Volume_9_-Tower_Design_and_Construction_Design_Standards.doc

Volume 1 – CIO Radio System Technical Standards USDA Forest Service

The Chief Information Office

Radio System Technical Standards

VOLUME 9

TOWER DESIGN AND CONSTRUCTION STANDARDS

Prepared for USDA Forest Service

FINAL Version 1.1.3 18 September 2008

Prepared by:

Communications Line of Service Radio Modernization Program Team

DOCUMENT HISTORY

RELEASE

LABEL

Debra Marohn

ADD RMP TEAM

Edited document, added acronyms RMP Team and Roger Garza Debra Marohn

REviewers

TABLE OF CONTENTS

11.0 Introduction

22.0 TOWER construction

22.1 General

22.2 Forest Service Structural Standards

42.3 Roles and Responsibilities

42.3.1 Zone Manager

52.3.2 Radio Design and Frequency Management (RD&FM)

52.3.3 CIO Radio Architect and CIO Budget Analyst

52.3.4 Contractor

63.0 Tower maintenance

74.0 Tower Inspection

74.1 Annual Inspections

74.2 Pre-Climb Inspections

8APPENDIX A – GLOSSARY

12APPENDIX B – ANNUAL TOWER INSPECTION CHECKLIST

Section 1

3.0 Introduction

Volume 9 establishes guidance for the regulation of towers, provides uniform direction for every Forest Service-owned tower, and establishes technical standards to accomplish the primary objective of providing the correct platform for mounting Forest Service (FS) antennas.

While CIO Radio System Technical Standards Volume 11 (Radio Operations Safety and Security Standards) establishes personnel safety standards and procedures for climbing towers, this volume provides technical specifications and structural standards for towers and guidelines for tower inspection. This volume also establishes roles for the FS personnel and contractors involved in tower contracts.

The implementation of these standards will result in high-level performance of Forest Service towers, their design and construction. In addition, these standards will assist the Forest Service in providing safe, reliable, modern towers on which to work as well as providing cost-effective tower standardization.

SECTION 2

2.0 TOWER construction

Structural standards and roles/responsibilities for new or existing towers are described in this section.

2.1 General

Tower contracts are site-specific and custom built for each site by qualified contractors, including equipment, mobilization and demobilization. Forest Service personnel will not install or modify towers. (Any deviation from this construct or modify rule will be handled through the change management process; however, any structural modifications made to a tower, including adding another section, may nullify the warranty and the PE certification. Such modifications must be resubmitted for recertification/warranty approval.)

Before developing the Tower Contract, the Zone Manager or assigned Project Manager meet with the Local FS Unit to understand the tower requirements, including the National Environmental Policy Act (NEPA). A full NEPA may be required for new sites; existing sites may require an abbreviated NEPA; or the Unit may elect to employ their ‘categorical exemption’ authority.

2.2 Forest Service Structural Standards

Following are the minimum standards required by the Forest Service for towers:

1. Tower will not be installed within falling distance of electrical or telephone lines.

2. Towers strength requirements must meet the requirements in ANSI/TIA/EIA-222-g “Structural Standards for Steel Towers and Antenna Supporting Structures”.

3. Tower height will be determined based on minimal acceptable Radio Frequency (RF) propagation for the area of required coverage.

4. Tower loading will not exceed the loading indicated on the applicable Professional Engineer-stamped tower specifications and/or drawings. Towers will be designed for 100% future antenna growth. Any additional solar arrays or microwave dishes to be attached to the tower will require reengineering of the tower by a licensed Contractor.

5. Tower grounding will be in accordance with local and national codes holding precedence and with the CIO Radio System Technical Standards Volume 7 (Lightning Protection and Grounding Standards).

6. Tower hazards, painting, and obstruction lighting will meet the requirements in http://www.faa.gov/airports_airtraffic/airports/regional_guidance/central/construction/part77/.

7. As specified in the contract, self-supporting towers are recommended; wherever possible, the use of guy wires will be avoided. Some applications may require solid core legs based on design requirements.

8. Solid core tower construction is preferred. Some applications may require other than solid core towers based on design requirements. Alternative solutions will be considered on an exception basis after contractor proposal and certification by PE of suitability to the location and site. The responsible Zone Manager and the RD&FM Manager must approve and sign for all exceptions.

9. The contract must verify that the actual site soil parameters meet or exceed E.I.A.”Normal” soil parameters and that the depth of standard foundations is adequate based on the frost penetration and/or zone seasonal moisture variation at the site. Foundation design modifications may be required in the event “Normal” soil parameters are not applicable for the actual subsurface conditions encountered.

