Predicting Chinese submarine technology using Russian technology as a proxy in a Dempster Shafer framework-Part 1
by Ganesh Sahathevan While attempting to predict what the state of the art in submarine technology might be even in 2020,let alone 2030, appears well beyond the capabilities of Australian defense planners, it is submitted an attempt can be made to determine the state of submarine technology in the future by comparing the best available today against its competitors,using information in the public domain.It is expected that this information will notalways be credible.For this reason the objective here is to create a framework within which the information might be evaluated while making adjustments for its provenance and accuracy.It is submitted that the Dempster Shafer model (which this writer has used with some success in the detection of hydrocarbons from satellite imagery) provides a simple, efficient model for creating such a framework.Russian submarine technology is used as the benchmark, based on an assumption that it is at present the best in the world.Cost considerations are excluded for the time being ,based on the assumption that savings can be found when one is copying from existing designs.In the process of working through the proposed exercise one ought to be able to make an estimation of what Chinese submarine technology might look like in the near future. The first step in this ongoing exercise is to gather the information. It is hoped that readers will add to what is here,and what will come, via the comments section or by emailing me directly.END
Battle of the Submarines: Akula
17 August 2012
Having sailed undetected into US waters; Russian Akula-class submarines are currently enjoying a spell in the limelight. Liam Stoker profiles the Akula-class against the American equivalent, the Virginia-class submarines, to determine which has the upper hand.
News of Russia sailing an Akula-class submarine into the Gulf of Mexico unnoticed may have highlighted a shocking shortfall of territorial security for the US, but it also underpinned the submarine's operational capabilities.
Boasting an improved stealth profile over its predecessors and an impressive top speed and diving range, the Akula-class submarines have become a crucial part of Russia's naval arsenal since their induction in 1984. The closest comparison to the Akula-class within the US Navy's fleet is the Virginia-class submarine, which has been in service with the US Navy since 2004.
With similar capabilities and operational profiles, just how do the Akula-class and Virginia-class submarines stack up against each other?
Weaponry and armament
Virginia-class submarines have one of the most advanced torpedo delivery systems in the US Navy fleet. Image courtesy of the US Navy.
Both attack submarines have distinctly similar levels of armament, with both the US and Russia complying with the START II Strategic Arms Reduction Treaty that capped the number of strategic missile submarines at 14. The Akula-class submarine's armament is split between four 533mm torpedo tubes, capable of carrying 28 torpedoes, and four 650mm torpedo tubes, capable of carrying 12 torpedoes. The Virginia-class submarines are also equipped with four 533mm torpedo tubes, however they are also equipped with 12 vertical launch systems capable of firing BGM-109 Tomahawk cruise missiles.
Development and unit cost
A Virginia-class submarine under construction by Electric Boat. Image courtesy of the US Navy.
The Virginia-class submarines are more costly than their Russian, Akula-class counterparts as well. The estimated cost of an Akula-class submarine is $1.55bn compared to the original $2.4bn per unit price tag of an individual Virginia-class submarine. The original cost of Virginia-class submarines caused controversy as they were intended to be a cheaper alternative to the costly Seawolf submarines, causing the Navy to trigger a cost-reduction programme. The extensive use of commercial off-the-shelf equipment onboard and improvements in shipbuilding technology has reduced this cost to approximately $1.8bn per vessel.
Reactor and propulsion
An artist's conception of a Virginia-class submarine's movement whilst submerged. Image courtesy of the US Navy.
The Akula-class submarines are powered by one 190MW pressurised water nuclear reactor, one OK-7 steam turbine creating 43,000 hp and two OK-2 turbogenerators that produce 2,000 kW of power. Two OK-300 retractable electric propulsors for low-speed and quiet maneuvering have also been installed to increase stealthier operation of the submarine, although the top speed using this method of propulsion is capped at 5kt.
The reactor onboard the Virginia-class submarines has been purposefully designed for the Virginia-class by Knolls Atomic Power Laboratory. The pressurised water reactor offers increased energy density and a new steam generator design which results in improved corrosion resistance and reduced life-cycle costs. The reactor itself is designed to operate for a total of 33 years without refuelling, providing a significant advantage over other submarines that are forced to refuel. Virginia-class submarines rely on pump-jet propulsors for quiet operation, and they also reduce the risk of cavitation, which can cause damage to components.
Maximum depth, speed and endurance
An Akula-class submarine preparing to dive.
Russia's Akula-class submarines trump the Virginia-class submarines on both operating depth and speed, being capable of diving deeper and travelling faster whilst submerged. Akula-class submarines have a maximum operating depth of 600 metres, whereas the listed operational depth of a Virginia-class submarine is noted as greater than 250 metres. The Virginia-class submarines have a maximum speed in excess of 25 knots, whereas Akula-class submarines are capable of top speeds between 28 and 35 knots, although this is reduced significantly to 10 knots when sailing on the water's surface. The Virginia-class submarines are, however, designed to serve for longer periods of time than the Akula-class submarines, which have a maximum endurance of 100 days. The endurance period of a Virginia-class submarine is capped only at its food supplies, allowing for longer periods at sea if required.
