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IsoTruss Structures, Inc. 2003 030915
Installation Manual for
IsoTruss Guyed Wire Towers
IsoTruss Structures, Inc. 1080 North Main Street
Suite One Brigham City, UT 84302 USA
Voice: 435.695.2000 Fax: 435.921.0303
Email: [email protected] www.isotruss.com
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To our valued customer- We appreciate and thank you for
purchasing an IsoTruss guyed tower. IsoTruss structures are
unprecedented in their combination of strength, weight, and value.
We hope this purchase will fulfill your needs and serve you for
years to come. Should you need any assistance, feel free to contact
us at [email protected]. When preparing this manual, the
following was our motto: OUR GOAL IS TO HELP REDUCE OUR CUSTOMERS
MANPOWER ERECTION COSTS AND THE TIME NEEDED TO ERECT OUR TOWERS.
YOUR SUGGESTIONS ON ANY TECHNIQUES, AIDING EQUIPMENT, OR TOOLS WILL
BE GREATLY APPRECIATED. PLEASE EMAIL THEM TO
[email protected]. SHOULD WE USE YOUR SUGGESTIONS IN OUR
MANUAL, WE WILL SEND YOU A GIFT OF THANKS. Once again, thanks for
your business. Sincerely, The IsoTruss Team!
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NOTICES AND SAFETY INSTRUCTIONS:
WARNING! - Caution! IF THIS TOWER COMES NEAR ELECTRIC POWER
LINES OR OTHER POWER/ELECTRICAL SHOCKING SOURCES, YOU COULD BE. .
.
SEVERELY INJURED OR KILLED!!! PLEASE LOOK UP AND AROUND YOUR
TOWER ERECTING AREA PRIOR TO AND DURING TOWER INSTALLATION/ERECTION
AND TAKE DOWN!
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Please read the following before erecting the tower.
1. READ INSTRUCTIONS: All notices, safety instructions, and
installation instructions should be read
and understood before tower erection. If you have any questions
about notices, safety instructions, or tower
installation, please call 435-695-2000 prior to tower
erection.
2. KEEP INSTRUCTIONS: The safety and installation instructions
should be retained for future
reference.
3. UNDERSTAND AND HEED ALL WARNINGS: All warnings on the tower,
on the base plate assembly, and in this installation
manual should be understood and followed. Guyed towers are not
self-supporting. IsoTruss towers are not designed to
be scaled or climbed. Do not climb this tower. This tower should
be installed by a tower installation professional.
4. MOUNTED EQUIPMENT:
Do not exceed the mounting weights or surface panel area limits
for the
tower you purchased. Failure to do so will void your
warranty.
5. GROUNDING
WARNING: THE LOCATION OF YOUR TOWER MAY REQUIRE PROPER GROUNDING
OR A PASSIVE POINT DISCHARGE SYSTEM. DO NOT INSTALL A TOWER THAT
HAS NOT BEEN PROPERLY PROTECTED. IT IS YOUR RESPONSIBILITY TO
DETERMINE THE NECESSITY AND PROPER
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INSTALLATION OF A LIGHTNING PROTECTION SYSTEM. YOUR SALES
REPRESENTATIVE CAN HELP YOU SOURCE AN APPROPRIATE SYSTEM.
The threat of damage to your tower and equipment during
lightning can be very high. It is important to do adequate testing
to ensure that the tower is installed in an appropriate location
and is properly protected to minimize the damage from a lightning
strike.
6. WEATHER:
WARNING: INSTALLATION OF AN ISOTRUSS TOWER DURING INCLEMENT
WEATHER MAY LEAD TO INJURY OR DEATH. PLEASE USE CAUTION! Do not
install IsoTruss towers during storms or the following weather
conditions: o When lightning is in the area o Rain, snow, or ice
storms
7. MANPOWER:
For ease of installation, the following table lists the
recommended crew size
based upon tower height:
TOWER HEIGHT MANPOWER
16m (54') 4
33m (107') 5
60m (197') 5
82m (269') 6
104m (341') 7
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8. TOWER KIT: Each tower comes with the necessary components to
assemble the tower sections together. Look in your tower shipment
invoice to confirm its contents. 9. ADDITIONAL ITEMS YOU MAY NEED:
For the erection process, you should have the following tools on
hand:
o Carpenters Level o Gin Pole o Winch o Blocks to support the
tower o Nut drivers
o OPTIONAL
Shovel Mechanical anchor driver Plumb bob
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THE ISOTRUSS TOWER - STEP BY STEP: The IsoTruss Tower is
assembled and erected through the following step by step
process:
STEP 1. Read the manual STEP 2. Lay out the erection site STEP
3. Assemble and position the base plate STEP 4. Position and secure
the ground anchors STEP 5. Assemble and attach the tower sections
STEP 6. Attach the support wires, also known as guyed wires STEP 7.
