitivity of the structure to variations in initial tension and, if necessary, to dynamic behavior (see note below). Consideration shall be given to the site ambient temperature range. In the absence of site specific data, the initial tensions shall be based upon an ambient temperature of 6O*F. (Note: The stated 8-15 percent initial tension extreme values are provided as recommended guidelines only. Specific site and terrain conditions may necessitate initial tension values outside this range. When using initial tension values above 15 percent, consideration should be given to the possible effects of aeolian vibration. mewise, when using initial tension values less tha.u g percent, consideration should be given to the effects of galloping and slack-taut pounding.) 10.3

Method of Measurement

10.3.1 Initial tension may be measured by vibration frequency, mechanical tensiometers, ~eas~~ent of guy sag, or by other suitable methods (see Annex E). 11

OPERATIONAL REQUIRE,MENTS

11.1

Definitions

11.1.1 Twist - The angular rotation of the antenna beam path in a horizontal plane from the no-wind load position at a specified elevation. 11.1.2 Sway - The angular rotation of the antenna beam path in a vertical plane from the no-wind load position at a specified elevation. 11.1.3 Displacement - The horizontal translation of a point relative to the no-wind load position of the same point at a specified elevation. 11.2

Standard (See Annex A)

11.2.1 Theminim Urn standard shall be based on a condition of no ice and a wind load basedon a 50 mph basic wind speed [22.4 m/s] calculated in accordance with 2.3. The operational requirements shall be based on an overah allowable 10 dI3 degradation in radio frequency signal level.

11.2.2 Unless otherwise specified, the operational requirements for reflector systems shall be determined using Annexes C and D. 12

FWXECITVE

12.1

Definitions

micrOWaVe

antex&

GROUNDING

12.1.1 Grounding - The means of establishing an electrical connection between the structure and the earth, adequate for lightning, high voltage, or static discharges. primary Ground - A wnchcting connection between the structure and earth or some conducting body, which servesin place of the earth. 12.1.3 Secondary Ground - A conducting connection between an appurtenance and the structure. 12.1.2

(Note: Ground wire should not be encased in the foundation.) Standard (See Annex A)

12.2

12.2.1

Structures shall be directly grounded to a primary ground.

12.2.2 A minimum ground shail consist of two 98 in. [16 mm] diameter galvanized stee! ground rods driven not less than 8 ft [25 m] into the ground, 180* apart, adjacent to the stmcmre base. The ground rods shah be bonded with a lead of not smaller than No. 6 [5 mm] tinned bare copper connected to the nearest leg or to the metal base of the structure. A similar ground rod shall be installed at each guy anchor and similarly connected to each guy at the anchor. 12.2.3 Self-supporting towers excee&ng 5 ft [1.5 m] in base width shall have one ground rod per leg installed as above. 12.2.4 All equipment on a structure shah be connected by a secondary ground. 12.2.5 Remote passive reflectok are exempt from the grounding requirements specified herein. 13

CLMMNG

13.1

Definitions

AND WORKING FACZIUTJES

13.1.1 Climbing Facilities - Components specifically designed or provided to permit access, such as fixed kkhs, step bolts, or snuctu.ral members. 13.1.2 Climbing Safety Devices - Equipment devices other than cages, designed to minimize accidental falls, or to Iitnit the distance of such falls. The devices permit the person to ascendor descend the structure without having to continually manipulate the device or any part of the device. The climbing safety device usually consists of acarrier, safety sleeves, and safety beits. 13.1.3 Working Facilities - Work platforms and accessrunways. 13.1.4 Hand or Guardrds facilities to prevent falls. 13.2

- Horizontal barriers erected along the sides or ends of working

Standard

13.2.1 Climbing and working facilities, hand or guardrails, and climbing safety devices shall be provided when specified by the purchaser. (See Annex A.) 13.2.2 Climbing facilities shah be designed to support a minimum 250 [l.l concentrated live load.

kN] pound

TIAEIA-222-F

13.2.2.1 When fmed ladders are specified as the climbing facility, they shall meet the fo~o~g minimum requirements: a. Side rail spa&g - 12 in. [300 mm] minimum clear width. b. Rung spacing maximum.

12 in. [30O mm] minimum center-to-center, 16 in. [410 mm]

C. Rung diameter -

5/8 in. [16 mm] minimum.

13.2.2.2 When step bolts are specified, they shall meet the following requirements: a. Clear Width - 4 l/2 in. [llO mm] minimum. b. Spacing - 12 in. minimum [300 mm] center to center, alternately spaced, 18 in. 1460

mm1maximum. c. Diameter - 5/S in. 116 mm] minimum. 13.23 Climbing safety devices shall meet the design requirements of the American National Standards Institute (ANSI) A14.3-1984, “Safety Requirements for Fixed Ladders”, Se&on 7. 13.24 Support structures for working facilities shall be designed to support a uniform live load of 25 lb/ft’ Il.2 kpa], but in no case shall the support structure be designed for less than a total he load of 500 pounds 12.2ItN]. Working surfaces, such asgrating, shall be designed to support two 250-pound [ 1.1 IrN] loads. These loads are not to be applied concurrently with wind and ice loads. 132.5 Hand or guardrails shall be designed to support a minimum concentrated live load of 150 pounds LO.67kN1, applied in any direction. . (Note: 13.2 is intended to provide m,i,nimm requirements for new structures. It is not intended to replace or supersede applicable laws or codes.) 14

-ANCE

14.1

Standard

AND INSPECTION

14.1.1 Maintenance and inspection of steel antenna towers and antenna supporting structures should be performed by the owner on a routine basis. (Note 1: It is recommended that all structures be inspected after severe wind and/or ice storms or other extreme loading conditions.) , (Note 2: Recommended inspection and maintenance procedures for towers are provided in Annex E.)

3: Shorter inspection intervals should be considered for structures in coastal salt water environments, in corrosive atmospheres, and in areas subject to frequent vandalism.) (Note

15

ANALYSIS OF EXNING

15.1

Standard

TOWERS AND STRUTS

15.1-l Steel antenna towers and other suppo~g stNctures should be analyzed when changes occur to the original design or operational loading conditions. Recommended criteria for the analysis of existing structures are provided in Annex F.

16

COUNTY LISTINGS OF MINIMUM BASIC WIND SPEEDS (SeeAnnex A) StatedALABAMA statf! of ALABAMA

c0uNl-Y AUTAUGA BALDWIN BARBOUR BIBB BLOUNT BULLOCK BUTLER CALHOUN CHAMBERS CHEROKEE (ZTHIEDN CHOCTAW E!tt&mE COFFEE COLJ3lXT CONECUH COOSA COVING-l-ON CRENSHAW DALE DALLAS DEKALB ELMORE EscAMBIA ErowAH FAYEITE

NOTE* 2

NOTE*

COUNIY MONROE MONTGOMEEtY MORGAN PERRY FICKENS

2

2 2 2 2 2 2 2

2

2

BENRY HOUSTON JACKSON JEFFERSON

2 2

LAUDERDALE LAmcE

2

ii 70 70 70 70 ii: 70 70 85 70 85 ii 80 70 80 70 70 70 90 70 70 70 90 70 70 80 85 70 70 70 70 70 70 70 75 70 70 75 70 70 95

*For notes, see end of Section 16

-

85

Ei

iEFDOiJ?H RUSSEL SAINTCLAIR SHEBY tiZ!it~GA TALLAPOOSA TUSCALOOSA WALKER WASHINGION WILCOX WINSTON

BASIC WIND SPEED(MpH) 70 70

2 2

GENEVA

LIMESTONE LOwNDE!z MACON MADISON MARENGO MARION MARSHALL MOBILE

BASIC WIND s=ED(Mpm 70 100 75 70 70

2 2

75 70 70 70 70 70 70 70

; : 70

state of ALASKA ALEunANIsLANDs ANCHORAGE I=?= BRISTOL BAY DILLINGHAM FAlRBANKS NO. STAR JUNEAU KENAIFENINSULA KEKEEANGAXEWAY KOBUCK KODIAK ISLAND; WANUSKA-SUSl’INA NOME NORTH SLOPE PRINCEOFWALES SIlKA SKAGWAY-%4KUTflANGOON SOUTHEASTFAIRBANKS VALDEZ-CORDOVA WADEHAMPTON wRANGELt--URG YUKON-KOYUKUK caution: Mound regicm af Alaskashouidbecxmsidered~ sYpdaiwin.dregions.

110 110 110 105 105 70 80

90

100 95 100 110 80 110 100 100 100 100 70

90 110 90 90

*

sta!eofARKANsAs

Stateof ARIZONA COUNTY

NOTE*

APACHE COCBlSE cocoNINo

BASIC WIND

BASIC WIND mED(MpH)

1 1

couIvIY

70 70 70

HOWARD INDEPENDENCE

E 70 70 75 75 70 75 75 70 75 70

JEFFERSON

JACKSON FEGAM LAPAZ MARICOPA MOHAVE NAVAJO

1

PINAL SANTACFUJZ YAVAPAI

JOHNSON WALAWRENCE IJNCOLN LmuzRrvER LOGAN LONOKE MADISON MARION

State of ARKANSAS ARKANSAS ASHLEY BAXIER BENTON BOONE BRADLEY CALHOUN CARROLL CBICOT CLAY EkG%!E% COLUMBIA CONWAY CRAIGHEAD CRAWFORD CRm-ENDEN CROSS DALLAS DESFIA DREW FAULKNER FUIXON GARLAND

HEMPSTEAD HOT SPRING *For notes,

seeend of Section 16

70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70

,

MISSISSIPPI MONROE MONTGOMERY NEVADA NEWIUN OUACHITA PERRY PHILLIPS P0Ixm-r PO= POPE iiiiEsI RANDOLPH sAINrFIuNas SALINE scorr SEARCY SEBASTIAN EE SroNE UNION VANBUREN WASHINGTON WOODRUFF

NOTE*

SPEEDWR) 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70

1 IA/tlA-7”-

stateafcALIFom

state of CALIF0RNr.A COUNTY

NOTE*

ALAMEDA ALPINE AMADOR BUTTE CALAVEMS COLUSA CONTRA COSTA DELNORTE ELDORADO FRESNO

BASIC WIND SPEED0

1 1

70 70 70 75 70 75 70 80 75 70

1 1 1

ii 70 70 70

1 1 1

HUMBOLDT

EEi KINGS

a

LASSEN LOS ANGELES MADEwi

1 1 1

MARIPOSA MENDocmo MEWED MODOC MONO MONTEREY NAPA NEVADA ORANGE PLACER PLUMAS -IDE SASANBWO SANBERNARDINO SANDIEGO sANFRANcIsc0 SAN JOAQUIN SANLUIS OBISPO sANlkulEo SANTABARBARA SANTACLARA SANTACXJZ SHASTA SEE&4 SISKIYOU SOLANO SONOMA

1

*For notes, see end

1 1

1 1 1 1

1 1

1 1 1

of Section 16

ii 75 70 70 75 ii: 70 70 70. 70 75 75 70 75 70 70 75 70 70 70 70 70 70 70 70 70 70 75 70 75 75 80

NOTE*

COUNTY

BASIC WIND SPEED (MPM 70 75 75 80 70 70 70 75 75

state of coLoRAD

ADAMS ALAMOSA ARAPAHOE ARBACA BENT BOULDER CLEARCREEK CONEIOS cosm CROWLEY CUSTER DEtTA DENVER DOLORES DOUGLA!3 EAGLE ET& FREMONT GARFIELD GlLPlN iiii%iON BINSDALE HUERFANO JACKSON JEFFERSON KIOWA KIT CARSON

85 1

1 1 1 1

1

1 1 1

ii 70 85 85 85 80 85 85 80 80 85 80 70 85 70 85 80 E 80 80 85 85 75 70

1 ii 1

LAPLCA 1

ii 85 80 70 85

F

1 lAftlA-7”-t a--

StateiofFLORIDA

state of COLORADO COuNlY

NOTE*

LASAMMAS LINCOLN LOGAN MESA

BASIC WIND SEED0

1

MOFEAT MONTEZUMA MONlROSE MORGm OlERO OURAY PARK PHILLIPS PIIXIN FROWERS PUEBLO RIO BLANC0 RIO GRANDE ROUTT SAGUACHE SANJUAN SANMXGUEL SEDGWICK SUMMIT 1.m WASI-BNGTON

80 E 70 75 80 70 ii 85 70 80 85 80 85 85

1

ii 85 80 70

1

ii 80 85 85 85 85

1 1

stare of CONTvEcl-ICUT FAIRFIELD HAKl-FORD Lrrm MIDDLESEX NEWHAVEN NEWLONDON TOLLAND WINDHAM

2 2 1.2 2 2 2 2 2

85 80 80 85 85 85 85 85

State of DELAWARE 2 NEW CASTLE 2 SUSSEX 2 Disnict of COLUMBIA DISTRICTOF *For

COLUMBIA

80 75 90 2

75

notes,seeend of Section 16

NOTE*

COUNTY ALACEIUA BBAY BRADFORD BREVARD BROWARD CALHOUN CHARLOTIE CnRus CLAY COLLIER COLUMBIA DADE DE SOT0 DIXIE DW& ESCAMBIA FLAGLER GADSDEN GILCHRIST GLADES HAMILTON HARDEE BENDRY .IiiERNANDo HIGHLANDS HILLSBOROUGH HOLMES fNDIANRlvEEz JACKSON JEFFERSON LAFAYEI-IE LEON LTBERTY MADISON MANATEE MARION MONROE NASSAU OKALOOSA OKEJXHOBEE

2 .

1 2 2 2 2 2 2 2 2 2 2 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 ; : 2

BASIC WI-ND SPEED0 95 90 100 95 105 115 100 105 100 95 110 90 115 105 100 95 100 100 105 95 95 100 105 90 100 105 105 100 105 95 105 95 95 95 100 105 95 100 100 95 105 100 105 120 95 1M) 100

F

1 l&&IA-~-

State of GEORGIA

State ofFLORIDA COUNTY

NOTE*

ORANGE OSCEOLA PALMBEACH PMCO PINELLAS F0I.K PUTNAM SAINTJOHNS SAINTLUCIE SANTA ROSA SARASOTA SEMINOLE SUMTER SUWANNEE TAmOR UNION VOLUSIA WAKULLA WALTON WASHINGTON

BASIC WIND sPEEDo

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

100 100 110 105 105 100 95 loo 105 100 105 100 100 90 100 95 100 100 100 95

State of GEORGIA APPLING MKINSON BACON BAKER BALDWIN BANKS BARROW BARTOW BENHILL BERRIEN BIBB BLECKLEY BRANTIXY BROOKS BRYAN BULLOCH BURKE BUTTS CALHOUN CAMDEN CANDLER CARROLL CMOOSA -TON

2 2 2 2

2

2 2

2 2

*For notes,seeend of Section 16

85 .80 85 80 75 75 75 75 80 80 70 75 90 85 90 85 80 70 75 95 80 70 70 90 95

COUNIY mAHoocHEE (ZHtUTOOGA CBEEIOKEE CLAY CLAYTON CLJNCH COBB COFFEE c0LQm-r COLUMBIA COOK COWEIA CRAWFORD CRTSP DADE DAWSON DECQUR DEKALB DODGE DOOLY DOUGBEKIY DOUGLAS =Y ECXOLS EFFINGHAM ELBEEa EVANS FANNIN FAYEITE FLOYD FORSYTH FULTON GLASCOCK GLYNN GORDON K HABERBAM HANCOCK HAULSON

NOTE*

BASIC WIND SPEEDm 70 75 70 75 75 70 85 70 80 80 75 80 70 70 75 70 75 90 70 75 75 75 70 80 85 90 75 80 85 70 70 70 75 75 70 70 75 95 70 85 75 75 75 75 75 70 70 75 70

*

TIAEIA-‘22-F

State of GEORGIA COUNTY

NOTE*

BASIC WIND sPJ330

HENRY HOUSTON it--ON JASPER JEFFDAVIS JEFFERSON JENKINS JOHNSON JONES iI%E LAURENS

70

2 2

2

LIBERTY LINCOLN LONG LOWNDES LUMPKIN MACON MADISON MARION MCDUFFIE MCINTOSH MlTcHEu MONROE MONTGOMERY MORGAN MURIUY MUSCOGEE NEWTON OCONEE OGLEl-HORPE PAULDING PEACH PICKENS PIERCE PIKE POLK PULASKI PUTNAM

