Tag Archives: Armament

Nanoenergetic Materials (nEMs) in Conventional Ammunition

(Published on 17 May 2016, CLAWS,http://www.claws.in/1571/nanoenergetic-materials-nems-in-conventional-ammunition-sanatan-kulshrestha.html)

Nanoenergetic Materials (nEMs) in Conventional Ammunition

 Nanotechnology “could completely change the face of weaponry,”

Andy Oppenheimer, Jane’s Information Group[1]

On 11 September 2007, Russians tested Father of All Bombs (FOAB), an Aviation Thermo baric Bomb of Increased Power (ATBIP). It was said to be the most powerful conventional bomb in the world, with a 7-Ton explosive mixture resulting in a devastating effect equivalent to 44 tons of TNT[2]. It was hinted that the FOAB contained a liquid fuel, such as ethylene oxide, mixed with energetic nano-aluminium powder, which was dispersed by a high explosive booster. Some reports speculated that the liquid fuel was purified using nano-filters. What caught the imagination of defense experts was the fact that the Russian FOAB had less fuel than the similar US device Mother of All Bombs (MOAB), the GBU-43/B Massive Ordnance Air Blast bomb, but was four times more powerful. It was also probably the first time that the nonprofessional learned of the lethal uses of nanotechnology. Not much information is available through open sources about the developments involving nanotechnology in explosives, much of it has to be gleaned from research papers and patents (for e.g. Patents like US6955732 – Advanced thermo baric explosive compositions and WO2013119191A1 – Composition for a fuel and air explosion).

            Since 2004, ‘Combat Safe Insensitive Munitions’ concept has shifted the focus of safety from a pure materials approach to making marine explosives insensitive to a platform based approach based upon mechanics to increase insensitivity[3]. US Navy has been at the forefront of R&D into new energetic materials since a long time and it is opined that nanotechnology enabled energetic materials would form the backbone of the future defense systems. Timely induction of nano enabled energetic systems with controlled energy release is the focus of current research at institutes like the U.S. Naval Academy, Naval Surface Warfare Center, and the University of Maryland.

            In simple terms, Nanoenergetic materials (nEMs) perform better than conventional materials because of much larger surface area, which increases speed of reaction and larger energy release in much shorter time. Addition of Superthermites[4] (nano-aluminium based) have shown instantaneous increase in explosive power of existing compositions[5]. Further, use of nano-sized materials in explosives has significantly increased safety and insensitivity by as much as over 30% without affecting reactivity. It is predicted that nEMs would provide the same explosive power at mass up to two orders of magnitude less than the current explosive systems[6].

In rocket, propellants nEMs have shown similar capabilities at Los Almos National Laboratories with nitrogen-energized nEMs[7]. In addition, incorporation of more than one burning rate in rocket propellants has given rise to novel design options by creating grains with continuously varying properties along the length as well as across the radius of the grain in Functionally Graded Materials (FGM).

While Nanosizing of high explosives leads to increasing their explosive power[8] and decreasing their sensitivity to external forces[9], it also decreases its thermal stability. The shelf life of such explosives could therefore stand reduced, however, some patents reveal that this issue has also been resolved technically (e.g. patent US20120227613 Thermal enhanced blast warhead). In India the work on explosives and propellants is being undertaken at HEMRL, a DRDO laboratory, and it is understood that the research in nEMs is progressing satisfactorily.

Projections

Nanotechnology is permeating in all fields of design & manufacturing of weapons and ammunition. It is bringing unprecedented precision in weapon systems, robustness in triggering mechanisms and opening new frontiers in propellant and pyrotechnic functioning. In addition to explosive and propellants, Nanomaterials have ushered in innovative improvements in many characteristics of ammunition such as guidance, penetration capacity, embedded sensors for monitoring condition, embedded antennae for guidance and so on.

It can be envisaged that nEMs would replace the conventional explosives in the next decade. This would provide existing conventional weapons with explosive powers higher in magnitude by a factor of two and enhance the safety to external stimulation by at least 30%. In simple terms, a missile warhead having an explosive content of 200 kg of TNT equivalent would have an explosive power of 20,000 kg of TNT equivalent when substituted with nEMs material of same weight of 200 kg!

This advancement could displace Tactical nukes from the battlefield.

What can also be foreseen is the mushrooming of new classes of extremely precise and lethal small/micro weapon systems, which could be scaled down by at least second order of magnitude from the current systems. Thus creating space for the likely paradigm shift from bigger & larger to the smaller & numerous holdings of weapons. This in turn would herald the era of Swarm Warfare.

[1] Gartner, John. “Military Reloads with Nanotech.” Technology Review, an MIT Enterprise, January 21, 2005. http://www.technologyreview.com/computing/14105/page1/

[2] http://news.bbc.co.uk/2/hi/europe/6990815.stm

[3] Insensitive munitions:

Improve the safety and survivability for Armed Forces and civilians in urban areas or near combat zones because they can safely be stored at closer distances. Reduce the vulnerability of platforms and resources against unintended or hostile aggression, violent reactions with blast overpressure and fragmentation damages are under control. Maximize the storage capabilities and improve flexibility logistics: IM can safely be carried by land/sea/air; storage platforms can be closer together and are key to Inter-Operability between the Armed Forces.

[4] Nano-Thermite or Super-Thermite is a metastable intermolecular composite (MICs) containing an oxidizer and a reducing agent, which are intimately mixed on the nanometer scale. This dramatically increases the reactivity relative to micrometer -sized powder thermite. MICs, including nano-thermitic materials, are a type of reactive materials investigated for military use, as well as for general applications involving propellants, explosives, and pyrotechnics.

[5] Gartner, John. “Military Reloads with Nanotech.” Technology Review, an MIT Enterprise, January 21, 2005. http://www.technologyreview.com/computing/14105/page1/

[6] Yang, Guangcheng, Fude Nie, Jinshan Li, Qiuxia Guo, and Zhiqiang Qiao. “Preparation and Characterization of Nano-NTO Explosive.” Journal of Energetic Materials, 25, 2007.

[7] Tappan, B.C., S.F. Son, and D.S. Moore. “Nano-Aluminum Reaction with Nitrogen in the Burn Front of Oxygen-Free Energetic Materials.” Shock Compression of Condensed Matter, American Institute of Physics, 2005

[8] Kaili Zhang, Carole Rossi, and G.A. Ardila Rodriguez. “Development of a Nano-Al/CuO Based Energetic Material on Silicon Substrate.” Applied Physics Letters No. 91, 14 September 2007.

[9] Guangcheng Yang, Fude Nie, Jinshan Li, Qiuxia Guo, and Zhiqiang Qiao. “Preparation and Characterization of Nano-NTO Explosive.” Journal of Energetic Materials, 25, 2007.

Dimensions of Submarine Threat in the Littorals –A Perspective

(Published :  “FEATURED | Dimensions of Submarine Threat in the Littorals –A Perspective by RADM Dr. S. Kulshrestha (Retd.), INDIAN NAVY.” IndraStra Global 01, no. 11 (2015): 0408. ISSN 2381-3652,)

Dimensions of Submarine Threat in the Littorals –A Perspective

Abstract

The littorals present a very complex environment in which the platform, weapon and the target interplay is dependent upon the real time and archival understanding of the medium parameters. The article aims to provide a perspective into the extent of the littoral underwater submarine threat and the constraints which hamper its successful prosecution. It also brings out the fact that the Blue water Navy would have to enhance its environmental understanding and modify its approach towards anti submarine operations to reduce likely attritions during littoral conflicts. The article brings out the imperative need to dove tail fundamental environmental research and Indian Naval requirements to tackle the threats in littorals.

 

 “…the very shallow water (VSW) region is a critical point for our offensive forces and can easily, quickly and cheaply be exploited by the enemy. The magnitude of the current deficiency in reconnaissance and neutralization in these regions and the impact on amphibious assault operations were demonstrated during Operation Desert Storm.”

Maj. Gen. Edward J. Hanlon Jr., Director of Expeditionary Warfare, Sea Power, May 1997

A blue water navy’s ability to execute manoeuvre in littorals is severely compromised due to confined sea spaces, lesser depths, heavy traffic, threats due to lurking quiet diesel submarines, coastal missile batteries, swarms of armed boats, deployed mines and threats from the air. The definition of a littoral region encompasses waters close to the shores as well as greater than 50 nm at sea. The Indian Navy, like all the other blue water navies has not been fundamentally positioned for close combat encounters. It is has generally been expected that sea warfare would have standoff distances of at least 50/60 km if not more between adversaries   (outside range of torpedoes and guns). If Carrier groups and anti ship cruise missile (ASCM) cruisers are deployed, the standoff can be up to a couple of hundred kms (ASCM and Air craft limits). However today littorals present an inevitable close quarter engagement situation with CSG remaining well clear of coastal missile batteries and aircraft operating from shore based airfields. In case of countries like China, the CSG may even remain a thousand km away to save itself from a barrage of carrier killer missile like the Don Feng 21 D with a range of over 2000 kms[i].

 Thus littorals have withered away the advantage of the CSG and the big ships as manoeuvring in close quarters is not feasible any more. The lighter ships would have to fight in the littorals with a much larger risk of attrition from the diesel electric submarine, mines, swarm of boats and shore based assets. The blue waters represent large swaths of sea with adequate depths for operations, and much less uncertainties in the sensor – weapon environment. The littorals are confined zones with reducing depths and a very adverse sensor environment. This has drastically compressed reaction times leading to requirements of great agility for the men of war.

 A worthy defender is always considered to be in an advantageous position in the littorals, fundamentally due to the intrinsic knowledge and experience in operating in his home environment. It constitutes what the US DOD calls an access denial area likely to impinge upon the US national interests in the Vision 2004 document this has been articulated as “To win on this 21st Century battlefield, the U.S. Navy must be able to dominate the littorals, being out and about, ready to strike on a moment’s notice, anywhere, anytime[ii] The Indian Navy has in all probability identified areas in Arabian Sea, Bay of Bengal and Indian Ocean where it may have to engage in littoral conflicts either singly or in concert with coalition of navies, should such a contingency arise. On the other hand 26/11 had opened the coasts to attack by terrorists and the Government of India has initiated efforts to tighten its coastal security. As to the plans of defending own littorals against a formidable expeditionary force, nothing much is known in the open domain, in all likely hood it remains a simplistic defensive model due to insufficient focus and the inevitable funding. The fact remains that ocean rim state navies today are focussing more on littoral capability than building a blue water navy. Indian Navy has to consider the littoral capability seriously whilst modernising and achieve a balance, depending upon its current and future threat perceptions. The blue water force has to have an embedded littoral component force so that the IN can operate in littorals far away from her home ports.

 The major under water threats comprise of mines and undetected diesel submarines. However as far as mines are concerned, they are every coastal country’s weapon of choice as they are economic, easy to lay but very hard to detect and sweep. They are the psycho sentinels of defence, since unless their existence is proved it has to be assumed that waters are mine infested and have to be swept before warships can attempt a foray in to the littorals[iii]. The clearing of mines for safe passage is a very time consuming and intensive exercise which introduces significant delays in any operation, while taking away element of surprise and granting time to adversary to plan tactics. Therefore in case delays are not acceptable, littoral operations would have to cater for some attrition on account of mines as well as navigation hazards posed due to sunken or damaged ships on the sea route.

