The 132 wooden H-frames will be replaced by about 35 steel towers.


Hydro-Québec plans to rebuild two 120-kV* transmission lines on wooden H-frames, between the Arthabaska substation tap and Bois-Francs substation in Victoriaville. These two lines will be dismantled and replaced with a new 10-km line on steel frames. This project will meet the growing electricity demand and ensure the reliability and long-term operability of the electrical system for all customers supplied by Bois-Francs substation.

* kV = kilovolt, or 1,000 volts.

The project is in the early detailed-engineering phase. To finalize the design of the tower foundations, Hydro-Québec will be undertaking geotechnical surveys to collect as much information as possible about the soil and bedrock.

  1. Why?
    Hydro-Québec is doing the surveys to determine the most suitable type of tower foundation for the conditions at the selected sites.
  2. When?
    The geotechnical surveys will be taking place in spring 2017.
  3. Who?
    An outside firm has been commissioned to do the work, under Hydro-Québec’s oversight.
  4. How?
    Before any work is started, Hydro-Québec makes sure that permission has been obtained from the landowner. Whenever possible, work is done within existing rights-of-way. The geotechnical surveys will be conducted by drilling (most common method). For more information: Les sondages géotechniques (in French only) [PDF – 824 Kb]
  5. Where?
    The geotechnical survey campaign will be conducted on the rights-of-way of existing lines, at the locations where the steel towers for the new 120-kV double-circuit line will be erected.