2

QRABUN RANDOLPH RICHMOND ROCKDALE *For notes, see end of Section 16

State of GEORGIA

I

ii 75 75 80 75 80 75 75 70 85 75 75 90 75 90 85 75 70 75 70 75 95 70 80 80 70 80 75 70 70 75 75 75 70 70 75 90 70 70 75 75 75 70 75 75 70

cow EEEN

NOTE*

SEMINOLE SPALOING

2 2

kFE%F liW3OT -0 3lxrrNALL TAnOR

2

zEiz% THOMAS

2 2

TOOMBS TOWNS TROUP TWIGGS UNION UPSON WAIXER WAIXON

2 EEEN WASHlNG’IDN WAYNE itziEz

WILCOX WILKINSON WORTH

2

BASIC WIND SPEED (Mm 70 80 85 70 75 70 70 70 75 85 70 80 75 8s 80 85 70 80 70 75 75 70 70 75 75 85 75 75 90 70 80 70 70 75 75 75 75

state OfHAwAlI HAWAII HONOLULU KAUAI MAUI

80 80 Emi

*

state of IDAHO COuNm

NOTE*

BASIC WIND sPEED(Mpm

ADA ADAMS BANNOCK BEARLIKE BENEWAH BINGHAM BLAINE BOISE BONNIER BOBOUNDARY BUTIE CAMAS CANYON CARIBOU CASSIA

70 70 70 75 70 70 70 70 70 75 70 70 70 70 75 70 70 70 70 70 70 75 70 70 70 70 70 70 70 70 70 70 75 70 70 70 70 70 70 70 75 70 70 70

CLEARWMER CUSTER ELMORE FREMONT GOODING IDAHO JEFFERSON JEROME K00TENAI L.f%rM Et2 LINCOLN MADISON MINIDOKA NEZPERCE ONEIDA OWYHEE PAYEITE POWER SHOSHONE TETON TWINFALLS VALLEY WASHINGTON

a

stateof xLLIN01s

I

1

COUNTY IzE4DER BOND BOONE BROWN BUREAU CAUIOUN CARROLL ~Z~ELPAIGN CHRISTIAN .CLAY CUNTON COXES COOK CRAWFORD CUMBW DEKALB DEWl’IT DOUGLAS DU PAGE EDGAR EDWARDS EFFINGHAM FAYEITE FORD FULTON GALJXlTV GRUNDY HAMILTON HANCOCK iii%i:SON BENRY IROQUOIS JACJLSON JASPER JEFFERSON JERSEY JO DAVIESS JOHNSON

KENDALL KNOX *For notes, see end of Section

16

NOTE*

BASIC WIND SF'EED(Mpm 70 70 70 80 70 75 ii 70 70 ii 70 70 70 75 70 70 75 70 70 75 70 70 70 70 70 70 70 70 70 75 70 75 70 75 75 75 70 70 7@ 70 80 70 75 75 75 75

TIAEIA-222-F

stateoflLLINoIs

state of ILLINOIS COUNTY

NOTE*

BASIC WIND SPEED0

1 LASALLE LAWRENCE LIVINGSTON LOGAN MACON MACOUPIN MADISON MARION MARSHAL;L MASON MASSAC MCDONOUGH MCBEN-RY MCLEAN MENARD MERCER MONROE MONTGOMERY MORGAN MOULIRIE OGLE PEmIA PERRY PIAIT PIKE POPE PULASKI PUTNAM RANDOLPH kG SAINTCL4IR SALINE SANGAMON SCHLJYBZ SCOTT SHEIJ3Y STARK STEPHENSON TAZEWELL UNION VERMILION WABASH WARRJ3 WASHINGTON WAYNE


80 75 70 75 75 70 70 70 70 70 75 70 70 70 80 70 70 75 70 70 70 ii: 75 70 70 70 70 70 75 70 70 75 70 70 70 70 70 70 75 80 70 70 70 70 ; 70 70

NOTE*

CouNn WHITESIDE %AMSON WINNEBAGO WOODFORD

BASIC WIND SPE’EDWm 80 75 70 80 75

StatedINDIANA ADAMS BARTHOLOMEW BENTON BLACKFORD BOONE BROWN CARROLL CASS E&ON CRAWFORD DAVIESS DEARBORN DECQTJR DEXAL33 DELAWARE DUBOIS FAYEI-IE FLOYD FOUNTAJN FUIXON GIBSON EEk HAMIIXON HANCOCK HARRISON HENDRxcKs HENRY HOWARD HUNTINGION JACKSON JASPER JAY

JERER!ZON JENNINGS JOHNSON

75 75 70 75 70 70 70 70 75 70 70 70 70 70 70 70 75 70 70 75 70 70 70 70 75 70 70 70 70 70 70 70 70 70 75 70 75 70 70 70 70

;

State ofINDIANA COUNTY KNOX KoscIusKo LAPORTE LAGRANGE

NOTE*

StatedINDIANA BASIC WIND SPEED0 70 75 75 75 75 70 70 70 75 70 75 70 70 70 75 75 70 70 70 70 70 70 75 70 75 70 70 70 70 75

1 1

LAWRENCE MADISON MARION MARS=

e

iEkE? MONROE MONTGOMERY MORGAN NEWTON NOBLE OHIO ORANGE OWEN PARKE PERRY PIKE PORTER POSEY PULASKI mAM RANDOLPH

1

RUSH ST. JOSEPH SCOTT SI3Eu3Y SPENCER STARKE STEUBEN SULLIVAN STIPPECANOE TIPTON UNION VANDERBURGH VERMIIUON VIGO WABASH WARREN WARRICK WASHINGTON WAYNE *For notes, see end of Section

TIAEIA-222-F

:8 70 75 75 70 70 70 70 70 70 70 70 75 70 70 70 70 16

BASIC WIND

NOTE* SF=D(MpH)

COUNTY

State af IOWA

ADAXR 2i?izLE .APPANoosE AUDUBON BENTON BLACKHAWK BOONE BREh4ER BUCHANAN BUENAVISTA BUTLER CALHOUN CARROLL CASS

WAR cER.RoGoRDo -0KEE CHICKASAW CLARKE CLAY CLAYTON CLINTON ClUWFORD DALLAS DAVIS DECAI’UR DELAWARE DES MOINES DICKINSON DUBUQUE ft%EE FLOYD FREMONT GRUNDY ZN HANcocK

80 80 Fl 80 80 ii 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 80 75 80 80 75 80 80 80 80 80 80 80 ix 80 80 80

TlAIEIA-221-F

State dIOWA

State of IOWA COUNTY

NOTE*

BASIC WIND sPEEDch4Pm

HARDIN HARRISON HENRY HOWARD HUMBOLDT IDA IOWA JACKSON JASPER JEFFERSON JOHNSON JONES KEOKUK KossuIH

75 80 80 80 80 80 80 80 80 80 80 80 75 80 75 80 85 80 80 80 80 80 80 80 80 80 80 80

LOUISA LUCAS LYON MADISON MAHASKA MARION MARSHALL MITCBELL MONONA MONROE MONTGOMERY MWXKINE O’BRIEN OSCEOLA PACE PALO ALTO PLYMOUTH POC4HONTAS POLK POTTAWAmAMlE P0wl3HlEK RINGGOLD SAC SCOTr SHELBY SIOUX STORY TAMA TAnOR UNION VANBUREN WAPEILO *For notes, see end of Section

ii 80 ix 80 80 80 ;z 80 80 85 80 80 80 80 75 80 16

NOTE*

COUNTY

BASIC WIND SPEEDWH)

WARREN WASHINGTON WAYNE WEBSTER WJNNBBAGQ WINNESWOQDBURY WOKm WRIGHT State &KANSAS . 75 ANDERSON AKHISON BARBBR BARH3N BOURBON BROWN BUILBR CHASE CHATAUQUA CHEROKEE

EEED EiEkBE COWLJZY CRAWFORD DECATUR DICKINSON DONIPHAN DOUGLAS EDWARDS Es mLswoRlH

iFi 80 80 70 80 80 80 75 70 85 80 80 80 75 80 80 70 ii: 80 80 80 ii: 80 85 85 75 80 85 85 85 85

State uf KANSAS

State of KANSAS COUNIY

NOTE*

BASIC WIND SPEED0

=OD

COUNTY

NOTE*

80 85 80 85 80

85 75

HAMILTON iiEE HODGA4AN JACKSON JEFFERSON JOHNSON KINGMAN KIOWA LABErIE =VJZNWORTH LINCOLN 2i.N LYON MARION MARSHALL MCPHERSON MEADE iEG!iaL MONTGOMERY MORRIS MORTON NEOSHO NESS NOKI’ON OSAGE OSBORNE C7ITAWA PAWNEE PHILuPS POTI-AWATOMIE RAWUNS RENO REPUBLIC RICE ROOKS RUSH RUSSELL

BASIC WIND SPEED(MpH)

ii 80 85 85 80

85 85 EEiORD STANTON STEVENS

xi 75 85 80 80 70

IHOMAS TREGO WABAUNSEE WUCE WASHING’IDN WI-A WILSON WOODSON WYANDm

ii 80 75 85 80

80 80 80 85 75. 80 75 80 85 80 75 85 85 80 80 80 80 85 80 80 85 80 80 80 80 85 85 80

. ADAIR

gk?zE gz?iE CARROLL EiF cHRETIAN

--

ii 85 85 80 85 80 85 75 75 75

state of KENTCJCKY

ANDERSON BALLARD BARREN BPilH BELL BOONE BOURBON BOYD BOYLE BRACKEN BRJXBllT BRECKINRIDGE J3~ll-r BUTLER


ii 85

70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70

.

- -- I rrr\-;,-r

ScateOfICENRJ=Ky

state OfKENTIJcKY COUNTY

NOTE*

BASIC WIND SPEEDt-Mm

EF CLINTON cxrITmDEN CUMBERLAND DAVIESS EDMONSON ELIOTI-

70

FUIXON GALILMTN GARR4RD zz

: 70 70 70 70 70 70 70 70 70 70 70 70 70

GRAYSON ziEh.JP

70 70

HANCOCK HARDIN

70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70

FAYFI-IE FLEMlNG FLOYD

HARRISON BENDERSON BENRY BICKMAN HOPKINS JACKSON JEFFERSON JESSAMINE JOHNSON KENTON KNOTT KNOX LARUE LAUREL LAWRENCE LESLIE LErcHER LINCOLN

LMNGSTON LOGAN LYON MADISON


COUNTY MAGoFFIN MARION MARsHAu MASON MCCRACKEN MCCREARY MCLJXN iiE!EE MERCER MErm MONROE MONTGOMERY MORGAN MUHLENBERG NESON NICHOLAS OHIO OLDHAM iEzi!EY PENDLETON PERRY RYXELL PULASKI ROBERTSON ROCKCASTLE ROWAN RUSSELL SCOTr SHELBY SIMPSON SPENCER TAYLOR TODD TRIGG TRIMBIX UNION WARREN WASmGTON WAYNE WEBSTER WOLFE WOODFORD

NOTE*

BASIC WIND SPEEDtMPH)

TIAIEIA-222-F

StateofLOlJISIANA COUNTY ACADIA

BASIC WIND =oMpR)

NOTE* 2 2

95

ASCENSION ASSUMPI-ION i AVOYELLES 2 m2AmAR.D 2 BlJ3MLLE BOSSIER CADDO CALCASIEU 2 CALDWELL CAMERON 2 CAIAHOULA CIAIBORNE CONCORDIA DE SOT0 EAST BATON ROUGE 2 EAST CARROE EASTFELICIANA 2 EVMGELINE 2 IBERIA 2 IBEwILLE 2 JACKSON JEFFERSON -ONDAVIS 2 LAEAYEmZ 2 LAPOURCBE 2 LASALLE LINCOLN LIVINGSTON 2 MADISON MOREHOUSE NiUCBITOCHES ORLEANS 2 OUACBlTA PLAQUEMIDEZ 2 PolNTcouPEE 2 RAPIDES REDRIVER RICBLAND SABINE SAINTBERNARD 2 SAINTCHARLES 2 SAINT-A SAJNTJAMES SAINTJOBNTBEBAFTIST SAINTLANDRY 2

StareofLOUISIANA

1z loo 85 90 70 70 70 95 75 100 80

NOTE*

COUNTY

; 2

TANciIpAHOA TENSAS TERREBONNE UNION -ON VERNON WASBINGTON Z~Z~~%NROUGE wEsTc4RRoLL WESTFELICIANA

ii 90

2

iii 100 loo 70 105 95 100 105 80 70 100 70 70 75 105 70 105 95 85 70 70 75 105 105 95 100 100 95

end of Section 16

100 105 100

;

ii 105 70 100 85 95

2

ii

2

ii 70

2 2

ii 70 95 State OfMAINE ANDROSCOGGIN AROO!XOOK CLJMBERLAND BArycocK KENNEBEC KNOX LINCOLN OXFORD PENOBSCOT PIS~AQUIS SAGADAIIOC SOMERsEr WALDO WASBINGTON YORK

1 .

80 85 80 75 90 80 85 85 75 85 80 85 80 85 100 80

StatedMARYLAND ALIEANY ANNEARUNDEL BALXIMORE CAL= CAROLINE CARROLL CEaL DORCBES-XER PREDERICK

*For notes, see

2

sAIlwMAK13N SAINTMARY SAINTTAZMMANY

BASICWXND SPEED(MpH)

2 2 2 2 2 2 2 2 2

70 75 75 75 80 70 75 75 80 70

TlA/ELW22-F

StateofMICHlGAN

state OfMttRYLAND COUNTY

NOTE*

GARREIT HARFORD HOWARD MONTGOMERY PRINCE GEORGE’S . ZEf?kEF: SOMERsEr TALBOT WASHINGTON wIcoMlc0 WORCBSTER

BASIC WIND SPEED0

2 2 2 2 2 2 2 2 2 2 2 2

;i

70 75 70 75 75 E 80

HAMPDEN HAMPSHIRE MIDDLESEX NANTUtXET NORFOLK PLm0Ul-H SUFFOLK WORCESTER

2 12 2 2 2 1.2 2 2 2 2 2 2 2 2

100 70 90 iii ii 75 90 105 90 95 90 85

State of MICHIGAN ALCONA ALGER ALlEGAN ALPBNA ARBNAC BARAGA BARRY BAY BHNZIE BERRJEN BRANCH CALHOUN CASS

1 1 1 1 1 1 1

75 75 75 75 75 75 75 75 75 80 75 75 75 75

1 1 1

*For notes, see end of Section

NOTE* 1 1 1

cHARLEvolx CHEBOYGAN CBIPPBWA CLJNTON QRAWPORD Dn DICKINSON iEi&

BASIC WIND SPEED0

;

70 75 75 ii 80 75

1 E

ii 90

State of MASSACHUSETTS BARNSTABLE BERKSHIRE BRISTOL DUKES ESSEX

COUNTY

16

iik?iiiY GRANDTMvERsE G&SHOT HJLLSDALE HOUGHTON HURON INGHAM IONIA IOSCO IRON ISABELLA JACKSON -00

1 1 1 1

1 ii 75 75 75 75 75 70 80

KEWEENAW LAPEER LEIZANAU LENAWEE LIVINGSTON LUCE MACKINAC MACOMB iizgEIE MASON MECOSTA MENOMINE MIDLAND MISSAUKEE MONROE MONT.CALM MONTMORENCY MUSKEGON NEWAYGO OAKLAND

E 75 75 75 70 75 75 75

1

1 1

1

ii 75 75 70 75 75 80 80 80 ii 75 75 75 75 75 80 80 75

’

TIA/EIA-222-F

Stateof MXCHlGAN COuNrY

NOTE*

OCEANA OGEMAW ONTONAGON OSCEOA OSCODA OTSEGO OTTAWA PRESQUEISLE ROSCOMMON SAGINAW SAINTCLUR SAINT JOSEPH SANTLAC SCHOOL CEuFr SHIAWASSEE TUSCOLA VANBUREN WMH’IENAW WAYT+JE WEXFORD

State dMINNESOTA

BASIC WIND spEED(MpH)

1

80 75 75 75

1

; 80 75 75

1 1 1 1

;

1 1

z 80

1 1

E

.

