Big Silver 138kV Submarine and Transmission

Westpark successfully negotiated an EPC contract in 2014 for the design, supply, and installation of a 138kV transmission line connecting the Big Silver Hydro Project back to existing facilities in the Harrison Lake region. The project consisted of both an overhead and submarine portion of transmission.

The submarine cable portion consisted of three separate, single core power cables, each installed approximately 4 kilometers across Harrison Lake to depths of over 250 meters. Due to access constraints on the lake, a modular lay barge had to be purpose-built for this lay.

The overhead transmission line was approximately 27 kilometers long, the bulk of which required helicopter support due to poor access. This contract included provision of ROW access and clearing works, which were subcontracted to a local forestry contractor.

Westpark Electric Ltd. was contracted directly by the owner to engineer, procure, and construct the overhead transmission line. The contract also included two 230kV x 13.8kV substations at the two generating stations.

The transmission line contract included the right-of-way clearing works as well as the necessary upgrade and new construction of road access throughout the site. This scope of work was successfully subcontracted to a local, First Nation-led, logging contractor, which helped achieve project goals of providing both local and First Nation employment on the project.

Extreme mountain conditions required the support of many unconventional supports for transmission line construction. A HETS team and specialized rope rescue consultants were relied on heavily for safe access of construction crews throughout the project. Helicopter support, for both construction and safety coverage, was required through the majority of the project.