The Engineering Guidelines and Practices Committee identifies the best safety practices related to telecommunications engineering from a design perspective, such as determining which design conventions facilitate a safer climbing environment.

Committee Lead

Jonathan Walsh, Tiller Engineering

UPDATED: January, 2020

While tower engineers take preventative steps to protect steel components from corrosion, buried anchor shafts that help support guyed towers are still at risk of corroding over an extended period of time. The STAC Anchor Shaft Corrosion project is bringing together leading engineers and carrier representatives to identify proper anchor shaft protection, inspection and replacement practices.

This project team is also developing resources to help site-owners better understand the factors that affect corrosion rates, and to provide them with the tools to make informed decisions about where best to locate their guyed towers to avoid risk of anchor shaft corrosion.

Resources developed through the STAC Anchor Shaft Corrosion Project Team so far include:

STAC Study – Mitigating Anchor Shaft Corrosion and Related Tower Failures

This document provides information about how corrosion affects below-grade steel anchor shafts on guyed communications towers, as well as factors that can affect corrosion rates.

The intent of this document is to provide communication tower owners and operators with a resource to help inform decisions relating to guy tower siting, anchor shaft corrosion protection and anchor shaft inspections. Notably, however, this document is not prescriptive and is not intended to provide explicit direction on how to apply protective measures or conduct inspections. Rather, this document outlines factors that companies and crews should consider when studying protection or inspection options and priorities.

Click here to download the STAC Study – Mitigating Anchor Shaft Corrosion and Related Tower Failures

Recommended Anchor Shaft Inspection Priority Matrix
This matrix is designed to assist communications tower owners assess the relative urgency of recommended anchor shaft inspections for each guyed tower in their inventory. Importantly, there may be additional considerations not accounted for in this matrix that may justify increasing the inspection priority for individual or groups of towers.

Click here to download the Recommended Anchor Shaft Inspection Priority Matrix

Members of the STAC Anchor Shaft Corrosion Project Team continue to hold biweekly meetings aimed at developing an additional product for tower contractors: the STAC Dig-to-Block Inspection Checklist. This checklist will provide step-by-step instructions for completing most dig-to-block inspections, as identified by a team of experienced contractors, tower engineers and site owners.

Now in the final stages of development, it is expected that the STAC Dig-to-Block Inspection Checklist will be available to STAC members in spring 2020. Please contact info@stacouncil.ca with any questions, or to get involved in the STAC Anchor Shaft Corrosion Project Team.

Project Volunteers
Jonathan Walsh, TEI (Project Lead)
Ali Raja, Rogers
Asma Arefeen, Rogers
Brent Hrywkiw, Stantec
Clay Parchewsky, WesTower
Darren Mann, WesTower
Ernesto Guevara-Ortiz, TELUS
Frank Tang, TELUS
Gregory Gasbarre, Titan AEX
Hany Danial, Rogers
Jason Bartsch, SaskTel
Jody Ali, Bell
Michael Morgan, P-Sec
Randy Caroll, WesTower
Serge Charron, SBA
Wolfgang Fieltsch, Stantec

Project Resources
STAC Recommended Anchor Shaft Inspection Priority Matrix
STAC 2017 – Guy Anchor Corrosion – Craig Snyder and Bart Roberts – AnchorGuard
STAC 2017 – Guy Wire Tensioning – Trevor Bolt – Varcon
STAC 2017 – Guy Wire Tensioning – Gregory Gasbarre – Titan AEX
CSA S37 – Annex F: Corrosion protection of guy anchorages (excerpt)
National Soil Database: Soils of Canada (map)

For more information about this project please contact info@stacouncil.ca.

UPDATE: January, 2020

Since its inception in early 2016, STAC has worked to advance the industry’s use and understanding of site-specific wind load calculations through a variety of means.

