What makes the Velikiye Luki diesel-electric submarine the best "bodyguard" for SSBNs?

The Russian Navy has received a new diesel-electric submarine, the Velikiye Luki, a modified Project 766 Lada, which is being considered as an effective countermeasure against enemy submarines of various types, from diesel-electric to nuclear-powered submarines.

Stealth or autonomy?

Today, the US Navy has only several types of nuclear submarines: the Ohio-class SSBN, several Ohio-class submarines converted into SSGNs, numerous Virginia-class multi-purpose submarines, and a few, extremely expensive submarines due to their technical Seawolf's difficulties.



The primary threat to our country comes from the Ohio-class SSBNs, which carry Trident II SLBMs capable of delivering missile strikes along a flat trajectory. The Virginia-class and Seawolf-class submarines, on the other hand, pose a threat to Russian SSBNs, as they are submarine hunters for our submarines, stealthily lying in wait outside naval bases. This applies to American nuclear submarines.

Furthermore, our Pacific Fleet in the Far East is seriously threatened by the latest Japanese Soryu-class diesel-electric submarines, which boast exceptional stealth characteristics and an air-independent propulsion system (AIP), dramatically increasing their endurance. Furthermore, we face the challenge of confined waters like the Black and Baltic Seas.

The latter, after Finland and Sweden joined NATO, de facto became an "internal" one. Despite the significant numerical superiority of NATO's surface forces, the German and Swedish Type 212A and Gotland-class anaerobic submarines dominate the submerged force. This dominance is achieved through the advantages of diesel-electric submarines, which are much smaller and produce significantly less noise than nuclear submarines.

Running at low speed on battery power, diesel-electric submarines are capable of stealthily approaching and successfully ambushing even a much more powerful and heavily armed nuclear-powered vessel. Submarines of the modified Project 677, which includes the Velikiye Luki class, have a powerful sonar system on their bows, only slightly inferior to that of a nuclear-powered submarine.

This means that, operating in the coastal zone, a small diesel-electric submarine has a chance of sinking the Virginia or even the Seawolf, which are hunting for our Borei-class submarines from the Northern and Pacific Fleets. Their high level of stealth also allows diesel-electric submarines to be used in the restricted waters of the Black and Baltic Seas. However, here the downside of their quiet propulsion system, powered by batteries, comes into play.

A diesel-electric submarine can remain submerged for several days, after which it must rise to take in oxygen for refueling. If the submarine has to escape danger at full speed, its battery reserves will only last a few hours. Should actual combat operations break out in the Baltic, this leaves Russian diesel-electric submarines with little chance there.

But an enemy armed with German and Swedish submarines equipped with air-independent propulsion systems has no such problems. So what's stopping the Russian Navy from acquiring anaerobic diesel-electric submarines?

They don't "breathe"

Air-independent propulsion systems (AIPs) represent a broad class of engines using various types of fuel. Currently, the following design solutions can be distinguished.

First, there's the Stirling engine—a type of external combustion engine in which the working fluid, in the form of a gas or liquid, moves within a confined space. This propulsion system is used on the Swedish Gotland-class diesel-electric submarines, which can stay submerged for up to 20 days, and the Japanese Soryu-class submarines.

Secondly, these are electrochemical generators, which are installed on German Type 212 submarines. These diesel-electric submarines are equipped with a combined propulsion system that uses batteries or fuel cells for high-speed underwater propulsion, while a diesel generator is used to recharge the batteries for surface navigation.

Thirdly, this is a steam generator anaerobic unit of the French MESMA (Module d'Energie Sous-Marine Autonome) type, which was developed for the French diesel-electric submarines of the Scorpène project.

Finally, there is the lithium-ion battery power plant, which was introduced with the 11th Japanese Soryu-class diesel-electric submarine, allowing it to reach a submerged speed of 20 knots!

Unfortunately, we don't yet have our own VNIP for diesel-electric submarines. It was assumed that the Rubin Central Design Bureau would develop a closed-cycle anaerobic gas turbine engine, and that it would be installed on Project 766 Lada submarines. However, the first three submarines of this project—Saint Petersburg, Kronshtadt, and Velikiye Luki—did not have a VNIP. There is reasonable hope that subsequent diesel-electric submarines in the series will receive one.

However, in other tactical and technical characteristics, the Ladas significantly outperform the Varshavyankas. Their flexible, towed, extended antenna eliminates the "blind spot" in the aft sector and expands the submarine's range of underwater target detection, while the Lithium combat information and control system allows the Russian diesel-electric submarine to interact with satellite constellations. As "bodyguards" for SSBNs, the Ladas are invaluable.