1.NAVAL WARFARE THORIES .pdf

NAVAL WARFARE THEORIES LT AGNES M SANCHEZ 08 August 2024 BMASC students  SCOPE OF PRESENTATION a) ASW Short History c) ASW Weapons World War I Non-guided weapons Inter-war Period -Depth charges World War II - ASW Mortar...

NAVAL WARFARE THEORIES LT AGNES M SANCHEZ 08 August 2024 BMASC students  SCOPE OF PRESENTATION a) ASW Short History c) ASW Weapons World War I Non-guided weapons Inter-war Period -Depth charges World War II - ASW Mortar Post-war and Modern - ASW Rocket b) ASW Detection Assets Guided weapons Surface Ships Sonar - Lightweight torpedoes Helicopter Dipping Sonar - Heavyweight torpedoes MPA Sonobuoys  ASW SHORT HISTORY World War I Submarines were a major menace -operated in the Baltic, North Sea, Black Sea and Mediterranean and North Atlantic. - limited to relatively calm and protected waters - Usually on the surface for charging batteries and in crossing long distances - vessels used to combat them were a range of small, fast surface ships using guns and good luck. Defense of warship to torpedoes – placing chain-link nets on the side of battleship - placing nets were also deployed across the mouth of a harbor or naval base - British warships were fitted with a ram with which to sink submarines - U-15 was sunk in 1914  Inter-war Period Development of the first active sonar (ASDIC ) and its integration into a complete weapons , & introduction of radar. introduction of electronics for amplifying, processing and display of signals. “Range recorder" was a major step that provided a memory of target position. New materials for sound projectors were developed.  Development of depth sounders -allowed measurement by moving ships and an appreciation obtained of the properties of the ocean affecting sound propagation. Invention of bathythermograph (1937) which was fitted to ASW Improvement in the performance of torpedoes  World War II Production of different types of U-boats. -Most notable are Type VII, known as the "workhorse" of the fleet, which was by far the most-produced type; Type IX boats were larger and specifically designed for long-range patrols, some travelling as far as Japan and the east oast of the United States. With the U-boat Type XXI "Elektroboot", German designers realized the U-boat depended on submerged ability both for combat effectiveness and survival; first submarine whose design favoured submerged performance. - propulsion system featured a large battery capacity, Sonar (ASDIC in Britain) allowed allied warships to detect submerged U-boats (and vice versa) beyond visual range but was not effective against a surfaced vessel. -Germans took the idea of the (snorkel ) Advantage: - Can recharge batteries while maintaining a degree of stealth Disadvantage: Noisy and deaf (in sonar terms)  Allied radar improved sonar in conducting advance detection of snorkel beyond visual range. Depth charges were dropped in combating submarines As a result, U-boats operate at night making sonar useless Depth charge  Throughout the war, Allied radar technology was much better than their German counterparts. From 1943-1945, radar equipped aircraft would account for the bulk of Allied kills against U-Boats. During the Second World War, the Allies developed a huge range of new technologies, weapons and tactics to counter the submarine danger.  Post-war and Modern Warfare More capable U-boats were invented and was adopted by the major navies. To counter this, new ASW weapons were essential. A number of torpedo carrying missiles were developed, as ASROC system, combining ahead- throwing capability (or longer-range delivery) with torpedo homing. ASROC system  Airborne ASW forces developed better bombs and depth charges, while for ships and submarines a range of towed sonar devices were developed to overcome the problem of ship-mounting. Helicopters transmit sonar information to CIC Aircraft can drop sonobuoys and launch homing torpedoes to positions many miles away from the ships actually monitoring the enemy submarine. A significant detection aid that has continued in service is the MAD ,a passive device.  ANTI-SUBMARINE WARFARE -a branch of naval warfare that uses surface warships, aircraft, or other submarines to find, track and deter, damage or destroy enemy submarines. - It also involves protecting friendly ships or harbors. -detect – classify- locating- track- destroy  ASW DETECTION ASSETS Surface Ships Sonar Sonar (Sound Navigation And Ranging) is a technique that uses underwater sound propagation to detect objects on or under the surface of the water, such as other vessels and principally submarines. 2 types Active sonar is emitting pulses of sounds and listening for echoes Passive sonar is essentially listening for the sound made by submarines or ships.  Hull Mounted Sonar (HMS) Active Hull-mounted sonars are widely used in surface ships (and submarines). When fitted in ships, this class of sonar generally has the following characteristics:  Variable Depth Sonar (VDS) To overcome the difficulty of searching for submarines that take advantage of hiding in Shadow Zones, an Active Variable Depth Sonar(VDS) may be used. -consists of multiple cables -there is a long cable that can be launched at different depths (light tow and heavy tow) Variable Depth Sonar (VDS) Variable Depth Sonar (VDS)  Advantages: It operates far from the carrier, so, far from own ship noise More detection capability due to adjustment of depth Omnidirectional detection unlike HMS Drawbacks: sea state limit of 4-5 Limited maneuverability No detection in shallow waters Low Frequency Active Towed Sonar System (LFATS) LFATS is a small, lightweight, air-transportable, ruggedized system Configurable: Stand-alone and can be integrated into the ship’s combat system Highly Maneuverable Specifically designed for easy installation on small vessels.  