Gatorfrey thanks for anything you send!

971:

There are different “batches” (if you want to call them in that way) of pr 971 “Schuka-B” (Akula) made in the USSR/Russia. As we know, 971 were built in two yards, Komsomolsk-na-amur (Zavod Imeni Leninskogo Komsomola N199) and at Severodinsk (Severnoe Mashinostrel’noe Predpryatie N 402) from 1983 to 1993 (dates of first boat being lay down at Komsomolsk to date of last boat being lay down at the same place (Drakon/Samara), last at Severodinsk in 1991, ony counting finished vessels!)…

The first boats built at Komsomolsk are “what we call” “Akula” in the west, and they’re the basic vessels. Once the first project 971 vessel was being tested, a lot of potential was found for further noise-level reduction capabilities, those capabilities, were introduced “mainly” (I don’t know if any Komsomolsk boat taked it) from the second boat being constructed at Severodinsk (Pantera) and introduced afterwards…those boats being built at Severodinsk after “Pantera” (not sure of those ones being built at the same time at Komsomolsk) were a little different to early boats _but_ they retained the tittle proekt 971. In the west were called Improved Akula…

Begining with “Vepr” (entered in service in 1996) more improvements were made, so the west (NATO/US god knows who) decided to call it “Akula-II”…

Then, Gepard, appeared in 2002, and nobody knows how to call it. Gepard is pretty different to Vepr (an Akula-II, improved over “Improved Akula”, and much improved over “early Akula”), main difference, new Towed Array. Some sources in the west call them “Akula-III”, some in Russia “Proekt 971M or Proekt 971B”…I don’t know how they are called…

THEN, we have two refurbished boats, one of them “Tigr” back into service and extesively upgraded…to wich level?, don’t know…we could assume, some “Gepard technology” (mainly new TA maybe?, computing/display/sensors improvement?), and now is in overhaul “Pantera” an old “Improved Akula”…if those boats are different to “old” “Improved Akula”, not being “Akula-II” (as Vepr), not being “Akula-III” (as Gepard)…what are they?…Akula-II improved?, Akula-II and half?, Akula-IV?…

Remind that most russkie submarines being in overhaul last time returned with new goddeys. An old 667BDR that returned to service in 2003 (the K-433 “Svyatoy Georgiy Pobedonosets”) showed a new Towed Array Sonar, very similar to that of “Gepard” (plausible due to time)…is very possible “K-114 Tula” refurbished 667BDRM finished this year would also show a new TA or more thingies…confusing boats?…really they’re!!!…

RSM55, thanks A LOT for your answers! (Trident too pal ;)!!) the part about Spiridinov was just awesome and trully revealling!, I would research more on this, did you recommend any literature about this intersting character?…

The time you take to answer was WORTH the value of the answer really!, as Neptune said, Impostor, is what you call MG-74 “Korund”, maybe that’s the traduction, but who knows!?…

Would return later with more comments ;), keep the god job pal 😀

K-336 Pskov, suffered a little fire while being in overhaul in 2003, read this:

Nuclear submarine on fire

A Sierra class nuclear-powered submarine caught on fire Wednesday while in dry dock.
Dry dock of naval shipyard no. 82 in Roslyakovo.
Nils Bøhmer/Bellona

Igor Kudrik, 2003-03-06 15:25

A Sierra I attack class submarine, K-336, or Pskov, suffered a fire on March 5th. The submarine was in the dry dock at Roslyakovo shipyard, situated between the city of Murmansk and Severomorsk, the home base of the Northern Fleet, on the Kola Peninsula.

Fire crews called to the shipyard managed to put the fire out in one and half hours, Russian news agency ITAR-TASS reported.

The cause of the fire is still unknown, but it may be possible that the welding works ignited the wood scaffolding surrounding the submarine.

No causalities or radiation discharge are reported, although the rubber coating of the submarine is damaged.

A similar incident took place in October last year when an Echo II submarine was undergoing decommissioning at Sevmorput shipyard, located in the north of Murmansk. The fire also started on the wood scaffolding in the dry dock surrounding the submarine, and then spread to the rubber coating of the submarine.

