Project 621 Transport Submarine

In 1948 the TSKB-18 began developing special-purpose "boats" under Project 621 for transporting landing with equipment and equipment and the subsequent supply of troops with ammunition, fuel and food. Marine infantry force of tankmen, gunners, pilots, and if necessary, paratroopers, as designed, on the move could set at the time of landing. For fighter planes, such as a designers created a type of catapult.

The submarine had a normal displacement 5845 tons, a length of 147.5 meters, a beam of 13.3 meters, and an average draft of 6.3 mwters. The maximum surface speed was approximately 15 knots, and 8.4 knots maximum underwater. Range on the surface was 6000 miles. Power plant was a steam-gas turbine, since in comparison with others this ensured the greatest submerged endurance range.

Armament included two 57-mm anti-aircraft automatic weapon and one pair of twin 25 mm automatic weapons. The launch platforms of 360 rocket projectiles were located for the fire support of landing on the deck. Load capacity for landing of the submarine was equal to 1550 Tons. Onboard were placed 10 tanks T -34, 12 trucks and 3 trailers, 4 passenger automobiles, 12 guns of 85 mm caliber, 2 guns 45 mm of caliber, 3 La -11 aircraft with the folding wings, machine guns, mortars, automatic weapons, the ammunition, fuel, provisions, and also 745 people for landing.

Since loading or unloading tanks and trucks was done under their own power, a powerful ventilation system was needed to exhaust engines fumes. Compartments, warriors, equipped regeneration and air-conditioning system. There were total beds-Nara, each for 4 persons, washbasins, two big stove for cooking, immersions, etc.

The developers of project rightfully considered the debarkation of landing forces the most complex operation. For the boat it planned to make a close approach with nose extremity the coast, after filling main tanks, actually to lie on ground, to open cargo hatch and to advance powerful ladder for gathering of technology and people. The cisterns of substitution were filled up in proportion to lightening submarine. For prospecting the touchdown point, mine clearing and destruction coast barrages through the airlocks in the rear portion of the boat the divers could leave.

With the examination of project 621 management of the Soviet Navy made a number of serious observations. The main things concerned questions of unloading technology and life support of such numerous landing force members upon prolonged transfer. In connection with this all work on project 621 was ended. However, the idea was not buried.