This includes efforts in 2016 by STAC and its members to work with Environment Canada to help the federal department communicate changes made to the department’s wind loading calculations. On June 1, Environment Canada released a memo that addresses each of the following issues with regards to these changes:

a.) an overview of how the changes in roughness coefficients could affect wind pressure values
b.) an overview on which cases might produce higher wind pressure values than before
c.) recommendations on when it might be useful for Environment Canada to perform a reanalysis

The Environment Canada memo can be viewed and downloaded here.

In early 2018, STAC also worked with Weisman Consultants to develop and host a webinar for STAC Members that looked at how the Weisman brothers and International Climatic Evaluation (I.C.E.) calculate site-specific wind loads, and provided additional context for interpreting the data they provide.

Recordings of the two-part webinar as well as presentation slides can all be found in the STAC Hot Topics blog post here.

STAC also hosted a session on site-specific wind load calculations at the STAC 2017 Conference & Exhibition in Niagara Falls, ON, featuring presentations from both I.C.E. and Environment Canada. Slides from each of these presentations can be downloaded via the following links:

Ka-Hing Yau and Phil Jarrett (Environment and Climate Change Canada)
Simon Weisman (International Climate Evaluation)

Project Resources
STAC Site-Specific Wind Load Calculations Webinar with International Climatic Evaluation Inc. (I.C.E.)
STAC 2017 – Site-Specific Wind Load Calculations – Ka-Hing Yau and Phil Jarrett – Environment and Climate Change Canada
• STAC 2017 – Site-Specific Wind Load Calculations – Simon Weisman – Guymast
Environment Canada Memo on Site-Specific Wind Load Calculation Changes

UPDATED: January, 2020

Shortly after STAC’s launch in early 2016, members of the STAC Steering Committee and the Canadian tower engineering community identified federal anchorage requirements as an issue of concern in relation to existing pinwheel mounts across the country. Specifically, STAC members were concerned about the federal requirement that any point on a structure that would be used for fall protection anchorage be capable of withstanding 17.8 kN of force, as there were significant worries that many pinwheel mounts did not meet this threshold.

In early 2017, STAC released a document – STAC Worker Antenna Mount Access: Current & Best Practices – recommending that tower climbers avoid tying off to a pinwheel mount, except for work-positioning purposes. The CSA S37 technical committee referenced this STAC document in its 2018 revision and provided detailed instruction on where climbers are permitted to tie-off to a tower or mount.

In summer 2019, the federal government released new fall protection regulations under the Canada Occupational Health and Safety Regulations, Part XII. Following this update, STAC has assessed that the federal regulations no longer contain the 17.8 kN requirement, though STAC is still awaiting confirmation from ESDC as of January, 2020.

While STAC will work to update or recall this document after consulting with federal regulators and the appropriate STAC project team members, STAC members can still download the STAC Worker Antenna Mount Access: Current & Best Practices document in the meantime.

Project Volunteers
Jonathan Walsh, TEI
Jody Ali, Bell
Asma Arefeen, Rogers
Serge Areseneault, WSP
Blair Bittner, WesTower
Trevor Bolt, Varcon
Jacques Bredenkamp, Nabatech
Jordan Camplin, Excel Tower
Cesar Galvez, Telecon
Marina Guerra, Bell
Iain Harrison, P-Sec
Gordon Lyman, eSystem Training Solutions
Clay Parchewsky, WesTower
Ali Raja, Rogers
Simon Weisman, Guymast

Project Resources
Canada Occupational Health and Safety Regulations: 12.06 (Fall Protection) [Updated as of December 2019]
• STAC – Worker Antenna Mount Access – Current & Best Practices
STAC 2016 – Hot Topics in Tower Engineering: Pinwheels and Fall Arrest – Panel Slides
Fall Arrest Anchor Requirements by Province
Case Study of Anchor Point Strength: Step Bolts
O. Reg. 213/91 (regulation for construction projects)(s.26: fall protection)

For more information about this project including available volunteer opportunities, please contact Nicholas Kyonka – STAC Program Director – or Jonathan Walsh – STAC Engineering Guidelines & Practices Committee Lead.

