For example, the most recent Virginia-class submarine, the USS California, was delivered to the Navy eight and a half months ahead of schedule and is much cheaper to manufacturer compared to earlier Virginia-class submarines. It also includes a variety of composite components, ranging from large parts like the composite sonar dome, array support plates and flood grates, to smaller parts like pump impellers. “A significant reason for the cost reduction is that the learning associated with making the unique resin transfer molded parts for Virginia-class submarines have improved the manufacturing process. The Navy expects the learning trends to continue, along with continued lower costs,” says Owen.
The Navy is currently developing new composite manufacturing techniques for large cylindrical parts. Today, the technology for providing such parts requires the use of a large autoclave, which is expensive and time consuming compared to other manufacturing methods. The Navy developments for an out-of-autoclave manufacturing technique will allow more vendors to participate in future Navy procurements requiring use of composite components, a positive naval investment for future composite integration.
Composites Moving Forward
Military composite structures, whether structural or nonstructural, large or small, are all players in a protection-heavy market. Several of them, including the Humvee Structural Chimney and the X-47B, are all still in the experimental phase. Others like the DDG-1000 deckhouse and the Virginia-class submarine sonar dome are pushing military departments to see the benefits of composite properties. Even though the battle for integration against legacy materials like steel and aluminum is difficult in the military market, these composite manufacturers are working to ensure that composite parts are worth the substitution and can save more lives than the metal counterpart. The composite parts provide innovative lightweight solutions for current military difficulties such as protecting troops from underbelly IED explosions, providing carrier-able unmanned flight and protecting Navy sonar equipment. Composite technology is steadily integrating into the battlefield, providing military solutions and pushing the boundaries of military equipment development.