Naval Coastal Warfare Base

Imperial Beach, Ca

Stornghold Engineering, Inc. served as the prime contractor for seven prefab steel buildings for the Navy at the 13th Street Naval Coastal Warfare Base in Imperial Beach, California. One of the critical challenges Stronghold faced was the installation of a new electrical substation that consisted of 4160V primary power to 120/280V user power to the new buildings.

Our in-house electrical team connected to this existing 4160V overhead line for the source power connection to the new substation. Part of the design process required a study of the existing circuit capacity for the fuse sizing. The circuit Stronghold installed traveled 1,000 feet underground to the new substation.

Stronghold also poured the concrete pad, while our certified line crew made the final terminations and performed tests on this 500KVA transformer that steps the voltage down from 4160V to 120/280V.

The final product gave the owner the capability of adding two large buildings in the future, for which underground provisions were made. This was a unique project where the existing service voltage was unknown by the owner, and upfront research and field analysis were key to completing the design to ensure that the project would be finished within the time allotted on the schedule. Stronghold Engineering, Inc. has since completed the second phase addition of a Headquarters Building and Rifle Simulator Building attached to this service. Both phases were completed on time.


“The contractor’s quality of workmanship was outstanding due to the quality of the QC personnel and the site superintendents’ constant over site of construction. The contractor’s management team did an outstanding job of managing their personnel and subcontractor’s.”

Mr. Dave Wilkins, Project Engineer, NAVFAC SW, FEAD