EE JACKSON KANABEC IMNDIYOBI KrITSON KOOCHKHING LACQUIPiUUE

iFI ii 75 75 80 85 85

LAKE OF TEE WOODS LE!mErJR LINCOLN LYON MAHNOMEN MARS=

8”o 80

MCLEOD

ANOKA

ii

85 80 80 90 80 80

*For notes, see end

85 80 80 75 80 80

ii 80 80 80 85 80

ii

BECKER BELXRAMI BENTON BIG STONE BLUEEARTH BROWN CARLXON CARVER

ERWMER COOK COTIONWOOD CROWWING DAKOTA DODGE DOUGLAS FARIBAUEI’ FILUAORE FREEBORN GOODHUE

HOUSTON -ARD

iz

Statedm0~~

iii%kWA CHISAGO

BASIC WIND

NOTE* SPEs>(MpH)

COUNIY

1

MlLLELAcs MORRISON MOWER MURRAY NIcouEr NO&ES NORMAN OLMSIED OTIERTAIL PENNINGION

:z 80 ii: ii: 85 85 80 80 85 80 80

PIPESTONE POLK

ii iz 75 90 80 70 85 i: 80 85 80

EEEY REDLAKE REDWOOD RICE ROCK ROSEAU sAlNTLouIs SCOIT SHERBURNE SIBLEY

ii 80 ii

ii

.?i-zz? SEVENS

ii 80

TODD TIMERSE

of Section 16

Yz 1

iti 85 E

.

state ufMx!sIssIPP1

State of h4lNNESOTA COUNTY

NOTE*

BASIC WIND SPEEDWH)

WABASHA WmENA WASECA WASBINGTON wmoNwAN

80 80 80 ii:

EE4 WRIGHT YELL0wh4ED1cINE

ii

80 85

state of MISSISSIPPI ADAMS ALCORN

80 2

KITilLA BENTON BOLTVAR CALHOUN CARROLL CBICKASAW CHO(JTAW CIAIE3ORNE

ii zi 70 ;i 70 70 75

2 CLAY coAHoMA COPIAH COVINGTON DE SOT0 FORREST GEORGE GRENADA HANCOCK HARRISON HINDS HOLMES HUMPHREYS ISSAQUENA lTAWAMBA JAQCSON JASPER JEFFERSON JEFFERSONDAVIS JONES

2 2 2 2 2 2 2

2 2 2

LAFAYEITE 2 LAuDEflDALE


$ 70 80 80 70 90 85 ii 70 100 100 75 70 70 70 70 100 75 80 85 85 70 70 90 75

COUNTY

NOTE* 2

E&E IJNCOLN LOWNDES MADISON MARION MARSHALL

MONROE MONTGOMERY NESHOBA NEWTON NOXCJBEE OKTIEBEHA PANOLA PEARLRIvER PERRY

2

2

2 2 2

EOTOC PRENTISS

QscolT SHARKEY SIMPSON SMIIH STONE SUIWXOWER TALLxmTcHlE Tm TIePAH TISHOMINGO TUN-ICA UNION WAJXHALL WARREN WASHINGION WAYNE CN WINSTON YALOBUSHA wzoo

2

2

2 2

BASIC WIND SPEED0 85 70 70 70 85 70 z 70 70 70 70 75 70 70 70 ii 90 70 70 70 75 75 70 80 75 95 70 70 70 70 70 70 70 90 70 70 85 70 90 70 70 70

stalebofMIssouRI

state of MISSOURI COUNTY

NOTE*

BASIC WIND SPEEDtMnD

AT'CBISON AUDRAIN BARRY BARTON BAIES BENTON BOLLlNGER BOONE BUCHANAN BUTLER CALDm CALLAWAY CAMDEN CAPEGIRARDEAU CARROLL

CLAY cLINKIN COLE COOPER CRAWFORD DADE DALI& DAVIEZS DEKALB DENT DOUGLAS DUNKLIN

GRUNDY HARRISON HENRY HICKORY HOIX HOWARD HOWELL *For notes, see end of Section

3

LINCOLN

16

E%s-I~N MACON MADISON

R

ESJ MCDONALD MERCER

ii:

MISSISSIPPI MONIlEAU MONROE MONTGOMERY MORGAN NEWMADRID NEWTON NODAWAY OREGON OSAGE OZARK PEMISCOT

70 70 70 70 70 80 70 75 80 70 70 80 70 70

EiitE!%E GENTRY

a

ZON JOHNSON KNOX LACLEDE L/WALAWRENCE

70 75 70 75 75 80 70 70 70 70 70

ZON

IRON JACKSON

75 80 80 70 70 70 70 70 70 70 75 70 70 70 75

CASS

COuNlY

EiEi PHELPS POLK PUTNAM luNDoLPH RAY REYNOLDS

NOTE*

BASIC WIND SPEED0 70 75 70 70 75 75 70 E ii 75 75 75 70 70 70 70 80 70 70 70 70 70 70 70 70 80 70 70 70 70 70 70 70 iii 70 70 75 70 70 75 70 70

1 Irv Cl&-&-t

state

COUNTY

StatedMONTANA

ofMIssouRI

NOTE*

BASIC WIND SPEED0

SAINTCHARLES SAINTCLUR sAINTFRANcoIs SAINTGENEVEW

70 70 70 70 70 70 75 75 75 70 70 75 70 70 75

SAINT LOUIS SAINTLOUIS CrIY SAWBE 3z

Sal-T SHANNON SBELBY STODDAEtD iEz!kJ

ii

EE VERNON WlRREN WASHINGTON WAYNE .-= WORTH WRIGHr

70 70 70

zi

80 70

StateofMONTANA BEAVERBEAD BIG HORN BLAINE BROADWm CARBON EEEiE cHouIEAu CUSTER

I

1

DAWSON DEERLODGE FAILON FERGUS

EiiEE? GOLDENVALLEY

ii

75 80 80 75

DANIELS

GAIJAIN

70

1 1 1


ii

80 80 70 80 80 70

iii 2

75 80

COUNIY

NOTE*

70 80 70 75 80

JEFFERSON JUDII-HBASIN

.

ELNDCLARK LJBEKE LINCOLN MADISON MCCONE MEAGHER iiiiEE4 MusPARK PEIROLEUM PHIlUPS PoNDEm POWDERRIVER KwELL RAVALU RICBLAND ROOSEVEU ROSEBUD

ii 80 75 70 70

85 80

ii 1

;z 1

1 ziiE!Ek SILVERBOW SITEWAIER SWEIXGRASS WON Tool-E TREASURE

BASIC m SPED(MpM

‘1 1

gggm, WIBAUX YELLOWSTONE

70 80 70 80 80 85 70 80 70 80 80 75 75 85 80 80

ii

state of NEBRASKA

BANNER BIdUNE BOONE BOXBU’ITE BOYD BROWN BUFFALO

: 85 85 85 i; 85

T.wEIA-222-F

StateofNEBRASIcA COUNTY

NOTE*

StatelTfNEWUSKA

BASICWIND spEED0vfPH-l

BURT BUTLER CASS CEDAR CHASE EiEFzkE CLAY coIx4x EKE? DAKOTA DAWES DAWSON DEUEL DIXON DODGE DOUGLAS DUNDY FILLMORE FRONTER FURNAS GAGE GARDEN GARFIELD GOSPER

80 80 80 85 85 80 85

ii E 85 85 ii 80 ii 85 iz 80 85 85 85 85 ii;

ii%i~T0~

KEYA PAHA KlMBALL KNOX LANCASTER LINCOLN LOGAN LOUP MADISON *For notes, see end of Section 16

NOTE*

MCPBERSON MERRICK MORRILL NANCE

: 85

ii 5 80 80 85 85 85 85 80 85 80

NUCKOIU OTOE PAWNEE PBELPS PERCE POLK REDwILulW RICHARDSON ROCK SALINE SARPY SAUNDERS SCOITS BLUFF

ii 80 80 85 ii: 85

iikz%zN SHERMAN SIOUX SlApON THAYER THOMAS THURSTON VAlXZY WASHING’TON WAYNE wEB!nER

iz 80 g 85 80 85 85 85 80

YORK ii: 85 85 80

%teofNEVADA CHURCHILL

ii 85 85 85 ifI 85 85 85 85

BASIC WIND SPEED(MpH)

ii

ii

GREELEY

HAYES HITCHCOCK HOIX HOOKER HOWARD EFFER!SON JOHNSON

COUNTY

DOUGLAS ELXO ESMERALDA HUMBOLDT .LANDER IJNCOLN LYON

75 1 1

;i 70 75 80 70 80 80 70

'.

stateofNEwh4ExIco

Stare c&NEVADA COUNTY

NOTE*


1 SlmEY WASHOE WBIIEPINE

1 1

70 70 70 75

s~of~HAMPsHlR.E BEIXNAP CARROLL CHESHIRE coos -ON HILLSBOROUGH MERRIMACK ROCKINGHAM sTRAFFoRD SULLIVAN

2 2 2 12 12 2 2 2 2 12

80 80 ; 70 :: 85 85 75

state of NEW JEEtsEY fXIUNTIC BERGEN BURLINGTON EEilY CUMBERLAND ESSEX GLOUCESTER HUDSON HUNTERDON MERCER MIDDLESEX MONMOUTH MORRIS OCEAN PASSAIC SALEM SOrvlEluEr SUSSEX UNION WARREN

*For notes, see end

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

of Section 16

85 80 80 80 85 80 80 f ii

75 80 80 85 75 ifi

80 80 70 80 70

NOTE*

COUNTY

BASIC WIND SF’EED(MpH) 70

BERNALILLO CKtRON cHAvl3 UBOLA COLFM CURRY DEBACA DONAANA EDDY

ii 70 80 80 80 70 75 70

tiEE!iLuPE HARDING HIDALGO

1

LmcoLN Los ALAMOS LUNA MCKINLEY MORA OIERO QUAY RIO ARRIBA ROOSEVETX SANDOVAL SANJUAN SANMJGUEL SANTAFE SlEEUZA SOCORRO TAOS TORRANCE UNION VALENCIA

1

ii

1

1 1

1

ii 75 ;i 70 80 70 80 75 80 70 70 80 75 70 70 80 75 85 70

stateofNEwY0R.K ALBANY AILEGANY BRONX BROOME ~ARAUGUS CAYUGA CHAUTAUQUA CBEMUNG CHENANGO CLINTON COLUMBIA CORTLAND

70 2

1

12

ix 70 70 70 70 70 70 70 70 70

stareofNEwYoRK COUNTY

NOTE*

DELAWARE DUTCBESS

State c&NORTH CAROIJNA BASIC WIND SPEEoMPm

12 1

ESSEX

12

70 70 70 70 ;

HAMILTON ;: iiiEi%J KINGS LIVINGSTON MADISON MONROE MONTGOMERY NASSAU NEW YORK NIAGARA ONEIDA ONONDAGA ONTiwO ORANGE ORLEANS 0swEGo OTSEGO F$ziir RENSSELAER RICHMOND ROCKLAND SAINTLAWRENCE SARATOGA ScBENEcI=ADY scHoHARIE SCHUYLER SENECA STEUBEN SUFFOLK SULLIVAN TIOGA TOMPKINS

2

2 2 1

12

2 2 2 2

2 2

1.2 kifizzk WASHMZTON WAYNE WESTCHESTER WYOMING Ym

2


ii 70 70 70 70 70 85 80 70 70 70 70 70 70 70 70 ii: 70 85 80 70 70 70 70 70 70 70 85 70 70 70 70 70 70 70 80 70 70

COUNTY

NOTE*

1

ANSON 1 1 2 2

AVERY BEAUFOIU BEKllE BLADEN BRUNSWICK BUNCOMBE BURKE CABARRUS CALDWELL CAMDEN

2" 1

2 .2

EitfEsF CMAWBA CHEROKEE CHOWS Ei%LAND COLUMBUS cm.. CUMBERLAND CURRIIUCK DARE DAVIDSON DAvlE DUPLIN DURHAM BDGECOMBE FORSYTH

2 2 2 2 2 2

2 2 2

GASTON iiiE?iM

9 L 1 2

iiisziw 2 iizis% HAYWOOD HENDERSON HEEZTFORD

HOKE HYDE IREDELL JACKSON

1 2 : 1

BASIC WIND -(MPH) 70 70 70 75 70 70 100 ii loo 70 70 70 70 100 110 70 70 70 70 95 70 70 95 loo 80 loo 110 70 70 95 75 80 70 75 70 90 70 70 85 70 80 75 70 70 85 75 110 70 70

State ofNORTH CAROLINA COUNTY

NOTE*

BASIC WIND SPEED0

JOHNSTON JONES

2 2

80 100

LENOIR LINCOLN MACON MADISON

2

iii 70 70 70 90 70 70 70 70

MCDOWELL MECKLENBURG MrrcHELL MONTGOMERY MOORE NASH NEwHANovER NORTHAMPTON ONSLOW

ORANGE

PAMLICO PAsQUOTANK PENDER PERQUIMANS PERSON PlTT POLK RAM>OLPH RICHMOND ROBESON ROCKINGHAM ROWAN RUTHEXFORD SAMPSON SCOTLAND STANLY STOKES suRRY SWAIN TFaNsYLvANIA

1 1 2

1 2 2 2 2 2 2 f 2

2

2 2

1 2

UNION VANCE WAKE WARREN WASBINGTON WMAUGA WAYNE WIUON YADIUN YANCEY

2 2 2 1 2 2 1


lli 105 80 100 70 105 95 100 95 70 90 70 70 75 80 70 70 70 85 80 70 70 70 70 70 loo 70 75 75 75 100 70 85 70 80 70 70

State of NORTH DAKOTA

I

COUNTY ADAMS BARNES BENSON BIKJNGS BOTTTNEAU BOWMAN BURKE BURLEIGH CASS CAVAWER DID DIVIDE DUNN EDDY EMMONS FOSTER GOLDENVALLEY GRAND FORKS EiZ BEITINGER KIDDER

LAMOURE LOGAN MCBENRY MCINTOSH MCKENZIE MCLEAN MERCER MORTON MOUNTRAlL NELSON OLIVER PEMBINA PIERCE RAMSEY RANSOM

NOTE* -.

BASICWIND SPEED0 80 ii 80 ii ifi 85 75 85 ; 80 80 80 ii 75 80 80 80 80 80 75 80 80 75 75 75 75 80 75 80 75

EiE STUTSMAN TOWNER

ii 75 90 75 90 75 80 80 80 80 80 75

WALSH

II;

RICHLAND ROLEI-IE SARGENT SHERIDAN SIOUX SLOPE

Stateo.f0BI0

State of NORTHDAKOTA COUNIY

NOTE*

BASIC WIND -0MpH)

COUNTY

state OfoBJo ADAMS ASHLAND ASHTABULA Al-HENS AUGLAQE BELMONT BROWN

70 75 70 70 70 70 70 70 70 70 70

1

EEL CHAMPAIGN EEEONT CLINTON COLUMBIANA COSHOaON cluwFoRD CUYAHOGA DARKE DEFiANCE DELAWARE

;:

70 70 70 70 70 70 75 70 70 70 70 70 75 70 70 70 70 70 75 70 70 75 70 70 70 70 70 70 70

1

1 FAIRFIELD FAYEiTE FiJITON GALLIA QAUGA

1

Es&Y HAMILTON HANCOCK %%!3N HENRY HIGHLAND HOCKING HOLMES BURON JACKSON JEFFERSON KNOX

1


16

BASIC WIND SPEED0

1

75 EtEi WILLIAMS

NOTE*

LICKING LOGAN limAIN LUCAS MADISON MAHONING MARION MEDINA MEIGS IbEEKER MONROE MONTGOMISY MORGAN MORROW MusKINGuM NOBLE O’ITAWA PAULDING PERRY PImWAY POWAGE PREBLE PUTNAM RIROSS SANDUSKY sclom SENECA SHELBY STARK TRUMBULL TUSCARAWAS UNION VANWERT VINTON WARREN WASHINGTON WAYNE WOOD WYANDOT

1

; 70 70 70 75 70 70 70 70 70 70 70 70 70 70 70 70 70 75 75 70 70 70 70 70 75 70 70 75 70 70 70 70 70 70 70 70 75 70 70 70 70 75 75 70

[ IA/ tln-A,A-r

stateofoKLAHoMA

state of OKLAHOMA

COIJNTY

NOTE*

BASIC WIND ~(MPH)

ADAJR ALFALFA ATOKA BEAKR BECKHAM EE CADDO CANADIAN tiiEE&E CHOClYAW CIMARRON COAL COMANCHE COT’IDN z CUSTER DELAWARE DEWEY

70 80 70 85 80 80 ii 80 70 70 70 85 75 70 80 80 70 70 80

IEFLORE LINCOLN LOGAN LOVE MAJOR MARSHALL MAYES MCUAIN MXUEEAIN MCINTOSH

;!I 80 80 70 75 80 80 80 80 70 70 80 75 70 75 80 80 70 70 75 75 70 80 70 70 75 70 70

*For notes. see end of Section

16

GARFED GARVIN GRADY

HARMON HARPER HASKELL HUGHES JACKSON JEFFEXON JOHNSTON KAY KINGFISHER KIOWA

NO-E*

COUNTY

BASIC WIND SPEEDWH) 70 70 75 70 70

MURRAY MUSKOGEE NOBLE NOWHA 0KFusKEE OKMHOMA OKMULGEE OSAGE OlTI’AWA PAWNEE PAYNE PIITSBURG FONTOTOC POnAWp;ToMIE PUSBMATAHA ROGER h4IUS ROGERS SEMINOLE SEQUOYM !TIEPBENS