The Soviet Union built four Sierra I class attack class submarines, or SSNs. The fifth submarine, which would be a Sierra II class, was decommissioned at the staples in 1993. The Pskov, which entered service in 1993, is the newest nuclear-powered Sierra I class submarine. The first Sierra class submarine, K-239, retired from service in 1998. The two remaining submarines allegedly remain in service. Sierra class submarines are equipped with one PWR reactor and titanium hull.

This is the article I wa taking about regarding active noise cancellation.

Any comments?

(c) Vladimir GUNDAROV, Captain 1st Rank

[..]
Project 677 Lada continues the line of 636s and 877s (Kilo, according to NATO classification), which for their low noise levels were dubbed in the West as the “Black Hole”). We can be proud of our new achievements, because basic performances of Sankt Peterburg are two to three times better than those of third-generation boats in combat efficiency.
The new submarine belongs to the fourth generation and features a number of fundamental differences. Above all, it is the high degree of automation of centralized control of all shipboard systems and weapons from operator’s consoles located in the main control room. The torpedo and missile system was made more powerful. Design offices, research and production associations and scientific research institutes have all contributed to that. Among them are CDB ME Rubin, NPO Avrora, FGUP TsNII Elektropribor, OKB Novator, and NPO Agat. A result of their joint efforts is the CLUB-S. It is an integrated missile system which represents a unique development that is in fact unmatched by anything else in the world.

Russian scientists, designers and builders have in fact made a breakthrough in technical and economic characteristics and technology in the Lada class. Dozens of new solutions were proposed in the course of research and development. All armaments, boat systems and materials are the last word in science and technology. The sonar system, for example, is built around the latest microchips and with the latest software. Located in the forward end is a highly sensitive sonar array. A fundamentally new all-purpose multi-functional periscope is installed. The hoisting mast devices are telescopic. They do not enter the pressure hull, with the exception of the attack periscope. A new system for receiving radio information from the shore in the submerged position has been introduced.
[..]

The Achilles’ heel of all our submarines, with the exception of the Kilo-class submarine and the Project 971 nuclear-powered submarine, has been their high underwater noise levels. Between 1968 and 1986, the CPSU Central Committee and the USSR Council of Ministers issued four (!) decisions on this problem. Every six years it was requested to reduce the noise level by 50 or 70 per cent. All of these instructions were fulfilled, except for the last one when work on this theme was halted because of lack of financing. Lastly, the nuclear-powered multi-purpose submarines of Project 971A managed to reduce the underwater noise level by 30 decibels, or in noise pressure terms by 96.7 per cent, and in irradiated sound power terms, by a thousand times!
Last month, one of these submarines — K-157 Vepr — demonstrated its soft catlike movement during an official visit to the French port of Brest.
But Sankt Peterburg is not for nothing described as the successor to the “Black Hole”. Its noise level is approaching sea background values. And in concealment it will surpass all submarines built earlier not only in this country but also abroad.

In Heaven’s name 30dB noise reduction levels!!!, is this true?, what is a 971A class?, Gepard?, Vepr?.

How could this be achieved? The answer was given at a state scientific centre called the Krylov Shipbuilding Research Institute (KSRI). Fourth-generation submarines are provided with specially developed noise-absorbing — down to low frequencies — rubber coatings only 40 mm thick. They are half as thick as those we used before. The new coating consists of 7 to 8 layers of rubber with different perforations and profiles. The idea is simple: the more air cavities there are, the more effectively they absorb noise of different frequencies and at different depths. This was said by Professor Ernst Myshinsky, Doctor of Engineering, head of the shipboard and industrial acoustics department.

But hydro-acoustic coating is only a passive defense against noise. And the Institute is already working on new tools for active defense. According to the scientist, development of such means of noise suppression is a super new direction in world science. In Russia the active methods appeared a quarter of a century ago, but then they were considered to be a “medicine”, like nitroglycerin.

“Twenty-five years ago electronics was appalling. And we all feared that instead of creating an anti-sound — a sound in the anti-phase — we could knock out electronic controls. And the noise, on the contrary, would intensify,” says Myshinsky. “But now electronics are normal, and so it is time to develop active comprehensive system of noise reduction.”
It is possible that they may appear on the next submarine, which will be built after Sankt Peterburg.

