Composite materials are used to make cars, planes and boats, and have been used to build minesweepers and small surface combatants. Now, the largest composite structure ever built—the DDG 1000 destroyer deckhouse—has been fabricated in Mississippi and is being shipped to Maine for assembly aboard the future USS Zumwalt (DDG 1000). In this dramatic example of a “shared build,” General Dynamics Bath Iron Works is the lead yard, but the superstructure and hangar are being built at Huntington Ingalls Industries (formerly Northrop Grumman Ship Systems) Composite Center of Excellence at Gulfport…