Low Frequency Active Towed Sonar System (LFATS) competitive advantages for detecting modern diesel- electric submarines operating in shallow waters Longer detection in shallow waters as it transmits high power at low frequency (1-2khz) from a compact towed body Results are displayed in CIC on the sonar console through Men Machine Interface (MMI)  Passive Towed Array System (TAS) -is a sonar array that is towed behind a submarine or surface ship. Main objective is to detect in passive the noise radiated or generated by a submarine. provides only the bearing of the target, not the distance. (old TAS)  Passive Towed Array System (TAS) long cable, up to 6 km with an array of hydrophones towed behind the ship. Available to surface ships and anti-submarine Advantage: sensor is away from own ship noise, improving Signal-to-noise ratio, and so detection and tracking performance. First 100 meters from ship’s propeller, no hydrophones placed. Effectiveness can be reduced by noise, vibration and turbulence. Surveillance Towed Array Sensor Systems that are utilized by surface vessels have a sonar array that are mounted on a cable that pulls a depth- adjustable remote operated vehicle (ROV). For lower depths, a weighted cable attached to the ROV connector may be dropped  hydrophones are used to detect sound sources. It can calculate distance and direction of the sound - It can identify the vessel type due to distinctive acoustic signature of its internal machineries - Future of TAS - It is the only technology capable of detecting faint acoustic targets on a long-range basis. Disadvantage of TAS: Limited maximum speed Advantage :towed array is useful since it offers better classification and range compared to any active sonar -It can identify the vessel type due to distinctive acoustic signature of its internal machineries Helicopter Dipping Sonar The dipping sonar from a helicopter is a variation of VDS system. From a hover, the helicopter lowers an active transducer by way of a cable to the desired depth. Advantages: Lower self-noise lower helicopter is less vulnerable to a submarine, compared to a ship The new generation of dipping sonar, as the FLASH by Thales, is capable to detect at long distance, even up to 10 Nm. To reach such result, the sonar must transmit at high power and low frequency.  MPA Sonobuoys A Maritime Patrol Aircraft (MPA) is a fixed-wing aircraft designed to operate for long durations over water in maritime patrol missions, in particular anti-submarine, anti- ship and search and rescue. It is equipped with various sensors can be deployed for missions such as - maritime surveillance and reconnaissance - coastal ground surveillance and reconnaissance - aerial surveillance and reconnaissance - Homeland Security (HLS) - Search and Rescue (SAR) - ecological and pollutant surveillance. MPA Sonobuoys A sonobuoy is a relatively small expendable sonar system that is dropped from aircraft conducting anti- submarine warfare. It is a miniature radio-acoustic system dropped to be used as an active or passive acoustic sensor. Sound information is received by a hydrophone hanging from a float and is transmitted to the aircraft by a low- power VHF emitter. Active sonobuoys transmit sound energy (pings) into the water and listen for the returning echo before transmitting, usually range and bearing, information via VHF radio to the aircraft. Max range for good propagation: 5NM The passive sonobuoy is a long-range acoustic system at low frequency, to detect, classify and locate submarines. -Efficient in detecting noisy nuclear submarines or snorting diesel submarines -Not efficient in modern, silent diesel-electric submarines even if they are snorting Summary of magnitude of detection of ASW using sound propagation  ASW WEAPONS two categories according to mode of operation: Guided weapons and Non-guided weapons. Non-guided weapons a. Depth charges - large canister filled with explosives and set to explode at a predetermined depth. Distance to Submarine must be near The effects of the explosion could damage a submarine from a distance, though a depth charge explosion had to be very close to the submarine. Depth charges can be dropped by aircraft or surface ships -can be carried by missiles to their target. Anti-submarine mortar The principle is similar to the depth charge, but a better effect is obtained by larger numbers of smaller explosions. Nevertheless, this weapons is dedicated to the exceptionally challenging task of littoral anti-submarine operations. Anti-submarine Rocket is an all-weather, all sea- conditions anti-submarine missile system Advantages: range and speed of attack compared to torpedoes Guided weapons Guided anti-submarine weapons seek out the submarine either via its own sensors or from the launching platform's sensors. ASW platform: ships, MPA and helicopters. Example torpedoes : a. Lightweight (launched by aircraft) b. heavyweight  MK 54 lightweight torpedo that combines the MK50 search and homing system with the propulsion system of the MK46 torpedo for optimized performance in shallow water. It can be launched from surface ships, helicopter or fixed wing aircraft -suitable for both deep water or littoral environments. Heavyweight torpedoes exclusively launched by submarines or surface units. wire-guided or not From submarines, most of torpedoes are wire- guided.  WIRE-GUIDED TORPEDOES can travel over more than 20,000 yards and they are used against ships or submarines. Used passive or active guidance, or a combination of both. The passive mode is unlikely to be effective at speeds higher than 30 to 35 knots. travel depth can range from surface to 800 meters deep. Some torpedoes can travel at speeds up to 55 knots (UK Spear-fish). QUESTIONS