Pubblicato in: Geopolitica Militare, Problemi militari

Russia. I siluri Khishchnik e VA-111 Shkval. Serie minacce alle portaerei.

Giuseppe Sandro Mela.

2017-08-16.

 2017-07-31__Siluro__Russo__ 1516090282365511054

Si resta sempre sorpresi su come riescano i russi ad impiegare in modo così produttivo un bilancio militare che ufficialmente si attesterebbe attorno ai 65 miliardi di dollari americani.

I russi dispongono di una marina sufficiente per svolgere compiti locoregionali, senza attuali ambizioni globali. Una flotta di tale impostazione strategica abbisogna sicuramente di armi offensive, ma soprattutto di quelle difensive: sistemi contraerei ed anti-missile, sistemi missilistici anti-nave e, ovviamente siluri efficienti.

Loro obiettivo conclamato è il dominio dei mari limitrofi la Russia, ossia impedire ad altre marine militari di potersi avvicinare pericolosamente alle loro coste.

Alla fine del secolo scorso l’allora Unione Sovietica aveva messo in linea il siluro VA-111 Shkval, prodotto militare altamente innovativo: poteva infatti navigare ad una velocità di circa 90 km/h al momento del lancio, raggiungendo in breve i 370 km/h. Se è vero che essendo molto rumoroso era altrettanto facilmente individuabile, la sua stessa velocità gli avrebbe assicurato alte probabilità di colpire e distruggere l’obiettivo.

Cerchiamo di comprendere, per quello che è dato di sapere, come funziona un simile marchingegno e di razionalizzare le conseguenze tattiche e strategiche.

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Supercavitazione.

«La supercavitazione è una tecnica che permette di utilizzare gli effetti dell’ordinaria cavitazione per creare una bolla di gas all’interno di un liquido, permettendo ad un oggetto di viaggiare ad altissima velocità all’interno del liquido stesso, rimanendo però completamente avvolto dalla bolla di gas. La bolla riduce drasticamente la resistenza dell’oggetto, permettendogli di raggiungere velocità impossibili da ottenere con una normale tecnica di navigazione. Occorre considerare che la resistenza incontrata da un oggetto in un gas è molto inferiore a quella riscontrata in un liquido.

Quando in un liquido la pressione statica è minore della relativa tensione di vapore, avviene una transizione di fase e il liquido passa in fase gassosa sotto forma di bolle. Questo fenomeno è detto cavitazione. In genere la cavitazione è dannosa e da evitare nelle applicazioni fluidodinamiche: genera rumore, diminuzione di efficienza degli oggetti coinvolti ed erosione delle superfici a contatto.

La supercavitazione è utilizzata da alcuni siluri superveloci. Un siluro a supercavitazione è progettato per generare appositamente queste bolle di gas: l’estremità anteriore del siluro ha forma piatta con bordi sagomati. Quando l’oggetto raggiunge la velocità dell’ordine di 45 m/s, l’estremità piatta deflette l’acqua, che, incontrando a valle dell’estremità una pressione inferiore alla sua tensione di vapore, passa in fase gassosa dando origine ad una bolla di gas attorno alla punta del siluro. Aumentando ulteriormente la velocità ed iniettando gas di altra origine è possibile far crescere la bolla gassosa fino a ricoprire l’intero siluro.» [Fonte]

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VA-111 Shkval

«Il VA-111 Shkval (in russo: шквал, “groppo”) è un siluro russo. Grazie all’utilizzo del fenomeno della supercavitazione può raggiungere delle velocità estremamente elevate (370 km/h). A causa di ciò la velocità e il rumore generato impongono un funzionamento più simile alla palla di fucile, che a quello di un siluro tradizionale e la portata è relativamente ridotta (tra i 7 e i 13 chilometri secondo le versioni).

