Preface
This is the first edition of CSA Standard S37—M, Antenna Towers and Antenna—Supporting Structures. It is written in SI units and adopts limit states design procedures, but is otherwise only a slightly revised version of CSA Standard S37—1976, with which it is intended to coexist.
Extensive reference is made throughout this Standard to CSA Standards CAN3—S16.1—M, S157, and CAN3—A23.3—M for designs in steel, aluminum, and concrete, respectively.
This edition includes a brief section on concrete towers, although few such structures have been built in Canada. It was the opinion of the Committee that this Standard should give some direction to a designer on such items as loads and reference standards. A more comprehensive Standard for concrete towers is desirable, but this subject might be better covered in a separate Standard on self—supporting concrete structures that would include chimneys, antenna—supporting structures, and other similar structures.
The subject of dynamic wind effects on guyed towers is one that requires further study by the Committee for preparation of the next edition of the Standard. It is recognized that some towers, and particularly tall guyed structures, may be subject to vibrations caused by .vortex shedding, aero—dynamic instability, or other wind effects.
This Standard was prepared by the Technical Committee on Antennas and Towers under the jurisdiction of the Steering Committee on Structures and was formally approved by these Committees.
Scope
1.1
This Standard applies to the design, fabrication, and erection of antenna towers and antenna—supporting structures of steel, aluminum, concrete, and timber. It also applies to those components, such as guys and foundations, which form an integral part of the supporting structure.
1.2
This Standard is not intended to apply to antennas, antenna arrays, antenna assemblies, amateur or domestic antenna—supporting structures, or ship or mobile equipment, although, at the discretion of the engineer, this Standard may be adopted in whole or in part for such applications.
1.3
Compliance with this Standard does not relieve any person from the responsibility of observing local, provincial, and federal building, fire, and safety regulations, and the requirements of the Department of Communications and Transport Canada, pertaining to antenna towers and antenna—supporting structures.
1.4
This Standard does not cover the effects of earthquake or the dynamic effects of wind, except for those upon concrete towers. It is recognized that some towers, and in particular tall guyed structures, may be subject to vibrations caused by vortex shedding, aerodynamic instability, or other wind effects. These dynamic loads may be more critical than the static loads specified in this Standard. The dynamic effect of wind may be determined by experimental methods or by dynamic analysis.
1.5
This Standard is intended to cover the requirements for most antenna towers and antenna—supporting structures, but it is recognized that some structures, which are unusual in themselves (for their height or shape, or for the shape and size of individual members) or unusual in the topographical, geological, or climatic conditions of their location, may not be adequately covered by the Standard.
1.6
Where reference is made to other publications, such references shall be considered to refer to the latest edition approved by the organization issuing that publication, unless specifically noted otherwise.
Note: Reference is made to Appendix A of the Canadian Electrical Code, Part I, which covers requirements for antenna systems.
