122-594: USS Sennet (SS-408) was a Balao -class submarine , a ship of the United States Navy named for the sennet , a barracuda . Sennet was laid down on 8 March 1944 by the Portsmouth Navy Yard in Kittery, Maine , launched on 6 June 1944, sponsored by Mrs. Roscoe W. Downs, and commissioned on 22 August 1944. Sennet was fitted out by 18 September. She held training exercises and torpedo-tube testing off
244-516: A "wet" mount with corrosion resistant materials, and with power-operated loading and aiming features removed. This conversion started in late 1943, and some boats had two of these weapons beginning in late 1944. Spadefish , commissioned in March 1944, was the first newly built submarine with the purpose-built 5-inch/25 submarine mount. Additional anti-aircraft guns included single 40 mm Bofors and twin 20 mm Oerlikon mounts, usually one of each. Like
366-405: A cargo carrier. Experimentation ended in early 1950, and she was decommissioned into the reserve on 30 June 1950. In 1955, she was converted to a Regulus missile submarine and redesignated as an SSG. As of 2007 Tusk , a Balao -class submarine, was one of the last two operational submarines in the world built during World War II. The boat was transferred to Taiwan 's Republic of China Navy in
488-562: A group of volunteers to sleep overnight in the crew's quarters. The following is a complete list of Balao -class museum boats: USS Clamagore (SS-343) served as a museum boat at Patriots Point in Charleston, South Carolina until being closed in 2021 and scrapped two years later. Additionally the USS ; Ling (SS-297) is aground in the Hackensack River at the site of
610-411: A hydrophone/transducer receives a specific interrogation signal it responds by transmitting a specific reply signal. To measure distance, one transducer/projector transmits an interrogation signal and measures the time between this transmission and the receipt of the other transducer/hydrophone reply. The time difference, scaled by the speed of sound through water and divided by two, is the distance between
732-522: A large oil slick and approximately 40 Japanese clinging to debris but no trace of the Nariu which had sunk. Sennet was refitted by Apollo (AS-25) in Apra Harbor , Guam , 9 March – 2 April. Patrolling off Honshū again from 3 April to 16 May, she was twice straddled by torpedoes fired from patrol boats while she was surfaced off Miki Saki on 16 April. Three days later, the submarine torpedoed and sank
854-495: A narrow arc, although the beam may be rotated, relatively slowly, by mechanical scanning. Particularly when single frequency transmissions are used, the Doppler effect can be used to measure the radial speed of a target. The difference in frequency between the transmitted and received signal is measured and converted into a velocity. Since Doppler shifts can be introduced by either receiver or target motion, allowance has to be made for
976-487: A pulse to reception is measured and converted into a range using the known speed of sound. To measure the bearing , several hydrophones are used, and the set measures the relative arrival time to each, or with an array of hydrophones, by measuring the relative amplitude in beams formed through a process called beamforming . Use of an array reduces the spatial response so that to provide wide cover multibeam systems are used. The target signal (if present) together with noise
1098-520: A steel tube, vacuum-filled with castor oil , and sealed. The tubes then were mounted in parallel arrays. The standard US Navy scanning sonar at the end of World War II operated at 18 kHz, using an array of ADP crystals. Desired longer range, however, required use of lower frequencies. The required dimensions were too big for ADP crystals, so in the early 1950s magnetostrictive and barium titanate piezoelectric systems were developed, but these had problems achieving uniform impedance characteristics, and
1220-512: A system later tested in Boston Harbor, and finally in 1914 from the U.S. Revenue Cutter Miami on the Grand Banks off Newfoundland . In that test, Fessenden demonstrated depth sounding, underwater communications ( Morse code ) and echo ranging (detecting an iceberg at a 2-mile (3.2 km) range). The " Fessenden oscillator ", operated at about 500 Hz frequency, was unable to determine
1342-565: A target ahead of the attacker and still in ASDIC contact. These allowed a single escort to make better aimed attacks on submarines. Developments during the war resulted in British ASDIC sets that used several different shapes of beam, continuously covering blind spots. Later, acoustic torpedoes were used. Early in World War II (September 1940), British ASDIC technology was transferred for free to
SECTION 10
#17328916398871464-476: A test depth of 450 ft (140 m) and a collapse depth of 900 ft (270 m). However, the limited capacity of the trim pump at deep depths, and lack of time to design a new pump, caused Rear Admiral E. L. Cochrane, Chief of the Bureau of Ships , to limit test depth to 400 ft (120 m). Fortunately, in 1944 a redesigned Gould centrifugal pump replaced the noisy early-war pump, and effective diving depth
1586-590: A thickened and taller mast. These mast arrangements, along with the tremendous variation in the gun layout as the war progressed account for the numerous exterior detail differences among the boats, to the point that at any given time no two Balao s looked exactly alike. The propulsion of the Balao -class submarines was generally similar to that of the preceding Gato -class. Like their predecessors, they were true diesel-electric submarines: their four diesel engines powered electrical generators , and electric motors drove
1708-497: A tube inserted into the water to detect vessels by ear. It was developed during World War I to counter the growing threat of submarine warfare , with an operational passive sonar system in use by 1918. Modern active sonar systems use an acoustic transducer to generate a sound wave which is reflected from target objects. Although some animals ( dolphins , bats , some shrews , and others) have used sound for communication and object detection for millions of years, use by humans in
1830-525: A unit of Submarine Squadron 12 (SubRon 12). The ship conducted training for submarine and antisubmarine personnel at Key West and Guantanamo Bay , Cuba . In 1951, Sennet was converted to a Fleet Snorkel submarine at the Philadelphia Naval Shipyard and returned to her homeport. On 4 November 1954, Sennet departed Key West on her first deployment to the Mediterranean and service with
1952-413: Is bistatic operation . When more transmitters (or more receivers) are used, again spatially separated, it is multistatic operation . Most sonars are used monostatically with the same array often being used for transmission and reception. Active sonobuoy fields may be operated multistatically. Active sonar creates a pulse of sound, often called a "ping", and then listens for reflections ( echo ) of