La modalità di costruzione di tali armi rimane uno dei segreti più gelosamente custoditi dell’industria bellica russa, ma nel caso dello Shkval è noto che il siluro invia una parte dei gas che fuoriescono dai suoi ugelli di scarico in direzione del suo muso, cosa che permette di mantenere il siluro in una bolla di gas stabile di forma adeguata che lo separa dall’acqua circostante (supercavitazione). Il naso del proiettile è relativamente piatto e il corpo dell’arma possiede numerose alette destinate a stabilizzarlo.

Non esiste siluro occidentale paragonabile.» [Fonte]

È entrato in servizio nei primi anni del novanta: supporta testate convenzionali oppure nucleari.

 

Khishchnik

Questo nuovo tipo di siluro a razzo dovrebbe essere un consistente miglioramento tecnico rispetto al VA-111 Shkval.

The National Interest titola in questa maniera:

Russia Has a Crazy Fast Torpedo That Seems Unstoppable

«Khishchnik may also be significantly faster than the 1970s Shkval. Very high speeds underwater are certainly possible. A US Navy lab succeeded in firing an underwater projectile at an incredible 1500 meters per second, and the Chinese have talked about supersonic underwater vehicles, though there is no evidence they have achieved this.

Very little information is being released on Khishchnik apart from the fact that it is being developed by Elektropribor, a design bureau which makes instruments for ships and subs as well as aviation components. Its existence was revealed in documents uncovered by Russian defense blog BMPD which revealed that the company had been working on Khishchnik since 2013 and that launch tests were expected in 2016 as part of a contract worth 3 billion roubles ($53m). There have been no official comments or announcements.

Other companies may also be working on the project. In 2016, Boris Obnosov, CEO of Russian company Tactical Missiles Corp, mentioned work in this area to Rambler News Service.

“Take for instance the well-known unique Shkval underwater missile. We are working on upgrading it heavily.”

The ‘heavily upgraded’ Shkval seems likely to be the Khishchnik.

Shkval has been upgraded several times previously, with improvements in range and guidance. A new name suggests a more significant upgrade. An export version of the Shkval, the Shkval-E was produced in 1999. There would be a big market for an unstoppable, carrier-killing torpedo.»

L’attuale tecnologia arriverebbe quindi a supportare velocità subacquee di 1,500 metri al secondo, ossia 5,400 km/h.

Da quanto sembrerebbe di poter capire, il Khishchnik potrebbe raggiungere la velocità di poco meno di 800 km/h con una portata utile di 30 – 50 kilometri. La testa generatrice del bubble sarebbe orientabile, consentendo quindi cambiamenti di rotta. Sembrerebbe anche verosimile che il sistema di guida sia stato migliorato afferendogli capacità di auto indirizzamento sull’obiettivo.

Considerazioni.

Stati Uniti e forze navali Nato non hanno sviluppato un simile sistema d’arma per il semplice motivo che, almeno al momento, le loro flotte militari non sono contrastate da forze navali degne di quel nome. In ogni caso, all’occorrenza, l’Occidente ha a disposizione tutte le tecnologie necessarie.

Opposta è invece la situazione sia della Russia sia della Cina, che solo del tutto recentemente inizia a sviluppare l’esigenza di flotte militari di altura.

Questi due stati hanno come preoccupazione principale le portaerei americane, che vorrebbero poter tenere più lontane possibile dalle loro coste e dalle loro basi navali. In questa ottica il VA-111 Shkval ed adesso il Khishchnik,  sono armi che le portaerei non possono ignorare. Se è vero che le portaerei navigano ben protette da flotte di difesa e rifornimento, è altrettanto vero che nel rapporto prestazioni / costo una portaerei vale quasi venti miliardi, tenendo conto dell’armamento di bordo, mentre un siluro Khishchnik costa circa 50 milioni.

Accanto a questa tipologia di siluri, russi e cinesi hanno sviluppato una vasta gamma di missili ipersonici a bassa quota anti – nave.

«La Russia ha iniziato la sperimentazione dei nuovi ipersonici da crociera anti-nave Zircon, come ha riportato giovedì Sputnik News citando RIA Novosti. I missili da crociera dovrebbero essere in grado di raggiungere cinque o sei volte la velocità del suono (Mach 5 o Mach 6), ha aggiunto il rapporto. ….