;

75 70 75 75 70 70 70 70 80 70 70 70

iiz

80 70 70

iFi?LN TULSA WAGONER WASHINGlON WA’SHITA WOODS WOODWARD

ii

80 80

State of OREGON BAKER BENTON CLACKAMAS CLATSOP COLUMBIA coos CROOK CURRY DESCHUIES DOUGLAS GILLIAM

HOOD RIVER JACKSON JEFFERSON JOS=

1 1

70 80 80 95 80 80 70 85 70 80 70 70 70 80 80 70 80

1ltL l2A-d”- t

state dPENNsYLvm

State of OREGON COUNTY

NOTE*

BASIC WIND SPEEDCMP~

1 1 1

75 70 80 90 80

1 1

iii 70 80 80

LINCOLN MARION MORROW MULTN0MA.H POLK SHEEMAN ‘I’LLAMOOK UMATILLA UN-ION WAUOWA WASCO WASHINGTON

1 1

1

COUNTY FOREST l%lNKLm flEz!i HUNTINmN INDIANA JEFFERSON =A LXKAWANNA LANCASTER LAWRENCE LEBANON

ii! 70 70 70 70 80 70 80

NOTE* 2

2 2 2

EEEE LYCOMING MCKEAN MERCER MONROE MONTGOhIEEtY

2 2

MONTOUR State!0fPENNSYLVAMA *

ADAMS ALLEGHENY ARMSTRONG BEAVER BEDFORD BERKS BLAIR BRADFORD BUCKS BUILER CAMBRIA CAMERON CARBON CHESTER CLARION

a

2

2

2

2 2

CLINTON COLUMBIA CRAWFORD CUMBERLAND DAUPHtN DELAWARE

FAYEI-IE *For notes, see end

of Section 16

70 70 70 70 70 70 70 70 75 70 70 70 70 70 75 70 70 70 70 70 70 70 75 70 70 70

NO-N NORI'HUMBPERRY PBILADELPIHA POTIER SSNYDER SOMERsEr SULLIVAN SUSQUEEiANNA TIOGA UNION VENANGO WARREN WASI3IN~N WAYNE WESTMOW WYOMING YORK

2 2 2 2 2

2

2

BASIC WIND SPEED0 70 70 70 70 70 70 70 70 70 70 70 70 70 70. 70 70 70 70 70 75 70 70 70 70 75 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70

State of RHODE ISLAND . BRISTOL NEWPORT PROVIDENCE WASHINGTON

2 2 2 2 2

90 90 90 90 90

L

. .

“-12

‘

---,

State of SOUTH DAKOTA

State of SOUTH CAROLINA COUNTY

NOTE*

BASIC WIND SPEEDOLIPH)

ABBEVILLE AmENDALE ANDERSON BAMEERG BARNWELL BEAUFORT BERKELEY CALHOUN CHARLESTON CHEROKEE =zzLErD (3LARENDON COILEIDN DARLINGTON DILLON DORCHESTER EDGEFIELD FAIRFlELD FLORENCE GEORGErOWN =EiEii HAMPION HORRY JASPER KERSHAW LwcAslER LWRENS

75 2

ii 75 80 80 100 100 80 105 70 75 75 85 95

2 2 2 2 2 2

2 2 2 2 2 2

ii: 95 75

2 2

ifi no 70

2 2 2

ii 100 95 75 75 75 80 75 85 80 75 75 70 80 70 75 75 70 80 75 90 70

2 EXINGTON MARION MARLBORO MCCORMICK NEWBERRY OCONEE ORM’EEEIURG PICKENS RKHLAND SALUDA %“ANBURG SUMIER UNION WELIMSBURG YORK

2 2

2

2


16

NOTE*

COUNTY AURORA BEtiDLE BENNEIT BONHOMME BROOJUNGS BROWN BRULE BUFFALO BUITE CAMPBELL CZARLESMIX CLAY CODINmN CCIRSON CUSTER DAVISON DAY DEUELI DEWEY DOUGLAS EOMUNDS FALLRIVER FAUIK GREGORY WON HANSON HARDING HUGHES HUTCHINSON HYDE JACKSON JERAuJa JONES KINGSBURY LAWRENCE mcom LYMAN MARSHALL MCCOOK M-ON

BASIC WIND SPEEDW~

.

80 ii E 85 ii ii 85 90 80 80 85 90 90 ii ii 85 90 85 80 90 : 80 80 85 85 80 85 80 90 85 80 ii 90 85 80 80 80 85 85

State of SOUTH DAKOTA COUNTY

NOTE*


MOODY PENNINGTON PERKINS POTIER ROBERTS SANBORN SHANNON

COUNTY

NOTE*

85 ii ii 85 80

EtELY SUUY TODD

ifi 80

zizzl32 UNION WALWORIH YANK’IDN ZlEE3ACH

ii 85 85 80 85 80

GRUNDY HAMBLEN HAMRXON HANCOCK HARDEMAN HARDIN HAWKINS HAYWOOD HENDERSON HENRY BICEMAN HOUSTON HWPHREYS JA(xsON JEFFERSON JOBNSON KNOX

1 1

state of TENNESSEE ANDERSON BEDFORD

BENIDN BLEDSOE BLOUNT BRADLEY CAMPBELL CANNON CARROLL EiiEiAM CLAIBORNE E& COFFEE CROCKEIT CUMBERLAND DAVIDSON DECQUR DEKALB DICKSON DYER FAYEITE FENIRIS GIBSON


BASIC WIND SPEEDWH)

70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70

LAUDERDALE LAWRENCE LINCOLN LOtJ’DON MACON MADISON MARJON MARSHALL MAURY MChtlNN MCNAIRY MEIGS MONROE MONTGOMERY MOORE MORGAN OBION OVEFCON PERRY PICKEIT POLK PUTNAM ROANE ROBERTSON RUlHERFORD SCOTT SEQUATCHIE

1

70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70

I lA/

IzlA-‘---‘r

state of TENNESSEE

COUNTY

NOTE* 1

SSE sm STEWART SULLIVAN SUMBIER TIPTON TROUSDALE UNICOI UNION VANBUREN WARREN WASHINGTON WAYNE

BASIC WIND SpEEDoAm

corn

70 70 70 70 70

2 2 2

2

2

2

*For notes. seeend of Section 16

70 80 70 95 80 85 75 80 80 70 70 80 85 70 75 70 80 70 70 100 70 75 80 85 70 70 70

it

70 85 70 80 95

EiEERs -0KEE CHILDRESS

ii 75 80 80 75

EGERAN EzzimN COLIJN COILINGSWORZIH COLORADO COMAL ’ COMANCBE CONCH0 COOKE CORYELL co-mx

.

z CROSBY CULBERSON DALLAM DALLAS DAWSON DEWIIT DEAFSMlTH DELTA DlENToN DICKENS DIMMIT DoNmY DW& EASTLAND ECTOR mwARDs ELPMO EEI FMJS FANNIN FAYETTE FISHER

BASICWIND SPEED(MPR)

if

ZN CASS

state of TEXAS ANDERSON ANDREWS ANGELINA ARANSAS ARCHER ARMSTRONG M’ASCOSA AUSTIN BAILEY BANDER4 BASTROP BAYLOR BEE BELL BEXAR BLANC’0 BORDEN BOSQUE BOWIE BRAZORIA BRAZOS BREWSTER BRI!XOE BROOKS BROWN BURLESON BURNET

NOTE*

i!izEF iiIzEF

;: 70 70 70 70 70 70 70 70 70 70 70

SSON WILSON

StateOfTEXAS

I

2

2

ii 80 70 70 75 70 70 80 80 75 80 75 8s 70 80 80 80 70 70 80 75 ii 75 80 75 70 70 70 70 70 75 80

.

S~ofTExAS COuNlY FLOYD FOARD FORTBEND

NOTE*

zii%Eks GRAY GRAYSON izzz GUADALUPE

BASIC WIND -0

COUNTY

NOTE*

2

2

2 2

2

HAMILTON HANSFORD HARDEMAN HARDIN

HOCKLEY HOOD HOPKINS HOUSTON HOWARD HUDSPEI-H HUTCBINSON IRION JA(x JACKSON JASPER JEFFDAVIS -ON JIM HOGG JIMWELLS JOHNSON *For notes. see end of Section 16

KAUFMAN KENDALL KENEDY

ifi ml 80 70 80 85 75 80 70 70 75

HARRBON i.iEiE HAYS HEMPBILL HENDERSON HIDALGO

2

:i 90 70 70

it 80 70 85 80 90 90 iii 80 ii 70 80 70 80 70 70 70 80 70 70 85 75 75 90 80 75 100 80 80 70

BASIC WIND SEarIm 80

JONES

FREESTONE FRIO *EELON GARZA GILLESPIE GLAsscocK

StateClflEXAS

2

KIMBIX KlNG KLEBERG KNOX IASALLE i?EF LAMFASAS LAVACA

.

Ei 70 90

EON LTBERIY IJMESTONE LIPSCOMB LJVEOAK LLANO LOVING LUQBOCK LYNN MADISON MARION

z 80 70 75 iFi 70 ii 70 95

MASON MKAGORDA MAYERIcK MCCULLOCH MCLENNAN MCMUILEN MEDINA MENARD MIDLAm MILLS MlTcHELL MONTAGUE MONTGOMERY MOORE MORRIS MOTEY NACOGDOCHEZ NAVARRO NEWTON

;: 70 95 80 70 75 80 75 90 80 75 70 80 70

2

2

E 70 80 75 75 80 70 70 80 70 85 85 ii: 70 70 85

.

- - ---

- ----I

StateOf-XEXAS

stare OfTExAs

COUNTY

NOTE*

BASIC WIND =Em(MpH)

NOLAN ii 85 85 95 70

iiEEiEE OLDHAM ORANGE R4LoPlNTO PANOLA

;: 80

iitEi!z PECOS POLK

ii 85 75 70

ilEE EEIIL REAGAN

ii 75 70

EiTkvER iEE0 ROBERTS ROBERTSON ROCKWAu RUNNELS RUSK SABINE SANAUGUSTINE SAN JAQNTO SANPmuao SANSABA SCHLEICBER SCURRY SHAaELFORD SHELBY SHERMAN SMIIH soMERvELL STARR STEPHENS sTERLlNG STONEWALL SUITON SWISHER TARRANT TAYLOR

2

2 2

z 80 70 70 75 70 75 75 80 ;: 75 80 80 70 85 70

2

THROCKMORTON TTIUS *For notes. seeend of Section 16

;: 75 ;o" 75 85 70 80 75 80 80 70

NOTE” TOMGREEN IRAVIS

ii

2 2

EfF

BASIC WIND SPEmRvzpH)

iiEi!F WALDE v.VERDE v.ZANDT VImRIA WALllEE! WALER WARD WmGKlN

70 80 70 ii $ 90 75 ii

tZL3N WICHCI-A WILBARGER 2 XON WILSON

2

WOOD YaAKuM YOUNG ZAPm ZAVALA

a 90 80 80 80 95 70 75 80 70 70 80 75 75 75

state of UTAH BEAVER BOXELDER CACEIE CARBON DAGGEIT DAVIS DUCHESNE EMERY GARFIELD IRON iif& MORGAN

70 70 70 70 75 70 70 70 70 70 75 70 70 70 70 70

state of UTAH COUNTY

NOTE*

RICH SALTLAKE SANJUAN SINPETE

BASIC WIND sP=D(Mp)I) 75 70 70 70 70 70

EErr TOOELE UINTM UTAH WASAKH WASHlNGTON WAYNE WEBER

;i 70 70 75 70 70

state of VERMONT ADDISON BENNINGIQN CALEDONIA -EN ESSEX GIUNDISLE LAMOILLE ORANGE ORLEANS RUILAND WASHINGTON WINDHAM WINDSOR

70 1 1 1

1 1

:2”

;i 70 70 70 70 70 70 70 70 70 70 70

Stateof VIRGIN-IA ACCOMACK ALBEMARLE ALLEGHANY AMIIERST APPomox ARLlNGlTlN AUGUSTA B4Xl-H BEDFORD BLAND BOTETOURT BRUNSWICK BUCHANAN

COUNIY

NOTE*

2 1 2 2

1 2

*For notes. seeend of Section 16

95 70 70 70 70 70 70 70 70 70 70 70 75 70

2 : i 1 2 2

EELER CUMBERLAND DIQUZNSON DINWIDDIE ESSEX FAIRE! FAUQUIER FLOYD EWANNA

2 2 2 2 1 2

iiiiEi%

2

iZEkTER GOOCHLAND GRAYSON

: 2 1 2 2

iiiE%AE HALIFAX HANOVER HENRICO HENRY HIGHLAND ISLEOFWIGHI’ JAMESCITY KlNGANDQUEEh KINGGEORGE KINGWILLIAM LANCASTER EEDOUN LOUISA LUNENBURG MADISON MIWIEWS MECKLENBURG MJDDLESEX MONTGOMERY NELSON NEWKENT NO-N

: 2 2 2 2 2 2 2 2 2 2 2 1 2 2

BASIC WIND sPEEDt-h@m 70 70 75 70 80 70 z 70 70 70 70 ii z 70 70 70 $ 80 70 70 70 80 70 75 75 70 70 85 80 80 75 75 80 70 70 70 70 70 85 2 70 70 80 95

* *fi

&An-----,

State afWASHINGTON

State of VIRGINIA COUNTY

NOTE* 2

NOKI’HLMBW ORANGE NOTTOWAY PAGE PmCK mTTsYLvANL4 PowHmAN PRINCEEDWARD PRINCEGEORGE PRrNcEwILuAM PULASKI mPPAHANNocK RICHMOND ROANaCE ROCKBRIDGE ROCKINGHAM RUSSELL SCOTr SHENANDOAH SMYTH SO-N SPOTSYLVANIA STAFFORD SURRY SUSSEX TAZEWELL WARREN WASHINGT’ON WESTMORELAND tz%E YORK

BASIC WIND SPEED0 80

2

: 70 70

2

;8 70 80 70 70 70 80 70 70 70 70 70 70 70 80 70 70 80 80 70 70 70 75 70

2 2 : 2

2 2 2 2 2 2 2 1 2

85

State of WASHINGTON ADAMS ASOTIN BENTON Ei!ztYm

z&n4 COwLnz DOUGLAS LizELm

1

1 1

GARFIELD

GRAYSHARBOR

1

*Fur notes. see end of Section 16

COUNTY

70 70 70 100 70

75 70 90 70 70 70 70 70 100

-ON KING KlTsAP KmlTAs IcLKKrrisr

NOTE* 1 1 1 1 1

LINCOLN MASON OKANOGAN PACSFIC PENDOREILLE PIERCE SANJUAN SKAGIISNOHOMISH SPOKANE SEVENS THCJRSTON WAHKLXUM WALLAWALLA WHAKOM

BASIC WIND SPEEDWH) 80 100 80 85 70 70 80 70

1 1 1 1 1 1 1

1 1 1

zi 100 70 80 80 70 70 75 70 70 80 100 70 70 70 70

State of WEST VIRGINIA BARBOUR BERKELEY BOONE BRAXTON BROOKE CABEU CALHOUN CLAY DODDRIDGE FAYEI-IE GILMER GREENBluER HAMPSHIRE HANco(x HARDY HARRISON JACKSON JEFFERSON

2

2

70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70

State ofWIScONSIN

StateofwESTvIRGl.~~ COUNTY

NOTE*

KANAWHA

70 70

LINCOLN LOGAN WON MARSHAIL MASON MCDOWELL ilttE?i MING0 MONONGAIA MONROE MORGAN NICHOLAS OHIO =NDEIZT’ON PLEASANTS POCAHONliU PRESTON PUINAM RALEIGH RANDOLPH RlTcHIE ROANE SUMMERS TAYLOR TucKI

BASIC WIND spEED(MpH)

1

1

UPSHUR WAYNE WEBSTER

WOOD WYOMING

;: 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70 70

NOTE*

COUNIY CBIPPEWA

.

