On March 5, 1927, the first Soviet submarines were laid down in Leningrad, which became the first-born of the USSR submarine building.
In the late 1920s, the question of modernizing the fleet was raised in the Soviet Union. The construction of new large ships was impossible without the creation of a powerful industrial and financial base, so the stake was made on the creation of submarine forces. On March 5, 1927, at the Baltic Shipyard in Leningrad, the laying of three submarines of the "D" ("Decembrist") series took place. And on April 14 of the same year, three more boats of this type were laid down in Nikolaev for the Black Sea Fleet. According to the project, the boats had great autonomy and were able to operate in any corners of the Black and Baltic Seas. The submarines carried 6 bow and two stern 533-mm torpedo tubes. The initial artillery armament consisted of one 102-mm and one 37-mm anti-aircraft machine gun. At the end of the 30s, the boats underwent modernization - the appearance of the wheelhouse changed. The 102-mm B-2 guns were replaced by 100-mm (B-24 PL) guns, and the 37-mm assault rifles were replaced by 45-mm guns or DShK machine guns. In total, according to the project, created under the leadership of B. M. Malinin, six boats of the "D" type were built, which received their own names: D-1 ("Decembrist"), D-2 ("Narodovolets", D-3 ("Krasnogvardeets"), D-4 "Revolutionary"), D-5 ("Spartak"), D-6 ("Jacobin"). The fate of these submarines was as follows.
D-1. In 1933, having passed through the newly built White Sea-Baltic Canal, it became part of the Northern Military Flotilla (since 1937 the Northern Fleet). At the end of the Soviet-Finnish war, she made a campaign, but did not meet with enemy ships. The submarine died with the entire crew during a training cruise on November 13, 1940. In Soviet times and today, several expeditions were prepared to investigate the place of the Decembrist's wreck, but none was carried out and the exact reasons for the death of the submarine are still unknown.
D 2. She acted as part of the Baltic Fleet. On October 14, 1942, a boat destroyed the German steamer Jacobus Fritzen with a cargo of coal. The attack by the "Narodnaya Volya" and the German railway ferry "Deutschland", on board of which there were about 1000 soldiers of the Norwegian Legion, had a great resonance. The torpedo tore off the stern part of the German ship. The Swedish press immediately disseminated information about the colossal tragedy that claimed the lives of more than 600 (or 900) people, which were later voiced in Russian literature as a notable success of Soviet submariners. In reality, 5 people on the ship died in a torpedo explosion and more than 20 drowned, throwing themselves overboard during a panic on the deck of the ship. In search of the submarine, the German command allocated significant forces of the fleet, which conducted an unsuccessful search for three days. D-2 went through the entire war, and in 1956 it was converted into a training station, and then in 1989, after renovation, it was installed in Leningrad on Vasilievsky Island and is currently a branch of the Naval Museum in St. Petersburg. This is the only Decembrist-class submarine that has survived to this day.
The D-3, which operated as part of the Northern Fleet, became the most famous submarine of the series and, according to official figures, the most effective Soviet submarine of the initial period of the war. In January 1942, the boat became a Red Banner, and on April 3 of the same year it was awarded the rank of the Guards. However, victories that would have found bilateral confirmation were not recorded."Krasnogvardeets" was killed in June 1942 during a campaign in the Tanafjord region
D-4 was active in the Black Sea, making a total of 19 campaigns. The most successful moment in the boat's biography was the attack of the enemy convoy on August 20, 1942, when, as a result of a torpedo hit, the Bulgarian transport "Varna" took off, transporting ammunition to the enemy-occupied Sevastopol. In December 1943, the D-4 did not return from a combat campaign.
D-5, which was part of the Black Sea Fleet, made 13 combat and three transport campaigns, participated in the landing and shelling of the coast occupied by the enemy. The artillery of "Spartak" near the Bosphorus destroyed a Turkish schooner. Since 1944, the boat was under repair and no longer took part in hostilities. In 1955, the D-5 was excluded from the Navy and a year later it was cut into metal.
By the beginning of the Great Patriotic War, the D-6 was being repaired and in the conditions of hostilities it was impossible to put the boat into operation. On June 26, 1942, the ship was blown up by the crew in Sevastopol shortly before the fall of the city.
The creation of D-class submarines was a significant step forward in the development of the Soviet submarine fleet in comparison with submarines built in the pre-revolutionary period. In general, type D boats, despite a number of shortcomings, turned out to be combat-ready ships corresponding to their era. It must be borne in mind that the construction of these submarines was carried out in the conditions of the country's just begun industrialization and without sufficient experience. In terms of combat use, the "Decembrists" showed their positive qualities and, above all, great autonomy. In total, boats of this type destroyed 3 enemy ships with a total displacement of 6407 tons and completed a number of other combat missions.