I moderni missili anti-nave russi, come gli Onyx, possono raggiungere velocità fino a 2,6 Mach (circa 750 metri al secondo). Il missile da crociera Kalibr viaggia ad una velocità di 0,9 Mach, ma mentre si avvicina al bersaglio la sua velocità di punta può arrivare fino a 2,9 Mach. ….

la portata del missile è probabile che sia di circa 400 chilometri.» [International Business Times]

In conclusione, anche se nessuno intende sottovalutare le capacità difensive delle navi militari della Nato ed americane in modo particolare, anche se li riteniamo essere troppo allarmistici, ben comprendiamo i titoli recentemente comparsi sulla stampa.

Il missile cinese CM-302 è la migliore arma antinave al mondo?

«Il missile supersonico CM-302 è in grado di colpire anche bersagli terrestri. ….

la Cina non possiede missili antinave simili ai russi P-1000 “Basalt” e P-700 “Granit”. Il P-700 da solo è grande come un piccolo aereo, con una massa di 7 tonnellate e colpisce il suo bersaglio ad una velocità Mach 2 e inoltre ha un proprio sistema di guida computerizzato dotato di contromisure EW (Electronic Warfare). Questi missili possono essere lanciati in salve, e durante il volo sono capaci di comunicare tra loro per coordinare l’attacco contemporaneamente su diversi bersagli. Il P-1000 può essere equipaggiato con una testata nucleare. Questi missili sono stati modernizzati più volte, possono essere lanciati dalle coste e sono stati progettati per colpire una portaerei a più di 700km di distanza.»

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La Russia rilancia la corsa al missile antiportaerei

Le nuove portaerei degli USA, ‘cimiteri galleggianti’ da 15 miliardi di dollari?


The Economist. 2017-01-19. A new Russian weapon may give it an underwater advantage

The principle of supercavitation continues to intrigue torpedo designers.

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WHEN introduced 40 years ago, the Soviet Shkval (“Squall”) torpedo was hailed as an “aircraft-carrier killer” because its speed, more than 370kph (200 knots), was four times that of any American rival. The claim was premature. Problems with its design meant Shkval turned out to be less threatening than hoped (or, from a NATO point of view, less dangerous than feared), even though it is still made and deployed. But supercavitation, the principle upon which its speed depends, has continued to intrigue torpedo designers. Now, noises coming out of the Soviet Union’s successor, Russia, are leading some in the West to worry that the country’s engineers have cracked it.

Life in a bubble

Bubbles of vapour (ie, cavities) form in water wherever there is low pressure, such as on the trailing edges of propeller blades. For engineers, this is usually a problem. In the case of propellers, the cavities erode the blades’ substance. Shkval’s designers, however, sought, by amplifying the phenomenon, to make use of it. They gave their weapon a blunt nose fitted with a flat disc (pictured above) that creates a circular trailing edge as the torpedo moves forward. They also gave it a rocket motor to accelerate it to a speed fast enough for that edge to create a cavity consisting of a single, giant bubble which envelopes the entire torpedo except for the steering fins.

The result is that most of the torpedo experiences no hydrodynamic drag, greatly enhancing its potential velocity. To take advantage of this it is propelled, when the booster rocket runs out of oomph, by a hydrojet—a motor fuelled by a material, such as magnesium, that will burn in water.

Shkval’s problems are threefold. First, it has a short range—around 15km compared with around 50km for America’s principal submarine-launched torpedo, the Mk 48. Second, the hydrojet is noisy, so opponents can hear the weapon coming. Third, it cannot track its target. Most torpedoes use sonar to home in on the ship they are intended to sink. Because Shkval travels inside a bubble, any sonar needs to be mounted on the cavitation disc, which is too small for the purpose. In addition, returning sonar pings would be drowned out by the hydrojet’s noise. As a consequence, Shkval’s only guidance is an autopilot which steers it towards the place where its target was located at the moment of launch, in the hope that the target has not moved.