2074-453: Is its zero aging characteristics; the crystal keeps its parameters even over prolonged storage. Another application was for acoustic homing torpedoes. Two pairs of directional hydrophones were mounted on the torpedo nose, in the horizontal and vertical plane; the difference signals from the pairs were used to steer the torpedo left-right and up-down. A countermeasure was developed: the targeted submarine discharged an effervescent chemical, and
2196-551: Is often stated as the maximum in various publications. In practice during the war, submarines went out with at least 8 torpedoes, and the largest minefields laid were 32 mines. Post-war, the Mk ;49 mine replaced the Mk 12, while the larger Mk 27 mine was also carried which only allowed one mine replacing one torpedo. This was the most numerous US submarine class; 120 of these boats were commissioned from February 1943 through September 1948, with 12 commissioned postwar. Nine of
2318-415: Is the source level , PL is the propagation loss (sometimes referred to as transmission loss ), TS is the target strength , NL is the noise level , AG is the array gain of the receiving array (sometimes approximated by its directivity index) and DT is the detection threshold . In reverberation-limited conditions at initial detection (neglecting array gain): where RL is the reverberation level , and
2440-427: Is then passed through various forms of signal processing , which for simple sonars may be just energy measurement. It is then presented to some form of decision device that calls the output either the required signal or noise. This decision device may be an operator with headphones or a display, or in more sophisticated sonars this function may be carried out by software. Further processes may be carried out to classify
2562-415: Is used for atmospheric investigations. The term sonar is also used for the equipment used to generate and receive the sound. The acoustic frequencies used in sonar systems vary from very low ( infrasonic ) to extremely high ( ultrasonic ). The study of underwater sound is known as underwater acoustics or hydroacoustics . The first recorded use of the technique was in 1490 by Leonardo da Vinci , who used
SECTION 20
#17328916398872684-402: Is very low, several orders of magnitude less than the original signal. Even if the reflected signal was of the same power, the following example (using hypothetical values) shows the problem: Suppose a sonar system is capable of emitting a 10,000 W/m signal at 1 m, and detecting a 0.001 W/m signal. At 100 m the signal will be 1 W/m (due to the inverse-square law ). If
2806-713: The Titanic disaster of 1912. The world's first patent for an underwater echo-ranging device was filed at the British Patent Office by English meteorologist Lewis Fry Richardson a month after the sinking of Titanic , and a German physicist Alexander Behm obtained a patent for an echo sounder in 1913. The Canadian engineer Reginald Fessenden , while working for the Submarine Signal Company in Boston , Massachusetts, built an experimental system beginning in 1912,
2928-618: The 6th Fleet . From her return on 30 January 1955 until 1 August 1959, the submarine conducted training, local, and fleet operations with her squadron. On 1 August, Sennett was reassigned to SubRon 4 and stationed at Charleston, S.C. For the next nine years, the submarine operated from Charleston with the Atlantic Fleet. She operated along the east coast, in the Caribbean , and in the Atlantic with her squadron until mid-1968. In November 1968,
3050-616: The Balao class. Elliott Company motors were fitted primarily to boats with Fairbanks-Morse engines. General Electric motors were fitted primarily to boats with General Motors engines, but some Fairbanks-Morse boats received General Electric motors. Allis-Chalmers motors were to be used in SS-530 through SS-536, but those seven boats were cancelled before even receiving names. Earlier submarines carried four high-speed electric motors (two per shaft), which had to be fitted with reduction gears to slow their outputs down to an appropriate speed for
3172-618: The Boston Navy Yard on 15 March 1945, after a yard worker mistakenly opened the inner door of an aft torpedo tube that already had the outer door open. No personnel were lost in the accident and she was raised, decommissioned, and never completed or repaired. Her 42 days in commission is the record for the shortest commissioned service of any USN submarine. Postwar, she was laid up in the Reserve Fleet until stricken in 1958 and scrapped in 1959. Postwar, 55 Balao s were modernized under
3294-469: The Fleet Rehabilitation and Modernization II (FRAM II) program. All except Tiru , the pilot conversion, were lengthened by 15 feet in the forward part of the control room to provide a new sonar space, berthing, electronics space, and storerooms. Tiru was lengthened only 12.5 feet, and both forward diesel engines were removed. The other GUPPY IIIs retained all four engines. A taller "Northern" sail
3416-452: The Royal Navy had five sets for different surface ship classes, and others for submarines, incorporated into a complete anti-submarine system. The effectiveness of early ASDIC was hampered by the use of the depth charge as an anti-submarine weapon. This required an attacking vessel to pass over a submerged contact before dropping charges over the stern, resulting in a loss of ASDIC contact in
3538-551: The hull or become flooded, the 60 Hz sound from the windings can be emitted from the submarine or ship. This can help to identify its nationality, as all European submarines and nearly every other nation's submarine have 50 Hz power systems. Intermittent sound sources (such as a wrench being dropped), called "transients," may also be detectable to passive sonar. Until fairly recently, an experienced, trained operator identified signals, but now computers may do this. Passive sonar systems may have large sonic databases , but
3660-507: The lead-acid type . This increased the total number of battery cells from 252 to 504; the downside was the compact batteries had to be replaced every 18 months instead of every 5 years. The Sargo II battery was developed as a lower-cost alternative to the expensive Guppy battery. All GUPPYs received a snorkel, with a streamlined sail and bow. Also, the electric motors were upgraded to the direct drive double- armature type, along with modernized electrical and air conditioning systems. All except
3782-488: The 1930s American engineers developed their own underwater sound-detection technology, and important discoveries were made, such as the existence of thermoclines and their effects on sound waves. Americans began to use the term SONAR for their systems, coined by Frederick Hunt to be the equivalent of RADAR . In 1917, the US Navy acquired J. Warren Horton 's services for the first time. On leave from Bell Labs , he served
USS Sennet - Misplaced Pages Continue
3904-492: The 1970s, compounds of rare earths and iron were discovered with superior magnetomechanic properties, namely the Terfenol-D alloy. This made possible new designs, e.g. a hybrid magnetostrictive-piezoelectric transducer. The most recent of these improved magnetostrictive materials is Galfenol . Other types of transducers include variable-reluctance (or moving-armature, or electromagnetic) transducers, where magnetic force acts on
