sentences:  The ship's delivery schedule was delayed by a year following the decision in January 2000 to use electric drive in the ship.But by early 2000 a "tumblehome" design had emerged that resembles that of the eventual "Zumwalt" class, albeit with differences in the weapons carried.Sources disagree on the displacement of the DD-21, and indeed it probably varied during the design process, but around 16,000 tons seems most likely.