 The aim of this article is to derive a perspective in to the fundamental dimensions of the littoral medium, platform and weapon with respect to the underwater submarine threat which constitutes the most potent hazard to a powerful navy.

Operating Littoral Environment

The littorals comprise of different types of zones in which a Navy has to operate. These include continental shelf, surf zones, straits and archipelagos, harbours and estuaries. The main thrust of naval operations hinges upon the underwater acoustics (sonic ray plots) which provide not so accurate measure of effectiveness of Sonars. In the continental shelf not much is known about the tactical usage of bioluminescence, plankton or suspended particles and other non acoustic environmental information. Quantifiable effect on performance of different sensors and weapons under various conditions is also not available to the Commander to help him deploy them optimally. Further predictions about conditions for naval operations in continental shelf areas of interest are at best sketchy and no reliable database exists to provide correlation between various environmental conditions that may be encountered. In the surf zone region (within 10 m depth line till the beach), temporal and spatial environmental data is required for effective planning of naval operations however, there are large variations in acoustic data over short and long term. Archipelagos and straits are subject to; swift changes in currents and water masses due to restricted topography, dense shipping, fishing and human traffic which complicate planning. Most of the harbours are estuarine in nature and present a highly intricate and variable environment (tides, currents, wave amplitudes etc) warranting a holistic approach to understand the same.

Thus it can be seen that carrying out missions in littorals also involve other aspects of environment in addition to the uncertain under water acoustics which have a direct bearing on the missions. These aspects include real time and archival data bases of; meteorological surface conditions required for efficient operation of IR, Electro optical, and electromagnetic sensor and weapon systems; under water topography, accurate bathymetry, bottom composition, and detailed assessment of oceanographic water column environment for under water sensors and weapons.

The availability of overarching oceanic environmental knowledge would provide insight into enemy submarine operating/hiding areas, location of mines and underwater sea ward defences. Currently the Indian Navy does not have the capability to carry out exhaustive littoral environmental scanning let alone field any sensor or weapon system that can adapt to the dynamic littoral environment and carry out missions with conviction. In fact, even for own littoral zones this type of information is not available which would enable effective deployment of static or dynamic defences.

Effect of Environment on Propagation of Sound in Shallow Waters

A brief description of the acoustic environment in shallow waters is relevant at this stage. The main factor affecting acoustic propagation in deep oceans is the increase in pressure of water column with increasing depth as the temperature remains nearly constant. The speed of sound increases with depth and the sound waves finally hit the bottom and reflect upwards. In shallow waters the rays tend to refract, that is bend upward without going to the bottom. This phenomenon takes place when the refracted sound velocity equals the sound velocity emitted by the source. On reaching the region of the source they again refract towards the depths and this process continues.[iv] In very shallow waters the sound rays are reflected upwards from the bottom. The amount of sound energy reflected upwards depends directly on the nature of the sea bottom. Harder the sea bottom better is the reflection and vice versa.[1]In shallow waters it is clear that the sound speed depends mainly on the temperature which in turn depends upon the amount incident solar radiation, wind speeds, wave action etc.

It can therefore be inferred that the acoustic signal in shallow waters is dependent upon factors like temperature, sea surface, nature of sea bottom, waves and tides, in-homogeneities and moving water masses amongst others. These present a very complex effect on the acoustic signal by altering its amplitude, frequency, and correlation properties. Further, multipath reflections from the bottom, as well as surface put a severe constraint on signal processing. The understanding of the underwater sound propagation remains unsatisfactory to this day. The complex interplay of acoustics, oceanography, marine geophysics, and electronics has bewildered Navies searching for submarines or mines in the shallow waters. Two fundamental issues that of beam forming and lining up the sonar are discussed in the subsequent paragraphs.

 Zurk et al[v] in their paper “Robust Adaptive Processing in Littoral Regions with Environmental Uncertainty” have addressed a real time problem in underwater, i.e. the dynamic nature of the sensor, target, medium and the interfering element’s geometry. The moving sensor, target and medium causes difficulties for adaptive beam former sonars which are designed to assume a certain level of stationary conduct over a specified time period . The time period required is dependent upon the number of elements in the array and the coherent integration time. Since large arrays give much better resolution  they have a larger number of elements, leading to a moving source transiting more beams during a given observation period. If target is in motion, the target energy is distributed over many beams weakening the signal and degrading the accuracy of targets location. The arrays with larger volumes thus have larger probability of motion losses. Some techniques to reduce these errors include sub-aperture processing, time-varying pre-filtering of the data, and reduced-dimension processing.

 Naval sonar systems have become more and more complex over time and require expert operators. Optimising sonar line ups has become essential in a littoral environment where the acoustic properties change rapidly over time and space domains. With the sonar automatically determining the optimal line up based upon desired inputs from the operator and the sensor feeds of operating environment, the sonar operator would be able to give his full attention to the task of detection, identification and classification of the targets. The necessity of   autonomous environmentally adaptive sonar control is imperative in littorals because of the tremendously large number of objects which may be present below the water line and skills of the operator would be put to test to sieve out the elusive submarines.

 Warren L.J. Fox et al. “Environmental Adaptive Sonar Control in a Tactical Setting.”[vi]  Have addressed the issue of sonar line up and have recommended neural networks for generating acoustic model simulations required.  Control schemes for Sonars are of two types, namely acoustic model-based and rule-based. Model-based controllers embed an acoustic model in the real-time controller. In acoustic model based controllers, acoustic performance predictions are inputted in to the controller, based upon available estimates of the existing environment, which in turn, gives the feasible sonar line ups. The choice of line up depends upon the chosen parameters for the operation. In the rule based controller, a generic set of operating environmental conditions are defined by the sonar and acoustic experts, which are then subjected to acoustic modelling and the sonar equations to generate the best possible line up. The existing environmental conditions would have to be assessed in real time prior to selection of the best line up available as per design. This approach however may not account for the large number of varying environments that are the hallmark of different littorals, and lead to discrepancies in results. Thus it appears that acoustic model based controller may be a better choice, as it largely takes care of the prevailing conditions at sea, than the rule based one, but it requires much more computational power and time to assess the situation prior to lining up the sonars. Warren L.J. Fox et al[vii] have recommended a method of training artificial neural networks for use in a sonar controller for ships as well as unmanned under water vehicles, to emulate the input/output relations of a computationally intensive acoustic model. Artificial neural networks are much faster and utilise far lesser computational capacity.

 The Submarine Threat in Littorals

 The shallow waters pose a serious problem for under water acoustics, they remain unfriendly to current sensors like towed arrays, variable depth sonars and air dropped sonobuoys due to depth limitations, deployment of torpedoes ( both ship and air launched) and depth charges. Shallow waters with close proximity to land also pose difficulties for radars and magnetic anomaly detectors thus providing a relatively safe operating area for small diesel electric submarines. Detection of surface craft by submarines in passive sonar mode is much easier because of their higher acoustic signatures. The surface ships would perforce resort to active sonar transmission as their passive capabilities are degraded in littorals. This in turn makes them more acoustically visible.

 The littoral submarine however has a limited period of quiet operation under water of a couple of days, as it has to either surface or snorkel for recharging its batteries by running its diesel generator sets. The battery capacity drainage is directly proportional to the running speeds, faster the submarine travels quicker is the discharge and hence larger is the discretion rate, which is the charging time required. Interestingly it is this discretion rate, which allows the submarine to be vulnerable to detection. During charging, the radiated noise of diesel generators, the IR signatures and the likely visibility of the snorkel make it susceptible to observation by trained crews. The submarine therefore prefers to lie in wait, barely moving or just sitting at the bottom for the prey to arrive.

 Development of Air independent propulsion technology (AIP) has enhanced the submerged time of submarines by a great extent (from a couple of days to about two weeks). The AIP is dependent upon availability of oxygen on board. The AIP while granting more submerged time to a submarine unfortunately provides the same level of acoustic signature as a snorkelling submarine, thus making it prone to detection.[viii]

 Fuel cell technology has been successfully interfaced with AIP and Siemens 30-50 KW fuel cell units have been fitted in the German Type 212A submarines since 2009, it is said to be much quieter , provides higher speeds and greater submerged time.

 The weapons for the submarines include mines, torpedoes and the submarine launched missiles. The technology ingress in computing, signal processing, hull design and materials have benefitted the submarine, its sensors, weapons and fire control systems. These advances coupled with vagaries of the acoustics in shallow waters have made the diesel submarine a very potent and lethal platform. While many countries have AIP submarines, of interest to India is the acquisition of these submarines by Pakistan[ix] since the Indian Navy does not operate an AIP submarine. The Indian Navy today even lacks the adequate numbers of diesel electric submarines required.

 The Unmanned Submarine (Unmanned Underwater Vehicle; UUV)

 An UUV generally is a machine that uses a propulsion system to transit through the water. It can manoeuvre in three dimensions (azimuth plane and depth), and control its speed by the use of sophisticated computerised systems onboard the vehicle itself. The term Unmanned underwater vehicle includes, remotely operated vehicles, Paravane, sea gliders and autonomous underwater vehicles.

It can be pre programmed to adhere to course, speed and depths as desired by the operator, at a remote location and carry out specific tasks utilising a bank of sensors on the UUV. The data collection can be both time and space based and is referenced with respect to coordinates of the place of operation. It can operate under most environmental conditions and because of this, they are used for accurate bathymetric survey and also for sea floor mapping prior to commencing construction of subsea structures. The Navies use them for detecting enemy submarines, mines, ISR and area monitoring purposes etc.

 The UUVs carry out their routine tasks unattended, meaning there by that once deployed the operator is relatively free to attend to other tasks as the UUV reaches its designated area of operation and starts carrying out its mission, be it survey, search, or surveillance.

Compared with many other systems, UUVs are relatively straightforward, with fewer interoperable systems and component parts, facilitating reverse-engineering of any components that might be restricted in the commercial market place. All of these factors, however also increase the likelihood that even a low tech littoral adversary could easily field offensive, autonomous UUVs, this in turn leads to seeking rapid developments in UUVs by major navies.

 UUVs are on the verge of three developments which would accelerate their induction into modern navies. First is the arming of UUVs to create Unmanned Combat Undersea Vehicles (UCUVs). This is virtually accomplished with UUV designs incorporating light weight torpedoes as weapons of choice. Heavier UUVs are contemplating missile launchers and/or heavy weight torpedoes as weapons in their kitty. However these appear to be interim measures, as a new class of weapons specific to unmanned vehicles are already under advanced development. These include much smaller and lighter missiles, torpedoes and guns firing super-cavitating ammunition.

 A second potential technology development is radically extended operational ranges for these armed UUVs. Already, the developed countries have invested in programs to create long-range underwater “sea gliders” to conduct long-range Intelligence Preparation of the Operational Environment (IPOE) missions[x]. While the technologies enabling the “sea glider” approach probably do not provide the flexibility and propulsion power to enable armed UUVs, such programs will significantly advance the state of UUV navigation and communications technologies. Leveraging these advancements, other nascent technologies such as Air-independent-propulsion (AIP) or Fuel Cell propulsion or perhaps Aluminium/Vortex Combustors, could provide the propulsion power necessary to effectively deploy armed UUVs even well outside of the operating area limitations of conventionally powered submarines.