These deficiencies have not stopped Western countries trying to build supercavitating torpedoes of their own. Diehl, a German firm, announced a programme for such a weapon, Barracuda, in 2004. In 2006 General Dynamics, a big American firm, was commissioned to look into the matter (though its brief did not include the word “torpedo”, referring only to an “undersea transport”) by the country’s Defence Advanced Research Projects Agency.

The firms’ engineers tried to overcome the guidance problem by developing a new type of cavitator. Rather than a flat disc, General Dynamics’ design had a curved surface, increasing the area available for sonar reception. In addition the sonar’s transmitters, mounted on the torpedo’s steering fins, were separate from the receiver, and the interference caused by engine noise was reduced by special filters. In the end, though, these efforts ran into the sand. Barracuda was never completed. General Dynamics’ project was shelved after a year. American naval research into supercavitation in general ended in 2012, though which particular problems proved insurmountable has never been revealed.

Russia, though, has not given up on the idea. In October 2016 plans emerged for a new supercavitating torpedo, Khishchnik (“Predator”). Few details have been released, except that the work is being carried out by Elektropribor, a design bureau specialising in high-precision systems for submarines. Combining a General Dynamics-style sonar with a better motor could, however, result in a weapon that the world’s navies would truly have to fear.

Such a motor is possible, according to Georgiy Savchenko of the Institute of Hydromechanics at Ukraine’s National Academy of Sciences. His supercavitation-research group estimates that with the right fuel (perhaps lithium, which packs more energy per kilogram than magnesium) a new torpedo could have ten times the range of Shkval. It would still be noisy, but, added to its speed, such a combination of range and tracking ability would make it hard to evade. Moreover, there is no theoretical reason why Khishchnik should not travel quite a lot faster than Shkval does. In laboratory tests, supercavitating projectiles have clocked more than 5,000kph.

Kanyon diabolo

The supercavitating design being developed for Khishchnik might also feed into the Kanyon project, a giant nuclear-powered torpedo with a nuclear warhead that is intended to attack coastal targets. In what was either a deliberate leak or a piece of disinformation, this project was revealed to the world in 2015 during a televised meeting between Vladimir Putin, Russia’s president, and senior officers of the country’s armed forces. The camera, looking over one of these officers’ shoulders, gave a picture of plans for the putative device, annotated with helpful information such as “speed of travel—185kph”.

The leaked design did not appear to use supercavitation—but if Kanyon is genuine, then thoughts of adding it cannot have escaped its designers. Even if Kanyon is smoke and mirrors, though, Khishchnik seems real enough. Perhaps, this time, aircraft-carrier skippers should be worried.


Navy Recognition. 2017-01-16. Russia developing Khishchnik high-speed torpedo to replace VA-111 Shkval supercavitating torpedo.

The Elektropribor Design Bureau in Saratov is developing a high-speed torpedo dubbed Khishchnik (Russian for ‘raptor’) and designed to replace the Shkval, expert Vladimir Tuchkov writes in an article with the Svobodnaya Pressa online news agency. The blog of the Center for Analysis of Strategies and Technologies (CAST) has reported that Elektropribor is soon to complete the development of a sophisticated high-speed torpedo. The weapon is designed for replacing the famous Shkval capable of accelerating to 200 knots under water. CAST learnt about that when Elektropribor applied for participating in the 2015 Aircraft Maker of the Year Competition held by the Union of Aviation Industrialists of Russia (UAIR).

Two applications have been submitted, with one of them dedicated to “the execution of the state defense order for developing components of advanced underwater vehicles.” The application continues: “Since 2013, the company has been developing and manufacturing prototypes and testing a component of the underwater missile embodying advanced boundary layer control principles.”