[..]

Better Than Energiser

Stale TV advertising about batteries “that will work, work and work” would look deflated if developers of “hydrogen batteries” for the Sankt Peterburg boat dared to put their ware on the air waves.

Thirty years ago TsKB Lazurit, NPO Kvant and Kriogenmash embarked on the development for submarines of propulsive systems with electro-chemical generators, ECGs. The S-273 submarine of Project 613, which was mentioned above, was converted under Project 613E Katran. While conventional submarines at two-knot speeds could not stay under water for longer than four days without battery recharging, the use of electro-chemical generators increased this period to a month.

A second area in which Russian designers work is development of Diesels operating in a closed cycle. Project 615 with a single engine was put into metal in the middle of the last century and marked a unique event in the world.

Since 1978, the Special Boiler-Building Design Office has been the leading developer of propulsive systems with ECGs It drew on the experience of the Urals electrochemical works and NPO Energia that developed ECGs for spacecraft. In that way, a Kristall-20 engine for submarines made its appearance, using oxygen and hydrogen. The latter is present in bound form — in an intermetallic compound. Second-generation Kristall-27 and Kristall-273 engines can now also be installed on new Diesel-electric submarines, increasing their endurance to 45 days. Without divulging all secrets of Russian shipbuilding, we may say that the endurance of Sankt Peterburg is exactly 45 days.

Amur, Cousin of Lada
Just like the German Howaldtswerke Deutsche Werft AG, Admiralteiskiye Verfi, in parallel with the Lada class sub for the Russian Navy, is also building for export a fourth-generation submarine of Amur-1650 class. They are almost look-alikes. Amur will be able to fire missile salvoes against surface single and group targets. Compared with submarines of the previous projects, its acoustic signature is several times lower. It also carries radioelectronic equipment of a new generation.

Automatic ship control, and management of its combat and technical systems, will be effected from the main control room. An inertia navigation system will ensure safe navigation and determination of movement parameters while staying under water for a long time with an accuracy sufficient for missile weapons. Amur will have an all-mode propulsion electric motor of a new type, and also a storage battery with an extended service life.

Like Lada, the export unit is equipped with a highly sensitive array of the Lira sonar system. The outer hull is covered in Molniya anti-sonar coating of a new generation.
FGUP Admiralteiskiye Verfi is contributing financing to the development of an air-independent propulsion unit for use as an alternative source of electricity.

Everything for Sale
Admiralteiskiye Verfi has what financiers describe as a good credit history. By 2002, it had handed over to foreign clients thirteen submarines of Projects 877EKM and 636, i.e. more than half of boats of this class built in this country. At the same time, it repaired four vessels.
New output of the enterprise will also find its consumers. The most promising market, according to specialists, is South East Asia. Among the probable buyers of Amur-class submarines are Vietnam, Thailand, and the Philippines. Last century Russia sold about 50 submarines. It is not ruled out that in the 21st century products of Russian shipwrights will still be in demand on the international arms market.

You’re a machine RSM55 😀

Happy to have you in the forum!!!

Thanks a lot for all

Pit

RSM55:

Your response was absolutely awesome and much more than I expected!!!

I will answer in lenght in a time

Pit

RSM55 have you heard anything about two “Akula-I” upgraded during the 90s-till-today?

I have heard the Tigr receieved upgrades…or it was just a refit?

Did they introduced new towed array sonar like Gepard?

BTW, did you appear to know the name and origin of this new TA?

Thanks

More about the Su-27BM this time from eDefenseonline

Su-35BM

In December 2003, after the Su-27SM modernization program had been deemed a success, Russia announced that it would proceed with the so-called “big modernization” program. The modernized aircraft is called the Su-35BM (also T-10BM) by Sukhoi, but it is not yet known what name will be adopted by the Russian Air Force. The Su-35BM program is to be a deep modernization of existing airframes, not newly produced aircraft.