 Finally, “autonomy” for these armed, long range UUVs will allow them the flexibility to conduct operations far away from the home port. Artificial intelligence (AI) based autonomous control systems are being developed at a frenetic pace, fuelled principally by demand for improved UAVs. Such developments will directly contribute to UUV autonomy, but in fact, are not actually necessary for the majority of “sea denial” missions envisioned for UCUVs. Even with current state of missile seeker technology, UCUVs would only need enough autonomy to navigate to a known area of operations (a port, choke point, or coastal location) and launch, and the missile would do the rest. For more complex missions, weapons could be guided by an on-site observer, for instance on a trawler or even ashore, in real-time or near-real-time. In short, there are a remarkably small number of “hard” technology barriers standing in the way of the long range, autonomous, armed and capable UUVs. There is little reason to think that this capability will be limited to high end, navies only. Thus networked operations of unmanned vehicles with PGMs are going to become the lethal weapon combo for the future.

 A request for information has been floated by the Indian Navy to meet its requirement for at least 10 autonomous underwater vehicles (AUVs). These AUVs are to be developed and productionised within four years of contract finalisation. The Navy has opted for a special category MAKE for the armed forces under the Indian Defence Procurement Procedure for high technology complex systems designed, developed and produced indigenously .Modular payload capability of the AUVs have been asked for, where in  payloads like underwater cameras for surveillance reconnaissance and high definition sonars can be mounted.

  UUVs in various configurations and roles such as communication and navigation nodes, environmental sensors in real time or lie in wait weapon carriers are going to be the choice platform in the littorals. These are expendable if required, economically viable, and offer flexibility in design as being unmanned they can have much lesser degree of safeties.

 Weapons

 “The Navy’s defensive MCM capabilities in deep water are considered fair today, but they are still very poor in very shallow water (VSW) – not much better in fact than they were some 50 years ago.” [xi]

Milan Vego.

 The naval mine is a relatively cheap, easy to employ, highly effective weapon that affords weaker navies the ability to oppose larger, more technologically advanced adversaries. The mere existence of mines poses enough psychological threat to practically stop maritime operations, and thus deny access to a desired area at sea. Further they can be used as barricades to deter amphibious forces and cause delays in any naval operation in the littoral. Thus, a mine doesn’t have to actually explode to achieve its mission of access denial. North Koreans were able to deter and delay arrival of U.S Marines sufficiently to escape safely, by mining Wonsan Harbour in October of 1950 with about 3000 mines.

 Mines are classified based upon their depth of operation, methods of deployment or the way they are actuated. The versatility of deployment can be gauged by the fact that mines can be laid by majority of surface craft, submarines, crafts of opportunity and aircrafts/ helicopters. Mines have been used by countries and non state actors alike with dangerous effects and thus continue to pose a credible threat to Navies as well as merchant marine.

   Types of mines are based upon the depth at which they are deployed. As per the  21ST Century U.S. Navy Mine Warfare document[xii] the underwater battle space has been divided into five depth zones of, Deep Water (deeper than 300 feet), Shallow Water (40-300 feet), Very Shallow Water (10-40 feet), the Surf Zone (from the beach to 10 feet) and the Craft Landing Zone (the actual beach). Mines are of three basic types namely, floating or drifting mines, moored or buoyant mines and bottom or ground mines.

  Drifting mines float on surface and are difficult to detect and identify because of factors like visibility, sea state and marine growth etc. Moored mines are tethered mines using anchoring cables to adjust their depths. These can be contact or influenced based mines. Bottom mines are most difficult to locate as they can also get buried under sediment layer which cannot be penetrated by normal sonars.

Mines can be actuated by contact, influence, and by remote or a combination thereof. With modular Target Detection Device (TDD) upgrade kits, the older contact mines can be easily upgraded to actuate by influence methods. The influence needed for actuation could be pressure, acoustic or magnetic or a desired combination. In addition ship counters and anti mine counter systems are also being incorporated in to the mines to make them much more potent and lethal.

Mine technology has kept a step ahead of the ships designs for low acoustic and magnetic signatures, and many countries are engaged in development and production of naval mines. Non metallic casings, anechoic coatings, modern electronics and finally reasonable costs have made mines a choice weapon for poor and rich nations alike. It is estimated that about 20 countries export mines while about 30 produce them. Sweden Russia, China and Italy are the leading exporters. Mine MN 103 Manta from SEI SpA of Italy is one of the most exported mines in the world with about 5,000 Mantas in inventories throughout the world.

 It is estimated that China has in its inventory about a hundred thousand mines of various vintages and from the WWI simple moored contact mines to modern rocket-propelled mines with advanced electronic systems for detection and signal processing. [xiii]

 The submarine torpedoes are an embodiment of a synergetic mix of engineering disciplines ranging from mechanics, hydraulics, electronics, acoustics, explosive chemistry etc. to sophisticated software and computing. Their development has therefore involved differences in propulsion designs from steam engines to electrical motors to thermal engines and rocket motors. The control and guidance systems have also evolved from simplistic mechanical/ hydraulic to sophisticated electronic and onboard computer based systems. The guidance has further diversified in to self guided and wire guided varieties. The simple straight runners have given way to active passive homers and wake homers to attack moving targets. The warheads have moved from minol based to TNT/RDX/Al and now on to insensitive explosives with a life of over 40 years. The warheads over the years have been fitted with simple contact exploders, to acoustic influence and magnetic influence proximity fuses. The diameter of the torpedoes has ranged from 324mm to 483mm to 650mm, and before settling for internationally acceptable 533mm. Interestingly with the advent of microelectronics space has never been a constraint for the torpedo and electronic/ software updates always get comfortably accommodated in the torpedo.

A major technical feature that sets apart a torpedo from a missile is the fact that a practice torpedo is recoverable for reuse; this enables excellent weapon capability assessment, crew training as well as analysis of vital firing geometry. Some of the noteworthy heavy weight torpedoes are the American Mk 48 Adcap, the Italian Blackshark, the German DM2A4 and the Russian 53-65 K oxygen torpedo.

The torpedo has been evolving with leaps in technology but some characteristics towards which the heavy weight torpedoes are headed include; faster speeds (~over 60 Kts), Quieter signature, better reliability in detection, enhanced ranges of operation (>100 Kms),smarter electronics, and increased lethality.

The cruise missile owes it origins to the German V1/V2 rockets and mainly to the fact that manned aircraft missions had proved to be very expensive during the wars (loss of trained fighter pilots as well as expensive aircraft). Unfortunately the cruise missile development until the 1970s resulted only in unreliable and inaccurate outcomes which were not acceptable to the armed forces. Cruise missiles overcame their inherent technical difficulties and owe their tremendous success and popularity to some of the technological advances in the fields of; firstly, propulsion, namely small turbofan jet engines which resulted in smaller and lighter airframes; secondly miniaturisation of electronic components, which led to much smaller on board computers thus to much better guidance and control abilities and finally,  high density fuels and much better explosives and smaller warheads.

  Cruise missiles have become weapons of choice at sea because of their ability to fly close to the sea surface at very high speeds (sub-sonic/supersonic), formidable wave point programming and lethal explosive capabilities. These make the missiles very difficult to detect and counter at sea. Some of the naval cruise missiles worth mentioning are the Brahmos, the Tomahawk, the Club and the Exocet family.

It appears that the trend towards hypersonic scramjet cruise missiles will continue to gather momentum and such missiles could be in the naval inventories by 2020. Coupled with hypersonic missiles would be real time target data updating and guidance by extremely fast computers and satellite based systems. The kinetic energy of hypersonic cruise missiles would be a lethality multiplier against targets at sea and therefore such a missile would be a formidable weapon without a credible countermeasure as on date. The costs continue to increase with new developments; however maintenance requirements appear to be reducing with canisterised missiles.

As Far as weapons are concerned the Indian Navy has a fairly reliable capability in mines, torpedoes and cruise missiles, however the numbers appear deficient for the defensive role in own littorals.

The submarines today can launch such missiles from their torpedo tubes or from vertical launchers which can also be retrofitted. In fact the submarines can launch torpedoes, missiles, UUVs and also lay mines comfortably. Thus making them, the toughest of platforms to counter.

Conclusion

“The marriage of air independent, nonnuclear submarines with over-the-horizon, fire and forget antiship cruise missiles and high endurance, wake homing torpedoes . . . [means that] traditional ASW approaches, employing radar flooding and speed, are not likely to be successful against this threat.”[xiv]

                                                                                    Rear Admiral Malcolm Fages

 The dimensions of submarine threat in the littorals, discussed briefly above encompass the underwater acoustic environment, the developments in submarine technology, the underwater unmanned vehicle, and the weapons. The discussion has brought out the potent danger an undetected submarine in littorals presents to the aggressor.

The Navy today faces a deficiency in an all inclusive understanding of the undersea environment in the coastal areas due to which it is difficult to counter the diesel electric submarine threat in the littorals. This deficit would not allow correct positioning and deployment of sensors for timely detection of the underwater peril. Research and development is also needed in the quality of sensors such that they are embedded with real time environmental information and can calibrate themselves accordingly for best results. As far as other environmental sensors are concerned, like those dependent on zoo plankton behaviour or bioluminescence fundamental research needs to be initiated with naval needs in focus. The acquisition of submarines and UUVs should be fast tracked if Indian Navy wants to be a credible littoral force.

 


[1] The speed of sound is given by the equation (available in text books):-C(T,P,S)=1449.2+4.6 T+0.055 T2+1.39 (S−35)+0.016 D(1)

Where: C is in m/sec, T in ° Celsius, D in metres and embodies density and static pressure effects. S in parts per thousand.

The speed of sound is dependent upon temperature and depth because the S, the salinity is nearly constant at 35 ppt for sea water.

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 [i] G D Bakshi China – Dong Feng 21-D: A Game Changer?

http://www.globaldefence.net/portals/aviation/21579-china-dong-feng-21-d-a-game-changer.html?showall=1    ( Accessed 20 Oct 12)

[ii] VISION | PRESENCE | POWER 2004, A Program Guide to the U.S. Navy, Chapter 1 http://www.navy.mil/navydata/policy/vision/vis04/vpp04-ch1.pdf ( Accessed 17 Oct 12)

[iii] US Navy DOD document, Concept for future naval Countermeasures inlittoral power projection 1998. http://www.fas.org/man/dod-101/sys/ship/weaps/docs/mcm.htm ( Accessed 23 Oct 12)

[iv] Robert J. Urick, Principles of Underwater Sound 3rd Edition Peninsula Pub (August 1, 1996)

[v] Lisa M. Zurk, Nigel Lee and Brian Tracey, “Robust Adaptive Processing in Littoral Regions with Environmental Uncertainty” in Impact of Littoral Environmental Variability of Acoustic Predictions and Sonar Performance, ed. Nicholas Pace and Finn Jensen [Bruxelles, Netherlands: Kluwer Academic Publishing, 2002], 515.  http://web.cecs.pdx.edu/~zurkl/publications/saclant_2002.pdf ( Accessed 30 Oct 12)

 [vi]  Warren L.J. Fox et al. “Environmental Adaptive Sonar Control in a Tactical Setting.” in Impact of Littoral Environmental Variability of Acoustic Predictions and  Sonar Performance, ed. Nicholas Pace and Finn Jensen [Bruxelles, Netherlands: Kluwer Academic Publishing, 2002], 595

 [vii] Ibid.