COLUMBIA CRAWFO~ DANE DODGE ERu

4B

1 1 1

CALuMEr *For notes. see end of Sea&m 16

90 75 80 75 90 75 80 90

ii 85 85 85

1 1

ii LFFLORENCE PONDDULAC FOREST

1

iELA.IE IOWA IRON JACKSON -ON

1

JUNEAU KENOSHA KEWAUNEE LA CROSSE LAPALANGLADE UNCOLN MANITowoc -ON

ii ii 85 80 ii iz

1 1

MARQUEITE MENOMINEE MILWAUKEE MONROE ocolvm ONEIDA OUTAGAMIE OZAUKEE PImcE POLK PORTAGE PRICE &mNE RIROCK RUSK SAINT CROIX

ii 80 85 85 80 85 85

1

1

1

State of WISCONSIN ADAMS AsHrAND BARRON BAYFIELD BROWN BURNEIT BUFFALO

BASIC WIND SPEED=

1

ii 85 90 90 80 85 90 80 90 So 80 80 75 90 ii: 85 80 ii

StateofWYOMNG

State of WISCONSIN COUNTY SAUK SAWYER SHAWANO SHEBOYGAN TAYLOR

NOTE*

85 1

TREMPEALEAU VERNON WLWORTH WASHBURN WASHINGTON WAUKE-SHA WAUPACA WAUSHAR4 WINNEBAGO WOOD

BASIC WIND spEED(Mpm

1 1

zl 85 80 80 85 ti 75 ii 90 90 90 90

BASIC WIND COUNTY ALBANY BIG HORN CAMPBELL CARBON t3mwRsE CROOK FREMONT GOSHEN HOT SPRINGS JOHNSON ImcoIJJ NAlRONA NIOBRARA PARK SHERIDAN SuBLElTE SwEErwAIER TETON iEzLKrE WESTON

NOTE* 1

SPEEDcMm

90 i!iE ii 80

85 85

ii!

*

85 75

1 1 1 1 1

E 80 90 85 80 80 75 75 85 80

.

References: 1. ASCE, ‘Minimum Design Loads for Buildings and Other Structures”, ASCE 7-88, American society of Civil Engineers, New York, NY, 1988. 2. MBMA, “Low Rise Building Systems Manual”, Metal Building &tmfacturers Association, Inc., Cleveland, Ohio, 1986. 3. UBC, “Unifmn Building Code”, International Conference of Building Officials, Whittier, CA 1988. Notes: 1. Site may be within a special wind region indicated on AXE 7-88 wind map.Check with local authorities before specifying basic wind speed. 2. County is within 100 miles from hurricane oceanline. Tabulated values of basic wind speed have been adjusted in accordance with AXE 7-88 to obtain 50-year recurrence intervals. 3. For locations not designated as a county, use basic wind speed for the closest county to the site. 4. The wind speedslisted in Section 16 are fastest-mile wind speeds.3-secondgust speedssuch as those contained in ASCE 7-95, and wind speeds averaged over other time periods, must be converted to fastest-mile wind speeds for use with this standard. (Refer to Annex A, Section 7’77)

ANNEX A: PURCHASER CHECKLIST ElM-IA-222 standards are intemkd to set minimum uitaia for the design, fabrication and ~o~~cth of antenna supporting stnrctures. It is the responsibility of the purchaser to provide Site-specific data and requirements differing from those contained in these standards. The following checklist is intended to alert the purchaser to the most common areas where specific data may be required. Reference Section

Purchaserchecklist

2.1.3

A. It is the responsibility of the purchaser to verify that the wind loads and design criteria specified meet the rquirements of the local building code. If other loading criteria are required, they shall be provided to the designer. B. This standard is basedon an allowable stressdesign (ASD) method. Therefore, the use of terms with an ambiguity in meaning and intent such as survival, shall withstand, etc. is not appropriate. C. Dividing the calculated wind pressure by a factor is considered inconsistent with this standard. See 2.1.3.1 for the proper definition of basic wind speed. 2.3.1.2 A. It is the responsibility of the purchaser to specify appropriate ice loads for locations where ice accumulation is known to occur. B. The standard does not specify ice-loading requirements since ice accumulation may vary subst~tially within a given geographical area. C. It is recommended that a rn,hhm. l/2 in. C12.7 mm] of solid radial ice be specified for locations where ice accumulation is known to occur. 2.3.3 A. For bidding purposes it is recommended that the purchaser specify the basic wind speed (V) to obtain designs based on identical criteria. Wind speedsspecified for use with the standard shall be fastest-mile wind speeds at 33 ft [lo m] above ground level. B. The basic wind speed from Section 16, the equations for the exposure coefficient (Kz), and the gust response factor (cH> are based on wind conditions in open, level country, and grasslands. C. The equations specified for Kz and G result in conswvative design wind loads for thm and wooded areas. D. It is the responsibility of the purchaser to specify basic wind speeds and appropriate equations for Kz and @ in hurricane, mountainous, and coastal areas, in the special wind regions indicated in Section 16 and where local conditions require special consideration. E. The purchaser shall identify the elevation of the base above average ground levei when the structure will be placed on another structure or on a hill or escarpment. F. The purchaser shall identify the relative elevations of the guy anchors with respect to the structure base and shall identify the maximum and minimum permissible guy radii. G. The basic wind speeds provided in Section 16 correspond to an annual probability of 0.02 (SO-year recurrence interval). If the purchaser requires another probability, the basic wind speed shall be provided to the designer.

I‘IA/EIA-‘/‘-I-

2.3.16 A. Due to the low probability that an extreme ice load will occur simultaneously with an cmeme wind load, wind load has been reduced 25 percent when considered to occur smm.baneously with ice (quivaient to 87 percent of the basic wind speed). B. For b&c wind speeds based on a 50-year recurrence interval (.02 annual probabi.Q),

the reduced wind load approximately corresponds to a 5-year recurrence interv~. C. It is the responsibility of the purchaser to specify other critical wind and ice loading

combinations for locations where mote severe conditions are known to occur. 5.1.1

A. Galvanizing is the preferred method of providing corrosion control. Alternate methods of cormion control, such BS epoxy paint, chlorinated latex paint, plating, elecuogdvanizing, etc., may be used only when specified by the purchaser. B. The pudmer shall specify the requirements of additional corrosion control systems when required. ( Refer to Annex J for corrosion control options for guy anchors in direct contact with soil.)

7.2.2

A. When standard foundations and anchors are utilized for a final design, it is the purchaser’s responsibility to verify by geotechnical investigation that actual site soil parameters equal or exceed normal soil parameters. If the purchaser elects to accept the normai soil foundation for construction, he accepts the responsibility and liability for the adequacy of the subsurface soil conditions. B. It is the responsibility of the purchaser to verify that the depths of standard foundations

are adequate based on the frost penetration and/or the zone of seasonal moisture variation. 7.2.3.2 A. The geOteCh&al engineer shall be informed of the provisions of this section.

11.2

A. The purchaser shall specify the operational requirements when the minimum standard does not apply.

12.2

A. The purchaser shall specify other grounding requirements for conditions where the minimum standard will not be adequate.

13.2.1 A. The purchaser shall specify requirements for climbing and working facilities, hand or _ -. . .. guardra% and climbing safety devices. 16

A. The purchaser is advised that the basic wind speeds listed in Section 16 are minimum values. Specific sites may have local extreme wind conditions that are more severethan the listed values. Topographical characteristics such as smooth terrain, bltis, ducting, mountain top exposure, and prevailing wind directions can significantly increase wind speeds. The purchaser is advised to consult local information sources such as the National Weather Service (NWS), local weather agencies, owners of existing towers at the same or nearby sites, local landowners, and consuking meteorologists.

TLVEIA-222-F

ANNEX B: DESIGN WIND LOAD ON TYPICAL MICROWAVE ANT~NAS/RJ~FLECTOR~ This Annex COnkns data for calculating the design wind load on typical microwave amen& reflectors. Wind-loading values have been compiled from a wide variety of sources. Some data are based on wind tunnel tests, and some are based on theoretical calculations. Precise antenna geometry may vaty between manufacturers, who should be consulted for data concemiitg their products.) mote:

Wmd force data presented in this annex for parabolic antennas (iucluding grid antennas) are described in the antenna axis system having the origin at the vertex of the reflector. The axial force PA.) acts along the axis of the antenna. The side force (Fs) acts perpendicular to the antenna axis in the phe of the antenna axis and the wind vector. ‘I’he twisting moment (M) acts in the plane cOn*g FA and Fs.. (See Figures B 1, B2, and B3.) For horn antennas, the origin is at the intersection of the vertical antenna axis with a plane tangent to the bottom of the boresight cylinder. The axial force FA acts parallel to the antenna boresight axis. The side force (Fs) acts perpendicular to FA in the plane 0fF~ and the wind vector. The twisting moment M acti in the plane containing FA and Fs. (See Figure B4.) For flat plate passive reflectors, the origin is at the cemroid of the plate area. The axial force FA acts along the normal to the plate. The side force (Fs) acts perpendicular to FA in the plane of FA and the wind vector. The twisting moment M acts in the plane containing FA and Fs, (See Figure BS.) In all c=es, the magnitudes of FA, Fs, and M depend on the dynamic pressure of the wind, the projected frmal area of the antenna, and the aerodynami.c characteristics of the antenna body. The aerodpdc characteristics vary with wind angle. The values of FA, Fs, and M shall be cakukted . from the following equations: FA = CA AKzGrrV2(lb)

Fs=Cs AKzeV2(1b)

M=CM

ADKz%V2(ft-lb)

Where: CA, Cs , and CM are the coefficients contained in Tables B 1 through B6 as a function of wind angle 0. Gl A

= Gust response factor from 23.4 = Outside aperture area (sq ft) of parabolic reflector, grid, or horn antenna 5 Plate area (sq ft) of passive reflector

D

= Outside diameter (ft) of paraboloid reflector, grid, or horn antenna = Width or length (ft) of passive reflector (see Figure B5)

V

= Basic wind speed (mph) fkrn 2.3.3 = Exposure coefficient from 2.3.3 with z equal to the height of the Origin of the axis system = Wind angle (deg); see Figures Bl through B5 for positive sign conventions

Kz 0

(Note: The coefficients described in Tables B 1 through B6 are presented in the customary system of units. When SI units are desired, the results of the above equations may be converted using the conversion factors provided in Annex G.)

Table BI. Wind Force Coefficients

WND ANGLE Q (DEG) 0 10 20 30 40 50 60 70 80

for Typical Paraboloid Without Radome

c,,

CA

.00397 .00394 .003% JO398 .OO408 .00426 AI0422 .00350 .00195

.ooooo -.00012 -JO013 -.00008 .oooo2 .00023 .00062 .00117 .00097

.OOOOOO -BOO065 -JO0097 -.000108 -.000137 -.000177 -JO0223 -.000020 JO0256

90 100 110 120 130 140 150 160 170

-.00003 -.00103 -.00118 -.00117 -.00120 -.00147 -.00198 -JO222 -.00242

.00088 .00098 .00106 .00117 .00120 JO114 .OOlOO BOO75 BOO37

BOO336 BOO338 .000343 .000366 .000374 BOO338 JO0278 .000214 .000130

180 190 200 210 220 230 240 250 260

-.00270 -.00242 -.00222 -.00198 -.00147 -.00120 -.00117 -.00118 -.00103

.ooooo -.00037 -BOO75 -.OOlOO -.00114 -.00120 -.00117 -.00106 -BOO98

.oooooo -.000130 -.0002 14 -.000278 -AI00338 -Al00374 -AI00366 -ho343 -BOO338

270 280 290 300 310 320 330 340 350

-.00003 .00195 .00350 xl0422 .00426 AI0408 JO398 .00396 AI0394

-.00088 -.00097 -.00117 -JO062 -BOO23 -.00002 JO008 .00013 .00012

-BOO336 -.000256 .000020 .000223 .000177 BOO137 .000108 .000097 .000065

Table B2. Wind Force Coefficients for Typical Paraboloid With Radome a

WIND ANGLE 0 @EG)

CA

aoooo

.ooooO -.ooo204 400285

0 10 20 30 40 50 60 70 80

.00221 .00220 .00210 .00195 .00170 .00140 .00107 .00080 JO058

.00038 JO076 DO105 SKI125 .OD136 .00128 .00118 .00112

-JO0277 -.Ooo205 -.ooo114 -.OoOOo2 .m130 .000268

90 100 110 120 130 140 150 160 170

AI0034 .00008 -.00017 -.00042 -.00075 -.00105 -.00133 -.oo 154 -.00168

.OOlCM .OOlOO JO095 .00089 .00082 .00078 .00070 .00058 .00038

.000390 .000434 .ooo422 .ooo4o4 .000357 JO0232 JO0132 AIOOO63 .000022

180 190 200 210 220 230 240 250 260

-.00177 A.00168 -.oo 154 -.oo 133 -.00105 -.00075 -.00042 -.00017 .00008

.ooooO -.00038 -.00058 -.00070 -.00078 -.00082 40089 -.OOO95 -.OOlOO

.oooooO -.000022 -.oOOO63 -A?00132 -.000232 -JO0357 -.w -AI00422 -.000434

270 280 290 300 310 320 330 340 350

.00034 .00058 .00080 AI0107 .00140 .00170 .00195 .00210 .00220

-.00104 -Do1 12 -.00118 -00128 -JO136 -.00125 -.00105 :.OOO76 -JO038

-.000390 -A?00268 -.000130 AKNlOo2 Am0114 JO0205 .000277 AM0285 mO204

* *cad

LI‘3-----,~

Table B3.Wind Force Coeffkients

for Typical Paraboloid With Cyiindrical

‘WIND ANGLE Q (DEG) 0 10 20 30 40 50 60 70 80

.00323 SKI323 JO320 .OO310 .00296 SKI278 AI0242 .00172 .00070

.OOOOO BOO25 AI0045 .ooo6o JO072 .00078 .ooo94 .00122 JO149

.oooooo -.000072 -.000116 -.000133 -.000125 -.000083 -.oOOO22 .000058 JO0178

120 130 140 150 160 170

-JO028 -.00088 -At0138 -JO182 -.00220 -.00239 -.00245 -.00249 -.00255

.00160 .00154 Al0136 .00112 .00080 AI0059 JO045 .00038 40025

AI00251 Al00288 .000292 .000266 AI00237 .000199 .000158 .000112 .000059

180 190 200 210 220 230 240 250 260

-.00260 -Al0255 -Al0249 -XI0245 -.00239 -.00220 -.00182 -XI0138 -.00088

.OOOOO -JO025 -JO038 -.00045 -.ooo59 -JO080 -.OOl i2 -JO136 -AI0154

.oooooo -.000059 -.000112 -.000158 -.OOo199 -JO0237 -JO0266 -.ooo292 -AI00288

270 280 290 300 310 320 330 340 350

-AI0028 .00070 JO172 AI0242 AI0278 .00296 .003 10 .00320 MI323

-.00160 -AI0149 -.00122 40094 -.00078 -.00072 -.00060 -.00045 -BOO25

-.000251 -.ooO178 -.000058 moo22 .000083 .000125 .000133 XI001 16 .000072

90 100 110

Shroud

Table B4. Wi.& F orce Coefficients for Typical Grid Antenna Without Ice

WIND ANGLE 63@EG) 0 10 20 30 40 50 60 70 80

CA

xl0137 .00134 .00130 .00118 .OOlO4 Jo088 .00060 .00033 .OOOlO

.ooooO .ooo26 .ooo46 .ooo59 .00067 .00070 .00072 .ooo70 .ooo64

.bOOOO .oOOO43 .oooO74 .000098 .000115 MO127 JO0135 DO0142 .000126

JO062 .00070 .ooo73 .ooo71 .00067 .00060 Al0052 .00040 .ooo22

.000111 .000120 .000129 .000131 .000127 .000114 .000095 .000070 .000038

90 100 110 120 130 140 150 160 170

-.00013 -.00030 -JO048 -.00068 -JO086 -.00104 -.00122 -.00140 -.00150

180 190 200 210 220 230 240 250 260

-.OO152 -.ilolSO -Ml140 -.oo 122 -Al0104 -JO086 -.00068 -JO048 -.00030

AMob -.ooo22 -.ooo40 -.00052 -JO060 -JO067 -.00071 &IO73 -.00070

.OOOOOO -.000038 -.000070 -.000095 . -.000114 -Al00127 -.000131 -JO0129 -.000120

270 280 290 300 310 320 330 340 350

-JO013 .OOOlO JO033 .00060 MO88 .00104 JO118 .00130 .00134

-.ooO62 -.ooo64 -.00070 -JO072 -.00070 -Al0067 -Al0059 -.ooo46 -JO026

-.000111 -.000126 -.000142 -AM0135 -.000127 -.000115 -.000098 -.000074 -.000043

Note: ln the absence of more accurate data for a grid antexma with ice, use wind force coefficients for typical paraboloid without radome from Table B 1.