The STAC Engineering Guidelines and Practices Committee is asking STAC members to share available studies and other information about different tower reinforcing solutions that have been tested at university labs, particularly those that relate to leg reinforcement.

To submit a study or study excerpt – or for additional information about this request – please email STAC staff at info@stacouncil.ca or contact STAC Engineering Guidelines & Practices Committee Lead Jonathan Walsh.

UPDATED: January, 2019

Members of the STAC U-Bolt Failure Project Team worked in the summer of 2018 to assist the CSA S37 technical committee in its review of new stress factor calculations for U-Bolts, as part of the 2018 revision of the standard.

Project Leads
Serge Arseneault, WSP
Sean Hayman, Varcon
Iain Harrison, P-Sec

Project Volunteers
Cesar Galvez, Telecon
Randy Caroll, WesTower
Khurram Javed, Bell
Ali Raja, Rogers
Frank Tang, TELUS
Jonathan Walsh, TEI
Walter Wannamaker, Vertical Specialties
Simon Weisman, Guymast

UPDATED: January, 2020

STAC has been monitoring issues relating to the effects of vortex shedding and galloping vibrations on communications towers since this issue was first identified in the Canadian industry in late 2017.

The STAC Tower Damping Project Team was formed in spring 2019 with the goal of helping to address recent tower industry issues relating to galloping vibrations and vortex shedding and their effects on some monopoles and shrouded tripoles. The project team, which now includes more than 50 STAC members, quickly identified two primary objectives:

• Sharing information about tower damping ratio measurement methodologies
• Commissioning a study that will identify factors that contribute to galloping vibrations and/or vortex shedding, and/or which will help identify proper procedures for measuring damping ratios on existing structures.

In recent months, STAC has also worked with Canadian tower owners to collect, aggregate and analyze data relating to Canadian communications towers that have been affected by galloping vibrations or vortex shedding, as well as data relating to in-field tower damping ratio measurements. In order to facilitate this project component, Tiller Engineering Inc. has agreed to withhold from pursuing any contracts performing tower damping measurements until after the completion of this project component, so as to provide independent and fair third-party analysis of the collected data.

Project Resources
STAC Alert: SA-0003 – Fatigue and Vibration of Shrouded Tripoles and Shrouded Monopoles Resulting in Weld Cracks at Connections and Base Plate
Alerte du CSPA: SA-0003 – Bris de soudure sur structures tripôles et monopôles blindées imputables à la fatigue et aux vibrations)
STAC Bulletin: SB-0001 – Shrouded Tripoles and Galloping Vibrations
CSPA Bulletin: SB-0001 – Problèmes de vibrations dans les tripôles – Recommandations d’inspection et de mesures d’atténuation
STAC Bulletin: SB-0002 – Shrouded Monopoles and Vortex Shedding Vibrations
CSPA Bulletin: SB-0002 – Problèmes de décollement de tourbillon dans les monopôles – Recommandations d’inspection et de mesures d’atténuation
STAC CSA S37 – Annex N Webinar Slides
STAC 2018 Presentation – CSA S37 Revision (Presentation by Marina Guerra, Bell)
STAC 2018 Presentation – CSA S37 Revision (Presentation by John Wahba, Turris Corp.)
STAC 2019 Presentation – S37 FAQ (Presentation by John Wahba, Turris Corp.)

Please contact info@stacouncil.ca for additional information about this project or to register for this STAC project team.

UPDATED: January, 2020

STAC is working with tower owners and the consultant engineer community to build structural analysis and design drawing templates with a goal of increasing harmonization of these reports across the industry.

In the first leg of this project, STAC project team members have been working to develop a base structural analysis template that will help ensure that SA reports include all of the information required by the CSA S37 standard or the tower owners. This effort is also designed to eliminate unnecessary, time-consuming components found in some structural analysis reports (either as requested by tower owners or as recommended by consultant engineers).