Assemble and position the gin pole and winch STEP 8. Test-lift the
tower STEP 9. Attach mounting brackets and equipment STEP 10. Fully
erect the tower STEP 11. Perform periodical inspection and
maintenance STEP 12. Take down and removal of an IsoTruss tower
STEP 1. READ THE MANUAL: Thoroughly read through and understand
this manual before erecting the tower. STEP 2. LAY OUT THE ERECTION
SITE: Lay out the proper locations for the tower base plate, guy
anchors, and winch anchor. For ease of reference and erection,
decals have been placed on the base plate at the 12, 3, 6, and 9
oclock positions. The erection layout should point the tower
downwind, or the 12 oclock position, allowing the tower to be
lifted into the wind. NOTE: An IsoTruss tower can be erected on a
slope up to 12 degrees. Wind conditions should be favored over
slope conditions. When laying out the erection site on a slope,
mark the spots for the anchors at the same locations as you would
on a flat surface. It is not necessary to compensate for the slope.
The supplied guy wires are cut long enough to allow installation on
slopes up to 12 degrees.
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NOTE: The side guy anchors and base plate should be in a
straight line with each other. If the anchors can not be installed
in a straight line at the preferred location, the anchor can be
moved up to, but not more than, 1.5m (5 feet) off this line. If the
anchors are installed on a slope, are not perpendicular to the
tower, or are not in a straight line with the base plate and
opposite side anchors, extra care must be taken when erecting the
tower. STEP 3. ASSEMBLE AND POSITION THE BASE PLATE: The base plate
permits pivoting of the tower and, when combined with the attached
side guy wires, provides lateral support while the tower is being
tilted up. The IsoTruss base plate cannot be installed on a slope
greater than 12 degrees.
The base plate is packaged in a kit and takes approximately 25
minutes to assemble.
Specific assembly instructions are attached to the base plate
kit. Check for nearby electric power lines or other potential
electric shocking
equipments when selecting a location for the base plate.
a. Assemble the base plate according to the instructions
supplied with the base plate.
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b. Align the base plate so the 12 oclock position faces
downwind, or is pointing in the direction of the wind. If you are
on a slope, the 12 oclock position should point uphill. Though, you
should always favor wind conditions over slope.
c. If the soil surface is soft, it may be necessary to set the
base plate on concrete, planks, or other suitable material to
spread the load.
d. Secure the base plate by driving the 2 supplied 4 ground rods
through the holes in the base plate. If the ground rods are not
sufficiently seated in the soil, it may be necessary to drive
additional ground rods. During erection, the base plate is
subjected to considerable force and must be firmly secured to
prevent shifting.
STEP 4. POSITION AND SECURE THE GROUND ANCHORS: Before the tower
is ordered, the soil type at the erection site should be determined
and the correct anchors selected. Anchor type should also take into
account maximum winds, icing, or other weather conditions the tower
will be subjected to. In addition, there may be certain safety and
legal requirements for anchoring the tower. Though the tower
installation kit is supplied with screw type anchors, these anchors
may not be appropriate for the specific erection site. The customer
is responsible for determining anchor requirements.
a. Place the anchors at their respective 12, 3, 6, and 9 oclock
positions from the base plate. Use Table 1 to identify the proper
distance of the anchors from the base plate. If your tower has
multiple levels of guy wire connections, the distance for the
anchors at each level is shown.
b. If the erection site requires different anchors than those
supplied in the tower kit, refer to the installation instructions
supplied with the anchors.
c. Once the proper location is identified for each anchor, screw
the anchors clockwise into the ground. A sturdy bar in the eye of
the anchor, or a mechanical anchor driver supplied by IsoTruss can
be used to screw the anchor into the ground.
d. Continue screwing the anchor until the eye of the anchor rod
is 150mm (6) above the ground.
