Evolution of design standards and recorded failures of guyed towers in Canada

This paper demonstrates that the failure rate for guyed towers designed to earlier versions of CAN-CSA-S37 Standard Antennas, Towers and is generally unacceptably high. General comments on standard developments and various design philosophies are presented. The evolution of the Canadian standard for the design of guyed towers is also examined, as deficiencies in earlier versions of S37 are partly accountable for the high observed failure rate. Other international standards for the design and analysis of guyed towers are also reviewed for their approach towards the upgrading of existing towers. Since guyed telecommunication towers are often reviewed for addition of new antennas, upgrading to the strength levels of the most recent edition of the standard - as required in many cases - can be very expensive. Yet, in many cases, much of this expense is unjustified for a variety of reasons. This paper proposes the need for the development of upgrading guidelines and further development work on S37.