ComEd TSS 51 McCook Substation

Advancing Reliability Through Smarter, Stronger Substation Design

Ardmore Roderick is providing Site Project Management and schedule oversight for the construction of a new 138kV Gas Insulated Switchgear (GIS) Control Building at ComEd’s TSS 51 McCook Substation. This project responds to ComEd’s need to modernize aging infrastructure, improve system reliability, and reinforce long-term grid resilience across a critical transmission node.

Ardmore Roderick manages work within a complex, active substation environment, including site modifications, coordination around in-service underground and overhead facilities, and the removal of abandoned duct packages and foundations. Key actions include supporting construction of a large cable-vault substructure and the erection of a new precast control building measuring 337 feet by 95 feet by 41 feet. The facility incorporates new MEP systems, fire protection, transmission structure foundations, electrical ductwork, and a fully integrated grounding system.

Once complete, the GIS building will replace existing 138kV air-insulated equipment, delivering enhanced performance, reduced maintenance needs, and improved safety. The project strengthens grid reliability for surrounding communities while preparing the substation for future operational demands.