Table B5. Wind Force Coefficients

for Typical Conical Horn Reflector Antenna

WIND ANGLE 0 (DEG) 0 10 20 30 40 50 60 70 80

cq .00338 .00355 JO354 Al0345 JO335 .00299 .00235 DO154 .00059

.ooooO .oooo4 DO025

aoooo

BOO77 .00142 .00181 .00208 .00237 JO248

-.00005 -.00007 -.OOOOl .OoOO9 .ooo23 JO035 .ooo44 mm46 .00040 BOO32 .00030 DO032 BOO27 .00021 .00014 .00007 .00003

90 100 110 120 130 140 150 160 170

-.00020 -AI0062 -.00088 -.00147 -JO225 -JO289 -AI0323 -AI0367 -.00375

.00245 .00240 .00235 .00225 AI0201 .00167 .00113 .00052 .OOOlO

180 190 200 210 220 230 240 250 260

-JO356 -.00375 -.00367 -.00323 -JO289 -AI0225 -.00147 -.00088 -BOO62

.ooooo -.OOOlO -JO052 -.00113 -.OO167 -AI0201 -.00225 -.00235 -.OO240

.ooooo -.00003 -.00007 -.00014 -.00021 -.00027 -.00032 -.00030 -.00032

270 280 290 300 310 320 330 340 350

-.00020 .00059 JO154 .00235 JO299 JO335 .00345 .00354 .00355

-AI0245 -AI0248 -AI0237 -.00208 -.00181 -.00142 -.00077 -.ooo25 -.00004

-.00040 -.ooo46 -.ooo44 -BOO35 -40023 -.00009 .00001 .00007 .00005

Table BG.Wi.nd Force Coefficients for Typical Passive Reflector WIND ANGLE WDW

- CA

cs .ooooo

.OOOOOO -.000077 -AI00134 -.000180 -AI00198 -JO0208 -.QOO262 -.ooo225 -.000129

0 10 20 30 40 50 60 70 80

JO35 1 .00348 .00341 .00329 .00309 .00300 .00282 AI0178 .0007 1

90 100 110 120 130 140 150 160 170

-.ooo 10 -.00108 -.00235 -.00348 -JO348 -Al0360 -.00376 -.00390 -.00400

.00030 a0035 .ooo39 BOO36 .ooo29 40023 a0019 .00012 .00008

.000030 .000180 .000225 ,000210 DO0148 DO0126 .000109 .000080 .000042

180 190 200 210 220 230 240 250 260

-.00403 -.00400 -.00390 -.00376 -.00360 -AI0348 -.00348 -.00235 -.00108

.OOOOO -.00008 -.00012 -.00019 -.00023 -.ooo29 -JO036 -.00039 -.00035

.oooooo -.000042 -.000080 -.000109 -.OOO126 -.OOO148 -.000210 -.bOo225 -JO0180

270 280 290 300 310 320 330 340 350

-.OOOlO .0007 1 AI0178 .00282 .00300 .00309 Al0329 a034 1 .00348

-.00030 -BOO27 -JO023 -JO021 -.00018 -AI0013 -.00010 7-.OOOO8 -.00003

-.000030 .000129 .000225 JO0262 .000208 .000198 .OOO180 .oOO134 .000077

.00003 .00008 .OOOlO .00013 JO018 .00021 .ooo23 .00027

TIAEJA-222-F

Wind Angle

r

Wind

Top View Positive Sign Convention Figure B 1. Wind Forces on Paraboloids and Grids

fl

Wind Angle

Top View Positive Sign Convention Figure B2. Wind Forces on Paraboloids With Radomes

Top View Positive Sign Convention Figure B3. Wind Forces on Paraboloids With Cylindrical Shrouds

.

Side Elev.

Top View

Angie

I Fs

Wind

Figure B4. Wind Forces on Conical Horn Reflector Antennas

0 = Horizontal Wmd Angle D = Width of Reflector (A) PLATE VERTICAL

(SIDE VIEW) 0 = Vertical Plate Angle D = Length of Reflector (Horizontal Wind Angle = 0 or 180 Deg Only) (B) PLATE TILTED

Figure B5. Wind Forces on Flat Plate Passive Reflectors

TLVEIA-222-F

ANNEX c: TABLE OF ALLOWABLE TWIST AND SWAY VALUES FOR PARABOLIC ANTENNAS, PASSIVE REFLECTORS, AND PERISCOPE SYSTEM REFLECTORS A

B

3dE

BCSII WgirQ

DCflCZIiOfl

Angie A;,”

Antenna OdY Note 8

Note 1 Note7

Len,l&lit&

Antenna

SlnJcture

Fhssivc

Movement with *ea

Movement Twistof Sway at Antenna Attachment Felt

stn~ture

DJZFLEE.S DEGREES

F

C D parabolic Asnemas Limitof Limit of

DEGREES

iii

ii

:5

ii

E

ti

ti

$78

ifi 2.6

ii

4.0 i:!

1.9 1.8 1.7

i: 3:1

2i

iii 1.9 1.8 1.7

ii 0.2

S:Z

:;” 1.4

ii 20 19 1.8 1.8

:4 1.45 1.4 1.35 1.3

0”;

t:

::

if

i::

tS”

:I

4.4 4.6

0.4 0:4

4i 4.0

:; i4

4.0 42

03 0.4

2’:;

21:; ::A

iI

0”; :;

2”:

25

i4

22; 2J 2.4

2i s-i

iI2 %

2”; 22

2.0 2.1 1.9

8:

ii

1.7 1.8

02 8:

1.4 :;”

82

1.5 1.4 1.3 1.2 1.1 0.9 i-7” i6

1.3 12 :i

i:: X::

0:9 i:; 8;”

0”:: 0.1 2

0.5

0.4

if: 0:1

z 22

::

i-F ok

t :

1.4 ::

1.1 1.0

0.8 0.75

0.1 0.1

1.5 ::‘:

12 1.1 1.0

iii

8:L

8::

ii;

E5

iI;

ii:

::5

0.7

05

x;”

E 0.1

:::

:: 0:1 0.1 iI:

ifi Oi5

ii 0:3

ii-f5 02 0:07 i-f4

k 0:1 0.95 0.9 0.85 0.8 0.75 0.7 0.65 iii5

::

:: io

iI:5

::

iii

ii5 0.3

0.1 iii5 ii5

i-k 1:2 1.15

0.1 :f 1.15 1.1

:;6

0:1 8f5

:-: lI5 1.4 :4

::;

zli i..9 1.8 1.7 1.6

:-; 1:7

:-; 1:6

.

1.7 ill

z

A!!1 hint

iis

:J

33::

*Ft

kg2

22

i-i

3’::

struTwistat

DEGREES DEGREES DBGREBS DEGREES DEGREES DEGREES

i-i

:: 0:3 2

I+iEzzt Rigct Stll!LR%

ii

4.2 4.0 ;4

h!iSiVC

Reector nviat Note4

Ibfkcmc S-Y Note4 Nooe5

i::

3.8 E

-of

I H Paiscope system Refkmfs ualitof Limitof Limitof G

0”::

::i 8::

i-i7 0:05

&

82 0.15 0.10 0.13

0.05 0:1 OdY fOr c0nfiilion where anunna is dirmly under the nflecmr. ’ I

NOTE:

See Notes On Following page.

rl)

TIAEIA-222~

Notes: a

1. If whes for columns “A” and “B” are not available from the manufacturer (s) of the antenna system or from the user of the antenna system then values &ail be obtained fkom Figure CL c2, or c3. 2.

Iimh of beta-nmovement for twist or sway (treated separatiy inmost anaiyses) will be the sum of the appropriate figures in CO~UIIIIS C 9; b, G & H.-and G-&zL c-ohm&G, k & L appiY to a Vertical periscope configuration.

3. It is not intended that the values in this table imply an accuracy of beam width determination or SbuCtud rigidity calculation beyond known practicable values and computational procedures. For most microwave structures it is not practid to require a calculated structural rigidity of less than 114 degree twist or sway with a 50 mi/h (22.4 III/S) Basic Wind Speed. 4. For passive reflectors the allowable twist and sway values are assumed to incbrde the effects of all members contributing to the rotation of the face under wind load. For passives not elevated far above ground (approximately 5 to 20 feet (1.5 to 6 m) clearance above ground) the stmcm.re and reflecting face supporting elements are considered an integral unit. Therefore, separating the structure portion of the defiection is only meaningful when passives are mounted on conventional microwave structures. 5. The allowable sway for passive reflectors is considered to be 1.4 times the allowable twist to account for the,amount of rotation of the face about a horizontal axis through the face center and paraki to the face compared to the amount of beam rotation along the direction of the path as it deviates from the plane of the incident and reflected beam axis. 6. Linear horizontal movement of antennas and reflectors in the amount experienced for properly designed microwave antenna system support structures is not considered a problem (no significant signal degradation atttibuted to this movement). 7. For systems using a frequency of 450 MHz, the half power beam widths may be nearly 2 @ degrees for some antennas. However, structures designed for microwave relay systems will usud.ly have an inherent rigidity less than the maximum 5 degree deflection angle shown on the chart. 8. The 3 dB beam widths, 2 0 HP in column “A” are shown for convenient reference to mamrfacmrers’ published antenna information. The minimum deflection reference for this standard is the allowable total deflection aneie Q at the 10 d.B

TIAEIA-222-F

R=w@= ‘TV or ‘Tr (feet) 10. 6%. i

sm. 40.

a.

-

me

20. --

7.8

IS. 6.0 s.e 10. 4.0

9.8 6.8 7.0

2.8

6.8 s.n -

f

6.8

4.0

6.e

1.S

10.

3.0

f + i

Flatface~m -on

2.0

1.s ~

lmifaml amplialde

’ Planor elevation of flat face dkCt0rS

Note:Fortherotatiun.u of thenaectorabout INS=ner. the defktion beam angie 0. may vary hm l pO2u~accordancewiththe~sys~gFameay. .

--w

e=.$& l-l Rectanguiar~squareapemrre HiHVaFetheprojected dimens~alongthebe~path

NOMOGRAPH, DEFLECTION ANGLE, 8 AT 10 dI3 POINTS FOR RIxT.GUUR APERTLJRE (FLAT FACE REFLECTOR) Figure Cl

cIircu& Paraboia

(degrees) .10

(E) m.0 .2a IS.8

30

--

-40 .m 18.8 9.8

.m

~

1.8

0.0 7.0 6.0 s.0

4.0

--

T

I

6.6

2.6

S.8

3.8 4.8

v

.

4.8

3.0

3.0

2.6

2.6

1.s

1.S

1.0.f

Parabolic nzflector 1odBtapr

Circniar apemm NOMOGRAPH. NOMINAL BEAM WlD-lH 3dBPOINrs (TYPICAL PARABOlXXEFLECI.OR~

Figure C2

i

1.8

l+YirF 30.0 20.8

i

tS.a

10.8 --& 9.8 8.0 z

7.8

s

5.8 6.0 4.8

6.8

f

3.0

Tv

2.8

i

s.0 4.8

Q

1.5

*

-L

7.8

. 2.0

1.s

1.0

--

-

Parabolic reflecror lOdEhap 60 ?L Q’T circular aperture

-

beamnorm2laxis

Plan or elevation of parabola

NOMOGIUPH - DEFLECI’ION ANGIE ~1OdBPOINTSFORCIRCULAR~ (PARABOLIC SURFACE coNTouR)

Figure C3

0

1.0

(LEFTBUNK

lNTENTIONALLY)

IWEIA-222-F

ANNEXD:

DETERMINATIONOFALLOWABLEBEAMTWISTANDSWAY LlMrrED SYSTEMS CROSS-POLARIZATION

A dual polarized antenna has a pa-

FOR

either Em Dl and D2. For most offset antennas the moss-polarized null is &p as shown in Figure Dl; for most center-fed antennasthe cross-polarized null is shallow and the envelope is as shown in Figure D2. In either case,as ~00x1as the antenna is deflected fhm its normal pi&~ the cross-polarization disuiminatioa XPD (the difference bemmn the co-polarized si@ 8IIcI the.c~~~~-p~latized signal), decreases. m

&at

&own

in

Where on-path cross-polarization &mation is critical to system pesformance, allowable beam ddkction 8 should be determined as shown in Figure Dl or D2. For &set-fed antennas,indUd@ horn reflector antennas,8 will determine twist only and the antennabeam width will determine sway. For center-fedantennas,8 will determine both tit and sway.

a

--..w.. .--,

Figure D 1. Offset Fed Antenna

‘3 .* 0L

t

TIAEiA-222-F

Table D 1. Table of Allowable Twist and Sway for fiOSS-pO~tiOn Lhhd SYSAllowable Twist For Offset-Fed htennas. Allowable Twist and Sway For CMter-Fed Allowable Sway Foaoffset-&d Anmnas

Beam Twist or Sway For crossPolarizatim Limited sys-

Movement with Respect To Structure

Movement at Antfznna Atcachmeat P&t

DEGREES

DEGREES

i-: 0:3 0.2 0.1 ii-:

607 0.06 0.05 0.04 0.03 0.02 0.01

E

i D C Limitof 3dB SkUCture BeamWidth

32 2:7 i:: 0.81 0.72 0.63 0.54 0.45 0.36 0.27 0.18 0.09

AtlOdB PhIUS

DEGREES 5.8 5.6 5.4 5.1 4.9 4.7 4.4 42 ;; 3’5 3% 3.1 iii 2.8 2.7 2.6 25 23 if 20 1.9 1.7 1.6 15 1.4 1.3 12 1.1 0.9 ii-; i6 05 0.3 02 0.1

Note: See Notes on Following Page.

z-

2QHP Par -MY

5.0 4.8 4.6 4.4 4.2 4.0 ;:: .

F

4

G

Limited SkllCt’Xe Sway 2tAxlmu Attachment Poillt DEG= 4.6 4.4 42 4.0 3.8 3’;’

i:;

;3 2:9

2:

;;

;; 2.6 25

i=.=. 24

ki

ii 2.1 2.0 1.9 1.8 1.7 1.6 15 1.4 13 12 12 1.1 1.0 0.9 0.8

ii!

ii2

ii: 0.4 0.3 0.2 0.1

El O> 025

Ei 2.2 2.1 2.0 1.9 1.8 1.7 1.6 1.5 1.4 1.3 13 1.1

Notes: *

1. If values for columns “II” and ‘Y of the swaytable and column “A” of the twist table are not available from the manufacturer (s) of the arnennasystem or from the user of the antenna system then values shall be obtained from Figure C2, or C3. 2. Limits of beam movement for twist or sway (treated separately in most analyses) sre the sum of the appropriate figures in columns 9” and T” of the twist table and the sum of the appropriate figures in columns “F” and ‘%,, of the sway table. 3. Linear horizontal movement of antennas and refiectoxs in the amount experienced for properly designed microwave antenna system support structures is not considered a problem (no significant signal degradation attributed to this movement). 4. The 3 dB beam widths, 2 9 HP in cohuun “ID” are shown for convenient refmen- to manufacturers’ standard published antenna information. The minimum deflection reference for this standard is the allowable total deflection angle 0 at the 10 dB points. 5. The values shown in this table depict angular deflections in two orthogonal planes no& to the boresight direction: vertical elevation (sway) aud horizontal azimuth (twist). No allowance has been made for initial offsets due to mount skew, installation tolerances, paths not normal to the suppon structures, etc. Special considerations will be required in those cases. 6. It is not intended that the values on this table imply an accuracy of beam width determination or ~buctural rigidity calculation beyond known practicable values and computational procedures. For most microwave structures it is not practicable to require a calculated structural rigidity of less than l/4 degree twist or sway with a 50 mi/h (22.4 m/s) Basic Wind Speed.

.

1INEIA-222-F

-I&V.&IA-2X-F

ANNEX E: TOWER MMJWE&MCE Of towers shadd perform zw

&mXs

and p&dic

AND JNSPECTION PROCEDURES tower inspection and rnaintenanCeto assure

safety ami to extend s&m life. It k recommended that major inspections be performed, at a -Urn, every 3 years for myed towers and every 5 years for self-supporting tOWeS see section 14. Ground and aerial procedures shodd be p&omxxi only by authkized personnel, experienced in c&bins and tower adjustments. SOme Ofthe items listed below may apply only to initial cmstmction I.

of new towers.

Tower Conditions (guyed and self-supporting) A. Members 1. Bent members (legs and lacing) 2. Loose members 3.

