Tower Loads
15
Tower Type Model US Towers HDX-555 55 50 70 29568 6.4 For Mast Calcs Sq. Ft Pressure 40M4LLDD 9.75 242.6112 12.5 36391.68 in-lbs 90 20.736 Hygain TH7-DX 9.4 233.9021 0.5 1403.41 in-lbs Mast Wind Load 2.08 51.84 6.25 3888.00 in-lbs 41683.09 in-lbs 77637.64 Worst-case mast bending stress calculated with wind speed in cell J6 to be sure mast Mast Calculations Mast Len is strong enough when in stowed position 15 5 12.5 2.08 51.84 Mast OD Mast ID Mom In 2 1.5 0.5369 Tower Loading Calcs 40M4LLDD 5054.4 Hygain TH7-DX 4006.656 Mast Wind Load 920 9981.056 Percent Loading: 33.76% Tower Height Wind Rating, MPH Sq Ft Rating Base Torque Ft-Lbs Wind Pressure Wind Load Position Above Tower Bending Moment Mast Bending Stress Wind Speed Mast in Tower Mast Above Tower Mast FPA Mast Force
Transcript of Tower Loads
Tower Type ModelUS Towers HDX-555 55 50 70 29568 6.4
For Mast Calcs
Sq. Ft Pressure40M4LLDD 9.75 242.6112 12.5 36391.68 in-lbs 90 20.736Hygain TH7-DX 9.4 233.9021 0.5 1403.41 in-lbsMast Wind Load 2.08 51.84 6.25 3888.00 in-lbs
41683.09 in-lbs 77637.64 Worst-case mast bending stress calculatedwith wind speed in cell J6 to be sure mast
Mast CalculationsMast Len
is strong enough when in stowed position
15 5 12.5 2.08 51.84
Mast OD Mast ID Mom In2 1.5 0.5369
Tower Loading Calcs40M4LLDD 5054.4Hygain TH7-DX 4006.656Mast Wind Load 920
9981.056Percent Loading: 33.76%
TowerHeight
WindRating,
MPH
Sq Ft Rating
BaseTorqueFt-Lbs
WindPressure
WindLoad
PositionAboveTower
BendingMoment
MastBendingStress
WindSpeed
Mast inTower
Mast AboveTower
MastFPA
MastForce
Tower Type ModelUS Towers TX-472 72 50 26.9 12567.68 6.4 FPA
72 70 7.9 7234.12 12.544 FPAExtended Height 72
Drag Coefficient, Cd 2.0 for FPA For Mast Calcs
PressureForce12 Delta 240 6.78 281.18016 8 26993.3 in-lbs 90 20.736Force12 C-31XR 16.54 685.94688 0.5 4115.681 in-lbsMast Wind Load 2.50 103.68 2.5 3110.4 in-lbs
34219.38 in-lbs 63735.95 Worst-case mast bending stress calculatedwith wind speed in cell J6 to be sure mast
Mast CalculationsMast Len
is strong enough when in stowed position
15 5 10 2.5 103.68
Mast OD Mast ID Mom In2 1.5 0.536893
MPH MPH MPH MPHTower Loading Calcs 50 70 Height 50 70 0.76699Force12 Delta 240 3471.36 6803.8656 72 3471.36 6803.866 0.768571Force12 C-31XR 7674.56 15042.1376 7674.56 15042.14Mast Wind Load 1192 2336.32 1192 2336.32
12337.92 24182.3232 12337.92 24182.32Percent Loading: 98.17% 334.28% 98.17% 334.28% Calculations at ANY Height Other
Than 72 Ft are Meaningless. Lower C31XR ONLY - 50 MPH C31XR & D-240- 50 MPH Heights Will Have Much LowerTower Hgt % Loading Tower Hgt % Loading Moment Around Tower Base
25 25.1 25 36.72
TowerHeight