NOTE: Guy wire anchors must be screwed in-line with the guy wire
and the tower. Therefore, the eye of the anchor will be closer to
the base of the tower than the
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helix of the anchor. The angle of the guy wire should continue
directly in-line with the anchor. The anchor should continue into
the ground in a straight line from the guy wire. Ensure that all
anchors are inserted at the proper angles.
e. Ideally, anchors should be directly opposite each other from
the base plate. If you encounter impenetrable rocks or other
hindrances in the soil, the anchor can be placed up to 1.5m (5)
away from its ideal position. Do not place the anchor further away
than this distance.
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TABLE 1 Anchor Distance from Tower Center
Guy
Wire
Atta
chm
ent P
oint
(ft)
Leve
l 1 A
ncho
r Dis
tanc
e (ft
)
Guy
Wire
Siz
e (in
)
Leve
l 2 A
ncho
r Dis
tanc
e (ft
)
Guy
Wire
Siz
e (in
)
Leve
l 3 A
ncho
r Dis
tanc
e (ft
)
Guy
Wire
Siz
e (in
)
16M tower
1/2" ice 35.8 40 3/16
53.7 40 3/16 33M tower
1/2" ice 35.8 70 3/16
71.6 70 3/16 89.5 80 3/16 107.5 80 3/16
60M tower no ice 54 166 3/16
107 166 3/16 161 166 3/16 197 166 3/16
1/2" ice 35.8 125 3/16
71.6 125 3/16 107 125 3/16 143 166 3/16 179 166 3/16 197 171
1/4
82M tower no ice 35.8 125 3/16
71.6 125 3/16 107 125 3/16 143 166 3/16 179 166 3/16 215 166
3/16 251 187 3/16 269 187 1/4 3/8" & 35.8 125 3/16
1/2" ice 71.6 125 3/16
107 125 1/4 143 166 1/4 179 166 1/4 215 166 1/4 251 187 1/4 269
187 1/4
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Example: 82M Tower
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STEP 5. ASSEMBLE AND ATTACH THE TOWER SECTIONS: a. Lay tower
sections end-to-end. Because of the IsoTruss tower design,
there
is no top or bottom of each tower section. Either end of the
sections can be used at the bottom and top connections.
b. Join tower sections with the supplied connectors. c. Follow
the step-by-step installation instructions supplied with the
connectors. d. Ensure that the connectors are properly installed
and tensioned. e. Bolt the bottom tower section to the base plate.
Use the supplied
connectors to bolt the tower to the base plate. NOTE: Ensure all
connectors are tensioned to proper torque specifications as
contained in the instructions supplied with the connectors. Over
tightening can damage the tower. Improper installation and torque
on the connectors will void all warranties. STEP 6. ATTACH THE GUY
WIRES: Your tower erecting kit comes with wires pre-cut and coded
for ease of
installation. All guy wires are 10% longer than necessary to
allow the tower to be
installed on uneven ground. At this time, only the guy wires
which connect at the 3 oclock and 9 oclock
positions of the base plate should be attached to their anchors.
a. Carefully roll out each spool of guy wire from the tower
attachment point to
its respective anchor. Take care not to twist or kink the wires.
Twisted and/or kinked wire may fail under load. To prevent kinking
or problems, ensure that the guy wires are fully unwound from their
spools before erecting the tower.
b. Line up each set of guy wires with their respective
attachment points on the tower. Each level of attachment on the
tower results in different lengths of guy wires. The shorter the
guy wire, the lower it attaches to the tower. The guy wires with
mid-wire gin pole attachment loops must be attached to the 6 oclock
side of the tower.
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c. Once the guy wires are laid out, slide three rope clips onto
the end of the wire which will attach to the tower. The forged, or
saddled, part of the rope clip should be slid onto the guy wire.
Loop the wire through the eye of the tower connectors and around
the provided thimble. Refer to the image below for proper
attachment of the rope clips.
