Universal Composite Submarine Camels - Design of a Prototype

The United States Navy relies on several classes of submarines, each of which serves a specific role in the nation's strategic defense and deterrent strategy. These extraordinary vessels require specific berthing accommodations, including a specialized energy-absorbing separator referred to as a "camel," which are different from camels used for surface ships since they must accommodate the convex shape of the submarine hull. Over the years, the Navy has developed almost twenty different camel designs, each of which was designed for a specific submarine class at a specific port. In addition, these camel designs used materials that require frequent maintenance. In 2010, the U.S. Navy sought to standardize its inventory of submarine camels by developing a universal camel design that could accommodate any class of submarine at any port in the world. The Navy also sought to significantly reduce maintenance efforts and costs by requiring the universal camel to be constructed of synthetic composite materials. The Universal Composite Submarine Camel was conceptualized, designed and constructed during a design-build project that allowed close coordination between the U.S. Navy, the design engineer and the fabricator. The geometry and stand-off requirements of the submarines determined the size and shape of the camel, while berthing energy calculations and finite-element analyses determined the forces used in the design. Buoyancy calculations ensured that the irregular-shaped camels would float within strict tolerances. The resulting camel is a fiber-reinforced polymer (FRP) composite structure approximately 36 ft. x 17 ft. x 18 ft. Rubber fenders contact the submarine and dissipate energy, while ultra-high-molecular-weight polyethylene rubbing strips contact the berthing structure. These materials provide excellent corrosion resistance to sea water and chemicals while requiring virtually no maintenance. The design and fabrication efforts described in this paper will be of interest to conference attendees since the coordination between the owner, engineer and fabricator resulted in a new generation of Navy submarine berthing equipment that successfully reduces maintenance needs and employs innovative materials to create a modern solution. The concepts and materials developed during this project can easily be applied to address other berthing situations.