 [viii] Benedict, Richard R. “The Unravelling and Revitalization of U.S. Navy Antisubmarine Warfare.” Naval War College Review 58, no.2, (Spring 2005), http://www.jhuapl.edu/ourwork/nsa/papers/art4-sp05.pdf ( Accessed 27 Oct 12)

  [ix]  Rajat Pandit, Pak adding submarine muscle as India dithers, The Times of India Apr 11, 2011.

 [x] K. L. Mahoney and N. D. Allen Glider Observations of Optical Backscatter in Different Jerlov Water Types: Implications to US Naval Operations, Research paper, 2009. Naval Oceanographic Office, Stennis Space Center, MS 39522 USA

 [xi] Milan Vego. “Future MCM Systems: Organic of Dedicated, Manned or Unmanned,” Naval Forces 26, no.4,(2005).

[xii]  21ST Century U.S. Navy Mine Warfare, http://www.navy.mil/n85/miw_primer-june2009.pdf

[xiii]  Scott C. Truver. TAKING MINES SERIOUSLY Mine Warfare in China’s Near Seas, Naval War College Review, Spring 2012, Vol. 65, No. 2

 [xiv] Malcolm I. Fages, Rear Adm., USN; remarks at Naval Submarine League Symposium, June 2000, as published in Submarine Review (October 2000), p. 34.

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The Naval Gun Continues to Reign!

 

(Published SP’s Naval Forces Aug-Sept 2015)

A naval warship is a platform that is meant to last at least 25 years and have flexibility to upgrade its systems with changes in technology during this period. It would therefore be worthwhile to look at some of the formidable modern warships and their armament packages to get a perspective in to trends in the coming decades. Starting with the US Navy’s Littoral Combat Ship (LCS) the second LCS, Coronado has been designed for littoral warfare and is being equipped to tackle anti-submarine warfare, mine warfare and anti surface warfare. It is being outfitted with reconfigurable payloads called ‘mission packages’. The Coronado is being constructed by M/s Austal USA, in Alabama, USA. Apart from the mission modules, it carries Evolved SeaRAM (Raytheon) 11-cell missile launcher, 4 × .50-cal guns (2 aft, 2 forward) and 57 mm gun (Mk 110, of BAE Systems). The US Navy’s Zumwalt class guided missile destroyers have been designed as land attack, multi mission ships. These ships boast of an integrated power system, which can power rail gun or free electron laser guns of the future. The main armament consists of, 20 × MK 57 VLS modules (Raytheon) with a total of 80 launch cells, Tactical Tomahawk(Raytheon/ McDonnell Douglas) 1 per cell,RIM-162 Evolved Sea Sparrow Missile (ESSM-Raytheon) 4 per cell, Vertical Launch Anti-Submarine Rocket (ASROC- Lockheed Martin) 1 per cell, 2 × 155 mm/62 caliber Advanced Gun System (BAE), 920 × 155 mm rounds, 70–100 LRLAP rounds(Lockheed Martin), 2 × 30 mm Mk 46 Mod 2 Gun Weapon System (General Dynamics).

The Russian Navy’s Steregushchy class multipurpose corvettes are meant for littoral combat missions including those of anti submarine warfare, anti surface warfare and naval gunfire support. The armament package includes, 2 x 4 Uran Kh-35 (SS-N-25), 12 x Redut VLS cells, 1 x Kashtan CIWS-M, 2 x 4 330mm torpedo tubes for Paket-NK anti-torpedo/anti-submarine torpedoes, 2 × 14.5mm MTPU pedestal machine guns, 2 x AK-630М CIWS, and 1 x 100mm A-190 Arsenal or 130mm A-192 naval gun. The PLAN’s type 052D guided missile destroyer (Kunming class) is under construction at
Changxingdao-Jiangnan Shipyard (JNCX). The main armament consists of YJ-18 or YJ-83 anti-ship missiles, CJ-10 LACM, CY-5 series ASW missiles, 64 VLS, HHQ-9 series long range SAM, DK-10A medium range SAM, 1 x HHQ-10 short range SAM in 24-cell launcher, 6 torpedo tubes, 1 x H/PJ-12 CIWS, 2 x 30 mm remote controlled guns, and 1 x H/PJ-38 130mm dual purpose gun.

The Swedish Visby class corvettes have been designed by Swedish Defence Materiel Administration (FMV) and built by Kockums AB. They carry, 4 × 400 mm torpedo launchers for Type 45 (Saab) torpedoes, 8 × RBS15 Mk2 (Saab Bofors) AshM, and 1 × Bofors 57 mm Mk3. The Indian Navy’s project 15 B, Visakhapatnam class stealth guided missile destroyers, would carry, 4 × 8-cell VLS for a total of 32 Barak 8missiles, 2 × 8-cell Universal Vertical Launcher Module (UVLM) for 16 BrahMos anti-ship and land-attack missiles, 4 × 533 mm Torpedo tubes, 2 × RBU-6000 anti-submarine rocket launchers, 4 × AK-630 CIWS, 1 × 127 mm gun Oto Melara SRGM (likely).

Lastly, the Global Combat ship of the Royal Navy has been designed for 13000 km range at 15 knots with an endurance of 60 days. Its versatile design caters for anti piracy, anti terror, maritime security, and HADR missions. Its armament includes; 3 × 8-cell strike-length Mk 41 VLS (Martin Marietta/ Lockheed Martin) suitable for Tomahawk, ASROC and LRASM; 8 × 6-cell CAMM VLS (MBDA) canisters for a total of 48 CAMM (MBDA) missiles; Sting Ray torpedo system(GEC Marconi-likely); 2 × Phalanx (General Dynamics) CIWS; 2 × 30mm DS30M Mk2 (MSI Defence Systems) guns; 2 × Miniguns; 4 × General purpose machine guns; and 1 × BAE 5 inch Mk 45 naval gun.

The Naval Gun

The most striking thing about the armament packages of the formidable warships mentioned above is the fact that the Naval Gun continues to form an integral part of the firepower of these warships.

The Swedish Bofors 57 mm MK 3 gun is a dual-purpose naval gun designed and produced by AB Bofors. It has a rate of fire of 220 rounds per minute with a 40-round magazine within the turret. It features a new lightweight gun turret and a new gun barrel of   monobloc steel with a new servomechanism. This makes the gun respond rapidly and engage sea-skimming missiles with faster rate of firing. The Ammunition for the Bofors 57 mm gun is produced by Bofors, Sako Limited in Finland, and Nammo in Norway. BAE Systems AB also offers the Bofors 57 mm 3P all-target programmable ammunition, this allows three proximity fusing modes as well as settings for time, impact, and armor piercing functions. It has the flexibility to choose ammunition mode at the time of firing. Further, it has the ability to engage ground, air, and surface targets. This year BAE has announced a new round the Mk 295 Mod 1 Ordnance for Rapid Kill of Attack Craft (ORKA) with single shot kills of air and surface targets.

The Russian AK-130 is a twin-barreled gun with a rate of fire of 20-86 rounds per minute and a range of over 20 km. PLAN’s  H/PJ38 is a single barrel 130 mm gun. It is copied from the Soviet AK-130 and is considered more reliable and powerful than the original. The Chinese carried out the crucial improvement of adapting the gun to fire both separate and semi-fixed rounds. China has also developed a variety of sub-caliber rounds for the H/P J38.

The BAE Systems AGS & MK45 Mod 4 127/62, the Oto Melara 127/64 gun & the 76mm Super Rapido continue to be the most advanced guns today.

BAE’s Advanced Gun System, AGS, is designed for delivering precision munitions at a high rate of fire and at over-the-horizon ranges. It includes an automated magazine, the ammunition uses a separate propellant canister for both conventional and guided munitions. Projectiles include ballistic projectiles as well as guided land & surface attack munitions using course correcting fuses (CCF). The rate of fire of Long Range Land Attack Projectiles, LRLAP is 10 rounds per minute.

BAE Systems Mk 45 Mod 4 is 5-inch (127-mm) 62-caliber gun mount used in the U.S. Navy . The enhanced gun system has significantly improved capabilities for Naval Surface Fire Support (NSFS), as well as overall gunfire mission performance. Upgrades have been carried out, which enable Mk 45 to handle and fire high-energy munitions. It also optimizes performance of new and existing ammunition types. As per BAE, firepower flexibility of the Mk 45 Mod 4 naval gun system is achieved with the combination of several features such as, Multi-mission ammunition inventory, mixed ammunition load capacity, Remote round-to-round selectivity, and  advanced fire control adaptability.

The Oto Melara 127/64 Lightweight Vulcano constitutes;  the large caliber 127/64 LW Gun assembly,  the Automated Ammunition Handling System, the Naval Fire Control Support, and  the VULCANO  family  of ammunition. It is a medium caliber naval gun meant for surface fire and naval gunfire support as its main role and anti-aircraft fire as its secondary role. The compactness of the gun feeding system makes it possible to install it on medium size warships also.  It has a modular automatic feeding magazine with four rotating drums, each holding 14 ready-to-fire rounds. It is thus able to fire 30/35 rounds per minute. The Fire Control System calculates the ballistic trajectories, programs the fuses and, it updates GPS data when the GPS-guided VULCANO rounds are fired.

Status of Ammunition Development

In addition to the standard round the 127 mm Oto Melara can fire the VULCANO, which is a steerable sub-munition with tail fins and canards. The VULCANO range comprises of; the BER (Ballistic Extended Range) with a range of 70 km;         GPS / Inertial Navigation System;   GPS / INS / Infra-red Imaging; and GPS / INS / Semi Active Laser (SAL).

The GPS/INS ammunition is used against fixed targets, with high accuracy. In case of the GPS/INS/SAL round, Diehl provides the miniaturized, shock-resistant Semi-Active Laser seeker and Oto Melara supplies the projectile. The SAL guides the shell to engage small, fixed, moving, and re-locatable targets with very high accuracy. The addition of a SAL seeker to the GPS and inertial navigation guidance makes this variant of the round extremely accurate. With external laser designation of the target, it can even engage moving targets with high accuracy. The IIR seeker is used for anti-ship role. The built-in IIR seeker scans the surface of the sea to detect and track the heat signature of the enemy vessel a few miles before entering the target zone. On acquiring the target, it can maneuver to counter evasive measures if any. The 4AP (4 Action Plus) fuse of the Vulcano is a microwave fuse, which can detonate on impact, time, airburst, or proximity. The development of the BER variant has been completed. The guided variants, are more or less in their final leg  of the development phase.