NOTE: The saddled part of the clip rests on the live end of the
wire. The U-Bolt part of the clip wraps around the dead end of the
wire. Always tighten the nuts on the rope clip evenly, alternating
from one side to the other. Each end of the guy wire will have
three (3) rope clips. The rope clips should be spaced evenly from
each other. In addition, the rope clip nearest the thimble should
be tightened as near to the thimble as possible. Refer to the table
below for rope turn back lengths and proper torque. Torque values
shown are based on the threads being clean, dry, and free of
lubrication.
Wire Rope Size Rope Turn Back Length Torque in Ft. Lbs. 4.76mm
(3/16") 143mm (5.63") 7.5 6.35mm (1/4") 181mm (7.13") 15
d. At the anchor end of all guy wires, slide three wire rope
clips. At this point,
only the guy wires at the 3 oclock and 9 oclock positions will
be attached to their respective anchors.
e. Run the guy wire through the anchor eye. Do not allow the
rope clips to go through the anchor eye. Loop the wire around the
provided thimble and double the wire back.
f. Slide the doubled back wire through the u-bolt part of the
rope clip. Leave a little slack in the guy wires and snug up the
rope clip nearest the anchor. Do not over tighten the rope clip,
because you will need to loosen and adjust
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the clips as the tower is erected. Leave the other two rope
clips loose until the tower is fully erected.
g. Throughout the tower erection process, the tension in the guy
wires will fluctuate. As a result, tension must be checked and the
guy wires must be adjusted accordingly as the tower is erected.
STEP 7. ASSEMBLE AND POSITION THE GIN POLE AND WINCH:
You will use Table 2 throughout the tower erection process:
TABLE 2
Recommended Winch, Anchor, Gin Pole Capacity Equipment Min. Gin
Min. # Winch Weight at Winch Pole Lifting Distance Top Capacity
Length Guys from Tower (kg/lbs) (kg/lbs) (M/ft) Base Plate 16M
22/50 1041/2296 3/10 1 2.7/9 45/100 1041/2296 3/10 1 2.7/9 113/250
1041/2296 3/10 1 2.7/9 226/500 1041/2296 3/10 1 2.7/9 33M 22/50
1041/2296 3/10 1 2.7/9 45/100 1514/3339 3/10 1 2.7/9 113/250
1425/3142 6/20 1 5.8/19 226/500 2575/5676 6/20 2 5.8/19 60M 22/50
1349/2974 6/20 2 5.8/19 45/100 1771/3904 6/20 2 5.8/19 113/250
2006/4421 9/30 2 8.8/29 226/500 2538/5594 12/40 2 11.9/39 82M 22/50
1803/3975 9/30 3 8.8/29 45/100 2224/4902 9/30 3 8.8/29 113/250
2514/5543 12/40 3 11.9/39 226/500 3110/6857 15/50 3 14.9/49 104M
22/50 2764/6094 9/30 4 8.8/29 45/100 2423/5342 12/40 4 11.9/39
113/250 2793/6157 15/50 4 14.9/49 226/500 3515/7748 18/60 4
18/59
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WINCH SETUP: The winch anchor must be placed directly in-line,
opposite the tower. Use Table 2 to determine the length the winch
anchor should be from the
base plate. The winch should be .3M (1 ft.) shorter than the gin
pole length. These distances should be followed to prevent the gin
pole from separating during the erection process.
Ensure that the winch being used is capable of supporting the
necessary weight. Minimum winch capacities are found in Table
2.
NOTE: Serious damage, injury, or death may occur if the minimum
winch capacities are not followed. It is important to follow these
minimum specifications to prevent
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problems throughout the erection process. Lifting a tower with
an inadequate winch will void any and all warranties.
a. Screw the winch anchor into the ground, according to the
distances
indicated in Table 2. b. Screw an additional anchor next to the
winch anchor. This anchor will be
used to attach the dead end of the winch cable. c. Attach the
winch to the anchor and ensure that the connections are secure.
GIN POLE SETUP:
To avoid injury or damage to the tower, you must securely attach
the gin pole safety wire. The safety wire slides through the middle
of the gin pole. The bolt which secures the gin pole to the base
plate also goes through the eye of the safety wire. This safety
wire prevents the gin pole from separating in the erection process.
Use Table 2 to determine the required length for the gin pole. Note
that the tower height and weight on the tower influences how long
the gin pole should be. Confirm that the gin pole is the proper
length before erecting the tower.