10. Foundation designs must be in accordance with ANSI/TIA/EIA-222-g-2005 “Structural Standards for Steel Antenna Towers and Antenna Supporting Structures”. The foundation will be designed for actual soil conditions.

11. Foundation installation will be the responsibility of Contractor, with appropriate engineering and/or management skills. Construction will be in accordance with generally accepted installation practices.

12. Work will be in accordance with local codes, safety regulations and unless otherwise noted, the latest revision of ACI 318, “Building Code Requirements for Reinforced Concrete”.

13. Concrete materials, proportions of concrete materials, durability requirements, reinforcement requirements, will meet or exceed the requirements of local, state and ACI 318 regulations.

14. Tower connections will be bolted with lock washers. Welding of components to tower after manufacture will not be allowed. Welding ground connections are only permissible if exothermic welds are used and applied within Tower OEM specifications.

15. Vertical bolts will be oriented with the head positioned downwards, as specified in the Tower OEM specification.

16. Cable lock safety device assemblies and climbing ladders will be installed on all new FS tower installations.

17. All Forest Service (FS) towers with ladders must meet the standards for safety as defined in OSHA CFR 1910.268 (h) (2), as follows:

The spacing between steps or rungs permanently installed on poles and towers shall be no more than 18 inches (36 inches on any one side). This requirement also applies to fixed ladders on towers, when towers are so equipped. Spacing between steps shall be uniform above the initial unstepped section, except where working, standing, or access steps are required. Fixed ladder rungs and step rungs for poles and towers shall have a minimum diameter of 5/8". Fixed ladder rungs shall have a minimum clear width of 12 inches. Steps for poles and towers shall have a minimum clear width of 4½ inches. The spacing between detachable steps may not exceed 30 inches on any one side, and these steps shall be properly secured when in use.

18. All FS communications towers will be inspected annually or per manufacturer’s recommendations for corrosion, loose bolts, and grounding integrity by qualified personnel.

19. All rules and regulations pertaining to Telecommunications Tower and Pole Climbing and Personal Protective Equipment must be adhered to. Reference 29 CFR 1910.208, 29 CFR 1910.132 (f) FSH 6709.11 sec 26.62 and FSH 6709.11 sec 72.

20. A warning plate, (anti-climb warning sign) will be installed in a highly visible location on the tower. If a guyed tower is used, a minimum of two “Watch for Wires” warning plates will be installed.

21. Safety Climb Attachments and Devices will be installed and must meet the requirements in ANSI/A14.3-1992 Section 7 and Section 12.0-12.5 and Annex 1: Climber Attachments.

22. No commercial or other cooperating agency tower may be climbed that does not meet the OSHA CFR 1910.268(h)(2) tower construction standard.

2.3 Roles and Responsibilities

The following describes the CTO business authority for project initiation and funding approval.

2.3.1 Zone Manager

The FS Communications Line of Service (CommLOS) Zone Manager oversees and manages all projects related to telecommunications within a specific geographical area. The Zone Manager acts on authority under FS CTO Radio Program authority for CommLOS (Information Solutions Organization) project initiation and business management.

Zone Manager responsibilities:

· Together with Radio Design and Frequency Management (RD&FM), the Zone Manager is responsible for decision and funding of tower projects.

· The Zone Manager is responsible for conduct and communications of project business with local units.

Service Area Lead Technician (SAT) responsibilities:

· As the Zone Manager’s local representative on a Forest, the SA Lead/Tech execute under Zone direction and authority.

· At the Zone Manager’s discretion the SAT may or may not hold any assignment applicable to local tower projects.

· Neither the SA Lead nor SA Tech initiate Forest communications or solicit Forest assistance regarding tower replacement without first engaging the Zone Manager.

Project Manager (PM) responsibilities:

· The PM acts under Zone Manager authority to manage a particular project.

2.3.2 Radio Design and Frequency Management (RD&FM) The FS CommLOS Radio Design & Frequency Management (RD&FM) group provides forest system design, frequency management and system assessment.

RD&FM responsibilities:

· RD&FM acts on project-specific delivery requirements to the Zone.

· Together, the Zone Manager and RD&FM are responsible for decision and funding of tower projects.

2.3.3 CIO Radio Architect and CIO Budget Analyst

The FS CIO Radio Architect approves the Radio Program of Work and specific projects submitted by the CommLOS.

The FS CIO Budget Analyst verifies that funding is available for Radio Program purchases orders.

