EPP has over 40 years of experience in the design, manufacture, and testing of large complex composite structures for naval applications. Past projects have included large composite structures weighing more than 50 tons, and measuring more than 40 feet long.
The 377-foot-long Virginia Class nuclear-powered submarines are designed for deep ocean anti-submarine warfare and littoral (coastal region) missions. EPP has been manufacturing Virginia Class Submarine (VCS) sonar bow domes since 2001, recently increasing the rate to two per year.
The VCS bow dome is a 25-ton hydrodynamically shaped composite structure that houses and protects the sonar transducer array – the “eyes and ears” of a submarine. The bow dome is 21-feet-long, has a diameter at the attachment end of 26 feet. A two-inch thick, single piece rubber boot is bonded to the dome as an acoustic performance enhancement. Minimal sound energy absorption and reflection properties inherent in the boot enhance submarine acoustic performance.
EPP's close proximity to a quay wall (a structure built parallel to the bank of a waterway) along the St. John’s River leading to the Atlantic Ocean facilitates shipment of the large submarine bow domes via deep-draft ships. Prior to shipment, the bow dome is secured in a shipping fixture to assist in movement and prevent damage during transit. Cranes lift the composite bow dome onto a flatbed truck that transports the giant structure to the quay wall. The composite dome is then loaded onto a deep-draft barge for delivery to the customer.
EPP has also designed and manufactured other numerous large, complex and advanced composite structures for the U.S. Navy. Recent projects include: surface ship sonar domes, naval lighterage/barge modules, Advanced Seal Delivery System (ASDS) exostructure, lightweight, radar absorbing louvers, composite sonar keel domes, and submarine high frequency acoustic windows.