ECI was contracted by Oklahoma Gas and Electric to provide cradle to grave services for transmission line design, environmental and land services, and construction management of a 36-mile, 345 kV transmission line from the Sooner Substation to the Cleveland Substation in Oklahoma.
This 345 kV single-circuit transmission line exits the Sooner Substation to the south and runs parallel to an existing 345/138 kV double-circuit line for approximately a mile before it turns southeast and crosses a lake.
Tripod steel structures were erected on two islands in the lake to complete the one-mile crossing. After crossing the lake, the line heads east for approximately twenty miles and then southeast for about four miles to an existing 138 kV GRDA transmission line.
The new line runs parallel with and on the north side of the GRDA line for seven miles until it crosses the Arkansas River, at which point it continues east for approximately three miles to the Cleveland Substation. Two-wire bundled 1590 ACSR “Lapwing” conductor was utilized along with a 36-fiber OPGW and 7#8 Alumoweld shield wire.
All structures are steel poles with an H-Frame configuration. Tangents are direct-embedded; angle and dead-end structures are supported on concrete pier foundations. All tangent and angle structures use V-string polymer insulator assemblies. Construction included erecting 175 tangent, four angle, and seven dead-end structures, as well as five steel dead-end tripod structures. Rock drilling to depths of approximately four feet for 25% of the line was required. The entire line was built in a new 150-foot right of way corridor that runs through private, BLM and BIA properties.
The Sooner to Cleveland Line crossed and bordered land parcels held by the Bureau of Indian Affairs (BIA) and the Army Corps of Engineers. Numerous environmental assessments, wildlife surveys, and pedestrian surveys were completed to meet the requirements of NEPA for approval by both federal agencies.