The main new feature of the aircraft is to be a new radar. It has not yet been decided whether it will be the Phazotron-NIIR N031 Sokol or the Tikhomirov NIIP Irbis. The first is actually the well-known Zhuk radar with a passively scanned phased array, while the Irbis is a version of the N011M Bars-M, also with a passively scanned phased array. In 2003 a new phased-array antenna was tested for Indian Su-30MKI aircraft, but it achieved only +/-45 degrees of horizontal field of view, instead of the planned +/-70 degrees. The remaining angle of 25 degrees was achieved mechanically via a hydraulic servo, which was an unsatisfactory solution. The Irbis is to differ from the Bars-M by having quick servos that are tightly synchronized with the radar electronics to achieve the 70 degrees of scan on either side of the fighter’s axis. Sources says that NIIP’s solution is preferred by the Russian Air Force, since NIIP radar sets were all proven in service. The radar is to have similar capabilities to the N011M Bars-M. The detection range of a fighter airplane (170 km) and a destroyer-sized naval target (300 km) more or less matches the N011M’s performance.

The Su-35BM is also to receive a small radar in a tail “stinger” to monitor the rear hemisphere. It is to be a NIIR N012 Kopyo-DL with a passively scanned phased-array antenna with a range of about 50-70 km. The unique arrangement indicates that Russia does not plan to rely as heavily on data exchange networks to maintain situational awareness, although the Aist data-exchange system for the Air Force is under development.

The weapons set for the Su-35BM is to be the same as the Su-27SM. Among the new weapons in development is a long-range air-to-air missile with required range of 300 km. Since the range is beyond radar range, external information is required to prepare the missile for launch. Two or four such missiles are to be carried. The missile is to be developed from either the Novator KS-172 technology demonstrator or the Vympel R-37M missile, also proposed for the MiG-31. Sukhoi prefers the first solution, and one can say that it is part of Sukhoi’s long-standing strategy to prompt the Air Force to “kill” the MiG-31s and replace them with the Su-27 family of aircraft.

The Su-35BM is also to receive a totally new self-protection system. It was developed by KNIRTI (Zhukov near Kaluga, Russia) and is designated the L-175M Khibiny-M. It has an integrated electronic-support-measures system of high accuracy, a separate display in the cockpit, a digital processor, and an integrated active radio-frequency jammer with pods on the wingtips. Probably in the future, the aircraft will also receive a missile-approach-warning system and a towed decoy (for example, the Lobushka). The aircraft will have RAM coatings and some internal changes to increase stealth features, such as a new windshield and canopy of slightly different shape covered with radar-absorbent material.

The modernized Su-27SM, together with the modernized Su-25SM and Su-24M, will form the core of the Russian Air Force for the next two decades, and this could lead to the complete withdrawal of MiG-29 aircraft, which are not going to be modernized. While the MiG-29SMT represents the ultimate modernization variant for this undervalued aircraft, without dividing the upgrade into phases, it could not be presently afforded by Russia. The Sukhoi approach, with “small” and “big” modernizations, was much more realistic and ultimately triumphant.

And about RCS reduction in the Flanker:

WEAPONS AND EQUIPMENT
Date Posted: 14-Dec-2004

INTERNATIONAL DEFENSE REVIEW – JANUARY 01, 2005

——————————————————————————–

Sukhoi Flanker aircraft benefit from low-observable modifications
More than 100 aircraft in the Sukhoi Su-27/30 Flanker family have been equipped with a set of low-observable (LO) modifications that reduce head-on radar detection range by 50 per cent, according to Dr Vladimir Kisel of the Institute for Theoretical and Applied Electromagnetics (ITAE) at the Russian Academy of Sciences in Moscow.

Speaking at the IQPC Defence conference on Stealth in 2004, Dr Kisel said that he was unable to say which air forces had received the LO modifications, which were carried out over the past 10 years. However, the Sukhoi has generated most of its revenues in that time through sales of the Su-27 series to India and China, raising the possibility that some of the Indian Air Force aircraft that performed unexpectedly well against US Air Force F-15Cs in last year’s Cope India exercise may have been LO-modified.