Joint CIO Radio Architect and CIO Budget Analyst responsibilities:

· Together, the CIO Radio Architect and CIO Budget Analyst have project funding authority.

2.3.4 Contractor

The Contractor works under authority of the FS Contracting Officer to evaluate, design, construct, install, modify and/or demolish towers according to the Tower Contract.

The Contractor must comply with the requirements in this volume as well as the CIO Radio System Technical Standards Volume 1 (Overview), Product Requirements.

SECTION 3

3.0 Tower maintenance

Tower maintenance includes visual inspections of the tower during each site visit to maintain the integrity, safety and operability of the tower. If corrective action is required, a service request is submitted for remediation.

SECTION 4

4.0 Tower Inspection

Tower inspections will be performed annually and before each climb.

4.1 Annual Inspections

Annually, towers will be inspected by a competent technician trained in tower inspection. Electronics Technician or the local Forest Engineer using the Tower Inspection Checklist in Appendix B. A record of this annual inspection will be completed for each tower and stored in the radio shop for a period of not less than 10 years.

The inspection will be looking for unsafe, dilapidated or deteriorated conditions. These conditions bring the structural integrity of the tower into question, and can include conditions with structural members, corrosion, foundation, or any other condition that causes a safety concern as to structural stability.

Unsafe towers will not be climbed under any circumstances. If they are structurally sound to hold antennas, work may be done by means that will not cause stress on the tower from a ladder at a height of no more than 20 feet or from a high-reach truck or other aerial lift vehicle. If the tower is out of compliance with standards, it is considered to be a high risk to safety. Tower facilities in this condition are structurally sound, but are not in compliance with OSHA standards or do not meet the requirements of ANSI/TIA/EIA-222-g, “Structural Standards for Steel Towers and Antenna Supporting Structures”.

Short towers (up to 20 feet in height) that are in use and are attached to buildings, etc. may be accessed via an appropriate ladder, the roof of a building, or an aerial lift truck if work can be accomplished safely. In such cases, the tower will be labeled with warning signs not to climb, and kept in service, with the situation documented and maintained as part of the facility records.

4.2 Pre-Climb Inspections

FS personnel who climb towers are both Class A (Basic Climber) and Class B (Skilled Climber). Before each climb, towers will be inspected as described in CIO Radio System Technical Standards Volume 11 (Radio Operations Safety and Security Standards).

APPENDIX A – GLOSSARY

ACRONYMS

ACI

American Concrete Institute

AGAR

USDA Department Regulations/Directives

ANSI

American National Standards Institute

CE

Civil Engineer

CFR

Code of Federal Regulations

CIO

Chief Information Office (formerly Information Resources Management) – organization operating under the Chief of the Forest Service.

CO

Contracting Officer

CommLOS Communications Line of Service – organization operating under the Forest Service Information Services Organization.

COR

Contracting Officers Representative

COTR

Contracting Officers Technical Representative

EE

Electrical Engineer

EIA

Electronic Industries Alliance (previously Electronic Industries Association) – a trade organization of manufacturers that sets standards for use of its member companies, conducts educational programs, and lobbies in Washington for its members’ collective prosperity.

ET

Electronics Technician

FAR

Federal Acquisition Regulations

FS

Forest Service – a department under the United States Department of Agriculture.

FSH

Forest Service Handbook

GSA

General Services Administration

IAS

Integrated Acquisition System – the procurement system for the FS.

IGCE

Independent Government Cost Estimate

ISO

Information Solutions Organization – organization operating under the CIO.

NEPA

National Environmental Policy Act

OSHA

Occupational Safety and Health Administration

PE

Professional Engineer

PR

Purchase Requisition

RF

Radio Frequency

RFP

Request for Proposal

SAT

Service Area Technician

SE

Structural Engineer

SR

Service Request

TIA

Telecommunications Industry Association – TIA represents the telecommunications industry in association with the Electronics Industry Association (EIA). TIA represents companies that provide communications materials, products, systems, distribution services, and professional services in the U.S. and around the world.

TIA/EIA

Telecommunications Industry Association/Electronics Industry Association

UHF

Ultra High Frequency

USDA

United States Department of Agriculture

USFS

US Forest Service

TERMS

ANSI/TIA/EIA-222-g – “Structural Standards for Steel Towers and Antenna Supporting Structures”.

Climbers – As described in the ANSI/TIA-222-g Standard, the types of climbers are used to describe the two major skill and experience levels of climbers. FS personnel who climb FS towers are both Class A and B.

