Unlike the United States, Great Britain or France, the Russian navy has never abandoned the use of diesel-electric submarines in favor of an entire nuclear fleet. Today she has 17 classic submarines, 11 Model 877 Kilo, and 6 Project 636.3 Improved Kilo serving in the Black Sea Fleet. In 2017, it ordered 6 new examples of the 636.3 currently under construction, which will be delivered between 2019 and 2021 to the Pacific Fleet.
Obviously, the Russian Admiralty seems very satisfied with its model, since according to the Tass Agency, at least two officials from the Admiralty shipyard in St. Petersburg, which manufactures the submersible, have confirmed that the country's military authorities are close to ordering a new series of 636.3, intended for the Baltic Fleet, this one not not being, today, equipped with submersibles other than 2 project 877 Kilo dating from the 80s, and soon to be withdrawn from service. The Admiralty, as is often the case, did not wish to comment on the subject. However, we will have to wait for official confirmation of the order, knowing that in Russia, it is common for manufacturers to anticipate future decisions by the Ministry of Defense too much.
It must be said that the 636.3 does not lack arguments to seduce. Weighing 2350 tonnes on the surface, and 4000 tonnes submerged, it carries 18 torpedoes and anti-ship missiles deployed by 6 torpedo tubes, and 4 launchers for Kalibr-PL cruise missiles, with a range of 2500 km . Capable of reaching a speed of 20 knots when diving, and a depth of 300 meters, it has a range of 7.500 miles on the surface or snorkeling, and 400 miles when diving at 3 knots. Above all, the submersible is reputed to be particularly quiet when diving at low speed on battery power, to the point of being very difficult to detect by the passive sonars currently in service in NATO. In addition, the building is economical, since it is sold for export for $250 million, suggesting that it would only cost the Russian forces $150 to $200 million. In other words, the Russian fleet can finance 4-6 636.3 submarines for the price of a single Antey-class SSN. For forces like the Black Sea or Baltic Sea fleet, the model is perfectly suited, and provides, at a lower cost, significant operational advantages.
If the order were confirmed, it would, however, send a very bad message about the Lada class, the model supposed to take over from the 636.3 since 2010, but of which only 2 out of 12 examples have actually been completed to date, and of which only the prototype, the Saint-Pertesbourg, actually entered service in 2010 in the Northern Fleet. The two other examples ordered, the Kronshtadt and the Velikiye Luky, were returned to dry dock following major modifications made to the model in 2013 and 2015. These two ships, once completed, must join the Baltic Fleet. The Ladas, initially supposed to use AIP propulsion, had to be equipped with conventional diesel-electric propulsion given the difficulties encountered by Russian engineers in designing efficient anaerobic propulsion.
It is possible, in fact, that the announcement of a new order for 636.3 Improved Kilo for the Baltic Fleet, means the end of the Lada program in its current form, and the cancellation of the 2 examples on order. Moscow has in fact proposed to New Delhi, as part of the P75i program relating to 6 AIP submarines, the co-development of a new class of submersibles of this type, after having announced that she had succeeded in conceiving effective AIP propulsion. Given the numerous difficulties encountered by the Lada program, and the proven performance of the 636.3, this decision would seem more than reasonable, especially considering the financial constraints of the Russian Navy.