Part 2 Self Supporting tower structures

www.fullertonengineering.com
Engineer Training Series – SST Towers
Part 2
Objective: Understand, Confirm, and Explore ... Past and Most Unique Practices
(1) Monopole
(2) Self Supporter
(3) Guyed Tower
The following information is presented in a 3 part series that
cover the Parts, Foundations, Erection, and Maintenance
efforts for each of the following structure types:
Fred Teichman 03/2014

Part 2 – SST Typical Use
Increased Height, Requires more Ground space,
Good loading Capacity & Mainly in Suburban areas

Part Two – Why use a Self Supporting Tower (SST) ?
Self Supporting
Self-supporting towers, sometimes referred to as “free standing antenna
towers” or “wireless communication towers” are the most popular and
versatile type of structure used today in the wireless industry.
Self Support towers have a larger footprint than monopoles, but a much
smaller one than Guyeded towers.
3 legged triangular base pattern are the most common. Angle or Pipe
(tubular and solid) for the legs, assembled in sections with a lattice work of
cross braces bolted and designed for medium to heavy loads. The wider the
base, the larger the acceptable antenna load.
As the industry matures - 4 legged structures are becoming more obsolete
due to the additional capital and construction costs and the ongoing change
in technology.

Part Two – What & How ... SST
Self Supporting
• Typical Parts & Pieces
(Structure & Accessories)
• Manufactures
• Foundations
• Assembly and Erection
• Installation & Maintenance
65% of the photos used in this material are from actual projects and referenced by customer & site.
Project drawings and costs information is available upon request. FredTeichmanHTH@gmail.com

SST - Typical Parts
The Tower Section

SST two basic Types – Bolted
Bolted sections – before Hot dip Galv
Based on the manufacture, it could be an All Bolted construction, All Welded or a
combination of the two.
Bolt-together Structures
X-brace designs are available in face sizes
up to 27'. K-brace designs are available up
to 40', and truss leg designs are available
for larger face sizes. The designs
accommodate a wide range of tower
requirements up to 900' in height.

SST Types – Welded – less common
All Welded sections
Based on the manufacture, it could be an All Bolted construction, All Welded or a
combination of the two.
Weld-together Structures
Designed in face widths from 12" to 72".
Straight and tapered sections, with designs
ranging up to 220'.
PiRod Sleeved flange

SST - Typical Parts
The Tower Legs

SST - Typical Parts – Legs
Tubular /Pipe/ Round - Solid and Hollow Leg
Angle Leg
Small Towers sections as legs
Or
Or

SST - Typical Parts
Bracing Designs
K X Z

SST - Typical Designs
“X” Bracing“K” Bracing “Z” Bracing

SST - Typical Parts
The Connection

SST #1 Common Connection – Flange
SST types continued
Circular Flange on Solid Leg
Hexagon Flange on Hollow Leg
Square Flange
there is also
Triangle shape
PiRod’s Sleeved &
special 2 bolt
flange (old school)

SST 2nd Most Common Connections – Plate
Plate Flange used on
on 3 and 4 angle leg
towers

SST - By Who
Manufacture

SST – Manufactures: Who and Where
Is now
Valley NE
Sioux City IA
South Bend IN
Ft Worth TX
Peoria IL
Plymouth IN
Newburg IN
Fremont IN

SST Typical Parts
Accessories
&
Mounts

SST Basic Parts & Accessories – How to climb?
A. Ladder (inside, outside or leg)
or
B. Step Bolts (leg)
Interior climbing
Tower leg is the ladderSafety climb
system
Step bolts - angle
or round tower
leg
This tower has both – step bolts and ladder

SST Typical Parts
1. Mounts
A. Three-sectored mounting frame
B. Side Arm mounts
C.Pipe mounts
2. Cable Support System
A. waveguide ladder
B. T or Cluster Brackets
3. Lighting system (structures 200’ or more)
A. Red Flash
B. White Strobe

SST – #1 Mounts
Source: Comscope & SitePro
Stand off
Arms for
Omni
antennas
M/W pipe
mounts
Universal Sector Frame
(capable of additional vertical
pipes)
Universal Adjustable Slope
Pipe Mount
Mounts are single leg , or across the face leg
to leg mounted
Stand-Off bracket
Face mount

SST – #2 Cable Support Systems
Tee Brackets
Cable Ladder (most common)
Cluster Bracket
Or combination of everything ...

SST – #3 Lighting Systems – Reference
FAA Marking for structures over 200’ or near Airport zone.
Red light flashing requires FAA Orange White paint bands
Strobe requires lights only (day night operations)

SST – #3 Lighting Systems
Old style - 2 bulb Red flashing beacon
*New LED Red beacon and side light
Medium Intensity
White Strobe
Old style - single
side lights
Dual System
Red flashing
and White
Strobe

Monopole Foundations
Foundations

SST FND Types – Pad & Pier and Drilled Caisson
Drilled CaissonPad & Pier
State of WI Genoa WI
X 3

SST Foundations – Pad and Pier
State - Genoa WI
The Pad & Pier requires more area & schedule
but clearly is a more costs effective approach.
34’ x 34’ x 2’3”pad with 7.5’ pier
Anchor Bolts and template plate

The pad is poured continuous and vibrated
to remove air pockets and allow proper flow
in, around and thru rebar.
State - Genoa WI

Once the pad is poured out and cured for
12 to 18 hours , the piers are formed using
Sonotube and poured with the anchor
bolts in place and secured by the template
plate and angles
The pad is then backfilled to
proper site grade

SST Foundations – Drilled Caisson
Drilled Caissons can be installed year round
Typical sizes 4-6’ diameter with depths ranging
from 18 – 28’ +
Rebar cages are
tied prior to
drilling

SST Foundations – Drilled Caisson
MNDOT – Blue Earth MN
One of the Three caissons
Note: the Drill
Rig is used for,
drilling removing
spoils, and lifting
the required
material used in
the foundation
Rebar cage is
lifted into hole
and secured
prior to
pouring
concrete.