The suite of LO modifications includes radar absorbent material (RAM) sprayed on to the inlet duct walls; RAM applied to the compressor face of the AL-31 engine; and the installation of a frequency-selective-surface (FSS) screen inside the radome, in front of the radar dish. (Similar modifications have been applied to the F-16 under the Have Glass and Have Glass II programmes.)

ITAE and Sukhoi make extensive use of real-world hardware in LO testing. Dr Kisel’s presentation showed outdoor radar cross-section (RCS) ranges using a modified aircraft (not an RCS model) and a line-up of operational air-defence radars rather than a specialised instrumentation radar. Signatures from the inlet ducts were measured with the engine running, to model the effects of rotating engine stages.

RELATED ARTICLES:

1 First upgraded Flankers have entered service, Jane’s International Defence Review, 20 January 2004

2 Show report – Aero India, Jane’s International Defence Review, 16 March 2003

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And:

Russian Stealth Research Revealed
Russia shows solid progress in a variety of low-observable technologies

by Bill Sweetman
Jan. 1, 2004

Russian research into low-observable (LO) technology has remained largely secret, despite the collapse of the Soviet Union and the semi-privatization of the aircraft industry. However, a newly published paper from the Institute for Theoretical and Applied Electromagnetics (ITAE) at the Russian Academy of Sciences (Moscow, Russia), presented at the International Quality and Productivity Center’s conference on stealth, held in London in October 2003, shows that Russian researchers have made solid progress in key technologies for LO aircraft and have test-flown some technologies – such as the use of plasmas to protect targets from radar – that are not known to have been studied in the West.

In the paper, entitled “Stealth Technology: Fundamental and Applied Problems,” Russian stealth researchers claim to have reduced the head-on radar cross-section (RCS) of a Sukhoi (Moscow, Russia) Su-35 fighter by an order of magnitude, halving the range at which hostile radars can detect it. The research group has performed more than 100 hours of testing on a reduced-RCS Su-35. According to other reports, the ITAE has demonstrated similar technology on a MiG-21bis, and it has been offered to India as part of a MiG-21 upgrade package. Similar modifications have been made to Western aircraft (such as the Have Glass package developed for the F-16), but it is not known whether they claim the same level of performance.

Russian investigators certainly have the basic scientific knowledge to apply stealth to aircraft. Some of the basic mathematical and optical theories that underlie stealth originated in Russia (such as Ufimtsev’s theory of edge diffraction), and some of the most significant early work on reducing the RCS of military vehicles was carried out by Russian warship designers. The Kirov-class battlecruisers – with a 22° “tumblehome” angle imposed on normally vertical bulkheads, screens, and skirts to shield high-RCS components from radar, along with extensive use of radar-absorbent material (RAM) – were remarkably stealthy despite their size. “If you saw a big wake with nothing in front of it,” British marine LO expert Peter Varnish has said, “you knew you’d found the Kirov.”

There is also an LO strand in Russian aircraft design. The Tupolev (Moscow, Russia) Tu-160 Blackjack bomber is a reduced-signature design reminiscent of the B-1 Lancer. Sukhoi has designed a series of supersonic bombers with low-profile, highly blended configurations. In early 2000, Russian military leaders considered that a new, stealthy medium bomber would be the next major Russian military aircraft project, to replace the Tu-22M.

Most current Russian military aircraft show little evidence of stealth in their design, but that is not surprising, given that they were defined in the early 1970s. The more recent MiG 1.42 and Sukhoi S-32 fighter prototypes were designed as details of US stealth projects became known and, thus, represent a compromise solution. They carry their primary weapons internally, and the Vympel R-77 missile – which corresponds to this generation of aircraft – is designed for internal carriage. However, they do not reflect features found on US designs, such as the careful organization of wing, tail, and inlet edges along a few common alignments. They look like aircraft in which aerodynamics dominate the basic shape, and materials are used to eliminate RCS hotspots – very much the same as the technology described in the ITAE paper.