BAE’s Standard Guided Projectile – Multi Service is a 127mm shell with GPS/INS guidance, propelled by a rocket booster. It has an in flight retargeting feature which is enabled by GPS feed to the shell. This enables it to engage even small moving targets. It has a range of up to 100 km with a CEP better than 10 m. It has a 16.3 kg warhead.

Oto Melara’s ‘Strales’ for its 76.2 Super Rapido Gun is a guidance kit, having a radio frequency beam antenna for use when firing the DART (Driven Ammunition Reduced Time of flight). It is a guided, sabot-discarding high speed round meant to engage airplanes, missiles and fast attack crafts. The DART comprises of a 2.5 Kg pre fragmentation tungsten cube warhead located in the rear, whereas the front portion is free to rotate with two canard wings. The tail has backward looking radio receivers and six fixed wings for line of sight guidance. It has the 3A PLUS programmable fuse. The DART can fly 5 km in 5 seconds. The development of STRALES kit has already been completed and it has been installed on the Italian aircraft carrier Cavour. Oto Melara has also developed  the Stealth gun shield, made of carbon fiber, with foldable gun barrel and sliding cover. It would be fitted on the new FALAJ-class corvettes of the UAE.

Ongoing Research

Composite Gun Barrel.       Texas Research Institute Austin, Inc. is researching in to the requirements of US Navy for a low-cost, lightweight, composite outer wrapped rifled barrel design suitable for firing high-energy projectiles from the Zumwalt destroyer advanced gun system. The rapid firing of high-energy projectiles using high-temperature propellants causes high dynamic barrel pressurization loads, rapid heating of the barrel, and increased fatigue & wear on the barrel bore. The US Navy requires a composite outer wrapped actively water-cooled barrel design using high-performance composite materials to provide a gun barrel with superior dynamic strength, fatigue, wear, and heat dissipation characteristics. Texas Research Institute Austin, Inc., is developing a polymer composite filament-wound outer wrapped gun barrel design that will meet requirements of the advanced gun system. Use will be made of developments of lightweight, high-temperature, fatigue-resistant, filament-wound composite applications in the offshore oil and gas, marine, automotive, and aircraft industries.

Development of Materials and Processes That Eliminate Large Gun Barrel Wear & Erosion from Advanced Propellants & Projectiles.        Materials & Electrochemical Research, Tuson, have  demonstrated that molybdenum-rhenium (Mo-Re) alloys exhibited negligible erosion and wear in terms of weight loss, as compared to chromium plated gun steel. Research is now being carried out to optimize the Mo-Re ratio versus vented bomb erosion and wear, followed by mechanical property characterization including fatigue life.

Conclusion

It is apparent that the shipbuilders and war planners have decided that no warship should be without the Naval Gun ! This is due to the compelling reasons that; guns can engage various targets like air, surface, land and FAC; they act as a contingency to missile systems; guns have short reaction time, and can engage selected land targets; they practically operate in most weather conditions; they have a sustained bearing on targets, they are not prone to jamming; and  they can engage a number of low flying missiles due to absence of dead zones.

Further the reason for the naval gun to remain relevant in the modern warships despite the missiles lies in the advent of long-range precision guided ammunition. Micro-miniaturization of guidance electronics and developments in gun propellants, has ensured very high accuracy of rounds at extended ranges and at costs, which were unthinkable a decade ago. The development of the precision guided ammunition implies that targets can be selectively engaged with great accuracy, maneuvering targets can be attacked, quick reaction times are available, and costs of engagement can be substantially reduced. Thus for the next two decades it appears that the naval gun would continue to be a major component of a warship’s outfit.

50.Policy Level Intervention Imperative for Accelerating Indigenous Manufacture of Weapon Systems for Indian Navy

(Published in  IndraStra Global – Strategic Information & Intelligence Forecasting on 16 May 2015)

Weapon systems on a warship depend upon the assigned role and mission of the warship in war. Generally, warships carry weapons to cater for threats emanating from the air, surface and underwater. For air threats like sea skimming missiles and air attacks, ships have surface to air missiles, guns in dual role, and close in weapon systems/point defense systems (multi barrel guns, short-range missiles). For surface threats, ships have surface-to-surface missiles and guns. For anti submarine warfare (ASW) ships have torpedoes and ASW rockets. Warships carry decoys for deception of enemy torpedoes and oncoming missiles, these comprise of chaff dispensers, infrared (IR) decoys, acoustic decoys etc. The warships also have an extended weapon capability on the helicopters they house on board; this could be a lightweight torpedo, rockets, or small caliber guns. The advent of weaponised unmanned vehicles is introducing another facet of weaponisation.

Naval weapons are complex in design due to the corrosive sea environment in which they have to operate, severe space and weight restrictions, and problems of stabilization as the ship rolls, pitches and yaws. Further, as with all weapons, they cannot be procured just by paying the currency required by the manufacturers. The pricing of weapons is based upon the need of the country, its relations with the producing country, its position in the world at large and other considerations like, foreign policy issues, type of technology, availability of similar systems for sale in other countries etc.

 In case of India, it has been the experience that the weapon systems it desires are not available for purchase, alternates offered are exorbitantly priced, and those affordable are invariably not required by India. The ideal solution is local availability of weapon systems, which will ensure maintainability, timely upgrades, and modularity for warship design. The indigenous effort has still not matured to provide viable weapon system or even subsystem solution within the time frame and the budgeted costs. Economic viability, arms export policy and non-availability of technological prowess, appear to be the main reasons. India is left with no alternative but to import and also prolong use of existing armament by process of life extension, constrained with improper/insufficient spares, inadequate documentation and testing methods. Weapons thus continue to be deployed well beyond their useful life without ascertaining if or at all, or to what extent they meet the designed parameters.

The defense procurement procedure (DPP) has been promulgated to enable the Armed forces to timely procure the desired equipment with least drain on national resources. The DPP is being regularly revised to cater for changing Indian conditions. It has been structured so that the Indian defense industrial base is progressively strengthened by offsets, transfer of technology, and joint venture regimes. ‘The Long Term Integrated Perspective Plan’, LTIPP, of the armed forces, is an indicative acquisition plan for the next 15 years but without any commitment of funds or frozen requirements.

The weapon procurement procedure commences with drawing the staff requirements, which the Defence Research and Development Organisation and industry claim are unrealistic, the armed forces justify it since weapons are used over decades and therefore once procured they should remain current and amenable to technological upgrades as long as possible.

Perhaps the only way the Government of India can resolve this issue is through policy level intervention. One of the suggested ways is by categorizing external threats at two levels depending upon their severity & extent and thereafter specifying two types of procurement, one (say P1) to the staff requirements of the Armed Forces and the other to a level (say P2 through local sources only) which meets at least 75% of the staff requirements. Killability studies may be carried out to assess the numbers (with sufficient redundancies) of P1 and P2 types required to meet the threats in their entirety. Further, it can incentivize the P2 procurement by increasing the defense budget proportionately and set up an accountability mechanism for timely delivery, maintainability, and functionability of the same.

It suffices to state that weaponistaion of warships is undergoing a change today forced by factors like economic slowdown, emergence of littoral threats, reduction in blue water engagements, development of powerful sensors and weapons as well as advent of unmanned vehicles on the horizon. It is imperative that policy level intervention be initiated in procurement of weapons to ensure that the Defense Industrial Base in India is strengthened to levels where it can sustain the requirements of the Armed forces.

48.Airborne Anti Submarine Warfare

(Published SP’s Special Supplement to Aero Inida 2015;19 Feb-21 Feb 2015)

Standoff antisubmarine capabilities continue to be of vital interest to the Navies across the world. The current environment of littoral warfare has once again brought in to sharp focus the threat of the lurking diesel submarine and the means of tackling it by the use of helicopters and aircraft. Some of the noteworthy anti submarine warfare platforms are discussed in brief in the succeeding paragraphs.

The Sikorsky CH-148 Cyclone is a twin-engine, multi-role shipboard helicopter being developed by the Sikorsky Aircraft Corporation. CH-148 is designed for shipboard operations and is intended to replace the CH-124 Sea King. It has a metal and composite airframe. A number of safety features such as flaw tolerance, bird strike capability, and engine burst containment have been incorporated into the design. It  is equipped to search and locate submarines during ASW. The Integrated Mission System and the Sonobuoy Acoustic Processing System are being developed by General Dynamics Canada. The sonar is an L-3 HELRAS, the radar is a Telephonics APS-143B, the Electro Optic System a Flir Systems SAFIRE III, and the ESM a Lockheed Martin AN/ALQ-210. CMC Electronics provides the flight management system CMA-2082MH Aircraft Management System. It carries 2 x MK-46 torpedoes on a bomb rack BRU-14 mounted in folding weapons pylons and a door-arm mounted general-purpose machine gun.

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The Agusta Westland AW101 is a medium-lift helicopter used in both military and civil applications. It has a digital automatic flight control system (AFCS) manufactured by Smiths Aerospace. This allows the operation of a four-axis (pitch, roll, yaw, and collective) autopilot and the automatic stabilization system, and is linked in with the aircraft’s flight management systems. The AFCS is a dual-duplex system using two flight computers to provide redundancy and fault-tolerance.

The AW101’s navigation system includes a GPS receiver and inertial navigation system, VHF Omni directional radio range (VOR), instrument landing system (ILS), Tactical air navigation system TACAN, and automatic direction finding. The Mk1 and Mk3 are equipped with a Doppler velocity system (DVS) which provides relative ground velocities; the DVS is also linked into the AFCS as part of the auto stabilization system. For safety, the aircraft is equipped with obstacle and terrain avoidance warning systems and traffic collision avoidance system (TCAS).

The AW101 is equipped with the Blue Kestrel search and detection radar, which is capable of 360 degree scanning and can detect small targets as far as 25 nautical miles. Royal Navy Merlins are equipped with the AQS901 anti-submarine system for processing sonographic data from sonobuoys to detect and target submerged submarines. Most variants of the AW101 are equipped with self-defense systems such as chaff and flare dispensers, directed infrared countermeasures (infrared jammers), ESM (electronic support measures in the form of RF heads), and a laser detection and warning system. Two hard points are present on the underside of the airframe on which it can carry four Sting Ray torpedoes or Mk 11 Mod 3 depth charges.

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The Airbus/Agusta Westland produced NH90 is designed to fulfill a NATO staff requirement for a multi-role, medium-sized military helicopter for both land and maritime operations. NH90 is the first helicopter in the world to be equipped with full fly-by-wire flight controls. NH90 is either fitted with Rolls-Royce Turbomeca RTM322 or General Electric T700E power plants.

The NH90 features a range of customizable avionics systems, dependent on customer selection and purpose. On some models, Thales Group provides various parts of the avionics, such as the glass cockpit, full-color multifunction displays, tactical mission and encrypted communication systems, the TopOwel helmet-mounted sight/display, IFF, and navigation systems, and the electrical power generation system. The naval NFH variant is outfitted with dipping sonar and sonobuoy processing equipment.

