Underground 138kV Transmission – Old Spanish Trail

Project Scope

Underground 138kV Transmission Project on Old Spanish Trail to serve the new Hermann Substation in the Medical Center, Houston.  Installation of 6-8”/4-3” Sch. 40  conduits encased in thermal concrete. The significance of thermal concrete is to dissipate heat from the 138kV circuits to be installed by others. Installed 1450lf of concrete encased  underground ductbank 16-17’ depth, and a 5’x5’ ID wood box tunnel (165 LF) one Precast Manhole 12’x32’x8’ under Old Spanish Trail.  Close attention to the quality of the workmanship in the conduit installation is paramount, since there can be zero blemishes, burrs are out of round conduits to meet the circuit installation specifications.   This project had a critical timeline under the control of an ERCOT Outage, and the new circuits had to be in placed by June 2025 with summer requirements and hurricane season. Critical timelines were met in accordance.