The Akula-II class submarines boast an impressive stealth profile, but not as impressive as the Virginia-class.
Having operated within the Gulf of Mexico undetected, the stealth capabilities of the Akula-class submarine have been vaunted in recent weeks. It is already acknowledged as the quietest nuclear attack submarine in service with the Russian navy, with sources claiming the Akula-II class submarines to possess a noise profile comparable to that of the US Los Angeles-class submarines.
The Virginia-class submarines can, however, go one further. Utilising newly-designed anechoic coatings, isolated structures and a new propulsor design, the Virginia-class submarines boast an acoustic signature lower than the Russian Akula-II class submarines, equivalent to that of the Seawolf-class submarines that they were designed to replace.
One of the U.S. Navy’s top submarine officers was so impressed with Russia’s new Project 885 nuclear attack boats that he had a model of K-329 Severodvinsk built for his office.
Rear Adm. Dave Johnson, Naval Sea Systems Command’s (NAVSEA) program executive officer (PEO) submarines said he had the model of Severodvinsk placed outside his office in a common area so that he could look at it every day on his way to his office.
“We’ll be facing tough potential opponents. One only has to look at the Severodvinsk, Russia’s version of a [nuclear guided missile submarine] (SSGN). I am so impressed with this ship that I had Carderock build a model from unclassified data.” Johnson said last week during the Naval Submarine League’s symposium in Falls Church, Va. “The rest of the world’s undersea capability never stands still.”
The Russian attack boat had been in construction since 1993 and only entered sea trials late in 2011. The boat finally became operational earlier this year. A cash-strapped Russian Federation had to repeatedly delay completion of the submarine in the chaos that followed the collapse of the Soviet Union.
Severodvinsk is the most capable Russian attack submarine ever built and leverages many of the technologies the Soviet Union invested in during the 1970s and 1980s.
Model of Russian submarine Severodvinsk built for NAVSEA. US Naval Institute Photo
The 13,800-ton, 390-foot long, submarine is highly automated vessel with a crew of only 32 officers and 58 enlisted submariners.
It is far quieter than previous Russian submarines and has a maximum “silent” speed of about 20 knots.
The U.S. Naval Institute’s Combat Fleets of the World said some reports suggest the vessel might have a maximum speed of between 35 and 40 knots. However, most Russian reports state a maximum speed of 35 knots. Like most new nuclear submarine designs, Severodvinsk’s reactor is designed to last for the life of the boat.
According the Office of Naval Intelligence (ONI), while the new Russian submarine is quieter than the Improved Los Angeles-class boats, the new vessel is not quite as silent as the Seawolf or Virginia-class. However, the Soviets were always only lagging slightly behind U.S. in quieting technology according to Navy sources. The Russians are already building improved versions of the Yasen design.
Unlike most Soviet submarine designs, the Yasen-class boats do not make use of a double-hull—instead it has hybrid design with a lighter structure over the vessel’s pressure hull according to Russia media reports.
Another unique feature for a Russian vessel is that it incorporates a spherical bow sonar called the Irtysh-Amfora for the first time. As a result, Severodvinsk has its torpedo tubes located at about mid-ship like U.S. submarines. The vessel has eight torpedo tubes, four of which are 650mm tubes while the rest are 533mm tubes. Combat Fleets of the World estimates that the Yasen-class might carry as many as 30 torpedoes.
Infographic of Project 885 submarine via RIA Novosti
Like most Russian attack submarines, the vessel’s primary weapons are in the form of heavy anti-ship missiles. The boat has 24 missile tubes which can carry the supersonic NPO Mashinostroyeniya P-800 Oniks anti-ship missile which can hit targets roughly 200 nautical miles away. Severodvinsk can also carry Novator RK-55 Granat nuclear-capable 1,600 nautical mile-range subsonic land attack cruise missiles. Additionally, the Yasen-class boats can also launch the 3M14 Kalibr and 3M54 Biryuza land attack and anti-ship missiles, which have a roughly 300-mile range, though its torpedo tubes.
It also carries 91R anti-submarine missiles and has the capability to lay mines along with its normal complement of torpedoes.
Some Russian sources such as Russia Beyond the Headlines suggest that Severodvinsk is equipped with active anti-torpedo defenses and some sort of anti-air capability. The later would not be unprecedented, the Project 941 Akula—known better as the Typhoon-class ballistic missile submarine—was equipped with a 9K38 Igla surface-to-air missile system for ship self-defense.
Russia is expected to build eight Yasen-class boats. Since Severodvinsk took almost two decades to finish, the subsequent boats have many technological refinements to improve on the original Project 885 design. The next two Yasen-class boats are already under construction at the Sevmash shipyards in Severodvinsk, Russia. Kazan was laid down in July of 2009 while Novosibirsk was laid down July of 2013.