Missing members

4.

Chding

facilities, platforms, catwalks - all secure

5. Loose and/or missing bolts B. Finish 1. Paint and/or galvanizing condition 2.

Rust and/or corrosion conditions

3. FAA or ICAO color marking conditions

. *

4. Water collection in members (to be remedied, e.g., unplug drain holes, etc.1 C. Lighting 1. Conduit, junction boxes, and fasteners weather tight and secmc 2. lhins

and vents open

3. Wiring Condition 4. Controllers functioning a. Flasher b. Photo control c. Alams 5. Light lenses 6. Bulb condition (Option: change all bulbs at one time) D. Grounding 1. Connections checked and secure

2. Corrosion observed and remedied 3. Lightning protection secure (as required) E. Tower Base Foundation 1. Ground Conditions a. Settlements or movements b. Erosion c. Site condition (standing water, drainage, trees, etc.1 2. Base condition a. Nuts and lock nuts tight b. Grout condition 3. Concrete Condition a. Cracking, spalling, or splitting b. Chipped or broken concrete C. Honeycombing

d. Low Spots to collect moisture e. Anchor-bolt corrosion F. Tower Assembly Profile (See Figures El and E2) 1. Antennas and feedlines (e&h) a. Frequency b. Elevation c. Type d. Size e. Manufacturer f.

Connectors and hangers

2. Optional appurtenances (walkways, platforms. sensors, floodlights, etc.) a. Elevation b. Arrangement c. Drawings or sketches 3. Foundation and anchors a. Plan b. Elevations (relative or true)

c. Size d. Depths e. Soil type (if known or necessary)

G. Tower Alignment (See Figures E3, E6, and E7) 1. ‘bmr

Plumb and l’kvist (See 6.1.2.1 and 6.1.2.2)

H. Insulators (As Reqtied) 1. Insulator Condition a. Cracking and chipping b. Cleanliness of insulators C.

Spark gaps set properly

d. Isolation transformer condition e. Bolts and connections secure f.

Manufacturer type and part numbers for future rephmms

II. Guyed Towers A. Anchors 1. Settlement, movement or earth cracks 2. Backfill heaped over concrete for water shedding 3. Anchor rod condition below earth (Maintain required structural capacity of anchor during exploration, inspection and maintenance. Attachment to temporary anchorage may be required.) 4. Corrosion control measures (galvanizing, coatings, concrete encasement, cathodic protection systems, etc., refer to Annex J.) 5. Grounding (Paragraph I-D) 6. Anchor head clear of earth B. Tower Guys (see Figures E4 and E5) 1. Strand a. Type (1x7 EHS, 1x19 bridge strand, etc.) b. Size c. Breaking strength d. Elevation e. Condition (corrosion, breaks, nicks, kinks, etc.) 2. Guy Hardware

TIAEIA-222-F

a. Turnbuckles (or equivalent) secure and safety properly applied b. Cable thimbles properly in place (if required) c. Service sleeves properiy in place (if required) d. Cable connectors (end fittings) i.

Cable clamps applied properly and bolts tight

ii. Preformed wraps - properly applied, fully wrapped, and sleeve in piace iii. Wire serving proPerly applied iv. Strandvices secure v. Poured sockets secure and showing no separation (Note: Connectors should show no signs of damaged cable or slippage.) e. Shackles, bolts, pins, and cotter pins secure and in good condition. 3. Guy Tensions a. Tension should be compared to design requirement. b. Tensions should be checked by acceptable methods (see Section IV and Figures Eg, E9, and ElO) C.

Notes:

Record tensions and weather conditions on attached charts (see Figures E4 and a) .

1) Variations in guy tensions are to be expected due to temperature and wind. These are minor variations. Should there be significant tension changes, the cause should be determined immediately and proper remedial action taken.’ Possible causes may be initial construction loosening, extreme wind or ice, anchor movements, base settlement, or connection slippage. 2) Tension variations at a single level are to be expected because of anchor elevation differences, construction deviations, and wind effects. Caution: DO not check or adjust guy

tensions

during times of excessive winds.

III. Antennas and Feedlines A. Antenna Mounts and Antennas 1. Members (mounting and stabilizing) a. Bent, broken, or cracked b. Loose c. Missing d. Loose and/or missing bolts 2. Adjustments secure and locked

3. Elements a. Bent, broken, cracked or bullet damaged b. Loose c. Missing d. Loose and/or missing fasteners 4. Corrosion condition 5. Radomes and/or cover conditions B. Feed Lines (waveguide, coax, etc.) 1. Hangers and supports a. Condition b. Quality c. Corrosion condition 2.

Flanges and seals (check integrity)

3. Line Condition a. Dents b. Abrasions c. Holes d. Leaks e. Jacket condition 4. Grounds a. Top ground strap bonded both ends b. Bottom ground strap bonded both ends 5. Feedline support (ice shields) a. Properly attached b. Loose and/or missing bolts c. Members straight and undamaged

TIAGIA-ZZZ-F

TOWER ELEVATION Show the following: -

Tower Height above ground Location of antennas

-

Figure El

Location of feed lines Location of platforms, ladders, etc.

TIA/EL4-222-1:

PLOT PLAN Show the following: -

-

Tower layout relative to North Anchors and assign letter designation

-

Relative or tme anchor and base elevations

Access roads and buildings Power lines and poles

.

Figure E2 --

TOWER LEG VERTICAL a

ALIGNMENT

1. Check with transit. %o transit setups are required Line transit paraiki to one face ad center on leg. Second setup should be at 90” on same leg. Show on sketch below the locations used for transit setup. Indicate North.

SelfSupporting EIevations

Guy Level Top to Bottom

Left

Transit #l Tower Lays 0 Right

-amit #2 Tower Lays Left 0

Cantilever Structure 1000’

10

--

900’

9

--

800’

8

--

700’

7

--

600’

6

500’

5

--

400’

4

--

300’

3

--

200’

2

100’

1

--

Approximate wind speed during measurements

mph

Note: This procedure is not sufficient to determine both twist and out of plumb. See Figures E6 and E7.

Figure E3

Right

S-WAY GUYED TOWER 0

Guy Leg B iGuy Leg B

Figure E4

I

I

I

6 5 4 3 2 1

I I

I I

I I

I I

. __---.

---

-

4-WAY GUYED TOWER

Guy Leg B

Note: See Note 2, Section II for details regarding guy tension checks. Data: Date TempIce -

Figure E5

Time Wind-

d=(Dl +D2+D3+04)/4 a = amin

(e)

x=(D2-D4)/2 g=(DI -D3)/2

OBSERVED

MASTDATA

CALmTED I

I

cflmJL4m OUT-OF-PLUMB

Figure I%. Twist and Out-of-Plumb Determination for Square Towers

I

ATION FOR TRTANGUUJRIOl-JIST- AND OUT-OF-PLUMBDETERMlN

d=(Dl+D2+03)/

3

e = (dfi)/A

a = u&n (e) I: = (D243)/fi p=(2xDl

Figure E7. Twist and Out-of-plumb

Detexminath

-D2-D3)/3

for Triangular Towers

IV.

Methods For Measuring Guy Initial Tensions There are two basic methods of measuring guy initial tensions in the field: the direct method and the indirect method. A. The Dimt Method (see Figure E8) A dynamometer (load cell) with a length adjustment device, such as a come-along is attached to the guy system by &mpmg onto the guy just above the turnbuckle and onto the anchor shaft below the turnbuckle, thus making the turnbuckle redundant. . The come-along is then tightened until the original turnbuckle begins to slacken. At this point the dynamometer carries all of the guy load to the anchor, and the guy tension be read directly off the dynamometer dial. may

One may use this method to set the correct tension by adjusting the come-along tumJ the proper tension is read on the dynamometer. lI,vo control points are marked, one above the clamping point on the guy and one on the anchor shaft, and the control length is measured. The dynamometer and come-along are then removed, and the original tu.rnbuckle is adjusted to maintain the control length previously measured. B. The Mhxt

Method (see Figures ES and E9)

There are two Common techniques for the indirect measurement of guy initial tensions: the pulse or swing method (vibration) (Figure E8) and the tangent intercept or sag method (geometry) (Figure E9). 1. The Pulse Method (see Figures E8 and EiO) One sharp jerk is applied to the guy cable near its connection to the anchor causing a pdse or wave to travel up and down the cable. On the fust return of the pulse to the lower end of the guy cable the stop watch is started. A number of returns of the pulse to the anchor are then timed, and the guy tension is calculated from the following equations: TM = YLE

8.05P2

(1)

1lAWA-222-F

in which (seeFigure El@ TA = Guy tension at anchor (lb) TM = Guy tension at mid-guy (lb) W = Total weight of guy, including ins-, L = Guy chord length (ft)

etc. (lb)

L=jrn

8)

V = Vertical distance from guy attachment on tower to guy attachment at anchor(fi) H = Horizontal distance from guy attachment cmtower to guy attachment at anchor (ft> N = Number of pulses or swings counted in P secd~ P = Period of time measured for N pulses or swings (s) Instead of creating a p&e that travels up and down the guy, one may achieve the same result by causing the guy cable to swing freely fkom side to side while timing N complete swings. The formulas given above wilI aiso apply fix this approach. 2. The Tangent Intercept Method (see Figure E9) A line of sight ik established which is tangential to the guy cable near the anchor end and which intersects the tower leg a distance (tangent intercept) below the guy attachment point on the mast. Th& tangent intercept distance is either measured or estimatedand the tension is &cu.&d kom the following equation: . WCJiiTyiq ’ TA =

HI

(4)

in which C = Distance from guy attachment on tower to the center of gravity of the weight W et> I = The tangent intercept (ft) If the weight is uniformly distributed along the guy cable, C will be approximately equal to H/2. If the weight is not uniformly distributed, the guy may be subdivided into n segmentsand the following equation may be used: TA =

SJm HI

0

in which N

S = c WC,

(6)

.

-

Wi = Weight of segment i (lb) Ci

= lkaXe

from the guy attachment on the tower to the center of gravity Of segmenti (ft)

If the intercept & dlfficdt to establish, one may use the guy slope at the =&or end with the following equation: TA = WCJl (v - Hm a)

m

in which 01= Guy angle at the anchor (see Figure E9) Note that

I = v - Htan a

(8)

and that

ami that WC in equation (7) my be replked with S, as was done in equation (5).

DYNAMOMETER

DYNAMOMETER COME-ALONG

TURNRUCKLE

METHOD

AS COME-ALONG IS TIGHTENED DYNAMOMETER CARRIES FULL LOAD WHEN TURNBUCKLE IS FULLY SLACKENED (NUTS BREAK FREE). ,

PULSE METHOD

SWING METHOD

PULSE TRAVELS UP AND DOWN THE GUY N TIMES IN P SECONDS. 0

GUY SWlhS FROM a TO b AND BACK N TIMES IN P SECONDS

0

Figure E8. Methods of Measuring Tnitial Tension

C t-i t

I

Figure E9. Tangent Intercept Method nn

.

V

‘ /

/ /

‘T

M

Figure ElO. Relationship Between Guy Tension at Anchor and at Mid-Guy

ANNEX F: CRITERIA

FOR THE ANALYSIS OF EXISTING

STRIJC-~URES

Periodic revisions to this standard a made by t&e Commitkz based upon comments received from the industry. The committee does not intend that tit&g structures be analyzed for eachrevision of the standard; however, structural maiysis of existing structuresshould be performed by qualified profes~on~ engineers using the latest edition of this standard when: a) l”h=e is a changein antennas, transmission lines, and/or appurtenances (quantity, size, location, fx type) b) There k a change in operational re.qui.rements(tit

and sway)

c) There is a need to increase wind or ice loading To perform the analysis, the following data is rquired: a) Member sizes, dimensions, and connections b) Material properties c) Existing and proposed loading; antennas (size, elevation, and azimuth), transmission lines, and appurtenances Data may be obtained from the following sources: a) Previous stress and rigidity ~IU$& (structure and foundation) b) Stn~tural

and detail drawings (design and as-built) ’

c) Specifications d) Construction records e) Field investigation

a

(LEFTBLANK

INTENTIONALLY)

TWEiA-222-F

ANNEX G: SI CONVERSION FACTORS COnV~iO~ CO~Ody

required using EIA/EA-222

for the Intemational System of Units

To Convert From

To

Multiply By

inches (in)

millimeters (mm)

25.40

feet (ft)

meters (m)

0.3048

square feet (ft2)

square meters (m2)

0.0929

cubic feet (ft3)

cubic meters (m3)

0.0283

pounds [force] (lb)

newtons (N)

4.4482

pounds per cubic feet

kilonewtons per cubic meter

rw~gw (pa

Wh3>

pounds per square foot Wfi2)

P=&

(Pa)

47.88

kips per square inch (ksi)

megapascals @lIPa)

6.8948

miles per hour (mi/h)

meters per second (m/s)

0.4470

0.1571

[Sri

m

-------

-.

(LEFTBLANK

INTENTIONALLY)

ANNEXH:

COMMENTARYON

ICEDESIGN CRITERIAFORCOMMUNKATION STRUCTURES

1

INTRODUCTION The meteorological phenomenon of ice accumulation is very difficult t0 predict with certainty. For tower and pole structures, ice accumulation can be one of the predominant applied loads. The first task in developing ice design criteria is to determine if the proposed or existing site is susceptibleto icing. If the site has a history of ice accumulation, the fiquency, thickness, type ad duration of icing must be determined Potential sourcesof this Mxmation inch& the National Weather Service (NWS), local weather agencies, owners of existing towers at the same site or nearby sites, local landowners, and consulting meteorologists.

Judgmentmust be exercised to detexmine if reported icing events are frequent-or rare ommnces. Likewise, in some geographical areaa, seasonal high winds and icing OCCUT simultaneously: For these situations, simultaneous application of maximum wind and ice loadings may be required. The effect of icing on a tower generally relates directly to the type and size of tower and to the we and thickness of icing. For example, a l/Z-inch radial ice accumulation will have more impact on a short tower with small members than a tall tower with larger members. Very dl tmers may experience large thicknesses of in-cloud icing over portions of the mast. Solki or clear glaze ice has a higher density than that of rime ice or hoarfrost. Consequently, the effects of increased dead *eight from ice accumulation will vary depending on the type of ice. Large accumulations of rad.iaI ice can dramaticaIIy increase the projected wind area of tower members and antennas.

a

2

TYPES OF ICING (1) (2) 0) There are several types of i&g which can accumuiate 011COm.Ulum ‘&on important to understand where and how they form. 2.1

sQwZUlZS. It iS

Hoarfrost Hoarfrost is a fluffy 0~ feathery deposit of interkking ice crptd formed on objects, usua~y those of d diameter fialy exposed to the air, such as tree branches, wires, etc. ‘I&e deposition of hoarfrost is similar to the process by which dew is formed, except that the temperature af the &osted object must be btiow freezing. It forms when air, with a dew point below kezing, is brought to saturation by cooling. Hoarfrost has densities less than 19 lb@ [3 kNjm3].

2.2

RimeIce Rime ice is a white or m.i,ky pm& deposit of ice formed by the rapid freezing of supercooied water drops as they impinge upon an exposed object. It is denser and harder than hoarfrost, but lighter, softer, and less transparent than glaze. Rime is composed essentially of discrete ice granules and has densities ranging from 56 w 19 WfG 19 to 3 kNjm3]. Rime is often described as soft or hard. Soft rime is a white, opaque coating of fine rime deposited especially on points and eilgcs of objects. It is usually fmed in supercooled fog. On the windward side, soft rime may grow to very thick layer% long feathery cones, or needles pointing into the wind and having a structure S&.&U to hoarfrost. Hard rime is an opaque, granti maas ofi rime fanned by a dense supercooled fog. Hard rime is compact and amorphous and may build out into the wind as glazed cones or feathers. The icing of ships and shortit structures by supercooled spray usually has the characteristics of hard rime.

2.3

Glaze Ice Glaze ice is a coating of ia, generally clear ‘aud smooth, but usually containing some air pockets. It is formed on exposed objects by the fretzing of a film of supercooled water, usually deposited by rain or drizzle. Glaze is denser, harder, and more transparent than either rime or hoarfrost. Its density may be as high as561b/ft3 C9kN/m3].

*

(1) AtmosphericIcing on S-s. Boyd& Williams. (2) Draft Guidelines for Transmissim Line Sati Ldhp. AXE (3) TaaeJman. P..andGring~rten. LL. “EstimatedGlaze Ice andWrndLoadsat &e ws ~R&x for the CQIX@OUS UnitedStates”.Air Force&bridge ~esearcfr m. B4fo1& Massachusetts. 1973.