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a. Assemble the gin pole with the appropriate number of
sections, per Table 2. b. Slide the safety wire through the gin
pole towards the base. As each
section of the gin pole is connected, thread the safety wire
through. c. Connect the gin pole to the base plate with the
supplied bolt. Ensure that
the bolt goes through the eye of the safety wire in the gin
pole. Additionally, the side of the gin pole with multiple
connectors should point towards the tower, or the 12 oclock
position. These multiple connections will be used to attach the guy
wires and lift the tower.
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d. Once the gin pole is secured to the base plate, anchor the
gin pole guy wires. The gin pole guy wires are necessary to prevent
the gin pole from swaying and possibly failing during erection.
e. Run the winch cable through the pulley at the top of the gin
pole. The winch should attach to the 6 oclock side of the gin pole.
Continue running the winch cable through the pulley and secure the
dead-end of the winch cable to a secured ground anchor next to the
winch anchor.
f. Attach the 6 oclock position tower guy wires to the multiple
connectors at the top of the gin pole. When attaching the guy
wires, keep them untangled and straight. Use Table 1 to determine
the number of guy wires that should be attached to the gin pole for
erection. You will find loops in the guy wires for attachment to
the gin pole.
g. When attaching the guy wires, start at the uppermost, or
tallest guy wire on the tower, and work down. Never attach a guy
wire to the gin pole unless it is looped for attachment to the gin
pole.
h. Note that for different equipment weights on the tower,
different numbers of guy wires are required. Attach the appropriate
number of guy wires.
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STEP 8. TEST-LIFT THE TOWER
a. Before attaching measuring devices/equipment to the tower,
test-lift the tower to ensure there are no tangles or obstructions.
Lift the top end of the tower approximately 3m (10) off the ground
to confirm solid connections between the various tower
components.
b. Recheck the path of erection on either side of the tower to
ensure that electrical transmission lines or other shocking
electrical devices will not come in contact with the tower.
c. Check the tension on the side guy wires to ensure that the
tower will not tip/tilt significantly to either side while going
up.
d. Confirm that the tower connector joints are properly
installed and secure. e. Prepare blocks upon which to place the
tower. These can be any type of
support that would elevate the tower but not damage the tower
surface. f. Once the test-lift is completed, lower the tower onto
prepared support
blocks placed every 6m (20) and fasten the necessary equipment.
STEP 9. ATTACH MOUNTING BRACKETS AND EQUIPMENT: Confirm that the
tower is securely set on the support blocks before
mounting and installing your equipment. An improperly supported
tower may fall causing damage to the tower, or possibly harm or
death to those around it.
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WARNING: ISOTRUSS TOWERS ARE NOT DESIGNED TO BE SCALED OR
CLIMBED. DO NOT CLIMB THIS TOWER FOR ANY REASON!! IF YOU NEED TO
SERVICE THE TOWER OR EQUIPMENT, YOU MUST LOWER THE TOWER AND
SERVICE IT FROM THE GROUND. CLIMBING THE TOWER COULD CAUSE FAILURE
OF THE STRUCTURE AND COULD TEAR OUT GROUND ANCHORS. IF SCALED, AN
ISOTRUSS TOWER MAY COLLAPSE, CAUSING HARM OR DEATH!!
a. Install the mounting brackets onto the tower according to the
instructions
supplied with the brackets. b. Connect your equipment, sensors,
antennas, etc. to these mounting brackets
only. Do not attach equipment directly to the composite lattice
structure of the IsoTruss tower. Doing so will void your
warranty.
c. Ensure the equipment is installed according to the
manufacturers specifications and requirements. IsoTruss is not
responsible for equipment that is damaged or destroyed on its
towers.
d. Cables from the attached equipment can be either tied to a
longitudinal of the IsoTruss tower, or dropped down the open
center.
NOTE: Free-hanging cables may whip in higher winds, causing
damage to the cables or surrounding objects. It may be best to
secure the cables to the tower. STEP 10. FULLY ERECT THE TOWER:
WARNING: CONFIRM THAT THERE ARE NO ELECTRICAL LINES OR
HIGH-VOLTAGE DEVICES WITH WHICH THE TOWER COULD COME IN CONTACT.
