Ship construction takes place in a shipyard, and can last from a few months for a unit produced in series, to several years to reconstruct a wooden boat like the frigate "Hermione", to more than 10 years for an aircraft carrier. During World War II, the need for cargo ships was so urgent that construction time for Liberty Ships went from initially eight months or longer, down to weeks or even days. Builders employed production line and prefabrication techniques such as those used in shipyards today.