4026-677: The 1990s, and Tusk remains active in Taiwan 's Republic of China Navy as Hai Pao . Interested in maintaining a ready pool of trained reservists , the Navy assigned at least 58 submarines from 1946 to 1971 to various coastal and inland ports (even in Great Lakes ports like Cleveland , Chicago , and Detroit ), where they served as training platforms during the Reservists' weekend drills. At least 20 Balao -class boats served in this capacity. In this role,
4148-716: The 52 US submarines lost in World War II were of this class, along with five lost postwar, including one in Turkish service in 1953, one in Argentine service in the Falklands War of 1982, and one in Peruvian service in 1988. Also, Lancetfish flooded and sank while fitting out at the Boston Naval Shipyard on 15 March 1945. She was raised but not repaired, and was listed with the reserve fleet postwar until struck in 1958. Some of
4270-458: The Admiralty archives. By 1918, Britain and France had built prototype active systems. The British tested their ASDIC on HMS Antrim in 1920 and started production in 1922. The 6th Destroyer Flotilla had ASDIC-equipped vessels in 1923. An anti-submarine school HMS Osprey and a training flotilla of four vessels were established on Portland in 1924. By the outbreak of World War II ,
4392-674: The British Board of Invention and Research , Canadian physicist Robert William Boyle took on the active sound detection project with A. B. Wood , producing a prototype for testing in mid-1917. This work for the Anti-Submarine Division of the British Naval Staff was undertaken in utmost secrecy, and used quartz piezoelectric crystals to produce the world's first practical underwater active sound detection apparatus. To maintain secrecy, no mention of sound experimentation or quartz
4514-678: The Fleet Snorkel and Greater Underwater Propulsion Power ( GUPPY ) programs, with some continuing in US service into the early 1970s. The last Balao -class submarine in United States service was USS Clamagore (SS-343) , which was decommissioned in June 1975. Seven were converted to roles as diverse as guided-missile submarines (SSG) and amphibious transport submarines (SSP). 46 were transferred to foreign navies for years of additional service, some into
4636-651: The French physicist Paul Langevin , working with a Russian immigrant electrical engineer Constantin Chilowsky, worked on the development of active sound devices for detecting submarines in 1915. Although piezoelectric and magnetostrictive transducers later superseded the electrostatic transducers they used, this work influenced future designs. Lightweight sound-sensitive plastic film and fibre optics have been used for hydrophones, while Terfenol-D and lead magnesium niobate (PMN) have been developed for projectors. In 1916, under
4758-456: The GUPPY conversions, the original pair of Sargo batteries were not upgraded. Each boat received a streamlined sail with a snorkel, along with upgraded sonar, air conditioning, and ESM. The original bow was left in place, except on three boats ( Piper , Sea Owl , and Sterlet ) that received additional upper bow sonar equipment. A few boats initially retained the 5"/25 deck gun, but this was removed in
4880-456: The GUPPY program in 1947. Their configuration lacked a snorkel and was not repeated, so no Balaos received this conversion. This was the first production GUPPY conversion, with most conversions occurring in 1947–49. Thirteen Balao -class boats ( Catfish , Clamagore , Cobbler , Cochino , Corporal , Cubera , Diodon , Dogfish , Greenfish , Halfbeak , Tiru , Trumpetfish , and Tusk ) received GUPPY II upgrades. This
5002-789: The U. S. Navy differs, considering every submarine not specifically ordered as a Tench to be a Balao , and further projecting SS-551-562 as a future class. This yields 62 cancelled Balao class, 51 cancelled Tench class, and 12 cancelled future class. Two of the cancelled Balao -class submarines, Turbot (SS-427) and Ulua (SS-428) , were launched incomplete and served for years as experimental hulks at Annapolis and Norfolk, Virginia . The cancelled hull numbers, including those launched incomplete, were SS-353–360 ( Balao ), 379–380 ( Balao ), 427–434 ( Balao ), 436–437 ( Tench ), 438–474 ( Balao ), 491–521 ( Tench ), 526–529 ( Tench ), 530–536 ( Balao ), 537–550 ( Tench ), and 551–562 (future). The Balao s began to enter service in mid-1943, as
USS Sennet - Misplaced Pages Continue
5124-675: The US Navy. These included 17 to Turkey, 2 to Greece, 3 to Italy, 2 to the Netherlands, 5 to Spain, 2 to Venezuela, 4 to Argentina, 5 to Brazil, 2 to Chile, 2 to Peru, 1 to Canada and 1 to Taiwan. One of the Venezuelan boats, ARV Carite (S-11) formerly USS Tilefish (SS-307), featured in the 1971 film Murphy's War with some cosmetic modification. At the end of World War II , the US submarine force found itself in an awkward position. The 111 remaining Balao -class submarines, designed to fight an enemy that no longer existed, were obsolete despite
5246-500: The United States Navy. An improvement on the earlier Gato class , the boats had slight internal differences. The most significant improvement was the use of thicker, higher yield strength steel in the pressure hull skins and frames, which increased their test depth to 400 feet (120 m). Tang actually achieved a depth of 612 ft (187 m) during a test dive, and exceeded that test depth when taking on water in
5368-508: The United States. Research on ASDIC and underwater sound was expanded in the UK and in the US. Many new types of military sound detection were developed. These included sonobuoys , first developed by the British in 1944 under the codename High Tea , dipping/dunking sonar and mine -detection sonar. This work formed the basis for post-war developments related to countering the nuclear submarine . During
5490-415: The area near the boat. When active sonar is used to measure the distance from the transducer to the bottom, it is known as echo sounding . Similar methods may be used looking upward for wave measurement. Active sonar is also used to measure distance through water between two sonar transducers or a combination of a hydrophone (underwater acoustic microphone) and projector (underwater acoustic speaker). When
5612-498: The attack had the advantage that the German acoustic torpedo was not effective against a warship travelling so slowly. A variation of the creeping attack was the "plaster" attack, in which three attacking ships working in a close line abreast were directed over the target by the directing ship. The new weapons to deal with the ASDIC blind spot were "ahead-throwing weapons", such as Hedgehogs and later Squids , which projected warheads at