GUYED TOWERS ARE NOT SELF-SUPPORTING. HENCE, ISOTRUSS TOWERS
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SHOULD NEVER BE SCALED OR CLIMBED. NEVER CLIMB AN ISOTRUSS
TOWER. The erection crew team leader should confirm that each
member of the
erection crew understands their respective responsibilities and
duties. Make sure the individuals attending the side guy wires are
familiar with and
can skillfully let out or take in side guy wires. Use the
recommended manpower to erect the tower. TOWER ERECTION:
As the tower is erected, concise, clear communication between
members of
the lifting team is necessary. Closely watch the guy wire
tension as the tower is erected. Stop the winch
and adjust the wires as necessary. The greatest requirement for
power is the initial raising of the tower. As
the tower is rises, the amount of power required greatly
reduces. Use a plumb bob to gauge the straightness of the tower as
it is erected.
Hold the plumb bob while standing at the winch, looking towards
the top of the tower, to check tower straightness. Adjust the guy
lines as necessary to keep the tower straight.
a. When lifting a 16M tower, there should be one person at each
outermost
anchor. For the 33M and 60M towers, the same should be followed,
with one extra person providing help where needed. For the 82M
tower, there should be two people at the 3 and 9 oclock positions
of the outermost anchors and one person at the 12 and 6 oclock
positions. For the 104M tower, the same team positioning as the 82M
should be followed, except one additional person should be placed
at the 12 oclock anchor.
b. Tilt the tower approximately 15 at a time. Lifting should be
slow and steady. At each 15 increment, stop the winch and adjust
the tension in the side guy wires. If necessary, the tension may be
adjusted more frequently. Never adjust the tension while the winch
is activated and moving. Fast uneven movements tend to cause the
tower to shake and swing.
c. As the tower is lifted, maintain sufficient tension in the
side guy wires at the 3 and 9 oclock positions to prevent the tower
from swaying during erection. Additionally, make sure that the base
plate is firmly in place and does not move during erection.
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d. At each 15 increment, adjust the guy wires as necessary. The
guy wires should have enough tension to allow for a little sag. The
guy wires should not sag more than 1m (3) during the erection
process.
e. When the tower is about 45 degrees to the ground, attach the
guy wires opposite the winch side, or the 12 oclock position, to
their appropriate ground anchors.
f. After the 12 oclock position guy wires are attached opposite
of the winch, a tower erecting crew member needs to maintain
constant tension on that side of the tower. For safety, keep the
crew member out from underneath the tower by attaching a rope
around the wire and applying tension by hand out from beneath the
tower. Allow the winch to pull against the tension produced by the
crew member. At this point, it will require little power for the
winch to continue lifting the tower.
g. Once the top of the tower is fully erect, attach the
remaining 6 oclock
position guy wires on the winch side to their respective
anchors. To do this, detach one guy wire at a time from the gin
pole and attach it to the anchor. You should attach the highest guy
wire first and work down towards the lowest level guy wire.
Constantly monitor tension at all anchor points to prevent the
tower from setting up crooked.
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h. The guy wires should sag about 0.6m (2) at the center. Use a
carpenters
level to set the tower perfectly vertical. i. Once proper
tension is set and the tower is vertical, tighten the remaining
wire rope clips on the guy wires. Tension in the guy wires can
be performed by hand. It is not necessary to mechanically increase
tension beyond the tension created from pulling the guy wire by
hand. If the guy wire is straight, without any sag, there is too
much tension in the wire.
NOTE: Too much sag on side guy wires could cause the tower to
buckle in the opposite direction. On the other hand, too much
tension can cause the guy wires, tower, or anchors to fail. If
there is no visible sag in the guy wires, there is too much
tension.
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STEP 11. PERFORM PERIODICAL INSPECTION AND MAINTENANCE
Over time, the tower and anchors will settle into the ground.
About two weeks after erection, check the tower, guy wires,
anchors, and base plate to ensure that proper tension continues and
that no anchors have pulled out of the ground.
The tower should be inspected semi-annually to ensure that it is
in proper working order, that all guys are properly tensioned, and
that all anchors are properly seated in the ground.
