Specifications include, but are not limited to: The Quartz Creek to Sterling 115kV Transmission Line is approximately 39.3 miles and is being upgraded to 230kV standards. The line was built primarily with wood H-frame tangents and guyed wood 3-pole angle structures. The existing conductor is 556.5 kcmil, ACSR “Dove” and the line is insulated to 115kV. The project to rebuild the line to 230kV standards has been split into three separate projects. Project 1 is approximately 8.2 miles from Structure 31-3 to the Sterling Substation. The existing transmission line structures, conductors, guys, and anchors will be retired and replaced with new structures, conductors, guys, and anchors, as well as the addition of an overhead fiber optical ground wire (OPGW) and a steel overhead ground wire (OHGW). The new line configuration for Project 1 will consist largely of wood and steel Hframe structures with direct embed foundations for the tangent structures. H-frames in soft peat bog areas will utilize driven pipe pile foundations. All angle structures including running angles and large angle deadends will be self-supporting steel poles. Foundations for the self-supporting steel poles will be driven pipe piles. The re-built line section of Project 1 will use mostly 795 kcmil, ACSR “Drake” conductor. However, the ties into the Sterling substation and the existing line will be 556 kcmil, ACSR “Dove”. All new structures will be insulated to 230 kV. The transmission line work begins at existing structure 32-3 which will be new structure 31-3, located next to Three Johns Street in Sterling, AK. The transmission line work ends at the Sterling Substation located just off Swanson River Road in Sterling, AK.