WindRating,
MPH
Sq Ft Rating
BaseTorqueFt-Lbs
(Ant Only)Wind
Pressure
Sq. FtNeed FPA
WindLoad
PositionAboveTower
BendingMoment
MastBendingStress
WindSpeed
Mast inTower
Mast AboveTower
MastFPA
MastForce
E1
JEC18741: This is the FLAT SA rating of the tower taken from the US Towers mechanical report
B7
JEC18741: This is the flat plate area of the antenna, mast, etc
G7
JEC18741: This is the bending stress for a 90 MPH wind loaded with antennas as indicated
30 29.96 30 43.2935 34.83 35 49.8740 39.69 40 56.4445 44.56 45 63.0250 49.42 50 69.5955 54.29 55 76.1660 59.15 60 82.7465 64.02 65 89.3170 68.88 70 95.8972 70.83 72 98.52
C31XR ONLY - 70 MPH C31XR & D-240- 70 MPHTower Hgt % Loading Tower Hgt % Loading
25 85.1 25 125.0330 101.61 30 147.4135 118.12 35 169.840 134.64 40 192.1945 151.15 45 214.5750 167.66 50 236.9655 184.18 55 259.3460 200.69 60 281.7365 217.21 65 304.1270 233.72 70 326.572 240.32 72 335.46
20 30 40 50 60 70 800
20
40
60
80
100
120
140
160
180
200Tower Loading as a Function of Height and Wind
C31XR Only - 50 MPHC31XR and D240 - 50 MPHC31XR Only 70 MPHC31XR and D240 - 70 MPH
Tower Height, Ft
% T
ower
Load
ing
50 MPH < 2" OD Elements 35 sq. ft flat elements FPA = 26.9 sq. ft
0.768571428571429
70 MPH < 2" OD Elements 10.3 sq. ft flat elements FPA = 7.9 sq. ft.
0.766990291262136
Section Surface Area7 5.9356 3.5085 2.7764
Cylindrical Surface Area Calcs
Notes
20 30 40 50 60 70 800
20
40
60
80
100
120
140
160
180
200Tower Loading as a Function of Height and Wind
C31XR Only - 50 MPHC31XR and D240 - 50 MPHC31XR Only 70 MPHC31XR and D240 - 70 MPH
Tower Height, Ft
% T
ower
Load
ing
50 MPH SA Type Rating Section Surface Area< 2" OD Rnd Elements 35 Ant 35Flat Elements 26.9 Mast 0.67
70 MPH 4 3.132< 2" OD Rnd Elements 10.3 4-5 Overlap 1.591Flat Elements 7.9 5 2.776
5-6 Overlap 1.93350 Calculation's MPH 6 3.508
64.19 With Gust Factor 6-7 Overlap 2.4767 5.935
Force 6.4 lb/sq-ft
Tower Height 30 Section 21 Olp
Mid For Adjustable Heights SA Force, lbs Moment No Gusts Included - Just Basic Wind Speed1 10.5 7.33 46.987 493.3652 13.500 5.67 36.346 490.6733 16.500 4.48 28.718 473.8464 19.5 3.87 24.808 483.750
Mast 28.5 1.667 10.684 304.487Ant 31 35 224.359 6955.128
9201.250
Mid For Adjustable Heights SA Force, lbs Moment1 1.500 1.047 6.712 10.067
1-2 12.000 11.142 71.423 857.0772 13.500 0.810 5.192 70.096
2-3 15.000 8.712 55.846 837.692 As the overlap becomes greater (lower tower height), errors increase3 16.500 0.642 4.115 67.904
3-4 18.000 7.164 45.923 826.6154 19.500 0.552 3.538 69.000
Mast 28.500 1.667 10.684 304.487Ant 31.000 94.500 605.769 18778.846
21821.785
50 MPH Cylinder FPA 60 MPH Cylinder FPAHeight Ant Surface Area Height SA
