• 200-ft of Underground 138 kV
• Full Design-Build
• Weathering Steel Structures
ECI and EPC Services Company provided full-scope engineering, design and construction of approximately 12 miles of 138 kV double circuit transmission line to integrate energy generated from the Taygete 1 and Taygete 2 Solar Projects into the AEP Pig Creek Substation in Western Texas. The design included weathering steel monopole structures supporting back-to-back braced post composite insulators for the majority of the line’s length. Vertical double-bundled 954 45/7 ACSR “Rail” conductor was installed along with a total of four individual 48-fiber vertically framed OPGW’s (two per circuit). The project included a short 200-foot segment of 138 kV underground construction w/ 2000 kcmil AL cable in duct.
Tangent structures were direct embedded utilizing engineered lean concrete backfill while dead-end and running angle structures were set on steel reinforced concrete caissons. Except for several specially designed double-circuit dead-end monopoles, all dead-end structures were designed as two-pole structures to accommodate a single circuit on each pole.
The Taygete 1 circuit traverses relatively flat ground on single circuit structures from the Taygete 1 Substation for approximately 1 mile before picking up the second circuit from the Taygete 2 substation. At that point, the double circuit transmission line runs for approximately ten miles before the circuits split to accommodate different entrance points into the Pig Creek Substation. The Taygete 1 circuit attached to an AEP POI structure located on the southeast side of the station while the Taygete 2 circuit crosses under an existing AEP 138 kV transmission line and attaches to a separate AEP POI structure located further northeast of the station.
The underground section of the Taygete 2 138 kV transmission circuit runs between a pair of 3-pole dead-end riser structures underneath the existing AEP 138 kV transmission line into Pig Creek Substation. It consists of three phases of 2000 kcmil aluminum cable in concrete encased duct bank for approximately 200 feet. The duct bank system also contains three #4/0 copper ground continuity conductor and a pair of loose tube 48-fiber circuit.