The dominant contributors to the Su-35’s head-on RCS are the inlets, which the ITAE researchers call “a huge problem.” With a straight duct that provides direct visibility to the entire face of the engine compressor, the inlet might have been designed to advertise the fighter’s presence at the greatest possible range. (Lockheed stealth pioneer Alan Brown’s comment on straight ducts is that “the energy comes romping out like a lighthouse beam.”) The ITAE, though, has developed a high-performance, ferro-magnetic RAM for the compressor face and duct walls. The material has to be thin, because it cannot constrict airflow or impede the operation of anti-icing systems, and must withstand high-speed airflows and temperatures up to 200°C. The ITAE team has developed and tested coating materials which meet these standards. A layer of RAM between

0.7-mm and 1.4-mm thick is applied to the ducts, and a 0.5-mm coating is applied to the front stages of the low-pressure compressor, using a robotic spray system. The result is a reduction of 10-15 dB in the RCS contribution from the inlets – more than halving the RCS.

Like the Have Glass F-16, the modified Su-35 also has a treated cockpit canopy that reflects radar waves. The ITAE has developed a plasma-deposition process to deposit alternating layers of metallic and polymer materials, creating a durable coating that blocks radio-frequency (RF) waves and does not trap solar heat in the cockpit. The plasma-coating process is carried out in a vacuum chamber by a robotic tool.

The ITAE and its partners use plasma technology for applying ceramic coatings to the exhaust and afterburner. Multi-layer coatings formed from microparticles of dielectric, metal, or semi-conductor material are deposited by an arc-discharge plasma under atmospheric pressure. Challenges include the need to keep the ceramic bonded to the metal structure over a wide temperature range (600°C to 1,200°C), despite the fact that the materials have widely different thermal-expansion characteristics. The coating materials also need to maintain constant electrical characteristics in the face of widely varying temperatures. Researchers describe this problem as “partially solved,” and engines treated with ceramic RAM have already been flight-tested.

Video at the conference also showed the use of hand-held sprays to apply RAM to R-27 air-to-air missiles. There is no point, researchers say, in reducing the RCS of the airframe unless the reflectivity of external weapons can be reduced as well.

The ITAE has flight-tested a unique and exotic technology to mask the Su-35’s huge 35-inch radar antenna: the use of a low-temperature, “plasma-controlled screen.” The screen is mounted in front of the antenna and is transparent to radar when switched off; it may be similar to a plasma TV screen, comprising cells filled with neon or xenon gas, which is excited by an electrical current. (Video shows a clearly defined luminous panel in front of the antenna.) When activated, the screen absorbs some incoming radar energy and scatters the rest in safe directions, over all RF bands lower than the frequency of the plasma-generation system. The screen switches on and off in tens of microseconds, according to the ITAE, thanks to years of intensive development of the gas mixture and plasma-generation system.

In principle, this is the same as the “plasma stealth” system that was reportedly developed by the Keldysh Scientific Research Center (also part of the Academy) in 1999. At the time, it was claimed that the system, using a 100-kg generator, could reduce the RCS of any aircraft by two orders of magnitude, or 20 dB. The ITAE has not attempted to develop a whole-aircraft system, which would use plasma-generating antennas to ionize the air flowing over the aircraft – an artificial version of St. Elmo’s fire – but researchers expressed the view that it would be difficult to apply except to a high-altitude, relatively slow aircraft, because the airstream would dissipate the plasma faster than it could be generated.

The ITAE paper gave some indications of the direction of stealth technology for future aircraft. Test facilities developed in Russia include compact, indoor RCS ranges for large-scale models and outdoor, ground-level ranges with short pylons, which can be used to test full-size aircraft (rather than the models used for US pylon tests). In future designs, one emphasis is on large, complex skin panels, reducing the number of gaps and mechanical fasteners in the skin. The ITAE paper showed an example of a single, 23-ft., monolithic fuselage panel, without indicating for which aircraft it was intended. However, it might form part of the upper fuselage of the S-32 Berkut prototype.

Russia’s ability to achieve an order-of-magnitude reduction in the RCS of a non-stealthy aircraft is significant for two reasons. First, it makes the Sukhoi family more competitive with Western aircraft, particularly in the case of export variants that may not feature LO modifications such as Have Glass. Second, it points to an ability to design low-maintenance, stealthy combat aircraft, missiles, and UAVs in the future.