Sister ship
A sister ship was a metaphorical term that described a ship of the same class as, or virtually identical to, another ship. The term was used by the Federation, Klingons, and Romulans.

Launched in 2154, Columbia was the sister ship to . Both were  vessels, though Columbia sported many new and redesigned systems. ()

By 2256, the two  starships  and  were considered sister ships. ()

The Federation  heavy cruisers  and  were sister ships during the 23rd century. () 

Similarly, the  and  were also referred to as sister ships. Both were  starships. ()

The  and Kuri's battle cruiser were sister ships of the D7 class. Following his witnessing of the Klothoss destruction, Kuri blamed the Enterprise and ordered them to surrender. ()

The entity known as Gomtuu destroyed the sister ship of a Romulan warbird in 2366, prompting a claim of Right of Vengeance from the warbird's commander. ()

See also 
 Mother ship

External link
 

de:Schwesterschiff
Spacecraft classifications