Cape Cod Highland Center Electrical Investigation

Henry Adams was engaged by the National Park Service to provide professional electrical engineering services at the Highland Center in Cape Cod National Seashore, Massachusetts. The project involved documenting, assessing, and performing calculations on the electrical distribution system so that the results could be used as a master planning tool to guide future infrastructure improvements.

The Highland Center occupies the former North Truro Air Force Station, a 125-acre property that once included nearly 70 structures. The site was first developed during World War II when the Army used it to train artillery crews. It later became a radar station for the Air Force beginning in 1950, playing a vital role in national air defense during the Cold War. The Air Force decommissioned the site in 1985. Part of the property was transferred to the Federal Aviation Administration, which continues to operate a long-range search radar as part of the Joint Surveillance System. The remainder of the property was transferred to the National Park Service in 1994. Since then, NPS has adapted portions of the site for new uses, though opportunities remain limited because many of the buildings are in poor condition. As of 2023, approximately 17 buildings remain standing, most with active electrical services.

The project began with the creation of as-built documentation and inventory of the electrical system from the 23kV point of service down to every electrical panel in each active building. The scope included a comprehensive site plan showing utility and power distribution equipment, one-line diagrams, panel schedules, and photographs. In addition, the team performed a full assessment of the electrical infrastructure across the campus, identifying code deficiencies and providing recommendations for corrective action.

Several electrical studies were also performed. A short-circuit study verified that existing equipment was properly rated for available fault current. An overcurrent protective device coordination study was conducted to evaluate system performance. An arc-flash study was completed and arc-flash labels were produced for installation on transformers, panelboards, and other equipment. The team also reviewed twenty-four months of utility bills from the local electric company to analyze usage.

To complete the field documentation, Henry Adams partnered with Ferrell Electric, a local electrical contractor. Three electricians, a bucket truck, and a service truck supported a week of planned power outages across the site in order to safely access and document equipment. Together, the teams documented 49 utility poles with overhead and underground distribution at 23kV, 4160V, and 208/120V. Equipment included pole and pad mounted transformers, medium voltage sectionalizing cabinets, panelboards, disconnect switches, automatic and manual transfer switches, and emergency generators. Information such as manufacturer, model, voltage, amperage, wire sizes, conduit sizes, fault ratings, and circuit breaker settings was captured for each piece of equipment. Special attention was given to grounding and bonding in order to identify deficiencies.

Throughout the study, numerous code violations and unsafe conditions were discovered. These included multiple instances of neutral-to-ground bonds in separately derived systems, improperly protected wiring, inoperable equipment, rodent nests inside energized equipment, and overhead wires draped across building roofs.

The results of this study will allow NPS to better understand the existing electrical capacity of the Highland Center and to evaluate the potential for repurposing underutilized or abandoned buildings. It will also provide a framework for future infrastructure upgrade projects and immediately improve worker safety by supplying accurate arc-flash labeling across the site.