Temporary stabilization of cross-rope suspension towers

Replacement of defective foundations without service interruption.

Several cross-rope suspension towers on 735 kV lines starting in James Bay, were showing signs of deficiencies at the foundation level. Hydro-Québec hired CIMA+ to design a system and method to replace defective foundations, while keeping power lines energized.

In the framework of this project, CIMA+ designed a support structure to maintain the base of a cross-rope suspension tower during the excavation and replacement of the foundation. One challenge was that the support structure needed to be transported by a helicopter, and set in place using excavation and hoisting equipment that also needed to be transported by a helicopter. Consequently, CIMA+ designed a light structure with several detachable sections.