5734-447: The austere "Fleet Snorkel" conversion was developed to add snorkels and partial streamlining to some boats. A total of 36 Balao -class submarines were converted to one of the GUPPY configurations, with 19 additional boats receiving Fleet Snorkel modifications. Two of the GUPPY boats and six of the Fleet Snorkel boats were converted immediately prior to transfer to a foreign navy. Most of the 47 remaining converted submarines were active into
5856-486: The austere GUPPY IB conversions for foreign transfer received sonar, fire control , and Electronic Support Measures (ESM) upgrades. The Fleet Snorkel program was much more austere than the GUPPY modernizations, but is included here as it occurred during the GUPPY era. The GUPPY and Fleet Snorkel programs are listed in chronological order: GUPPY I, GUPPY II, GUPPY IA, Fleet Snorkel, GUPPY IIA, GUPPY IB, and GUPPY III. Two Tench -class boats were converted as prototypes for
5978-505: The beam pattern suffered. Barium titanate was then replaced with more stable lead zirconate titanate (PZT), and the frequency was lowered to 5 kHz. The US fleet used this material in the AN/SQS-23 sonar for several decades. The SQS-23 sonar first used magnetostrictive nickel transducers, but these weighed several tons, and nickel was expensive and considered a critical material; piezoelectric transducers were therefore substituted. The sonar
6100-469: The bearing of the iceberg due to the 3-metre wavelength and the small dimension of the transducer's radiating face (less than 1 ⁄ 3 wavelength in diameter). The ten Montreal -built British H-class submarines launched in 1915 were equipped with Fessenden oscillators. During World War I the need to detect submarines prompted more research into the use of sound. The British made early use of underwater listening devices called hydrophones , while
6222-576: The boats were rendered incapable of diving and had their propellers removed. They were used strictly as pierside trainers. These were in commission but classed as "in service in reserve", thus some were decommissioned and recommissioned on the same day to reflect the change in status. The large numbers of relatively modern, but surplus U.S. fleet submarines proved to be popular in sales, loans, or leases to allied foreign navies. 46 Balao -class submarines were transferred to foreign navies, some shortly after World War II, others after serving nearly 30 years in
SECTION 50
#17328916398876344-576: The bridge and sail proved to be efficiently laid out, well equipped, and well liked by the crews. For the masts and periscope shears, the original arrangement for both the Government and Electric Boat designs had (forward to aft) the two tapered cone shaped periscope support shears, followed by a thin mast for the SJ surface search radar, and then by a thin mast for the SD air search radar. There were minor differences in how
6466-501: The cargo ship Hagane Maru . On 22 April, Sennet attempted to save a P-51 pilot who had bailed out near her but the man went under only 100 feet (30 m) from the ship. Attempts to find him were in vain. A repair ship was attacked on 28 April with two electrical torpedoes. The first blew the bow off and the second hit under the mainmast. Hatsushima sank by her stern. On 1 May, Sennett fired five steam torpedoes at an Asashio -class destroyer but it maneuvered and avoided them. At
6588-444: The characteristics of the outgoing ping. For these reasons, active sonar is not frequently used by military submarines. A very directional, but low-efficiency, type of sonar (used by fisheries, military, and for port security) makes use of a complex nonlinear feature of water known as non-linear sonar, the virtual transducer being known as a parametric array . Project Artemis was an experimental research and development project in
6710-670: The class served actively in the US Navy through the middle 1970s, and one ( Hai Pao ex- Tusk ) is still active in Taiwan's Republic of China Navy . SS-361 through SS-364 were initially ordered as Balao -class, and were assigned hull numbers that fall in the middle of the range of numbers for the Balao class (SS-285 to SS-416 & 425–426). Thus, in some references they are listed with that class. However, they were completed by Manitowoc as Gato s, due to an unavoidable delay in Electric Boat 's development of Balao -class drawings. Manitowoc
6832-493: The coast of Connecticut and Rhode Island until 22 October. The submarine then tested mines and torpedoes for the Mine Warfare Test Station , Solomons Island, Md. On 11 November, Sennet proceeded to the operations area off Balboa , C. Z. and conducted further training exercises. The submarine departed Balboa on 29 November for Pearl Harbor and arrived there on 16 December 1944. Sennet' s topside armament
6954-430: The combined gunfire of Sennet , Haddock (SS-231) , and Lagarto (SS-371) . Three days later, the submarine attacked the minelayer Nariu with an offset spread of torpedoes from her stern tubes, then went deep to 200 feet (60 m). Two torpedoes were heard to explode. While going deep, Sennet was rocked hard by two aircraft bombs which exploded beneath her. The submarine surfaced an hour later and saw
7076-434: The depth charges had been released, the attacking ship left the immediate area at full speed. The directing ship then entered the target area and also released a pattern of depth charges. The low speed of the approach meant the submarine could not predict when depth charges were going to be released. Any evasive action was detected by the directing ship and steering orders to the attacking ship given accordingly. The low speed of
7198-534: The diesel engines were not directly connected to the shafts, the electric motors drove the shafts all the time. Many targets in the Pacific War were sampans or otherwise not worth a torpedo, so the deck gun was an important weapon. Early Balao s began their service with a 4-inch (102 mm)/50 caliber Mk. 9 gun . Due to war experience, most were re-armed with a 5-inch (127 mm)/25 caliber Mk. 17 gun , similar to mounts on battleships and cruisers but built as
7320-466: The early 1950s. This was generally similar to GUPPY IA, except one of the forward diesel engines was removed to relieve machinery overcrowding. Thirteen Balao -class boats ( Bang , Diodon , Entemedor , Hardhead , Jallao , Menhaden , Picuda , Pomfret , Razorback , Ronquil , Sea Fox , Stickleback , and Threadfin ) received GUPPY IIA upgrades in 1952–54. One of these, Diodon , had previously been upgraded to GUPPY II. This
7442-465: The early 1970s, when many were transferred to foreign navies for further service and others were decommissioned and disposed of. Although there was some variation in the GUPPY conversion programs, generally the original two Sargo batteries were replaced by four more compact Guppy (GUPPY I and II only) or Sargo II batteries via significant re-utilization of below-deck space, usually including removal of auxiliary diesels. All of these battery designs were of
SECTION 60
#17328916398877564-504: The early 1970s. The Tench -class ex- Cutlass is the other one. They are named Hai Pao and Hai Shih , respectively, in Taiwanese service. Six Balao -class submarines are open to public viewing. They primarily depend on revenue generated by visitors to keep them operational and up to U.S. Navy standards; each boat gets a yearly inspection and a "report card". Some boats, like Batfish and Pampanito , encourage youth functions and allow