The next portion of this project will identify information that should be contained in all design drawings, and to develop optional design drawing templates that will be made available to STAC consultant engineers to use as they deem fit.

Project Volunteers
Jonathan Walsh, TEI
Alexandru Talmacean, Trigenex
Asma Arefeen, Rogers
Benjamin Faucher, Pinargon
Blair Bittner, WesTower
Brent Hrywkiw, Forbes Bros Ltd.
Cesar Galvez, Telecon
Dany Toulouse, Pinargon
Diana Samy, Rogers
Frank Tang, TELUS
Iain Harrison, TEP Canada
Ioan Giosan, Valmont
Laura Marciniwe, Teletek Structures
Di Franco, Marco, WSP
Mihaela Onita, Videotron
Michael Pan, Wesbell
Mirjana Lukac, Turris
Roy Holland, Rogers
Serge Arseneault, Core One Consultants
Yves Mayodon, Bell

UPDATED: January, 2020

STAC will launch a new project team in January 2020 dedicated to developing resource documentation about preventative maintenance options for tower owners and tower engineers.

STAC is actively seeking additional project team members to add to this team. For more information or to join the project team, please email info@stacouncil.ca

Standards
CSA Standard S37-18 – Antennas, towers, and antenna-supporting structures
CSA Standard S37-01 (Commentary)
National Building Code of Canada 2010
CSA Standard S16-14 – Design of Steel Structures

STAC Bulletins
STAC Bulletin SB-0001 – Shrouded Tripoles and Galloping Vibrations
STAC Bulletin SB-0002 – Shrouded Monopoles and Vortex Shedding Vibrations

Presentations

Other Resources
STAC Recommended Anchor Shaft Inspection Priority Matrix
OHSA Report – Investigation of the April 19, 2018 Communication Tower Collapse in Fordland, Missouri
STAC – Worker Antenna Mount Access – Current & Best Practices
Study – Compressive Strength of Solid Round Steel Members Strengthened with Rods and Angles
Environment and Climate Change Canada’s recommendations regarding site-specific wind pressure analyses (memo)

STAC Engineering Guidelines and Practices Committee Notes – November 27, 2019
STAC Engineering Guidelines and Practices Committee Notes – August 15, 2019
STAC Engineering Guidelines & Practices Committee Notes – May 16, 2019
STAC Engineering Guidelines & Practices Committee Notes – December 12, 2018
STAC Engineering Guidelines & Practices Committee Notes – September 21, 2018
STAC Engineering Guidelines & Practices Committee Notes – June 15, 2018
STAC Engineering Guidelines & Practices Committee Notes – February 23, 2018
STAC Engineering Guidelines & Practices Committee Notes – October 27, 2017
STAC Engineering Guidelines & Practices Committee Notes – August 18, 2017
STAC Engineering Guidelines & Practices Committee Notes – May 19, 2017
STAC Engineering Guidelines & Practices Committee Notes – March 17, 2017
STAC Engineering Guidelines & Practices Committee Notes – January 20, 2017
STAC Engineering Guidelines & Practices Committee Notes – October 13, 2016
STAC Engineering Guidelines & Practices Committee Notes – July 27, 2016
STAC Engineering Guidelines & Practices Committee Notes – May 13, 2016
STAC Engineering Guidelines & Practices Committee Notes – April 12, 2016
STAC Engineering Guidelines & Practices Committee Notes – April 1, 2016
STAC Engineering Guidelines & Practices Committee Notes – March 4, 2016

Pinwheel Fall Arrest Team Meeting Notes
STAC Pinwheel Fall Arrest Team Meeting Notes – September 7, 2016
STAC Pinwheel Fall Arrest Team Meeting Notes – May 25, 2016

Submit questions to info@stacouncil.ca