Having largely completed the infrastructure of the indigenous light torpedo with its current work on the TORK, ASELSAN has gained significant infrastructure and technological knowledge in the field of torpedo technologies.
Building on what it has gained in this field, ASELSAN is walking with firm steps towards its goal of becoming a technology centre for light torpedoes in the short term, and for supercavitating torpedoes in the long term.
Considering the development and technological advances of torpedoes, it is expected that the need for countermeasures will increase even further both in Turkey and around the world. With the prospects of supercavitating torpedoes becoming even more significant threats with the acquisition of acoustic capabilities, the significance of countermeasure systems is expected to peak in the forthcoming period.
Since the 2000s, ASELSAN has focused on the indigenisation of naval electronic systems, particularly those within the scope of the MİLGEM project. In this context, it has made significant investments in the field of underwater acoustic system technologies, which previously did not exist in Turkey. The company has given specific priority to torpedo countermeasure systems, since technology transfer from abroad was not possible.
ASELSAN first started to work on torpedo countermeasure systems following the contract signed with the Ministry of Turkish National Defence for the Development of Acoustic Decoy System for Submarines, and also with the development of the HIZIR torpedo countermeasure system for surface ships, which was conducted concurrently with the company’s own resources. Within the context of these projects, which were initiated around 2007, and using ASELSAN’s experience in military electronic systems and electronic warfare, internationally competitive torpedo countermeasure systems for acoustic warfare were developed within a very short time. ASELSAN, that has become Turkey’s technology centre in the field of torpedo countermeasure systems through these projects, is continuing to work for integrating these countermeasure systems to naval platforms, while improving existing technologies and developing new ones.
A Lethal Underwater Threat: The Torpedo
Today, as in the previous century, torpedoes still represent a lethal underwater threat for submarines and surface ships. As a result of advances in technology, conventional torpedoes of the early 20thcentury that lack acoustic guidance, are replaced by wake-homing torpedoes with active, passive and combined active/passive search, detection and tracking capabilities. Modern torpedoes can be controlled via cables up to 30 miles away from the launching submarines; reach speeds of more than 50 nautical miles per hour and owing to high energy density battery technology, conduct tasks for longer durations.
In parallel with developments in material technologies, it has become possible to use high performance transducers with a broad working frequency range in the torpedo’s sonar head. Likewise, thanks to developments in micro and nano-technologies, sonar head electronics have achieved a very high power processing capability on a smaller scale. These developments have not only enabled torpedoes to detect, track and categorise multiple targets simultaneously in 3D and with high resolution, but have also enabled them to be equipped with advanced counter-countermeasure algorithms. Additionally, in line with the developments in fibre-optic technology, torpedoes can now be remotely controlled with fibre-optic cables. This ability to relay a large amount of information from the launching platform has transformed torpedoes into a much more dangerous weapon.
Apart from acoustic guided modern torpedoes, significant developments in the area of supercavitating torpedoes are also expected in the near future. Supercavitating torpedoes operate on the principle of a layer of air forming around the torpedo, enabling its movement within this layer. This minimises the torpedo’s contact with water, resulting in minimum friction and very high speeds.
It is certainly very alarming for submarines and surface platforms that, thanks to this supercavitation capability, the VA-111 Shkval torpedo can reach a speed of 200 nautical miles per hour, while the Barracuda torpedo can reach even higher speeds. Although these torpedoes do not yet have acoustic guidance, it is known that there is an ongoing work to provide the Shkval torpedo with guidance at speeds of 60 nautical miles per hour, and an assault capability at 300 nautical miles per hour [1]. Likewise, works are currently being conducted with the objective of equipping the Barracuda torpedo with acoustic guidance capability [2].