The Boeing P-8 Poseidon is a military aircraft developed for the United States Navy by Boeing Defense, Space & Security. The P-8 conducts anti-submarine warfare (ASW), anti-surface warfare (ASUW), and shipping interdiction, along with electronic signals intelligence (ELINT) role. The P8 can carry torpedoes, depth charges, SLAM-ER missiles, Harpoon anti-ship missiles, and other weapons. It is able to drop and monitor sonobuoys. It is designed to operate in conjunction with the Northrop Grumman MQ-4C Triton Broad Area Maritime Surveillance unmanned aerial vehicle.

ASW Armament

The ASW armament carried today by maritime aircraft and helicopters includes lightweight torpedoes, depth charges, and bombs.

Air Dropped Depth Charges and Bombs. Depth charges have again come into focus because of the ASW threat in littorals. These can be very effectively utilized for flushing out the lurking diesel submarines. Two depth charges are worthy of mention, these are the MK11 depth charge of UK and the BDC 204 depth charge of Sweden.

The Mk 11 depth charge was developed by British Aerospace (now BAE Systems) for air delivery from maritime aircraft and helicopters. The Mk 11 depth charge was designed for shallow water operations against submarines on the surface or at periscope depths. It is fully compatible for carriage and release from a wide range of ASW helicopters and fixed-wing maritime patrol aircraft. The Mod 3 version incorporates a 4 mm mild steel outer case and nose section, which is designed to withstand entry into the water at high velocities without distortion. It has been cleared for carriage on Lynx, Merlin, NH90, Sea King, and Wasp helicopters.

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The BDC 204 depth charge was developed by Bofors Underwater Systems (now Saab Dynamics) for air delivery from maritime aircraft and helicopters of the Swedish Navy. The depth charge can be deployed in patterns, with different depth charges set to detonate at different depths to achieve profound shock and damage to submarines. They have been cleared for carriage on the Boeing Vertol 107 helicopter and CASA C-212 Aviocar maritime patrol aircraft.

Air Launched Torpedoes. Few of the prominent air launched torpedoes are described below.

Stingray is a LWT manufactured by BAE Systems. It has a diameter of 324mm, weight of 267kg, and length of 2.6m. Its speed is 45kts with a range of 8km and its warhead is 45kg of Torpex. It can dive up to 800m.Stingray is fed with target data and other associated information prior to its launch, after entering water it searches for target autonomously in active mode and on acquiring the same, attacks it. It is carried by Nimrod aircraft. Stingray Mod1 is reported to have a shaped charge warhead and improved shallow water performance.

Mk46 Mod5 torpedo is the mainstay of US Navy’s air launched lightweight torpedoes. It is manufactured by Alliant Tech systems. It has a diameter of 324mm, length of 2.59m, with a weight of 231kg.It runs on Otto fuel, has a range of 11km with a speed of 40kts, and can dive upto365m. It has a PBXN-103 warhead of 44kg. It has an advanced digital computer control system with a built in logic and tactics for search and re-attack. It has effectively performed in both deep and shallow waters and can attack both the nuclear as well as the smaller diesel submarine. Over 25000 MK46 torpedoes have been supplied to customers until date. Interestingly the Chinese YU-7 torpedo is said to have been developed from the MK46 Mod2.

The Mk 54 Lightweight Torpedo is a hybrid of technologies taken from MK 46, MK48 and MK50 torpedoes. It is supposed to have homing and warhead of the MK50 and propulsion package of the MK46 torpedo. It has incorporated COTS processing technologies for an advanced guidance and control system. It is stated to have sophisticated shallow water capabilities for littoral threats. The MK54 torpedo has been finalized for P8i aircraft by India.

The A244/S developed by WAAS and currently manufactured by the Euro Torp consortium is a 324mm diameter, 2.8m long, and 244kg weight torpedo. It has a cruise/surge speed of 30/39kts, with a range of 6km and depth up to 600m. Its Homing head can function in mixed, active, or passive modes. It has special signal processing to distinguish target from decoys.

A244/S Mod.3 is the latest upgrade of the A244/S. It has more powerful propulsion battery, with an increased number of cells, which ensures a 50% increase in the endurance of the weapon to13.5 km. It has an Advanced Digital Signal Processor module to counter sophisticated torpedo countermeasures .The homing head has preformed multiple transmission and reception beams and multi-frequency operating capability. It can classify and track several targets simultaneously, and discriminate between the target and countermeasures.

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 MU90/Impact is in mass production for 6 major NATO and Allied Countries. The MU90/IMPACT torpedo is 323.7mm ‘NATO Standard’ caliber, 2.85 mm long with a weight of 304 kg. It is powered by an Aluminum-Silver Oxide seawater battery using dissolved sodium-dioxide powder as electrolyte with a closed-loop electrolyte re-circulation system, the torpedo is propelled by an electronically controlled high-RPM brush-less motor driving a skewed multi-blade pump jet propulsor allowing a continuously variable torpedo speed automatically selected by in built logic of the torpedo. The control and guidance electronics has embedded operational and tactical software including the signal processing, the data processing, and the torpedo guidance algorithms, which enable the MU90 to continuously self-adapt its configuration and tactics. The inertial system is based on ‘strap-down’ technology enabling all-attitudes capability including bottom following capability. The warhead consists of V350 explosive, fully insensitive, shaped charge warhead, with an impact type exploder incorporating two mechanical and six electrical independent safety devices.

 Low Cost Anti Submarine Weapon (CLAW) A200/A is a miniature torpedo developed by WASS. LCAW has been developed as an intermediary between air launched torpedoes and conventional depth charges. It is a low cost option, which provides propulsion and guidance to a depth charge without the costs of a torpedo. The air dropped version A200/A is deployed from aerial sonar buoy dispensers. The weapon is primarily designed to engage targets in shallow water, like midget submarines. The A200/A version has a length of 914.4mm, weight of 12kg, and a diameter of 123.8 mm. The warhead is a 2.5kg PBX shaped charge and the LCAW has an operating depth from 15m to300m. It has a speed of about 18kts with a range of 2km.

Indian Navy

The Indian Navy has ordered 8 in number of the P-8I Neptune version of the Boeing P-8 Poseidon. The aircraft includes six additional body fuel tanks for extended range from Marshall Aerospace; three of the tanks are located in the forward cargo compartment and three in the rear. In-flight refueling is via a receptacle on top of the forward fuselage, just aft of the cockpit. In order to power the additional electronics, the P-8 has an 180kVA electric generator. The P-8 uses data fusion software to combine its various sensors for target tracking.

The Bharat Electronics Limited (BEL) Data Link II communications allows the P-8I to exchange tactical data between Indian Navy aircraft, ships, and shore establishments. The P-8I features an integrated BEL-developed IFF system. India has purchased AGM-84L Harpoon Block II Missiles and Mk 54 All-Up-Round Lightweight Torpedoes for the P-8I. The Indian Navy inducted its first P-8I on 15 May 2013. The second and third P-8Is were received on 16 and 22 November 2013 respectively. In 2014, several Indian Navy P-8Is conducted search operations for the missing Malaysia Airlines Flight 370. The aircraft carries Raytheon APY-10 multi-mission surface search radar and is likely to have Advanced Airborne Sensor surface search radar and SIGINT package in the follow on program. It has 5 internal and 6 external stations for AGM-84H/K SLAM-ER, AGM-84 Harpoon, Mark 54 torpedo, missiles, mines, torpedoes, bombs, and a High Altitude Anti-Submarine Warfare Weapon system.

India’s Navy has selected Sikorsky Aircraft Corp., a subsidiary of United Technologies Corp. (NYSE:UTX), to fulfill the  Multi-Role Helicopter requirement for anti-submarine and anti-surface warfare (ASW/ASuW). Negotiations will now commence to procure 16 S-70B SEAHAWK helicopters, with an option for eight additional aircraft, along with a complete logistics support and training program. The Indian Navy S-70B variant will include avionics and flexible open architecture Weapons Management Systems that integrate advanced sonar, 360-degree search radar, modern air-to-surface missiles, and torpedoes for the ASW role. A blade and tail fold capability will facilitate shipboard storage.

Indian Navy has a requirement for 120 Helicopters (NMRH) in the 9-12.5 tons category. The NMRH is envisaged to carry out the ASW as well as the ASuW roles. Indian Navy is also interested in procuring 56 light utility helicopters for ASW and other support roles in the 4.5-ton class. In addition, there is a need to build an Indian Multirole Helicopter domestically in collaboration with HAL in the 12-ton class

47. Resurgence of the Naval Gun

(Published in Defence and Security of India; Feb 2015)

“Without a decisive naval force we can do nothing definitive, and with it, everything honorable and glorious.”
President George Washington