· Class A – Authorized (Basic) Climber – an individual with the physical capabilities to climb, who may or may not have previous climbing experience but has training in fall protection regulations, the equipment that applies to the field, including instruction for their proper use; able to climb designated fixed access routes equipped with safety climb devices.

· Class B – Competent (Skilled) Climber – an individual with the physical capabilities to climb, has actual climbing experience and training in fall protection regulations, including the equipment that applies to the field, and who is capable of identifying existing and potential fall hazards; and who has the authority to take prompt corrective action to eliminate those hazards; and who is able to safely climb a structure away from fixed access routes.

Exposure Categories – As described in the ANSI/TIA/EIA-222-g Standard, the exposure categories are used to describe the three major environments in which structures are located. The majority of the towers built by the FS are in Exposure C.

· Exposure B – Structures located within urban or suburban areas. The structure is surrounded, with numerous and closely spaced obstructions the size of a single-family dwelling or larger, in all directions for a distance of at least 2360’ or ten times the height of the structure, whichever is greater.

· Exposure C – Structures located in open terrain scattered with obstructions that are less than 30’ tall. This exposure includes terrain in hurricane prone regions including flat, open country, grasslands or shorelines.

· Exposure D – Structures located in flat, unobstructed shoreline exposed to wind flowing over open water, excluding shorelines in hurricane-prone regions. The exposure includes terrain including inland waterways, lakes, smooth mud flats, salt flats, and other similar terrain. The exposure extends inland 660’ or ten times the height of the structure, whichever is greater.

Structure Classification – As described in the ANSI/TIA/EIA-222-g Standard, the structure classifications are used to describe three general risk factors for various structures. The majority of the towers built by the FS are in Class II and Class III.

· Class I – The least expensive of the three classes, in which the risk factors of hazard to human life, damage to property, and service delay are all considered to be “low”. New structures in this classification are used for services that are optional or in which a delay in returning the services would be acceptable. These applications include: residential wireless and conventional 2-way radio communication; television, radio and scanner reception; wireless cable; amateur and CB radio communications.

· Class II – The default classification, in which the risk factors of hazard to human life, damage to property, and service delay are all considered to be “medium”. New structures in this classification are used for services that may be provided by other means. These applications include: commercial wireless communications; television and radio broadcasting; cellular, PCS, CATV, and microwave communications.

· Class III – The most costly of the three classes, in which the risk factors of hazard to human life, damage to property, and service delay are all considered to be “high”. New structures in this classification are used primarily for essential communications. These applications include: Civil or national defense; emergency, rescue or disaster operations; military and navigation facilities.

APPENDIX B – ANNUAL TOWER INSPECTION CHECKLIST

Tower Inspection Worksheet

Combined Radio Strike Team

Version 1.4 08/22/08

Prepared by: _____________________ _____________________ Phone:_____________________________

E-mail: ________________________________________________ Date Prepared:______________________

Site Name: _____________________________________________ Forest:_____________________________

District: ________________________________________________ Zone:______________________________

Local Service Technician: ______________________________________ Phone:______________________ E-mail: _______________________________________________________

A: SITE ACCESS/LOCATION

Site Latitude: ______________________________

Site Longitude: _____________________________

Site Elevation: ________________________ ft.

Is there a perimeter fence? Y N Gate Locked? Y N Combo or Key (pick one) ___________ Key access (Point of Contact): ___________________________________ Phone: _________________________

B: SITE INFORMATION

Site/Tower Hazards? (Nearby cliffs, loose/broken guy wires etc. Include all towers including non-FS towers, etc.)

Please describe: _______________________________________________________________________________

High traffic area? (Foot traffic, camp sites, off road traffic, etc.) Please describe: __________________________

Noticeable vandalism? Please describe: __________________________________________________________

Safety signs posted on tower/perimeter? Y N

C: TOWER INFORMATION

Manufacturer: ___________________________________ Model: ____________________________________

Tower Height: ______________ ft.

Year installed: _______________

Type: (stand alone, monopole, etc.) ________________________________________________________________

Is this an FS lookout tower? Y N Guyed? Y N

Safeclimb device installed? Y N Type __________________________________ (Is device 3/8” or ½” cable or pipe?)

Condition of Safeclimb: ________________________________________________________________________ (Inspect connection points on top and bottom of Safeclimb, check for looseness, corrosion, and strength. Look for rust, corrosion, or kinks. Check looseness of cable, if cable makes a wave or whipping action it must be tightened. Ensure strength of cable by hanging on cable with a cable grab.