Figure 1. Shkval torpedo [3] (on the left) and Barracuda torpedo (on the right)
Once supercavitating torpedoes also acquire acoustic capabilities, the reaction time will become shorter and consequently the ability of platforms to avoid such threats by manoeuvring, or by only using soft-kill countermeasure systems, will be greatly reduced. This shows that torpedoes will pose much higher threats against surface platforms and submarines in the future, indicating the need for more complex, faster and more efficient countermeasure systems, offering a broader range of capabilities, and incorporating both soft-kill and hard-kill solutions simultaneously.
Torpedo Countermeasure Systems
Today’s torpedo countermeasure systems are classified in two groups: soft-kill and hard-kill. The aim of the soft-kill method, which relies on the use of acoustic decoy and jammers, is to let the torpedo battery run out before it reaches its target, either by jamming or decoying the torpedo sonar through the use of appropriate tactics. The other method of defence against torpedoes, the hard-kill method, an anti-torpedo torpedo seeks to destroy a threat torpedo directly or to cause sufficient structural damage so that it becomes unserviceable.
Although there are many companies, such as ARGON, WASS, ULTRA, DCNS and RAFAEL, that are currently developing torpedo countermeasure systems, currently there exists no countermeasure system on the market that is effective against all types of torpedoes threats, and which incorporates both soft-kill and hard-kill solutions.
Soft-Kill Torpedo Countermeasure Systems
Soft-Kill Torpedo Countermeasure Systems generally consist of:
- A Tactical Development Simulator aimed at improving evasive tactics against torpedo threats,
- A Decision Support System which, depending on the threat situation, recommends to the user the most appropriate evasive tactic, and ensures its implementation,
- Acoustic decoy and acoustic jammer effectors,
- Outside pressure hull (submarine) and deck (ship) launchers enabling the launching of effectors (Figure 2).
Figure 2. Components of a General Soft-Kill Countermeasure System
With soft-kill countermeasure systems, the performance and number of decoys and jammers, together with their launching time, affects the success of the system, as does the evasive manoeuvres conducted by the platform. As every second is crucial, the use of advanced acoustic decoys and jammers, together with the Tactical Development Simulator and Decision Support System, is of critical importance against torpedo threats. The Tactical Development Simulator is used for developing and validating the tactics that will provide the highest likelihood of evasion in different threat scenarios; these tactics are then installed on the Decision Support Systems in the submarines or surface platforms. When an actual torpedo threat is detected, the system uses the scenarios and algorithms stored in its database, and advises the operator on the most appropriate tactics, depending on the threat situation. The tactic proposed by the system includes an evasive manoeuvre for the submarine or surface platform, as well as the launching times and working parameters of the acoustic decoys, jammers or both.
Hard-Kill Torpedo Countermeasure Systems
In parallel with the development of counter-countermeasure algorithms in torpedoes, hard-kill methods, which support soft-kill evasive measures, have also become common. Hard-kill methods mainly aim to cause structural damage to the torpedo, so that its mobility is restricted, or it is totally destroyed. Even partial damage to the torpedo will cause it to abort its assault phase, allowing the ship to gain precious time.
Various different hard-kill methods are recommended, such as placing a net near the platform, opening an umbrella towards the direction of the incoming torpedo, or using an underwater bomb or supercavitating ammunition [4]. There are also certain systems, such as the Israeli-made Torbuster, that aim to attract the torpedo with a soft-kill based effector, and then explode it under the right conditions [5]. However, the most important shortcoming of these systems is their lack of effectiveness against torpedoes with wake-homing capability. Nowadays, the most important and commonly used hard-kill method involves the use of another defence torpedo that physically eliminates the torpedo threat or renders it unserviceable.
With this method, the defence torpedo uses its acoustic sonar head to find the torpedo threat and physically neutralises it at the estimated intercept point. Although manufacturers’ reports state that the European-made MU90 and the Russian-made PAKET-E/NK light torpedo can potentially be used as defence torpedoes, the main work currently being conducted on the defence torpedoes is the German Sea-Spider and US Countermeasure Anti Torpedo (CAT). For the first time on a ship, the US Navy plans to integrate in 2018 the CAT system – which performed its initial naval trials in 2013 – as a sub-component of a Surface Torpedo Countermeasure System [6].