Blue water navies across the world are reassessing their capabilities to meet the demands of littoral warfare. The shallow waters harbor threats like small submarines, mines, hostile boat swarms, shore based aircrafts/UAVs, gun batteries and missiles. The Navies have to focus on tackling challenges emanating from shores before getting unfettered access to coastal areas of interest. Neutralizing swarms of small hostile craft in littorals due to their intermingling with local fishing craft in restricted maneuverability and short reaction times pose a formidable problem to Navies designed for standoff operations. Scenario and simulation studies have established that most of the NATO frigates are vulnerable to an attacking swarm of four to eight such small hostile craft. The small hostile craft’s weapons of choice include hand held weapons (the PK / RPK 7.62 mm, the NSV 12.7 mm, the Rheinmetall MG 3, the AK 47, AK 74, the FN FAL, the H&K G3 etc), and rockets launchers like the RPG-7.
Navies are modernizing the main & auxiliary gun and Close in weapon system CIWS out fits because various studies have brought out that ships using a mix of sophisticated high and low caliber weapons with high probability of hits, have much greater chance of survivability then those with semiautomatic systems. Navies are upgrading both the ordnance and the software. The goal is to achieve very high hit probabilities with high firing rates.
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Further, Studies carried out in the US to meet the requirements of the US marines, have concluded that; naval surface fire support NSFS had been crucial during the past operations. Larger caliber guns provide support at much longer ranges and are essential for destroying fortified positions. With the advent of Precision Guidance in larger caliber rounds, collateral damage has been considerably reduced. Their penetration ability in case of hard targets is practically as good as ordnance delivered by air. In order to achieve similar effects in suppressing the enemy, using smaller caliber guns like the MK 45 (5 inch), much greater number of rounds would have to be fired. During protracted war, the large caliber gun outshines the missiles because of high replacement costs of the missiles. It has a definite edge over the smaller caliber guns as the smaller caliber rounds have much lesser lethality. Both missiles and smaller caliber gun ammunition also require a large quantity to be stored on-board. The Air support operations in high threat environments are hindered by availability, mission priorities, weather, as well as prohibitive costs. All these make the large caliber gun a very cost beneficial solution in Naval Surface Fire Support (NSFS) missions.
Thus, it can be seen that the Naval Gun is likely to continue for a much longer period than previously anticipated. Conventionally the gun outfits of naval ships have included a heavy gun (57 mm caliber up wards), an auxiliary gun of up to 35 mm caliber, and a small caliber gun for close air/ missile defense. The number of turrets has depended upon the size and the role of the ship. Some of the heavy naval guns are, AGS 155, OTO Breda 127/54, OTO Melara 127/64, OTO Melara 76 mm gun (traditional /compatto/rapid), Bofors 57/70 mm MKII / MKIII, CADAM Turret / Loire 100mm / MK55 Mod 68, and Giat CADAM Turret. Examples of auxiliary guns are, Rheinmetall GDM-08 with MSP 500, Rheinmetall RH 202,OTO Breda 40/L70 twin, Mauser EADS MLG 30/27 mm, Allied Telesyn DS 30M Automated Small Caliber Gun System and Oerlikon Gam/BO1. Some of the CIWS are, Raytheon / Diehl RIM 116 Block 1 HAS, Signaal GAU-8/A, GE / GDC MK 15 Mod 2, and Mauser Oerlikon MeRoKa. However, the inability of these guns to rapidly train, elevate, or depress to prosecute swarming targets from different directions at close quarters has resulted in their poor effectiveness in littoral warfare. Navies are therefore opting for modernized or new gun systems having the feasibility of retro fitment on existing and under construction warships. An apt example is the selection of the MK 46 GWS for US Navy’s LCS and LPD 17 programs. The MK 46 GWS is capable of defeating small, fast, highly maneuverable surface craft.
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Indian Naval ships have the following main guns; A-190(E) 100mm, AK-100 100mm naval gun,AK-176-M 76mm gun,AK-76/62 76mm gun, Twin mount gun (76mm), OTO Melara SRGM 76 mm gun. The CIWS guns include; AK-630 six-barreled 30 mm Gatling gun, and the AK-230 twin 30 mm gun. Indian Navy had placed an RFP for 127 mm guns in Nov 2013, reports in the media indicate that Oto Melara has been shortlisted by the Ministry of Defense to supply thirteen 127mm guns to the Indian Navy. Two of the guns would be supplied directly and 11 would be license produced by BHEL Haridwar. Oto Melara emerged as a single bidder since BAE Systems UK had failed to respond. As far as smaller caliber guns are concerned, a RFI for 30 in number 40mm guns with EOFS has been issued in 2011 and the DAC has in addition cleared a proposal for 116 in number 30 mm guns for the warships. Indian Navy has also raised an RFI for 12.7 mm heavy machine guns for ships and rigid inflatable boats (RHIB).
Some of the popular and interesting guns and gun systems are briefly described in the succeeding paragraphs.
Heavy Guns. The Oto Melara 127/64 LW – VULCANO System consists of four key sub-systems, namely, the medium caliber 127/64 LW Gun assembly, the Automated Ammunition Handling System, the Naval Fire Control Support and the VULCANO family of ammunition. It is intended for surface fire and naval gunfire support as main role and anti-aircraft fire as secondary role. The compactness of the gun feeding system makes possible the installation on even narrow section ships. It is designed with a modular feeding magazine, having four drums with 14 ready to fire rounds each. The drums can be reloaded during firing and there is flexibility in selection of type of ammunition. The ammunition flow is reversible as rounds can be downloaded automatically. The gun can fire standard 127mm / 5 inches ammunition as well as the new VULCANO family of ammunition. The VULCANO allows a smooth integration with any Combat Management System since it has digital / analogical interface and ballistic calculation capabilities.
The Automatic Ammunition Handling System is a modular solution, which can be adapted to any ship’s ammunition magazine layout; the loading of the feeding magazine of the gun does not require gunners during operation and thus permits sustained firing of the gun. The Naval Fire Control Support is a mission planning system that can also support the Combat Management System for definition of possible firing solutions, ammunition selection, trajectory definition, and best ship course identification. VULCANO ammunition family, comprises of Ballistic Extended Range (BER) and Guided Long Range (GLR) ammunition with different multifunctional fuses, sensor and final guidance. This provides extended the ranges of the gun up to 100km. It is also noteworthy that the 127/64 LW VULCANO System is free of the International Traffic in Arms Regulations (ITAR).
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The OTO MELARA 76/62 SR, in service with 58 Navies worldwide as also with Indian Navy, is a multirole medium caliber naval gun mount, designed for anti-missile and anti-aircraft roles. The 76/62 gun can fire at the rate of 120 rds/min, thereby delivering a large amount of ammunition payload on the target.
The advancements in ammunition for this gun would be of significant interest to the Indian Navy as the 3AP fuse increases the lethality of this gun significantly in asymmetric and air threats. It is effective in meeting requirements of both, high speed maneuvering missiles and the new NSFS and ASuW, emerging from Littoral warfare. The 3AP fuse can fit the 76/62 pre-fragmented ammunition, ensuring reliable performances in critical engagement conditions, such as those involving sea skimming missiles and fast maneuvering boats. The 3AP fuse is programmable in three modes; Impact (Fast and Delayed Action); Time (Volume Saturation and Air Burst); and the Proximity (Standard, Gated, Anti-Missile, Conventional Air Defense, Air Defense, Anti Surface). The 3AP fuse has a microwave RF sensor, which behaves like a seeker detecting the target at long range. The relative velocity and position are measured and a built-in CPU sets up the trigger point of maximum lethality. In addition, a Digital Signal Processor provides full rejection of sea clutter at minimal distance from sea surface. What is of importance is the fact that the 76/62 gun mount including the ones already in service can be upgraded by the introduction of a Fuse Programmer Device.
DART (Driven Ammunition with Reduced Time of flight) guided projectile, has also been developed by Oto Melara, it can be re-vectored towards the target during its flight. It can be fired by 76mm Strales system. The STRALES is highly effective against anti-ship missiles. DART is a sub-caliber projectile with canard which is directed to the target by the guidance beam generated by an antenna placed on the gun mount. Its effectiveness is further increased by 3AP microwave programmable fuse .and pre-fragmented warhead.
As far as coastal gun batteries are concerned the Indian Navy can look at heavier gun systems like the 155mm (6-inch) Advanced Gun System Light, manufactured by BAE Systems (Minneapolis) , which provides a heavy volume, precise and sustained gun fire support. The Long Range Land Attack Projectile, LRLAP ammunition is being developed by BAE Louisville, Kentucky and Lockheed Martin Missile and Fire Control, Orlando, Florida. The LRLAP for AGS-L is capable of hitting targets at a range of 74 nm at the rate of six rounds per minute with the rocket booster assisted launch. It is multi piece ammunition and the shell is loaded with modular launch charges and rocket booster. AGS-L can also fire a high capacity ballistic 155 mm ASuW projectile (ASuWP). The AGS-L can store up to 240 LRLAP and 48 ASuWP.
Guns below 40 mm caliber. BAE Systems is working on the Mk 38 Mod 3, in partnership with Rafael, Israel. The Mod 3 uses a 30 mm ATK cannon with a coaxial .50-caliber M2 heavy machine gun in place of the 25mm M242 cannon that is fitted on the Mod 1 & 2 mounts. The 30mm cannon provide a 500-meter longer effective range over the M242 Bushmaster. The Mod 3 has a greater range of elevation: -20 degrees to +75 degrees to engage air targets such as unmanned aerial vehicles (UAV) and helicopters. The Mod 3 mount carries about three times the ammunition load of the existing gun mounts.
The MK 46 GWS is a remotely operated naval gun system that uses 30mm high velocity cannon, a forward looking infrared sensor, a low light television camera, and a laser rangefinder for shipboard self defense against small, high speed surface targets. The gun can be operated locally at the gun turret or remotely at the Remote Operating Console in the Combat Information Centre (LPD 17 class)/Mission Control Centre (LCS class). It has a range of 2000 meters and a rate of fire of 200 rpm. The system includes the MK 44 Mod 2 30mm Bushmaster II cannon, i.e. a single barrel, open bolt, dual feed, electrically powered, chain driven automatic cannon.
Oto Melara claims that its twin Fast Forty 40 mm gun, firing 900 rounds per minute, can kill an incoming supersonic missile at ranges up to 3,280 yards (3,000 m). The mount automatically switches from the lighter HE round to the heavier APFSDS when the missile reaches a range of 1,100 yards (1,000 m).
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The Bofors 40 Mk4 naval gun system has been designed to be an agile, flexible weapon system that enables a very quick response. Its long range and a high rate of fire are complemented by its low weight and compact dimensions. It has the capability to switch between optimized ammunition types, including programmable 40mm 3P all-target ammunition.
The Nexter Narwhal (Naval Remote Weapon Highly Accurate Lightweight) naval remote weapon system is particularly designed for use in light ships with very high maneuverability for monitoring and close-in combat actions but may also be suitable for heavier tonnage ships. The fully stabilised NARWHAL rapid-fire gun system comes in two variants: NARWHAL 20A with a 20mm M621 cannon and NARWHAL 20B with a 20mm M693 cannon. In its basic configuration, the NARWHAL consists of a gyro stabilised mounting armed with a 20 mm cannon, a day camera, and a fire-control system. It is remotely-controlled from a control panel enabling system operation, target acquisition and tracking and fire opening by the operator.

Fire Control Systems. BEL has developed ”Gun Fire Control System” (GFCS) for the Indian Navy for the P-28 class of ships. The GFCS is a quick reaction, multi-sensor, and multi-weapon, short/medium/long range defense system against air, surface, or shore targets on board naval ships. The GFCS is designed to provide air or surface defense with 76mm and 30mm guns. It will track hostile targets through radars or video tracking systems, based on data provided by early warning search radars. Data generated by sensors is processed and used to control the weapons by directing them in the direction of incoming missiles. It comprises five functional sub-systems: tracker, weapon control, sight control, combat management system, and support systems, each of which can be used as an independent system.
Sagem is modernizing fire control systems for French Naval surveillance frigates. It is using new-generation Electro-Optical Multifunction System (EOMS-NG) to provide fire control for the ship’s 100mm gun as well as contribute to their tactical situation awareness and self-defense. The single unit high-performance EOMS-NG optronic system features day-night infrared search and track (IRST) type passive panoramic observation, identification, tracking and fire control as well as very short reaction time between detection and engagement. Ideal for fighting piracy and illicit traffic, the EOMS-NG will replace the existing Najir optronic system. SAGEM’s VIGY MM is a high precision electro optic fire control system which can be Integrated in a Combat Management System or operated in a stand-alone mode. VIGY MM allows manual or automatic sector surveillance, automatic target tracking, aid to identification and transmission or reception of 3D target designation information. VIGY MM is able to control several guns of different calibers simultaneously. It is easy to operate and maintain. VIGY MM comprises of, a high-performance gyro stabilized platform providing an accurate line of sight, a ballistic computer allowing high accuracy gun firing, and a Man-Machine Interface (MMI). VIGY MM has high reliability, performance, and accuracy. Over 400 systems in the VIGY MM range (formerly PANDA, LYNX, NAJIR Mk1, Mk2, and 2000, VIGY 20) are currently operated by 30 navies worldwide.
Conclusion. Promising development of the laser weapon system ‘LaWS’, whose prototype has undergone successful trials on board USS Ponce in the recent past may lead to a very cost effective solution against small boats and UAVs, but it cannot replace the naval gun in all its roles. The electromagnetic rail gun, has potential and can fire non explosives shells to large distances (>100Kms) with great accuracy at velocities up to 7.5 Mach, but it is still some time away. The missiles, despite their falling prices cannot match the cost benefits accrued by the traditional naval gun. On the other hand, rapid technological improvements in gun shells and fuses have satisfactorily demonstrated very high ranges (>100Kms) and accuracies. The naval gun thus continues to be entrenched in its position as the main work horse armament on board ships of the major navies and is likely to remain the mainstay of warships at least until 2025 if not up to 2040.