7686-412: The echoes. Since the original signal is much more powerful, it can be detected many times further than twice the range of the sonar (as in the example). Active sonar have two performance limitations: due to noise and reverberation. In general, one or other of these will dominate, so that the two effects can be initially considered separately. In noise-limited conditions at initial detection: where SL
7808-456: The electro-acoustic transducers are of the Tonpilz type and their design may be optimised to achieve maximum efficiency over the widest bandwidth, in order to optimise performance of the overall system. Occasionally, the acoustic pulse may be created by other means, e.g. chemically using explosives, airguns or plasma sound sources. To measure the distance to an object, the time from transmission of
7930-574: The end of this patrol, the submarine sailed to Pearl Harbor for upkeep and leave. Sennet' s most profitable patrol was from 1 July to 9 August in the Sea of Japan . During the patrol, she sank one passenger-cargo ship, two cargo ships, and one tanker totaling 13,105 tons. When the war ended in the Pacific, Sennet was assigned to the Atlantic Fleet and operated from New London, Conn. In June 1946, she
8052-427: The entire signal is reflected from a 10 m target, it will be at 0.001 W/m when it reaches the emitter, i.e. just detectable. However, the original signal will remain above 0.001 W/m until 3000 m. Any 10 m target between 100 and 3000 m using a similar or better system would be able to detect the pulse, but would not be detected by the emitter. The detectors must be very sensitive to pick up
8174-636: The extra personnel, to avoid excessive snorkeling they were equipped with a CO 2 scrubber and extra oxygen storage. Initially, a squadron of 12 SSPs was considered, capable of landing a reinforced Marine battalion, but only two Balao -class SSPs (out of four overall) were actually converted. Perch landed British commandos on one raid in the Korean War , and operated in the Vietnam War from 1965 until assignment to Naval Reserve training in 1967 and decommissioning in 1971, followed by scrapping in 1973. Perch
8296-524: The fact they were only one to three years old. The German Type XXI U-boat , with a large battery capacity, streamlining to maximize underwater speed, and a snorkel, was the submarine of the immediate future. The Greater Underwater Propulsion Power Program (GUPPY) conversion program was developed to give some Balao - and Tench -class submarines similar capabilities to the Type XXI. When the cost of upgrading numerous submarines to GUPPY standard became apparent,
8418-501: The fleet. Radar picket destroyers and destroyer escorts were put into service, but they proved vulnerable in this role as they could be attacked as well, leaving the fleet blind. A submarine, though, could dive and escape aerial attack. Four submarines including the Balao -class boat Threadfin prototyped the concept at the end of World War II but were not used in this role. Ten fleet submarines were converted for this role 1946-53 and redesignated SSR as radar picket submarines. Burrfish
8540-413: The former New Jersey Naval Museum . As of 2022, efforts to find a new home for this vessel have been unsuccessful. Sonar Sonar ( sound navigation and ranging or sonic navigation and ranging ) is a technique that uses sound propagation (usually underwater, as in submarine navigation ) to navigate , measure distances ( ranging ), communicate with or detect objects on or under the surface of
8662-675: The forward torpedo room while evading a destroyer. The Balao s were similar to the Gato s, except they were modified to increase test depth from 300 ft (90 m) to 400 ft (120 m). In late 1941, two of the Navy's leading submarine designers, Captain Andrew McKee and Commander Armand Morgan, met to explore increasing diving depth in a redesigned Gato . A switch to a new High-Tensile Steel (HTS) alloy, combined with an increase in hull thickness from 9 ⁄ 16 inch (14.3 mm) to 7 ⁄ 8 inch (22.2 mm), would result in
8784-500: The government as a technical expert, first at the experimental station at Nahant, Massachusetts , and later at US Naval Headquarters, in London , England. At Nahant he applied the newly developed vacuum tube , then associated with the formative stages of the field of applied science now known as electronics , to the detection of underwater signals. As a result, the carbon button microphone , which had been used in earlier detection equipment,
8906-505: The largest individual sonar transducers ever. The advantage of metals is their high tensile strength and low input electrical impedance, but they have electrical losses and lower coupling coefficient than PZT, whose tensile strength can be increased by prestressing . Other materials were also tried; nonmetallic ferrites were promising for their low electrical conductivity resulting in low eddy current losses, Metglas offered high coupling coefficient, but they were inferior to PZT overall. In
9028-498: The late 1950s to mid 1960s to examine acoustic propagation and signal processing for a low-frequency active sonar system that might be used for ocean surveillance. A secondary objective was examination of engineering problems of fixed active bottom systems. The receiving array was located on the slope of Plantagnet Bank off Bermuda. The active source array was deployed from the converted World War II tanker USNS Mission Capistrano . Elements of Artemis were used experimentally after
9150-404: The magnetostrictive unit was much more reliable. High losses to US merchant supply shipping early in World War II led to large scale high priority US research in the field, pursuing both improvements in magnetostrictive transducer parameters and Rochelle salt reliability. Ammonium dihydrogen phosphate (ADP), a superior alternative, was found as a replacement for Rochelle salt; the first application
9272-417: The main experiment was terminated. This is an active sonar device that receives a specific stimulus and immediately (or with a delay) retransmits the received signal or a predetermined one. Transponders can be used to remotely activate or recover subsea equipment. A sonar target is small relative to the sphere , centred around the emitter, on which it is located. Therefore, the power of the reflected signal
9394-875: The many problems with the Mark 14 torpedo were being solved. They were instrumental in the Submarine Force's near-destruction of the Japanese merchant fleet and significant attrition of the Imperial Japanese Navy . One of the class, Archerfish , brought down what remains the largest warship sunk by a submarine, the Shinano (59,000 tons). Tang , the highest-scoring of the class, sank 33 ships totaling 116,454 tons, as officially revised upward in 1980. Nine Balao s were lost in World War II, while two US boats were lost in postwar accidents. In foreign service, one in Turkish service