Number of antennae on tower: ___________

Microwave dishes: ___________________ Other appurtenances: __________________________________________________________________________ Are appurtenances appropriate for tower? (Types of appurtenances that are not appropriate for a tower include equipment that does not relate to radio or wireless transmission or power for equipment)

Appurtenances in climb path: __________________________________________________________________ Explanation of climb path (Tower leg bolts, climb ladder, etc.): _______________________________________ Plumb and Twist of tower (To check plumb and twist stand away from tower and hold a level at arms length and compare to the tower. If tower is straight and has no twist, it passes).

Is tower structurally sound and suitable for climbing? (If tower has excessive rust, corrosion, missing hardware, cracks, or any issues not covered in check sheet include them in this section).

Overall condition of tower (missing bolts, torqued or bent segments, etc.):

D: FOUNDATION

Type of foundation: _______________________________ Above/below ground: _______________________ Damage to foundation (cracks, corrosion, etc.) Inspect above and below ground level:

Tower to foundation point of contact condition (corrosion, missing nuts or locknuts, etc.): __________________ Is foundation satisfactory for climbing and/or load bearing? Y N (Check for splitting, cracking, chipped or broken, sinking into ground or movement)

If not, explain ________________________________________________________________________________

E: GUYS

Point of daylight corrosion? Y N (Point of daylight refers to the point at which the anchor shaft for guys exits the ground)

Explain: _____________________________________________________________________________________ Guy Foundation condition: _____________________________________________________________________ Soil Condition (Inspect soil around guy anchors, look for soil looseness, sinking guys, or soil bulging indicating guys being pulled up from soil): ___________________________________________________________________ Stress level of guy wires (Guy wire should only easily shake about halfway up. Rigorously shake guy wire up and down, if wire is hard to shake it is too tight, if wire rises to a point that it makes an oval shape between its top and bottom apex it is too slack. Guy wire should not gallop or make a wave motion.):____________________________ Condition of guy safeties (thimbles, preform, turnbuckle threads at limit, missing parts, etc.): _________________ Are anchor points level to base of tower? (Anchor points should be at a level point elevation wise to the base of the tower, explain how far above or below if they are not consistent) _____________________________________ Fencing around guy wires? Y N Condition: ________________________________________________ Guy/Tower connection condition: ________________________________________________________________ Overall condition of guy wires: __________________________________________________________________

F: GROUNDING

Type of ground (AWG, mesh): __________________________ Type of soil: ________________________ Ground wire welded, crimped or bolted to tower legs? ______________________________________________ All legs grounded? Y N If no, is there a reasonable explanation? _________________________________

Does ground wire go through foundation? Y N Site grounded by Halo? Y N

Does ground wire connect to site halo? Y N

Type of connection to halo ______________________________________________ Type of Halo (Driven rod, chemical rod, strap, etc…) _________________________ Is Tower ground connected to shelter ground? Y N

Meter reading on all exposed ground wires:

(Use only approved clamp style ground resistivity meter)

Lightning Protection (Lightning rods, etc.): ________________________________________________________ Is grounding system acceptable? Y N If not, what must be done to bring it to an acceptable level?

G: TRANSMISSION CABLING

How are the transmission cables fixed to the tower?_________________________________________________ Condition of transmission lines: _________________________________________________________________ Is there a ground kit on each cable? Y N

Condition __________________________________ Is there a cable ladder? Y N

Condition __________________________________ Are transmission lines color coded for easy recognition? Y N

Is there an ice tray between tower and shelter? Y N Condition ________________________________

NOTES:

Notes/Points of interest concerning anything not covered in checklist:

Take in to account that one does not need technical reasons not to climb, if there are reasons that you feel personally should stop one from climbing a structure please address them here.

________________________________________Picture Log

A: Site Access/Location

1._________________ ___________________________________________________________________

2.________________________________ ____________________________________________________

3._____________________________________________________ _______________________________

4.___________________________________________________________________ _________________

5.__________________________________________________________________ __________________ B: Site Information

3._____________________________________________________ _______________________________

4.___________________________________________________________________ _________________

C: Tower Information

3._____________________________________________________ _______________________________

4.___________________________________________________________________ _________________

D: Foundation

3._____________________________________________________ _______________________________

4.___________________________________________________________________ _________________

E: Guys

3._____________________________________________________ _______________________________

4.___________________________________________________________________ _________________

F: Grounding

3._____________________________________________________ _______________________________

4.___________________________________________________________________ _________________

G: Transmission Cabling

3._____________________________________________________ _______________________________

4.___________________________________________________________________ _________________

5.__________________________________________________________________ __________________

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