A video from the Russian Ministry of Defense’s official television channel has offered an inside look at the country’s titanium-hulled, nuclear-powered Sierra class attack submarines, including relatively close-up views of their wake detection systems. The footage shows interior spaces, including the inside of the escape pod on one of the submarines, as well. It also gives a look at various force protection measures the Russian Navy employs, including divers armed with specialized underwater guns and shoulder-mounted launchers that fire small depth charges used to engage enemy combat swimmers.
The episode of TV Zveda‘s “Military Acceptance” program that aired over the weekend, which you can watch in full below, centered on the Russian Navy’s Project 945 and Project 945A submarines. These are also known in Russia as the Barrakuda and Kondor classes, respectively, while NATO refers to them as Sierra I and Sierra II class submarines.
Within the first minute of the episode, the camera pans across Pskov, the second Sierra II class submarine built, and the last of only four Sierra class boats constructed, overall. Elements of its “Wake Object Detection System,” known in Russian as the System Obnarujenia Kilvaternovo Sleda, or SOKS, are clearly visible on the sail, including two protrusions right at the front on the top of it.
There is also a relatively small mast on top that appears similar to one associated with SOKS array found on some Project 971 nuclear-powered attack submarines, also known as Akula class boats to NATO. It is worth noting that the mast on Pskov lacks the protrusions seen on the SOKS-associated one on some Akulas and maybe be unrelated to that sensor suite. There is also a sponson on the right side of Pskov‘s sail that could also be part of this sensor system.
Interestingly, the other Sierra II class submarine, Nizhniy Novgorod, does not have the small mast on top of the sail, though it does have the pair of protrusions at the front and the side-mounted sponson.
Wake detection systems have been almost exclusively associated with Soviet and subsequently Russian submarines, though other countries have explored the concept over the years, including quite recently in the case of the U.K. Royal Navy. From what is known about the various SOKS suites, which first emerged in the 1960s, they are primarily designed to detect other submarines underwater by picking up the changes in water density they leave in their wake.
There have also been reports suggesting that at least some SOKS versions may be able to detect traces of certain chemicals, such as flakes of sound-reducing coatings peeling off or oxygen-generating system byproducts released into the water, as well as nuclear radiation. Regardless, SOKS and similar systems are intended to offers a passive, non-acoustic sensor option to supplement active and passive sonars. You can read more about the advantages this could offer for stealthily tracking and then potentially engage enemy submarines in this past War Zone piece.
SOKS is just one of the reasons why the Sierra IIs, the first of which entered service in 1990 and that are understood to be very quiet, making them difficult to detect and track, remain some of the most capable attack submarines in Russian Navy service today. Their titanium alloy hulls are another core focus area of the “Military Acceptance” episode, as its title, “Titanium Submarines,” makes clear. Using titanium provides added strength and, as a result, allows these boats to dive deeper than their steel-hulled counterparts.
Titanium also has the benefit of being more corrosion-resistant, a very positive attribute for warships and submarines that spend much of their time plowing through saltwater, and are also only very weakly magnetic. At one point during this recent episode of “Military Acceptance,” a Russian Navy sailor shows how a magnetic flashlight will not stick to the inside of the hull. Despite some suggestions that this could help the submarines evade detection by aircraft with magnetic anomaly detectors (MAD) or escape magnetic mines, there is more than enough other metal used elsewhere in their construction to negate any such signature reduction from the titanium hull.
However, titanium is also expensive and complicated to work with, especially when building large structures, such as the pressure hulls of submarines. Workers building the Soviet Union’s Project 705 submarines, another titanium-hulled design also known as Lira or Alfa class, reportedly had to perform many of their tasks inside specialized facilities filled with inert argon gas while wearing cumbersome “moon suits.” The later Akula class, a design that did not have a titanium hull, was similar in many respects to the Sierras, but was also cheaper to build.
Ultimately, only four Sierra class submarines, two of each subclass, were ever built. The first Project 945 boat entered Soviet Navy service in 1984, followed by the second example in 1987. As already noted, the first of the Project 945As joined that service in 1990, right before the collapse of the Soviet Union, with independent Russia taking delivery of the second example of this subclass in 1993. A major difference between the two types was in the composition of their torpedo tubes, with the Sierra Is having four 530mm tubes and two 650mm ones, while the Sierra IIs had six 530mm tubes. From these tubes, both subclasses could employ a variety of torpedoes and torpedo tube-launched missiles, including the unusual SS-N-16 Stallion anti-submarine missile, which you can read more about here.
All of these boats were assigned to the country’s Northern Fleet, but only the pair of Project 945As, Nizhniy Novgorod and Pskov, remain active today. There had been plans to overhaul the two older Project 945 boats, but it’s unclear what the status of that modernization effort is. The Sierra I class Kostroma, which is reportedly inactive, is seen in the TV Zvezda presentation docked together next to the two Sierra II class submarines.
The TV Zvezda footage also includes various shots of the inside of Nizhniy Novgorod, including the main command center onboard, where significant portions are blurred out. Various posters with details about warships, submarines, and aircraft operated by the United States and other potential adversaries are seen on the wall.
We also get a look into other spaces, including the commander’s personal quarters, bunks for other sailors, the mess, and the galley. Oh, and like some other Russian submarines, the Sierra II class boats have a banya, or sauna.
We also get a look inside of Nizhniy Novgorod‘s detachable escape pod on one of the submarines. In addition to providing a way for the crew to get out of the boat if it gets severely damaged in combat, it could also be employed in the event of a major accident, something the Russian Navy’s submarine force is, unfortunately, no stranger to.
This episode of “Military Acceptance” also spends considerable time exploring how the Russian Navy protects these and other submarines from hostile combat divers and other security threats. At one point, TV Zvezda‘s reporter walks by a checkpoint on shore defended, in part, by an 8×8 BTR-82 wheeled armored vehicle.
It also shows personnel ashore employing the DP-61 anti-saboteur grenade launcher, which looks like a shoulder-fired rocket launcher, but instead lobs what is effectively a small depth charge. The DP-61 is one of a number of individual and ship-mounted anti-diver weapons that the Russian Navy employs that fire similar rounds.
At one point, a group of Russian Navy combat swimmers is also seen training to more directly engage their enemy counterparts who might be trying to covertly attack submarines, or other ships, sitting pier-side. These personnel are seen armed with SPP-1M underwater pistols and APS underwater assault rifles.
The SPP-1M features four separate barrels with their own chambers, each of which holds a single specialized underwater cartridge that fires a long dart-like projectile. The APS is visually similar to an AK-series assault rifle, but also fires a unique underwater round with a long dart instead of a traditional bullet.
Both of these weapons have very limited range underwater, with the APS only being able to hit targets at around 100 feet away at relatively shallow depths. The SPP-1M can only hit targets at around half that distance. Both of their maximum effective ranges get progressively shorter at greater depths. They can be used above the water, if absolutely necessary, but with even greater range and accuracy penalties as their projectiles are designed to be stabilized in water, not air.
All told, this episode of “Military Acceptance” is an interesting look at some of the Russian Navy’s most unique submarines, as well as what it does to keep them safe. This presentation from TV Zvezda also comes as the service continues to modernize and expand its submarine, as well as surface fleets, something that continues to be an area of major interest and concern to the Kremlin’s potential adversaries, including members of NATO, and chiefly the United States.
As it stands now, the two remaining titanium-hulled Sierra IIs with their SOKS suites and other features look set to be important parts of the Russian Navy’s submarine force for years to come.
Contact the author: joe@thedrive.com