What does it feel like to build the largest aircraft carrier on earth — a floating city that will serve as a combat airport, defending American security around the world? The $4.5 billion USS George Bush is now midway through its four-year construction period in the Western Hemisphere's biggest dry dock at Newport News, Va. The critical superlifts are now underway. These cranes can lift 900 tons, and need every pound of that strength to hoist 160 massive sections of completed flight deck sections into place. The pressure is on as every lift must happen with metronomic accuracy — any delay sets the entire project back.