This article includes a
The lead ship, name ship, or class leader is the first of a series or
Large ships are complicated internally and may take as much as five to ten years to construct. Any changes or advances that are available when building a ship are likely to be included, so it is rare to have two that are identical. Constructing one ship is also likely to reveal better ways of doing things and even errors.
The second and later ships are often started before the first one is completed, launched and tested. Nevertheless, building copies is still more efficient and cost-effective than building