sentences:  These modifications were later included into the official blueprints and were the foundation of the later, completely domestically build production series.These series were produced for all four fleets, with boats for Baltic, Northern, and Pacific Fleets being built in Leningrad, Black Sea Fleet boats in Nikolayev, and some boats for Baltic and North in Gorky.During the war, the former riverboat production yard #638 in Astrakhan was employed for completion of several boats constructed in Leningrad and Gorky.