____--- - --

3

CONDITIONS OF ICE FORMATION ‘be me of ice formed is determined by combinations of air temperature, wind speed,&oP size, and liquid water content or rainfall intensity. The icing problem, therefore, can be &Gfkd either by the meteoroIog&I conditions that produce the formation of ice or by the type of ice that is formed 3.1

Precipitation Icing This is the most Common icing me&n&m and can occur in any area subject to freezing rain or drizzle. The ice is formed when warm, moist air is forced Over a sub-freezing, denser layer of air at the ground surface. As the watm air rises and condenses, rain falls through the coider air and freezes on objects near the ground. This frozen deposit is a clear glaze type of ice. Since this kind of weather is caused by frontal activity, it usually doesn’t last more than a day or two. Because it is necessary for excess water to be present for glaze to form on exposed surfaces, often the excess water may freeze into icicles or other distended shapes. In actd practice, glaze ice can be seen to form on cables and guys in a variety of shapes ranging from the classical smooth cyhndxical sheath, through crescentson the windward side and icicles hanging on the underside to large irregular protuberances spaced along the cable. In most cases, glaze ice develops on st.nmms as a fairly smooth layer on tie windward surfaces with icicles forming below horizontal members. The shape of the glaze is apparently dependent on a combination of factors, such as wind speed, variations in wind speed, the angle of the wind, the turbulence of the flow, variations in air temperature and duration of the Storm. Since most of these factors vary @om storm to storm, and even during the storm a @i.ndticai shape of equivalent weight is assumed for design purposes.

3.2

In-Cloud Icing This type of icing condition is caused by the impingement of super-cooled water dropiets of a cloud on the structure or cable. This is rime ice. It can occur in mountainous areaswhere ciouds exist above the freezing level or in a super-cooled fog at lower elevations produced by a stable air mass with a strong temperature inversion. These conditions can last for days or weeks. The total amount of in-cloud ice deposited is dependent on wind speed. Since wind speed increases with height above ground, larger amounts of ice will occur towards the top of taller towers and on the cables that support or are mounted on taller towers.

.

ANNEX I: GEOTECHNICAL

IWESTIGATIONS

FOR TOWERS

A ~0i.i investigation by a geotecfinical @n&g firm is recommended for each tower site to determine its unique soil and physical &ract&&cs, and to provide data to develop safe design p==eters, economical foundation &maths, ami installation procedures. To ensure that the EPOn furnishes useful information to the foundation designer, the ‘geotechnical firm should be provided with the following information: a. A plot plan and site location map with tower, equipment building and other site improvements located. b. Tower base vertical reaction and shear and anchor vertical and horizontal reactions for guyed towers; or i’rhkrn~m compression and tension (uplift) reactions with shear for self-supporting towers. C. Any special conditions or requirements of the specifications.

d. The minimum depth of borings for guyed tower bases should be 15-20 ft; for guyed tower anchors lo- 15 ft; for self-supporting towers, boring depth will vary depending upon the type of foundation being considered. The magnitude of the structure reactions, site and sod COndiuons may require altering the boring depth requirements. The geotechnical report should provide the following information at minimum: a. Boxing logs.

1. Date, sampling methods, and number and type of samples. .

2. Description of the soil strata according to the Uxkied Soil Classification System. 3. Depths at which strata changes occur referenced to a site datum. 4. Standard Penetration Test blow

counts.

5. Soil densities. 6. Elevation of free water encountered and its level after 24 hours, and recommended ground water elevation to be considered for design. 7. Maximum and average depth of frost penetration. b. Other soil characteristics or properties which may be required because of local conditions. (Refer to Annex J for corrosion control options for guy anchors in direct contact with soil.) c. A description of alternative foundation methods with recommendations for ultimate values for passive pressure, bearing pressure and shin friction, the angle of internal friction and other appiicable soil properties and appropriate safety factors.

lin

ANNEX J: CORROSION CONTROL OPTIONS FOR GUY ANCHORS IN DIRECT CONTACT WITH SOIL 1 INTRODUCTTON WY gUY mChOfi in direct contact with soil, designedin accordance with ETA/IIA Standards,have performed We.ii without detrimental corrosion. However, depending on the required design life of the stmture and on site-specific conditions, corrosion control measures, in addition to hotAp gdvmg, may be required to prevent the premature deterioration of these types of Eu1cfior~ Hot-dip galvanized mater& have been proven m be very effective in resisting corrosion when in direct contact with soil. In a lo-year study involving 45 types of soils performed by the National B=au of Standards, only one sample had some penetration of the base steel. A 13-year test in ciab ( Oneof the most corrosive subgrade enti~nments), indicated that corrosion was effectively reduced, even thou& the zinc coating was destroyed within the first two years. One theory for this b~vh is that the alloy layer between the zinc and steel surface, formed during the hot-dip &V&g process, results in a major source of protection. Also, in some soils, a protective layer of * a zh compound fmm during the corrosion process, slowing the rate of corrosion. Despite the protective nature of hot-dip gakmixed materials, there have been reports of unacceptable adm corrosion occurring within 10 years after installation. Anchor inspectionsare W=dve to de-e if accelerated corrosion is occurring at a given site. Corrosion activity may VarY widely across a site. Anchor corrosion could occur at one or more of the anchors at a site and axid O~X at anY depth along a given anchor. Some of the site conditions which may result in accelerated corrosion are briefly described in this annex. Under these conditions, additional comsion control measures should be co&k&. I This annex is not intended to be a treatise on the subject of anchor corrosion but is provided to heip owners become aware of the potential anchor corrosion problems and the importance of anchor inspections; and to encourage owners to pursue further information from appropriate specialists for both new and existing construction. A corrosion specialist may recommend methods to curtaiI or monitor corrosion discovered at existing sites or present options to consider for proposed sites. 2

“IVES 2.1

OF CORROSION

Galvanic Corrosion

Galvanic anchor corrosion occurs in soil when a self-generated current exists due to the connection of dissimilar metals or due to non-uniform conditions existing along the surface of an anchor. When a dissimilar metal is electrically connected to an anchor, a difference in potential exists between the two materi&. If the dissimilar metal is also in contact with a low resistivity soil, a complete circuit will exist. Current will flow from one metal to the other due to the electrical connection and return through the soil completing the circuit. This naturally occunin g phenomenon is why current is obtained from a battery when its terminals are electrically Connected. Dissimilar metals behave in this manner because of the difference in potential each metal inherently has. Metals may be listed in order of their potential. Such a list is called a galvanic series. A galvanic series of commonly used metals and alloys is given in Table Jl. When a complete circuit exists, corrosion occurs on the metal listed higher in the galvanic series. This is the location where current exits and travels through the soil towards the metal 111

listed lower on the galvanic se&. For example, if a large copper ground Systemin a conductive soil is directly or i&,rdy @rough guys) ekctridy connectedto a steel anchor, corrosion will occur on the anchor&cc steel is listed higher on the galvanic series than copper. The rate of corrosion wiU dependlargely on the a&uctivity of the soil and the relative locationsofthemetalsinthegalvanicstrics.Thehi9)lnthtsQil~u~~~,andthc~er apart the metals are in the gaIv&~ s&, the fas&z the &osion. Many 0thfZ f=tOrS beyond the scope of this commentary could innuence the rare of corrosion and result b =&med anchor carrosion. Galvaniccorrosionmay alsooccur~~~~rateswithouttheprrsenccafa~metal when conditions along the surface of the anchor are not uniform. ‘Es situation may exist The moist concrete, being much when the base of the anchor is embeddedin COOCTC~~. different than the soil surrounding the expo& portion of the anchor,will have a different potential. If the surrounding soil conducthi@ is high, afdemed corrosion of the anchor moisture may occur. Backfill conditions with n~-unif~ composition, compaction, wntent, porosity, etc., may result in similar localized difkcnces in potential along the anchor. 2.2

Electrolytic Corrosion Electrolytic corrosion is very S+ to @~a& msion. The differencebeingthe current responsible for electrolytic corrosion is from an outside source as opposed to a self-generated current which is responsible for galvanic corrosion. Outside sources of current which may result in eiectiolytic ~sion inch& ckctric rail transit systems, mining operations, welding a&vi&s, mnr.hincry, or the corrosion control systems for ., pipelines or nearby stcuctur~. For electrolytic corrosion to occur, the md,hg soil must be conductiveand a CWTtnt from an outside source must enter and tit an anchor on its path to a hcation Of lower potential. At the point of entry, the anchor is generally unaffected.At the point of exit, BS with galvanic corrosion, acceleratedcorrosion may occur.

3 CORROSION POTENTIAL OF SOL The corrosion potential at a given site is a function ofmany variables:Fortunately,one of the most important variables, the conductivity of soil, may be determinedby a geotectical investigation. 3.1

Soil Conductivity The conductivity of a soil is usually deby measuringrcsistivity. Resistivity is most often measuredin units of ohm-centimeter (&m+m). 7&e lower the resistivity, the higher the conductivity. For example,salt water, a very mosive environment,has a resistivity of approximately 25 ohm-cm. Cleandry sand,which is usually a non-corrosive environment, may havea resistivi~ of more that 1,000,000ohm-cm. A soil with aresistivity below 2,000 Ohm-cm is generally consideredto be highly carrosive.

0

3.2

Other Factors soil resisfivity may vary seasonablyand is gcnemlly a function of mine!ralcomposition, moisture content and the concentrationof dissolvedsalts. Clays and high moisture content soils generally have lower resistitiq &an sandsor low moisture contentsoils. However, a

113

dry sandysoil may becomevery aggressiveuponanincreasein moisturecontentif dissolved Saks ax present. Likewise, a wet soil my not be aggressivewithout the presenceof didvd salts. TemperatureE&O affects resistivity values. The resistivity of a soil may @ me-e vefy high if measuredunder nearfreezingconditions,yet bevery aggressiveunder wanner wnditio~. MAY 0th~ factors influence the corrosion potential of soil to varying degrees.Someof &se famm are: drainage, soti porosity (aeration), acidity or akalinity @h), certain ~miml iqmti~, the metabolic activities of certain micr~+~@sIE, adjacentand/or ~~O~C~Y pmead stnrctures.Thesefactors may also vary seasonablyor vary due to 0th~ ~thities at a site,suchasthe doping of soil to increasethe efktiveness of agrounding system. Due to the my possible’ factors i~~volved, it may not always be possible to &mm&e the controlling factor when acceleratedcorrosion occurs. 3.3 GeotechnicalInvestigations When a geotechnicalinvestigation is performed,asa minimum, thelocal soil resistivi~ and the type and wncentration of dissolved saltsshould be established.With this information, together with a description of all existing and/or proposed construction, a corrosion spm*t shdi beableto recommendvariouscorrosioncontrol measuresto beconsider& Additional site testingmay berequired by thecorrosionspecialistin order to properlydesign ad implement a Corrosioncontrol system. 4 OPTIONS FOR CORROSION CONTROL None of the following options for wrrosion wntrol eliminate the needfor proper monitoring and maintenance over the life of the structure. l

4.1

Site Modifications

.

Improving drainageor placing an impermeablelayer of soil at an anchor location may be beneficial in reducing the rate of corrosion. Under some situations it may be possible to ba&ill afouIlcl sn anchor with a high resistivity soil. Adding chemicals to neutralize existing corrosive soils or to mitigate the actions of micro-organisms may also be sn alternative. Caremust be taken to ensurethat the required structural capacity of an anchor s~ppt is maintained during excavationsand to avoid contaminating the local soil with toxic substances.Relocating sn anchormay alsobe a reasonablealtemative if the causeor possibility of acceleratedwrrosion at a site is known to be a localized, isolated condition. If coppergroundrods serveasgrounding for ananchor,replacingthemwith galvanizedsteel rods would reduce galvanic corrosion by el’ ’ .* g the presenceof a dissimilar metal. Special attention should be paid to the ground lead and its connectionto a galvanizedrod, particularly when the connectionis placed below grade. Isolation Of anchors from the structure using guy insulators may help to reduce the transmission of stray currents from outside sourcesand therefore minim& ekctrolytic corrosion. Galvanic corrosion due to the presence of copper ground rods would be eliminated if the ground wires were connectedon the tower side of the isolation point. Isolation may also increasethe efficiency of sacrificial anodesdescribedin 4.4. Bonding the anchorsto adjacentcathodicallyprotectedpipeliuesor structures may protect the anchorsss opposedto subjectingthem to possible ekcsolytic corrosion. This should only be donein accordancewith recommendationsfrom a corrosion specialist.

a

4.2

4.3

Protective Coatings co&ngs are available. Theeffectivenessofa Many types of organicm&orga&prote&e coating is highly dependentupon the preparation of the anchor aUrfa% the method Of application and the v&nerabfity of the coating to e during cwStructk)n- Rotective coatings may be particularly effectve when usedin conjunction with a cathodicman sys- describedin 4.4. Concrete Encas~~t Direct amact with soi my beavoidedby ~g~~onYifh~orcedcon~~0~~ the entire embeddedlength of an anchor The encasementshould extend a minimum of + inchesabovegrade.~~acwMete~~~blockisusedwithan~~,thtreiaforeingin the concrete encasementmust be prop&y developed into the anchar block t0 prev=t ~wssive cracking. Sulfate resisting coll~ctc e &sip should be used for all wncrete below gd when soluble sulfatesexist in the soil or ground~atcr=

4.4

Cathodic Protection

For both galvanic and electrolytic corrosion,corrosion occurswhen current fi~ws from the anchor into the surrounding soil. me objective of cathodic protection is to reversethe dir&on of current, resulting in current flowing to the anchorinsteadof away from it, thus preventing corrosion of the anchor.This may be accomplishedby installing galvanicanodes or by ~tmhing an impressedcurrent. BY “iectrically connectinga metal (galvanicanode)hatedhigher on the galvanic series and burying it in close proximity ment w be f&ed to fhw to the protected item from the anode. This will resdt in corroSi0n of the installed metai an&

instead of the item to be

protected.Forthisreason,theinstalledmetalis~asacrificislaMdesadalsowhythese anodesmust be periodically ir;spectedto & sure they have not corroded away beyond use. Additiimal stid anode material by cvemdly have to be added. A common mixturetoenhanceits ~acrificiaianodeusedismagncsiumpackagedina~p~bar?kf?ll conductivity with soit. The number,size, type andlocation ofgalvanic anodesshould be determinedby a corrosion specialist and must be adequateto ensurem flows in theecomxt direction, overcoming the efkts Of ail other influences at the site. The efkliveness of an installed SyStemShould bepcriodicallymonitoredoverthelifeofthestructure byacorrosionspeciahst.Thismaybe done by measuringthe potential of the protectedanchorwith respectto a rckence electrode placed in the ground. A Largeenoughnegativepotential indicates that current is flowing to the ~dxxs as desiredfor corrosion control. anodes to cssurc current will flow Under certain circumstances,installing ~IIOII~~I gahnic in the desireddirection may not be feasibleor eccmtical. Using animpressedcurrentwith ananodemayberequiredunderthesecircumstances.Theimprtsstdcumntrequinstheuse of a reliable power sourceto producethe’&sired current The positive tuminal of thepower sowe is wnnected to the anoderesulting in current traveling from the anode,through the SOfi to the anchor, overcoming the effects of all other infhrences. Since cutrent would be entering the sxhor from the soil, corrosion of the anchorwould be controlled. The voltage of the POW=some, the size,location andtype of anoderequired, andthe possibleeffectson adjacent stnmm should be determined by a ccurosion specialist. overprotection may

1lA

result in accelerated coxrosionof surroundingstructuresandmay alsodamagetheax-&or or

anchor coating as a result of&# current hning hydrogen gas at the anchor.

undeisirablechemicalcompoundsand/or

5 REFERENCES wg, H. H., “‘Ibe Corrosion Handbook”, John Wiley & Sons,NY, 1948. mg, H. H., Revie, R. W., “Corrosion and CorrosionControl”, Third Edition, JohnWhey Bi Sons, NY, 1985. W&O% C. L., oat=, J. A, “Cmosion and the MaintenanceEngineer”, Hart Publishing Company, NY, 1968. Huock, B., “‘F~chmds Ohio.

of CathodicProtection”, HARCO TechnologiesCorporation,Mexiina,

TABLE Jl GALVANIC

SERIES OF COMMONLY

USED METALS AND ALLOYS

MAGNESIUM ZINC ALSTEEL, IRON LEAD,m :

BRASS, COPPER,,BRONZE SILVER GRAPHITE

a

EIA TIA 222 F Structural Standards for Steel Antenna Towers and Antenna Supporting Structures

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