The weapon in question is the Khishchnik, of which very little is known due to the program being very hush-hush.
The torpedo is under development by the company developing components for military planes, and the weapon has been submitted for the competition to be held by UAIR. The thing is, the type of weapons is called rocket-assisted torpedo, and Elektropribor is developing electrical units for its rocket motor and the control systems.

The NII-24 Research Institute (now the Region State Research and Production Company, a subsidiary of Tactical Missiles Corp.) kicked off Shkval’s development in 1960. The requirements specification called for a torpedo with a cruising speed of 200 knots and a range of 20 km for launch via the standard 533-mm torpedo tube.  

The first prototype was made as soon as 1964. The same year, it launched its tests at Lake Issyk-Kul followed by tests in the Black Sea near the city of Feodosiya. The tests failed. The designers developed one model after another that kept on failing to meet the stringent requirements specification. It is the sixth prototype that passed the tests and was cleared for full-rate production. The torpedo entered the Soviet Navy’s inventory in 1977.

Its high speed resulted from cavitation. Research into this field was started by a TsAGI affiliate in the Soviet Union in the late ‘40s. In the late ‘50s, the scientists came up with a harmonious theory of cavitation movement and issued recommendations for applying its principles to high-speed underwater vehicle development. Cavitation boils down to an object (a torpedo in this case) moving inside an air bubble, overcoming the drag caused by the air, rather than by water. A combined-cycle gas turbine unit in the nose section creates the air bubble enveloping the torpedo.

The weapon is propelled by a jet from its solid-propellant rocket motor, rather than by a screw or a waterjet. The Shkval’s power plant is two-stage. First, the solid-propellant motor accelerates the torpedo to the cavitation speed. Then, the sustainer – an underwater ramjet – kicks in.

The development of the underwater ramjet proved to be as difficult as that of the cavitation generator. It is radically different to the ones used in planes and rockets. It uses seawater as actuating medium and oxidizer, while hydroreactive metals are its fuel.

The speed requirement was met, but the range proved to be a mere 13 km. The torpedo’s launch depth was 30 m, and the weapon dashed to its target at 6 m below the surface. Initially, its warhead was nuclear and had a yield of 150 kilotons. The torpedo weighed 2,700 kg and measured 8,200 mm long.

While having a huge speed, the torpedo lacked a seeker. There were two reasons for that. First, maneuvering worth mentioning is impossible at such a speed, because the air bubble will disintegrate. Second, the torpedo is very noisy and it vibrates, which will make the seeker hear nothing but the motor.

Naturally, the heading of the enemy ship subject to sinking as well as its speed and other factors is taken into consideration prior to the Shkval’s launch, i.e. a lead is allowed for, but it is short, because the Shkval covers 13 km inside 130 s – a bit more than 2 min. The torpedo’s baseline model carried a 150-kt nuclear warhead. It was replaced with a high-explosive one weighing about 250 kg, when the time came to slash the nuclear stockpiles. However, the launch of the torpedo exposed the submarine, for the Shkval’s wake gave its position away lock, stock and barrel. The torpedo’s short range was fraught with another problem: to attack an aircraft carrier or other major combatant, the submarine had to enter its antisubmarine coverage area, which reduced its own chances for survival. In other words, although the designers produced high technical characteristics, the weapon proved to be of little use in practical terms. The Shkval was removed from the inventory.

Designers in two more countries echoed the ideas embodied in the Shkval. In 2005, Germany announced the development of the Barracuda supercavitating torpedo with a speed of 400 km/h, and, two years ago, the Iranian chief of naval operations mentioned a torpedo travelling at 320 km/h. However, these are not weapons ready for combat, rather prototypes undergoing the trials.

The Khishchnik is not a version of the Shkval. Serious money has been set aside for its development. The two contractors alone – Elektropribor and the SEPO-ZEM plant in Saratov – co-pursuing the Khishchnik-M program have received more than 1.5 billion rubles ($25 million).

Therefore, it is possible that the torpedo will have a seeker and be able to maneuver and its range and stealth will increase, expert Vladimir Tuchkov writes in the article on the Svobodnaya Pressa news website.

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