31. Safety of Ammunition on the High Sea

(Published in SP’s Naval Forces Dec 13- Jan 14)

Safety of Ammunition on the High Sea

“Unfortunately, naval warfare always will be an exceedingly dangerous activity, whether ships are operating in blue or littoral water. The potential for catastrophic casualties in ships at sea is related both to the availability of modern, accurate, and powerful ordnance and to the propensity for secondary explosions and shipboard fires….”

Capt Arthur Smith, USNR, Medical Corps

 
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Safety of ammunition and explosives on board is of paramount importance for the survival of the warship. There are two aspects, which merit attention in this regard; one pertains to the safety and prevention of fire during storage of these potentially hazardous items, and the other to making the explosive devices safe for storage by improving their compositions. The aim of this article is to bring out general design aspects of magazines on board ships, as well as the ongoing efforts to improve explosive compositions so that a clear perspective is available to the reader about the explosive stowage on board a warship.

Stowage of Ammunition and Explosives on Board

A warship takes on board only that ammunition which has been certified fit for use by the armament inspection agency. Stowage of ammunition and explosives on board is a complex design exercise due to space constraints, positioning of adjacent equipment compartments depending upon hazards posed, ease of weapon handling, positioning of ammunition delivery mechanisms, minimizing of damage, ease of fire fighting and so on. The problem is further complicated as the stowage has to be secure against roll, pitch and yaw motions of the ship, extremely high humidity levels, and various intensities of storms. There are explicit design guidelines, which are refined periodically for safety enhancement. As for the ammunition, its remaining operational life is calculated depending upon the levels of environmental stresses experienced by it during its storage on board as well as the prevalent shock and vibration levels of a particular type of ship.
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There are different types of stowage spaces for different types of ammunition & explosives and they are stored in separate lockers or magazines. The lockers and magazines are clearly marked indicating type of explosives, its fire safety hazard, and the permissible quantity in that space. The warnings on stowage spaces are prominent and visually indicative leaving no doubts in the minds of personnel entering the area.

There are various types of magazines namely primary, missile, ready use magazines and lockers. Primary magazines are generally located below the water line and are equipped with temperature control, heat insulators, and adequate means of ventilation. Missiles magazines are a special category since missiles are largely integrated in nature i.e. the safety and arming mechanism is pre-assembled to the warhead, which in turn is connected to the electronics and the rocket propellant thus raising its hazard level. Further, they are housed in special casings, boxes, or canisters and stored separately. The handling equipment to bring them to the launcher could be operated by combination of electric-pneumatic and/or hydraulic systems. Extreme care is required during handling as the rocket propellant may ignite in case the missile falls and thereby launch the missile in a confined space causing havoc. Ready use magazines are located near the weapon for which they are intended, they are also well ventilated, insulated from heat and fitted with sprinklers. Ammunition lockers are used to store special types of explosives and ammunition such as detonators and pyrotechnics. The lockers are secured to the deck of the ship and it is ensured that ammunition inside does not move or rattle about during routine motion of the ship at sea.

Single purpose magazines are those which store a single type of explosive store for e.g. Rocket motor magazine, small arms magazine, fixed ammunition magazine, missile magazine, fuse magazine, detonator locker, pyrotechnic locker, and so on. Mixed explosive storages are also permissible in certain combinations of explosive stores depending upon the severity of explosive sensitivity. It is ensured however that the ammunition stored on board is as per regulations, and within permissible limits.

Environmental control of magazines. Magazines are fitted with safety and environment control features so that the ammunition and explosives remain protected from excessive humidity & temperature. Ventilation and exhaust systems are installed in the magazines and they are regularly vented to evacuate accumulated toxic gases if any. Missile magazines are vented to the atmosphere for the simple reason that in case a missile rocket motor functions its exhaust is immediately vented to atmosphere before it can spread to other areas.
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Sprinklers and alarms. Largely, all types of magazines have sprinkler systems fitted in such a way that water is sprayed on to the ammunition & explosives and the entire magazine is flooded in case of smoke/fire detection or rapid rise in temperature. These can be operated automatically, by remote control or manually. Ammunition, which functions by ingress of water, is not stored in such magazines. The alarm system comprises of alarms that operate on, detection of high temperature, activation of sprinklers and functioning of flooding systems.

Inspections. Magazine inspections are carried out by qualified sailors and recorded in inspection logs. Daily inspection involves ensuring that ammunition is properly secured, magazine is clean, there is no presence of fumes or odor, and that there is nothing out of the ordinary in and around the magazine. Special attention is paid to the fact that there should be no, hindrances to entry and exit to the magazine, abnormality in rise of temperature & humidity charts,  unnatural accumulation of material in or around the area etc. In addition, the magazine and surrounding area is inspected for leakages or breakages in sprinkler systems, functioning of alarm systems and abnormal heating in adjacent compartments. Each magazine is monitored for temperature and humidity and records of maximum and minimum values are entered in the magazine’s log card inside the magazine. The magazines are inspected prior to locking and remain locked when no activity is being carried out, only authorized personnel can access them.

Movement of ammunition. Shifting of ammunition for routine firing exercises, rearrangement or during ammunitioning /deammunitioning are inherently dangerous activities where slightest mistake can lead to catastrophic situations therefore utmost care is exercised during such work. Explicit orders are available for each activity and it is ensured that the orders are complied with at all times. Ammunitioning and deammunitioning is carried out at designated jetties or explosive anchorages so that in case of any accident the damage is limited to that ship only. Transfer of ammunition at sea is carried out only in exceptional circumstances, as it is a very dangerous activity. Detailed orders are prepared by both ships and preparations checked and rechecked prior to carrying out this operation. The ships remain in highest degree of nuclear, chemical, and biological damage control readiness during the process.

Insensitive Munitions

Despite all the precautions during design and operation of magazines accidents do take place with ammunition, which lead to terrible outcomes on warships and loss of precious lives. The men on board a warship work and sleep virtually next to the magazines, accidental fires in other areas may also lead to explosions or large fires in magazines due to cook off or other causes. A need was therefore felt to make explosives inherently less sensitive so that they remain passive to external stimuli like heat, shock, bullet or fragment impact and sympathetic detonation in case nearby munitions function. The genesis of the thrust in insensitive ammunition development lay in two major accidents in the US, namely the 1966 Palomares B-52 Crash and the 1968 Thule Air Base B-52 Crash in which the high explosive devices used in the nuclear bombs had detonated on impact. The US navy too had been witnessing a large number of accidents in the sixties. In 1966, there was a fire on board USS Oriskany due to mishandling of an aircraft flare, which led to detonation of 2.75 rocket warheads and resulted in the death of 44 sailors. In 1967 a 5-inch Zuni rocket loaded on the pod of an F-4 aircraft on board USS Forrestal was accidentally fired, which in turn led to fires and functioning of several bombs, rockets and missiles. The disaster resulted in deaths of 134 personnel. In 1969, on board USS Enterprise the exhaust from an aircraft engine starter unit caused detonation of 5-inch Zuni rockets, whose warheads were filled with composition B explosives. This resulted in 18 warhead explosions and 28 deaths. In December, the same year ammunition ship SS Badger encountered rough seas during a storm due to which the bombs broke loose from the pallets and led to explosions as they were tossed around the deck. The ship had to be abandoned and 26 lives were lost. In addition, the US navy experienced sixteen premature explosions of shells of high caliber guns during the period December 1968 and January 1973. The shells were either filled with Composition A-3, Composition B or explosive D. Incident on board USS Newport News on 01 Oct 1972, deserves mention in which a the projectile of 8-inch ‘bag gun’ detonated in ram position in the gun chamber. In the explosion and ensuing fire 20 sailors died. Compositions of the type mentioned above are prone to ignition when subjected to adiabatic heating during operation/acceleration of projectile in the gun barrel. The above incidents and similar ones in the Army depots provided impetus in to research on insensitive munitions.

Conceptually insensitive munitions should not explode but only burn when subjected to slow and fast heating, hits by bullets, shrapnel, or shaped charges. Research is being progressed adopting approaches, like externally protecting the explosive device during transportation by incorporating thermal insulation & venting, and by improving explosive compositions to provide high stability. Insensitive munitions contain shock and fire resistant ‘insensitive high explosive’ like plastic/polymer bonded explosives or TATB (triaminotrinitrobenzene). TATB’s shock and thermal stabilities are higher than that of any other comparable material, further it is a reasonably powerful high explosive thus favoring its induction in munitions. Some of the newer compositions are Insensitive Munitions Explosive IMX-101 (consisting of 2,4-dinitroanisole and nitrotriazalone amongst others, developed by BAE Systems and cleared for use by US Army) and FOX-7(1, 1-diamino-2,2-dinitroethene (DADNE) of Sweden).

A major opposition to use of insensitive munitions has been the view that the explosive power of these is inferior to the ones filled with TNT/HMX, however, this objection is more than offset by high accuracy of new delivery systems, where in, much fewer munitions are required to achieve the same impact on target. During Operation Desert Storm, laser guided bombs accounted for about ~50% of destroyed targets, despite the fact that their numbers were less than 5% of the total ordnance fired. The Navies across the globe are today committed to the use of insensitive munitions and are gradually replacing the TNT/RDX/HMX compositions. This is not to say that completely insensitive munitions have been developed and are available for use by the armed forces or that all the requirements of insensitive munitions are met prior to its induction. Incremental improvements are being accepted as they are helping in reducing the risks and increasing survivability at sea as compared to the older explosives, as an example PBXN-109 meets all requirements except that of sympathetic detonation and hence has been inducted in bombs and missile warheads since the older filling had not met even a single insensitive munitions criterion. The U.K. Ordnance Board Proceeding 42657 commenting upon usefulness of Insensitive Munitions have stated:-

“In Wartime.

        Improved survivability of weapon systems and platforms as a result of reduced levels of damage caused by enemy strikes or credible accidents.

Reduced casualty rates and mission losses.

Reduced losses of ammunition as a result of enemy strikes on, or credible accidents in, magazines and storage areas.

In Peacetime.

Reduced risks in storage leading to better utilization of and a probable reduction in both the number and size of storage areas.

Reduced risks in handling and more economical use of transport.

Reduced damage from accidents and hence, relaxation of restrictions applied to achieve an acceptable level of safety.”

Many NATO countries and other allies of the US are supporting the insensitive munitions program. As far as indigenous developments are concerned, the High Energy Materials Research Laboratory of DRDO claims to have developed 12 compositions in the insensitive munitions category along with CL-20 the worlds ‘most powerful’ non-nuclear explosive. These would find applications in warheads, rockets, or gun propellants. Laboratory production of these has also been established.

In conclusion it can thus be seen that Navies are very conscious and proactive about structural safety of magazines, safety procedures during handling as also researching in to sensitivity reduction of explosives to ensure enhanced safety of men and material onboard warships.
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