Tiller Engineering - Trust in Strength

Bell Aliant – Labrador

Major Inspections, Structural Analysis and Reinforcing Design of Twenty Towers

Client: Bell Aliant
Location: Multiple Sites throughout Labrador
Date of Completion: December 2010
Project Maintenance/Construction Cost: Unknown

Scope of Work:
TEI completed mapping, field inspections, structural analysis, reinforcing design and reporting for twenty (20) existing tower structures after an extreme icing event.

Description:
The tower structures included self-support and complex guyed structures as part of Bell Aliant’s microwave system.
All work was completed in conformance with CSA S37-01 Antennas, Towers and Antenna Supporting Structures. Our team completed all inspection tasks in accordance with CSA S37-01 Appendix D Recommendations for Maintenance

Project Preparation:
An initial project “kick off” meeting with the client was held, where resources, scheduling, client coordination, reporting requirements, general contractual issues and safety protocols were all established.

Field Mapping of Tower and Site:

The towers were given a detailed inspection by our field team as per Appendix D of CSA S37-01. The following items were inspected:

  • Type and age of tower, field measurements/mapping
  • Coordinates of tower
  • Visual examination of tower members and connections
  • Visual examination of ladders, gratings and handrails
  • Visual examination of safety rails and anti-climbs
  • Foundations (visible portions)
  • Antennas and other appurtenances
  • Tower alignment
  • Tower verticality and twist
  • Waveguide bridging
  • Transmission lines
  • Grounding
  • Electrical and lighting installation
  • Painting and galvanizing
  • General comments

Structural Analysis:
A Structural Analysis was conducted to the requirements of CSA S37-01 using site-specific environmental loadings approved by the owner. The analysis was performed using the industry standard software GUYMAST/TSTower.

Reporting:
Detailed reports as per the client’s requirements were prepared. The reports outlined the findings of the field inspections, structural analysis and various reinforcing designs. The reports summarized our observations aided with color digital photos. The reports were completed with conclusions and recommendations and systematically prioritized the recommended remedial work and deficiencies in a risk management approach ranging from emergency to routine priority. The report also included a detailed tower profile which included dimensions and sizes of all structural members. The report also provided a full structural assessment report with included recommendations for the short, mid and long-term and a complete structural summary.