9516-403: The moments leading up to attack. The hunter was effectively firing blind, during which time a submarine commander could take evasive action. This situation was remedied with new tactics and new weapons. The tactical improvements developed by Frederic John Walker included the creeping attack. Two anti-submarine ships were needed for this (usually sloops or corvettes). The "directing ship" tracked
9638-545: The newer engines had greater displacement than the old, but were rated at the same power; they operated at lower mean effective pressure for greater reliability. Both the Fairbanks-Morse and General Motors engines were two-stroke cycle types. Two submarines, Unicorn and Vendace , were to receive Hooven-Owens-Rentschler (H.O.R.) diesels, which proved unreliable on previous classes, but both boats were cancelled. Two manufacturers supplied electric motors for
9760-490: The ocean or floats on a taut line mooring at a constant depth of perhaps 100 m. They may also be used by submarines , AUVs , and floats such as the Argo float. Passive sonar listens without transmitting. It is often employed in military settings, although it is also used in science applications, e.g. , detecting fish for presence/absence studies in various aquatic environments – see also passive acoustics and passive radar . In
9882-403: The other factors are as before. An upward looking sonar (ULS) is a sonar device pointed upwards looking towards the surface of the sea. It is used for similar purposes as downward looking sonar, but has some unique applications such as measuring sea ice thickness, roughness and concentration, or measuring air entrainment from bubble plumes during rough seas. Often it is moored on the bottom of
10004-403: The periscopes were braced against vibration, but both designs were nearly identical. About halfway through their production run, Electric Boat altered their design, moving the SJ radar mast forward of the periscopes, then altered it again a few boats later by enlarging the SD radar mast. Late in the war, many Balao s built with the original design had the SD air search radar moved slightly aft onto
10126-429: The previous Tambor / Gar and Gato classes, the Balao class could substitute mines in place of torpedoes. For the Mk 10 and Mk 12 type mines used in World War II, each torpedo could be replaced by as many as two mines, giving the submarine a true maximum capacity of 48 mines. However, doctrine was to retain at least four torpedoes on mine laying missions, which further limits the capacity to 40 mines, and this
10248-704: The program was discontinued in favor of Polaris . A number of fleet boats were equipped with Regulus guidance equipment 1953–64, including Cusk and Carbonero following the Loon tests. Sealion and Perch were converted to amphibious transport submarines in 1948 and redesignated as SSPs. Initially, they were equipped with a watertight hangar capable of housing a Landing Vehicle Tracked (LVT), and retained one 5-inch (127 mm)/25 caliber deck gun for shore bombardment. Both torpedo rooms and one engine room were gutted to provide space for embarked Special Operations Forces (SOF) and their equipment. Snorkels were fitted. Due to
10370-402: The projectors consisted of two rectangular identical independent units in a cast-iron rectangular body about 16 by 9 inches (410 mm × 230 mm). The exposed area was half the wavelength wide and three wavelengths high. The magnetostrictive cores were made from 4 mm stampings of nickel, and later of an iron-aluminium alloy with aluminium content between 12.7% and 12.9%. The power
10492-410: The pulse. This pulse of sound is generally created electronically using a sonar projector consisting of a signal generator, power amplifier and electro-acoustic transducer/array. A transducer is a device that can transmit and receive acoustic signals ("pings"). A beamformer is usually employed to concentrate the acoustic power into a beam, which may be swept to cover the required search angles. Generally,
10614-456: The radial speed of the searching platform. One useful small sonar is similar in appearance to a waterproof flashlight. The head is pointed into the water, a button is pressed, and the device displays the distance to the target. Another variant is a " fishfinder " that shows a small display with shoals of fish. Some civilian sonars (which are not designed for stealth) approach active military sonars in capability, with three-dimensional displays of
10736-580: The shafts. There was no direct connection between the main engines and the shafts. Balao -class submarines received main engines from one of two manufacturers. General Motors Cleveland Model 16-278A V-type diesels or Fairbanks-Morse 38D 8-1/8 nine-cylinder opposed-piston engine . The General Motors Cleveland Model 16-248 V-type as original installations, while boats from Sand Lance onward received 10-cylinder engines. Earlier General Motors boats received Model 16-248 engines, but beginning with Perch Model 16-278A engines were used. In each case,
10858-596: The shafts. This reduction gearing was very noisy, and made the submarine easier to detect with hydrophones . Eighteen late Balao -class submarines received low-speed double armature motors which drove the shafts directly and were much quieter, but this improvement was not universally fitted until the succeeding Tench class . The new direct drive electric motors were designed by the Bureau of Ships ' electrical division under Captain Hyman G. Rickover , and were first equipped on Sea Owl . On all US World War II-built boats, as
10980-448: The submarine was found unfit for further Naval service. Sennet was struck from the Navy list on 2 December 1968. On 18 May 1973, her hulk was sold to Southern Scrap Material Co. Ltd., New Orleans, La. Balao class submarine The Balao class was a design of United States Navy submarine used during World War II , and with 120 boats completed, the largest class of submarines in
11102-431: The submarine was unable to submerge until after launch. Cusk was eventually fitted with a watertight hangar for one missile and redesignated as an SSG. Following a brief stint as a cargo submarine, Barbero was converted in 1955 to carry two surface-launched Regulus missiles and was redesignated as an SSG, joining the Gato -class Tunny in this role. She made strategic deterrent patrols with Regulus until 1964, when
11224-437: The surfaces of gaps, and moving coil (or electrodynamic) transducers, similar to conventional speakers; the latter are used in underwater sound calibration, due to their very low resonance frequencies and flat broadband characteristics above them. Active sonar uses a sound transmitter (or projector) and a receiver. When the two are in the same place it is monostatic operation . When the transmitter and receiver are separated it