ASELSAN: Torpedo Countermeasure Technology Centre
In line with its corporate mission, ASELSAN has, as in other fields of defence, undertaken an important role in establishing the necessary infrastructure and technology, as well as acquiring critical knowledge in the field of underwater defence. ASELSAN first started its studies on the development of underwater acoustic systems in 2006, and has made important technological achievements in a very short time, particularly in the field of torpedo countermeasure systems.
As a result of these studies, the ZARGANA Submarine Torpedo Countermeasure System has been developed indigenously and included into the inventory of the Turkish Naval Forces Command (TNFC). Meanwhile, using its own resources, ASELSAN has also developed the HIZIR Torpedo Countermeasure System for surface ships. The Torpedo Detection Array (Towed Sonar) used in the HIZIR system, which is vital for defence operations against torpedoes and enables the long range detection of torpedoes, has been designed and manufactured using indigenous capabilities.
As a result of said capabilities, expandable effectors – the most critical components of the ZARGANA and HIZIR systems – have been developed indigenously. These effectors, called ZOKA family, are available in two different types: decoy and jammer. An extensive range of ZOKA effectors have been created that mainly differ according to the type of platform on which they are used. ZOKA effectors are equipped with advanced acoustic jamming and decoy algorithms, so that they can be effective against all torpedoes with acoustic guidance.
Conversely, rather than expandable effectors using soft-kill methods, hard-kill methods are needed against torpedoes without acoustic guidance. That is why ASELSAN, in addition to their already existing soft-kill capability, has been working extensively to provide the HIZIR and ZARGANA systems with hard-kill capability. The aim of the project, which was launched in 2014 with the support of the TÜBİTAK TEYDEB (The Scientific and Technological Research Council of Turkey, Technology and Innovation Grant Programs), was to develop a Defence Torpedo Against Torpedoes (TORK) in order to eliminate torpedoes physically. With the integration of the TORK to HIZIR and ZARGANA in the near future, surface ships and submarines are to acquire top-level countermeasure capability against torpedoes.
ZARGANA
ZARGANA is a soft-kill countermeasure system which, by using the data collected from the platform’s undersea systems, designates and implements the tactic that offers the highest probability of success against the relevant underwater threat. The system’s torpedo countermeasure tactics include evasive manoeuvre advice for the submarine and the launch pattern and timing of acoustic decoys/jammers. The system can operate in integration with operator-controlled input data or underwater systems that automatically provide real time data, and consists of the following components:
- Tactic Development Simulator (Ground Based)
- Decision Support System
- Launcher (Port/Starboard)
- Expandable Effectors (Acoustic Jammer/Acoustic Decoy)
Thanks to their modular design, expandable effectors – the most critical components of the ZARGANA system – can be manufactured in different types depending on requirements, and be adapted to various different sizes. On one hand, acoustic jammers can operate in active, passive or combined active and passive modes, and generate wide band high-level noise to cover the operating frequencies of classical and modern acoustic-guided torpedoes. Acoustic decoys, on the other hand, misguide the torpedo by simulating with high fidelity the acoustic and dynamic characteristics of the platform.
Figure 3. ZARGANA Launcher Sub-System
ZARGANA system is in use in the inventories of TNFC. Owing to its flexible design and modular structure, enabling its easy adaptation according to need, the system can be integrated to different submarine platforms.
HIZIR
Indigenously developed by ASELSAN for corvettes and higher-class ships, HIZIR is a soft-kill countermeasure system equipped with the most up-to-date technology. The HIZIR system consists of the following sub-systems:
- Torpedo Detection Array (Towed Sonar)
- Towed Acoustic Decoy
- Expandable Acoustic Decoy
- Towing winch
- Electronic Cabinet
- Launcher (Port/Starboard)
- Operator Display and Control Units (COC, Combat Operations Centre/Bridge)
(Figure 4) The HIZIR system can operate in integration with ships’ sonars, command control systems and data distribution units.