SST Foundations – Drilled Caisson finished
Template angles and plates
position the anchor bolts for
proper fit with the bottom
tower section
Leveling jacks, C-Clamps and
proper forming material result in
quality caisson installation
Finished grade and
removed steel caisson
casing on two of the 3
piers
MNDOT – Blue Earth MN

SST Foundation – upside down P&P? – No
MNDOT – Wykoff MN
Drilled caisson shortened in length to
reduce costs, then added an
engineered pad ! This approach
allowed us to be low bidder on 5
additional site
One of three tower legs – the costs to drill
the extra 13’ per twr leg was more
expensive than installing this pad on each
of the three tower legs

SST New Caisson Foundation that is modified
Engineered approach in turning a costly
Drilled caisson into a semi inverted pad
and pier construction. This approach
was presented and state approved on 5
tower sites – MNDOT
MNDOT – Wykoff MN
Once the shortened Caisson was
drilled & cured the excavation,
rebar doweling and pad was
poured added only 5 days to the
schedule.

SST – Offload, Assembly & Erection
Offload
Assembly & Erection

SST Tower Assembly and Erection
What a 330’ SST solid leg heavily loaded tower looks like before it goes vertical
MNDOT – Bicay & Baxter MN
Everything that can be assembled on the ground is completed prior and during erection

K & X
sections
are pre
assembled
Antenna
mounts
Boom truck or
small crane is
used to set
lower sections
and assist in
assembly

SST Tower - Erection with Large Crane 90 - 270 ton
2 – 3 tower
workers
are on the
tower to
receive, pin
and bolts
sections
Sections being set prior to jib
needed
Jib extension added to boom

SST Tower Erection
With
sections pre
assembled
and material
properly
staged, the
time
required for
the crane to
be on site
can be
controlled $$
Topping out !
Weight
is less of
an issue
than
height

Gin Pole and Skid Winch – note the pivot action of the pole to center the load
Crane costs,
availability,
capability,
contractor skill,
weather, and
schedule all play a
role in the decision
to use of a gin pole
vs crane to stack
the tower.

Tower Erection – Winch & Gin Pole process
Double block
to lift the load
and jump the
pole
Double drum
winch allows
dual function
required with
using a gin
pole – raising
the tower
section then
jumping the
pole higher for
the next
section
Gin pole basic use for SST
and Guyeded structures

SST – What goes on
Installing Equipment

Installing Equipment on SST Towers
Once the tower is stack , next is to
Install the equipment. Since the
hourly rate for crane is expensive, the Crew
breaks down the crane (removes jib),
and gets the crane off the project to
stop the billable clock.
Then a block is used at the top or mid point of
the structure and the tower is now part of
the lifting equipment - here shown is a mini
gin pole used to set the m/w antenna
Capstan winch
with foot switch
Single drum
winch with
Rope capstone on
the side

Most Common Equipment – Support Hardware
Here are a few of the most common equipment accessories (support hardware)
used to secure the equipment to tower, on the mounts and into the equipment
enclosure:
Angle Adapter
Round Member Adapter
(with standoff)
Hoisting Grip
Snap-in and Standard hanger

SST Tower for Multiple use – M/W, Cellular, etc
WSDOT – Sumas Mtn
Here shown top view for raising 10’ m/w HP dish.
Note a tag line is used to keep the dish safely away
from the tower as it is raised

Installing & Alignment on SST
AAT – Antenna
Alignment Tool
Digital Level
LTE, PCS, Cellular, M/W
antennas jumpers, etc all need
to be secured and protected
from high winds & extreme
weather conditions
Tools used to Align
the antennas
Important point – 99% of the
antennas are mounted to the
tapered legs of the SST
resulting in consistent effort to
make sure the vertical pipe on
the antenna mount are plumb
Sample mount that adjusts to
the slope of the tower leg
Pendulum
M/W path
gear

SST Typical Service
Maintenance
Up and Down

SST Tower Maintenance – 3 areas
Basic maintenance covers 3 areas:
1. Tower Surface condition (Galvanizing)
2. FAA marking (Paint and lights) if required
3. Confirm no lose bolts (tight)
Most towers are marked
with an identity tag/plate
that references ownership,
manufacture and drawings
Sample
tower
plates
#1 product used in the
field for repairing
damaged galvanizing

SST Tower Maintenance – FAA Marking (Painting)
The FAA has strict guidelines for marking structures over
200’. When specific zoning requirements prevent a tower
owners from using strobe lights, painting the Orange & White
bands on the tower become required. Repainting is a natural
occurrence every 5 – 7 years .
Fade chart is used to determine
if paint condition is compliant
Most Common

SST – Summary & Key Points
• Most Common for Telecom
• Requires More Area
• Taller Heights
• Low Maintenance
• FAA Marking over 200’
• Construct with Crane under 300’(+-)
then gin pole for more !
• Drilled Caisson & Spread footing both
common – costs, customer and skill

Specialized Suppliers & Resources
www.sabretowersandpoles.com
www.valmont.com/valmont-
structures/products/wireless-communication
www.wirelesscomponents.com
Specialty Manufacturing LLC
www.ep-ind.com Fred Teichman
www.linkedin.com/in/fredteichman
www.engend.com
www.primuselectronics.com
www.us-instrument.com
www.wirelessestimator.com

Part 2 Self Supporting tower structures

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