11346-600: The target and localise it, as well as measuring its velocity. The pulse may be at constant frequency or a chirp of changing frequency (to allow pulse compression on reception). Simple sonars generally use the former with a filter wide enough to cover possible Doppler changes due to target movement, while more complex ones generally include the latter technique. Since digital processing became available pulse compression has usually been implemented using digital correlation techniques. Military sonars often have multiple beams to provide all-round cover while simple ones only cover
11468-405: The target submarine on ASDIC from a position about 1500 to 2000 yards behind the submarine. The second ship, with her ASDIC turned off and running at 5 knots, started an attack from a position between the directing ship and the target. This attack was controlled by radio telephone from the directing ship, based on their ASDIC and the range (by rangefinder) and bearing of the attacking ship. As soon as
11590-458: The torpedo went after the noisier fizzy decoy. The counter-countermeasure was a torpedo with active sonar – a transducer was added to the torpedo nose, and the microphones were listening for its reflected periodic tone bursts. The transducers comprised identical rectangular crystal plates arranged to diamond-shaped areas in staggered rows. Passive sonar arrays for submarines were developed from ADP crystals. Several crystal assemblies were arranged in
11712-409: The two platforms. This technique, when used with multiple transducers/hydrophones/projectors, can calculate the relative positions of static and moving objects in water. In combat situations, an active pulse can be detected by an enemy and will reveal a submarine's position at twice the maximum distance that the submarine can itself detect a contact and give clues as to the submarine's identity based on
11834-481: The very broadest usage, this term can encompass virtually any analytical technique involving remotely generated sound, though it is usually restricted to techniques applied in an aquatic environment. Passive sonar has a wide variety of techniques for identifying the source of a detected sound. For example, U.S. vessels usually operate 60 Hertz (Hz) alternating current power systems. If transformers or generators are mounted without proper vibration insulation from
11956-436: The water was initially recorded by Leonardo da Vinci in 1490: a tube inserted into the water was said to be used to detect vessels by placing an ear to the tube. In the late 19th century, an underwater bell was used as an ancillary to lighthouses or lightships to provide warning of hazards. The use of sound to "echo-locate" underwater in the same way as bats use sound for aerial navigation seems to have been prompted by
12078-513: The water, such as other vessels. "Sonar" can refer to one of two types of technology: passive sonar means listening for the sound made by vessels; active sonar means emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water. Acoustic location in air was used before the introduction of radar . Sonar may also be used for robot navigation, and sodar (an upward-looking in-air sonar)
12200-894: Was a follow yard to Electric Boat, and was dependent on them for designs and drawings. Also, USS Trumpetfish (SS-425) and USS Tusk (SS-426) are listed with the Tench class in some references, as their hull numbers fall in the range of that class. A total of 125 U.S. submarines were cancelled during World War II, all but three between 29 July 1944 and 12 August 1945. The exceptions were three Tench -class boats, cancelled 7 January 1946. References vary considerably as to how many of these were Balao s and how many were Tench es. Some references simply assume all submarines numbered after SS-416 were Tench class; however, Trumpetfish (SS-425) and Tusk (SS-426) were completed as Balao s. This yields 10 cancelled Balao -class, SS-353-360 and 379–380. The Register of Ships of
12322-465: Was a large array of 432 individual transducers. At first, the transducers were unreliable, showing mechanical and electrical failures and deteriorating soon after installation; they were also produced by several vendors, had different designs, and their characteristics were different enough to impair the array's performance. The policy to allow repair of individual transducers was then sacrificed, and "expendable modular design", sealed non-repairable modules,
12444-559: Was a replacement of the 24 kHz Rochelle-salt transducers. Within nine months, Rochelle salt was obsolete. The ADP manufacturing facility grew from few dozen personnel in early 1940 to several thousands in 1942. One of the earliest application of ADP crystals were hydrophones for acoustic mines ; the crystals were specified for low-frequency cutoff at 5 Hz, withstanding mechanical shock for deployment from aircraft from 3,000 m (10,000 ft), and ability to survive neighbouring mine explosions. One of key features of ADP reliability
12566-531: Was being loaded on the cable-laying vessel, World War I ended and Horton returned home. During World War II, he continued to develop sonar systems that could detect submarines, mines, and torpedoes. He published Fundamentals of Sonar in 1957 as chief research consultant at the US Navy Underwater Sound Laboratory . He held this position until 1959 when he became technical director, a position he held until mandatory retirement in 1963. There
12688-669: Was chosen instead, eliminating the problem with seals and other extraneous mechanical parts. The Imperial Japanese Navy at the onset of World War II used projectors based on quartz . These were big and heavy, especially if designed for lower frequencies; the one for Type 91 set, operating at 9 kHz, had a diameter of 30 inches (760 mm) and was driven by an oscillator with 5 kW power and 7 kV of output amplitude. The Type 93 projectors consisted of solid sandwiches of quartz, assembled into spherical cast iron bodies. The Type 93 sonars were later replaced with Type 3, which followed German design and used magnetostrictive projectors;
12810-419: Was developed as an austere upgrade for two Gato -class and two Balao -class boats ( Hawkbill and Icefish ) prior to transfer to foreign navies in 1953–55. They lacked the sonar and electronics upgrades of other GUPPY conversions. Nine submarines, six of them Balao s ( Clamagore , Cobbler , Corporal , Greenfish , Tiru , and Trumpetfish ), were upgraded from GUPPY II to GUPPY III in 1959-63 as part of
12932-592: Was developed as an austere, cost-effective alternative to full GUPPY conversions, with significantly less improvement in submerged performance. Twenty-three Balao -class boats ( Bergall , Besugo , Brill , Bugara , Carbonero , Carp , Charr , Chub , Cusk , Guitarro , Kraken , Lizardfish , Mapiro , Mero , Piper , Sabalo , Sablefish , Scabbardfish , Sea Cat , Sea Owl , Segundo , Sennet , and Sterlet ) received this upgrade, six immediately prior to foreign transfer. Most Fleet Snorkel conversions occurred 1951–52. Unlike
13054-425: Was included, to allow improved surfaced operations in rough seas; this was also backfitted to some other GUPPYs. The BQG-4 Passive Underwater Fire Control Feasibility Study (PUFFS) sonar system, with its three tall domes topside, was fitted. Additionally, fire control upgrades allowed the Mark 45 nuclear torpedo to be used. The advent of the kamikaze demonstrated the need for a long range radar umbrella around