An important feature of the system is a triple hydrophonic structure with advance detection, classification and positioning algorithms that immediately detect the direction of incoming torpedoes threats, without requiring the ship to manoeuvre. Owing to this feature, the HIZIR system can detect torpedoes over long distances, providing the ship with sufficient reaction time. Once a torpedo is detected, the system promptly recommends to the operator the most appropriate tactic for evading the torpedo threat. These tactics include the evasive manoeuvre of the ship, the planning for a towed decoy operation, towed decoy parameters, and the launch timing of expandable decoys.
Figure 4. HIZIR system
The HIZIR system – which received an Innovative Product award at the TESİD (Turkish Electronic Industrialists Association) Innovation & Creativity Awards in the large companies category for its indigenous design and superior technological features – has a modular structure that can be updated or adapted according to new threats that may arise in the future.
TESİD award for HIZIR system
ZOKA
ZOKA effectors, which have been developed for submarines and surface ships, are capable of operating effectively against any torpedo threat in the world that has acoustic guidance, and can be used in active, passive or combined mode. ZOKA effectors are used in HIZIR and ZARGANA Torpedo Counter Systems in two different types: jammer (Figure 5) and decoy (Figure 6). ZOKA jammers emit wide band high-level noise to cover the acoustic operating frequency range of all existing torpedoes. By doing so, they mask the noise of submarines against passive torpedoes, and reduce the detection range of eco signals reflecting from the submarine by increasing the noise of environment against active torpedoes. Conversely, ZOKA decoys deceive and confuse the torpedo by simulating the acoustic and dynamic characteristics of the platform and attracting the torpedo to themselves. The combined use of ZOKA decoys and jammers has been highly effective against acoustic torpedoes.
Figure 5. ZOKA mobile jammer
Figure 6. ZOKA mobile decoy
Hard-Kill System: TORK
The most efficient defence for submarines and surface ships against a possible torpedo threat is the combined use of soft-kill and hard-kill methods. Work on the Anti-Torpedo Against Torpedoes (TORK) was initiated by ASELSAN in 2014 with the support of TÜBİTAK TEYDEB program. The system, which was developed by ASELSAN to provide hard-kill defence capability against torpedoes, consists of indigenous hardware and software components. TORK is an anti-torpedo torpedo being developed for eliminating acoustic-guided, wire-guided, unguided and wake-homing torpedoes aimed at surface ships. With its sonar head, TORK is capable of accurately locating a torpedo threat as it approaches the platform. Currently under development, this system uses advanced prevention algorithms to detonate to render any torpedo threat in its range unserviceable.
The TORK is currently undergoing manoeuvre trials in a sea environment, while performance tests with its acoustic sonar head are expected to take place in early 2017.
Figure 7. TORK: The ASELSAN Hard-Kill Countermeasure Torpedo
TORK will ensure that high value and strategically important assets, such as submarines and surface ships can navigate much more safely at sea. TORK, which is planned to be effective against all types of torpedoes, is being developed so that it can operate integrated with soft-kill countermeasure systems.
The Road from TORK to the Light Torpedo
Torpedoes are divided into two groups, as heavy-weight and light-weight. While heavy-weight torpedoes are approximately 53 cm in diameter and about 6 meters long, a light-weight torpedo has a diameter of approximately 32 cm and a length of 3 meters. Heavy torpedoes are launched from submarines against submarines and surface platforms, and can be controlled from the launching submarine with a cable. Heavy torpedoes can operate for up to 60 minutes. Light torpedoes, however, are launched from aerial units or surface platforms against submarines and cannot be controlled by cable. Their duration of operation range is likely between 10 to 20 minutes.
The operating principles, size and sub-components of the TORK system are largely similar to that of a light torpedo. Thus, by taking into consideration both the domestic and international market needs that may arise in the near future, ASELSAN has also been developing the TORK system to create a basis for light torpedoes. The warhead, battery compartment, and acoustic sonar sensor array (wet-end) have been developed with a modular design, so that they can be adapted for use on light torpedoes. For example, the electronic sub-system (dry-end) that is developed for the TORK acoustic sonar can also be used in the light torpedo acoustic sonar sensor array (Figure 8).