25 115 88.39 25 64.3 49.4230 94.5 72.63 30 52.7 40.5040 69.1 53.11 40 37.6 28.9050 53.8 41.35 50 28.6 21.9855 48.3 37.12 55 25.3 19.4460 43.6 33.51 60 22.4 17.2265 39.7 30.51 65 20.1 15.4570 36.3 27.90 70 18.1 13.9172 35 26.90 72 17.3 13.30
Antenna is 1 foot above top of tower
20 30 40 50 60 70 800
20
40
60
80
100
120
140
TX-472 Tower
50 MPH
60 MPH
70 MPH
Tower Height
Allo
wa
ble
Su
rfa
ce
Are
a
C15
JEC18741: US Towers appears to use cylindrical SA for legs, cross braces, etc
C21
JEC18741: This is the cylindrical SA for the antenna
25 31% 80%30 37% 98%40 51% 139%50 64% 188%55 72% 215%60 79% 247%65 87% 281%70 95% 319%72 98% 334%
Based on Sq Ft Values of Antennas on "TX-472" Sheet
AntHgt
50 MPH% Total Tower Loading
70 MPH% Tower Loading
20 30 40 50 60 70 800
20
40
60
80
100
120
140
TX-472 Tower
50 MPH
60 MPH
70 MPH
Tower Height
Allo
wa
ble
Su
rfa
ce
Are
a
20 30 40 50 60 70 800%
20%
40%
60%
80%
100%
120%
140%
160%
180%
200%
Tower Loading vs Height
50 MPH70 MPH
Tower Height, Ft
% L
oadi
ng
Mid-Height Cq Ce qs L73 16352
72.5 556.863.5 1527.41453 647.6006
44.5 948.725836 534.4358
27.5 740.889619 361.29798.5 387.4368
22056.6
18.000
No Gusts Included - Just Basic Wind Speed
As the overlap becomes greater (lower tower height), errors increase
70 MPH Cylinder FPA 0.6667 MPH HeightHeight SA SA 20
25 44.7 34.28 30 0.16630 36.1 27.69 4040 25.2 19.33 5050 18.5 14.19 6055 16.1 12.35 70 7460 14 10.7465 12.3 9.4370 10.8 8.2872 10.3 7.90
20 30 40 50 60 70 800
20
40
60
80
100
120
140
TX-472 Tower
50 MPH
60 MPH
70 MPH
Tower Height
Allo
wa
ble
Su
rfa
ce
Are
a
20 30 40 50 60 70 800
20
40
60
80
100
120
140
TX-472 Tower
50 MPH
60 MPH
70 MPH
Tower Height
Allo
wa
ble
Su
rfa
ce
Are
a
20 30 40 50 60 70 800%
20%
40%
60%
80%
100%
120%
140%
160%
180%
200%
Tower Loading vs Height
50 MPH70 MPH
Tower Height, Ft
% L
oadi
ng
C31XR FPAElement Dia Len FPA Dia Len FPA Total FPA Number
1 0.375 36.5 13.6875 1 48 48 303.555 30.5 33 16.5
0.625 33 20.6250.73 33 24.09
0.875 33 28.875
2 0.375 33.5 12.5625 0.75 36 27 168.375 40.5 33 16.5
0.625 45 28.125
3 0.375 26 9.75 0.75 18 13.5 114 70.5 45 22.5
0.625 18 11.25
4 0.5 3 1.5 1 48 48 226.50.625 33 20.625
0.75 33 24.750.875 21 18.375
5 0.375 33 12.375 1 48 48 300.930.5 33 16.5
0.625 33 20.6250.73 33 24.09
0.875 33 28.875
6 0.375 21.5 8.0625 0.75 36 27 137.6250.5 45 22.5
0.625 18 11.25
Mast 2 372 744
sq in Length910.665 433
2382.165 sq. in16.54281 sq. ft FPA - Elements Only
673.5 29521.70948 sq. ft Elements and Boom
798 214
K-z G-h q-z0.67 73 73 1.254633 1.185664
TowerSection
ProjectedArea
AnalysisHeight
zHeight
w(plf)
Shear(lbs)
Moment(ft-lbs)
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