 Other features included an expanded electrical plant and increased endurance.A major design innovation was the use of "macks"—combined masts and stacks—on which the radars could be mounted without smoke interference.The first three ships were constructed at Bath Iron Works, the next two at New York Shipbulding Corp, and the rest at Puget Sound Bridge and Dry Dock Company, Todd Shipyards, San Pedro, CA, San Francisco Naval Shipyard and Puget Sound Naval Shipyard.