Figure 8. TORK (on the left) and Light Torpedo (on the right) Sonar Sensor Arrays
Other important sub-systems of the TORK, such as the engine, propulsion-direction, guidance and control, have been developed to be used in light torpedoes without need for modifications. The best example of this is the Motor Driver Unit developed for the TORK (Figure 9). Currently, the Motor Driver Unit adequately meets the needs of TORK and is capable of driving two engines simultaneously at the power levels required by a light torpedo.
Figure 9. Motor Driver Unit developed for joint use by Light Torpedo and TORK
Having largely completed the infrastructure of the indigenous light torpedo with its current work on the TORK, ASELSAN has gained significant infrastructure and technological knowledge in the field of torpedo technologies. Building on what it has gained in this field, ASELSAN is walking with firm steps towards its goal of becoming a technology centre for light torpedoes in the short term, and for supercavitating torpedoes in the long term.
Future Outlook
As in all areas of defence systems, the concepts of ‘threat’ and ‘countermeasure’ evolve continuously in close relationship with one another. In parallel with new advances in technologies, torpedo manufacturers have been constantly updating or renewing their torpedoes to make their torpedoes faster, more silent, and smarter when moving. Similarly, countermeasure systems are also continually developing against threats, so as to maximise the defence capability they offer. In this competition between threat and countermeasure, new methods are also being developed to allow submarines and surface ships to better evade torpedo threats.
Considering the development and technological advances of torpedoes, it is expected that the need for countermeasures will increase even further both in Turkey and around the world. With the prospects of supercavitating torpedoes becoming even more significant threats with the acquisition of acoustic capabilities, the significance of countermeasure systems is expected to peak in the forthcoming period.
With its growing experience in torpedo and torpedo countermeasure systems, ASELSAN is continuing its work on the advanced technologies of the future. The ‘development of new generation smart effectors’ project regarding torpedo countermeasure systems stands as the best example of this. This technology development project, which aims to enable communication between underwater units through an automatically established acoustic network, was initiated in 2015 with the support of the TÜBİTAK TEYDEB program. The technology that will be gained from the project, which scheduled for completion in 2017, will in the near future be used not only in new generation torpedo countermeasure effectors, but also in other fields of underwater acoustics.
Building on its 40 years of experience in technology, ASELSAN will continue to contribute to the development of all the underwater acoustic system technologies required by Turkey. It will continue to provide the most advanced technology for national defence in the field of torpedo and torpedo countermeasure systems, through the use of modular systems compliant with the relevant performance, functionality and logistic requirements. These systems will soon earn their rightful place in the world market.
Bibliography
[1] Joseph, Austin,
Modern Torpedoes and Countermeasures, Bharat Rakshak Monitor – Volume 3(4) January-February 2001
[2] DIEHL-BGT Defence,
Company Presentation, UDT 2009, Cannes
[3]
https://en.wikipedia.org/wiki/VA-111_Shkval
[4] Yılmaz, Sacit, Ircı, Ayhan,
Yeni Nesil Torpidolara Karşı Hard-Kill Karşı Tedbir Sistemleri (Hard-Kill Countermeasure Systems Against New Generation Torpedoes), SAVTEK, 2012
[5] RAFAEL Advanced Defence Systems,
Torbuster Hardkill Torpedo Defence, Euronaval 2008, Paris
[6] America’s Navy,
First carrier Countermeasure Anti-Torpedo Launched, www.navy.mil/submit/display.asp?story_id=74665, 6 June 2013
Turkish STM Company, which design Milgem Class Corvettes, has proposed to Pakistani Navy to develope mini-submarine to replace Cosmos MG110 class.
DATUM design
Test submarine 9m long and carry 3 person. The bigger one will be operational SDV.