STEP 12. TAKE DOWN AND REMOVAL OF AN ISOTRUSS TOWER Throughout
the life of the tower, it may be necessary to lower it to
perform
maintenance on equipment, or to make changes. In order to
perform such maintenance, the tower must be lowered. Do not climb
the tower to work on the attached equipment. A moving load on a
guyed tower behaves very differently than a deadweight load.
A tower that has been erected and in service may have shifted
over time. When taking down a tower, be careful to observe any
indications of movement, shifting, or settling that may have
occurred. Compensate accordingly.
As a tower is lowered, the tension in the guy wires will
fluctuate. As a result, tension must be checked and the guy wires
must be adjusted as necessary throughout the lowering process.
Lowering an IsoTruss tower is the opposite of raising it. The
following steps should be followed:
STEP 1. Assemble and position gin pole and winch STEP 2. Attach
the guy wires to the gin pole STEP 3. Lower the tower STEP 4.
Disassemble all tower components
Before lowering an IsoTruss tower, confirm that the tower is
clear from
falling on any power lines, electric devices, or electrical
shocking equipment.
a. Prepare and place tower support blocks down the 12 oclock
direction of the base plate. These blocks will support the tower
when it is laid on its side and
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allow the necessary maintenance to be performed. In addition,
they will prevent damage to the equipment.
b. Follow Step 7 to secure the gin pole to the base plate and
winch. The gin pole should be horizontal. Use Table 2 to determine
the proper length of the gin pole and winch location. Secure the
winch with a winch anchor and ensure that the gin pole is properly
connected.
c. Once the gin pole is in place, consecutively transfer the guy
wires at the 6 oclock position with gin wire attachment loops from
their ground anchors to the gin pole. Begin at the lowest, or
innermost guy wire, and work your way up. Continue until half the
guy wires are attached. Once the lower half guy wires are
connected, begin transferring the outermost, or highest, guy wires
with gin pole attachment loops to the gin pole. Once again, working
your way down the tower. Continue this process until all the guy
wires at the 6 oclock position are attached to the gin pole.
d. When transferring wires to the gin pole, maintain proper
tension on the gin pole with the winch cable. If the gin pole is
not properly secured to the winch, the tower may fall.
e. Tension needs to be applied to the guy wires in the 12 oclock
position in order to pull the tower down and away from the winch.
To prevent injury or death, ensure that no one is underneath the
tower as it is lowered. Loosen the top guy wire at the 12 oclock
position and tie a rope around it. Position a crew member on the
rope to pull and tension that side of the tower. This tension will
pull the tower away from the winch.
f. As the tower is lowered, the tension on the side guy wires
will vary. As necessary, stop the lowering of the tower and tighten
the guy wires.
g. Continue to lower the tower to a 45 angle. At this point, it
is no longer necessary to apply tension on the guy wires opposite
the winch. Check the side guy wires and confirm they are properly
tensioned.
h. Continue lowering the tower, knowing that as the tower nears
the ground, the winch is subjected to increasing pressure and
force.
i. Lower the tower onto previously placed blocks and perform the
necessary maintenance or upgrades to the equipment.
j. If the tower is being removed, disassemble the parts.
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ONCE AGAIN, OUR GOAL IS TO HELP REDUCE YOUR MANPOWER ERECTION
COSTS AND THE TIME NEEDED TO ERECT OUR TOWERS. YOUR SUGGESTIONS ON
ANY TECHNIQUES, AIDING EQUIPMENT, OR TOOLS WILL BE GREATLY
APPRECIATED. PLEASE EMAIL THEM TO [email protected]
SHOULD WE USE YOUR SUGGESTION IN OUR MANUAL, WE WILL SEND YOU A
GIFT OF THANKS.
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Disclaimer: Statements in this manual may not represent the best
or only methods for installing a tower. These instructions are
subject to change. IsoTruss is not undertaking any obligation to
release publicly any updates to any manuals to reflect events,
updates, or circumstances after the date of this manual or to
reflect the occurrence of unanticipated changes. IsoTruss is not
responsible for negligence on the part of the user. In no way does
this manual represent a contract, agreement, guarantee, or warranty
between IsoTruss Structures, Inc, and the customer. Though, not
following the steps and instructions contained in this manual may
void your warranty.