13176-672: Was increased to two 5-inch (130 mm) guns, two 40 millimeter guns, and three .50 caliber machine guns before departing Pearl Harbor for her first war patrol on 5 January 1945. Sennet patrolled north of the Bonin Islands until 28 January. She made two attacks on a large tanker with three escorts on 21 January but scored no hits. The following week, the submarine sank one 500-ton picket boat and damaged another. Sennet refitted at Saipan from 31 January to 7 February, when she began her second war patrol off southern Honshū , Japan . On 13 February, two 300-ton picket boats were sunk by
13298-402: Was increased. The Balao s incorporated the fairwater , conning tower and periscope shears reduction efforts that were being retrofitted to the Gato s and the preceding classes in the original design, refining the reductions and reducing the sail to the smallest practical size. By the time the boats began to be launched, lessons learned from patrol reports had been worked into the design and
13420-409: Was insufficient to protect a fast-moving carrier group. The radars were removed and the boats reverted to general purpose submarines after 1959. Burrfish was decommissioned in 1956 and, with her radar equipment removed, transferred to Canada as HMCS Grilse (SS-71) in 1961. The Regulus nuclear cruise missile program of the 1950s provided the US Navy with its first strategic strike capability. It
13542-426: Was little progress in US sonar from 1915 to 1940. In 1940, US sonars typically consisted of a magnetostrictive transducer and an array of nickel tubes connected to a 1-foot-diameter steel plate attached back-to-back to a Rochelle salt crystal in a spherical housing. This assembly penetrated the ship hull and was manually rotated to the desired angle. The piezoelectric Rochelle salt crystal had better parameters, but
13664-627: Was lost in a collision in 1953, one in Peruvian service was lost in a collision in 1988, and Catfish was sold to the Argentinian Navy. She was renamed the ARA Santa Fe (S-21) and was lost in the 1982 Falklands War after being damaged, when she sank while moored pierside. Santa Fe was refloated and disposed of a few years after the war by being taken out to deep water and scuttled. Additionally, Lancetfish , commissioned but incomplete and still under construction, flooded and sank pierside at
13786-593: Was made – the word used to describe the early work ("supersonics") was changed to "ASD"ics, and the quartz material to "ASD"ivite: "ASD" for "Anti-Submarine Division", hence the British acronym ASDIC . In 1939, in response to a question from the Oxford English Dictionary , the Admiralty made up the story that it stood for "Allied Submarine Detection Investigation Committee", and this is still widely believed, though no committee bearing this name has been found in
13908-505: Was preceded by experiments with the JB-2 Loon missile , a close derivative of the German V-1 flying bomb , beginning in the last year of World War II . Submarine testing of Loon was performed 1947–53, with Cusk and Carbonero converted in to guided-missile submarines as test platforms in 1947 and 1948 respectively. Initially the missile was carried on the launch rail unprotected, thus
14030-567: Was provided from a 2 kW at 3.8 kV, with polarization from a 20 V, 8 A DC source. The passive hydrophones of the Imperial Japanese Navy were based on moving-coil design, Rochelle salt piezo transducers, and carbon microphones . Magnetostrictive transducers were pursued after World War II as an alternative to piezoelectric ones. Nickel scroll-wound ring transducers were used for high-power low-frequency operations, with size up to 13 feet (4.0 m) in diameter, probably
14152-474: Was reassigned to Submarine Squadron 6 (SubRon 6) at Balboa, C.Z. From 10 December 1946 to 13 March 1947, Sennet participated in Operation Highjump , the third Byrd Antarctic Expedition. Sennet used the first basic under-ice sonar to establish the feasibility of United States under-ice operations. Sennet operated from Balboa until 1949 when she was assigned to operate from Key West , Fla. , as
14274-660: Was redesignated as an auxiliary submarine (AGSS) in 1949 and converted to a sonar test submarine in 1958–59 to test a system known as LORAD. This included a 12-foot (3.7 m) extension aft of the forward torpedo room, with 40-foot (12 m) swing-out arrays near the bow. Later, three large domes were installed topside for a wide aperture array. Barbero was converted to a cargo submarine and redesignated as an SSA in 1948. The forward engine room, after torpedo room, and all reload torpedo racks were gutted to provide cargo space. From October 1948 until March 1950, she took part in an experimental program to evaluate her capabilities as
14396-507: Was replaced by the precursor of the modern hydrophone . Also during this period, he experimented with methods for towing detection. This was due to the increased sensitivity of his device. The principles are still used in modern towed sonar systems. To meet the defense needs of Great Britain, he was sent to England to install in the Irish Sea bottom-mounted hydrophones connected to a shore listening post by submarine cable. While this equipment
14518-603: Was replaced in the Pacific Fleet transport submarine role by Tunny in 1967 and Grayback in 1968. Sealion operated in the Atlantic, deploying for the Cuban Missile Crisis and numerous SOF-related exercises. She was decommissioned in 1970 and expended as a target in 1978. The LVT hangar and 5-inch gun were removed from both boats by the late 1950s. They went through several changes of designation in their careers: ASSP in 1950, APSS in 1956, and LPSS in 1968. Baya
14640-411: Was stripped and converted into berthing, and the boat lost two of her forward torpedo tubes to make room for additional berthing and electronics. The radars were raised up off the deck and put on masts, giving them a greater range and hopefully greater reliability. The SSRs proved only moderately successful, as the radars themselves proved troublesome and somewhat unreliable, and the boats' surface speed
14762-491: Was the only Balao -class SSR. Experiments on the first two SSR submarines under the appropriately named Project Migraine I showed that placement of the radars on the deck was inadequate and that more room was needed for electronics. Thus Burrfish was given the Migraine II (project SCB 12 ) conversion, which placed a Combat Information Center (CIC) in the space formerly occupied as the aft battery room. The after torpedo room
14884-420: Was the only production conversion with Guppy batteries. This was developed as a more cost-effective alternative to GUPPY II. Nine Balao -class boats ( Atule , Becuna , Blackfin , Blenny , Caiman , Chivo , Chopper , Sea Poacher , and Sea Robin ) were converted in 1951–52. The less expensive Sargo II battery was introduced, along with other cost-saving measures. The Fleet Snorkel program
#886113