The purpose of this bulletin is to provide site owners and contractors with recommended best practices for identifying and inspecting shrouded tripole towers that may be potentially affected by Galloping vibrations and for mitigating the potential damages caused by repetitive Galloping vibrations, up to and including structural fatigue causing failure. (For more information about the effects of Galloping vibrations, please see STAC Alert 0003 here.)
This bulletin also provides recommendations relating to inspection frequency of shrouded monopoles, as well as mitigation strategies for new towers. These recommendations are expected to serve as stop-gap measures until the release of the CSA S37-18 standard, which may provide further guidance on the design requirements.
Please note that a follow-up bulletin will also be provided shortly to address similar issues relating to flag poles and shrouded monopoles.
Click here or on the images below to download a copy of this bulletin.