This article is written like a personal reflection, personal essay, or argumentative essay that states a Wikipedia editor's personal feelings or presents an original argument about a topic.(March 2023) |
Submarine signals had a specific, even proprietary, meaning in the early 20th century. It applied to a navigation aid system developed, patented and produced by the Submarine Signal Company of Boston. The company produced submarine acoustic signals, first bells and receivers then transducers, as aids to navigation. The signals were fixed, associated with lights and other fixed aids, or installed aboard ships enabling warning of fixed hazards or signaling between ships. ATLAS-Werke, at the time Norddeutsche Maschinen und Armaturenfabrik, of Germany also manufactured the equipment under license largely for the European market.
The system used more reliable underwater sound to project acoustic signals from a shore station or an undersea hazard on which a signal was placed. The signals were usually associated with a lightvessel, a bell buoy or hung on a tripod frame on the sea floor connected to a shore stations by cable. At first the system depended on bells operated by electric strikers. Receivers aboard ships could detect the acoustic signal and when equipped with receivers on each side the ship could determine approximate direction from which the signal came. A ship-to-ship system was also produced allowing ships so equipped to detect each other and estimate direction in fog. The company collected data from ships including ranges at which the signals of specific stations were detected. The collected data formed an early base of ocean acoustical properties. The original bells were quickly replaced by the Fessenden oscillator, a transducer, after its invention by Reginald Fessenden with development starting in 1912 at the Submarine Signal Company. That transducer allowed both sending and receiving leading to major advances in both submarine signals and extension into submarine telegraphy and experiments with underwater telephone communication and eventually sonar.
Ships, commercial or naval, equipped with submarine signaling capability had that equipment noted as one of the ship's navigation capabilities in registry information from the first decade of the century until nearly mid century. In 1907 the information was important to insurance underwriters and American Bureau of Shipping required that ships so equipped by indicated by the note "Sub. Sig." in ship's registry information. Commercial lines advertised the capability as a safety measure. Submarine signaling was made obsolescent and overtaken by advances during World War II.
In 1946 the Submarine Signal Company was acquired by and merged with Raytheon, becoming Raytheon's Marine Division, after having become the national leader in underwater sound, sonar and other work with the Navy during the World Wars and branching into other marine systems.
In 1826 Jean-Daniel Colladon and Jacques Charles François Sturm used a submerged bell for experiments in Lake Geneva. Lucian I. Blake in association with the United States Lighthouse Service did similar work in 1883 using a submerged bell with the explicit purpose of using sound as an aid to navigation. [1] [2] Experiments in England and the United States occurred independently afterward.
Reception problems related to ship noise were partially solved when A. J. Munday, who had worked with Dr. Elisha Gray on signaling by underwater bells to include actual messages, found that a microphone placed in a metal box filled with water and attached to a ship's skin from inside allowed clear reception. In further experiments placement of such microphones on each side of a ship allowed finding the direction of the source. Intensity on one side showed the source to that side of the ship and equal intensity showed the source to be directly ahead. [1] [2] [3] A direction indicator box allowed the selection of receivers individually for comparison of signal strength for direction. [4]
Experiments determined modifications to bells used in air that optimized them for underwater use. Electrical striking systems allowed the bells to be connected to surface aids. Canadian experiments showed the practicality of determining direction by comparison of the reception by two receivers mounted on each side of a vessel's bow. [5]
The Submarine Signal Company, was established in Boston, Massachusetts, to turn the research into a navigational aid. The company developed, patented and began manufacturing electromechanical bell signals and shipboard receivers based on previous research introducing the world's first electronic, underwater acoustic navigation aid in 1901. [2] [6] [7] [8] [note 1]
The signal system was of particular importance for safe navigation in fog. Fog signals, horns and whistles, conducted by air were unreliable and erratic. Sonic signals through water were more reliable and had more range. [1] Offshore hazards could be marked by a tripod mounted bell connected to a shore station by cable. [9] A similar system of underwater bells mounted on ships enabled signaling between ships to avoid collisions in fog. [2] The Cunard liner Lucania was equipped with the first ship-to-ship submarine signal device. [10]
The United States Lighthouse Board had some interest but they did not take immediate action. [2] The British Admiralty and Trinity House and, in Germany, the North German Lloyd Steamship Company took more immediate notice of the potential and became pioneers in implementation both at signal stations and as shipboard receivers. [2] The German company Norddeutsche Maschinen und Armaturenfabrik (1902), becoming Atlas Werke in 1911, manufactured the system under license from the Submarine Signal Company. [11] Major lines were equipping it ships with the apparatus so that in 1905, after experience with Lucania and Norddeutscher Lloyd liners Kaiser Wilhelm II, Kronprinz Wilhelm and Kaiser Wilhelm der Grosse were successfully using the system, Cunard announced its entire fleet would have the apparatus. [12] An example of significant commercial advantage, being able to operate when other ships were fog bound, was a case in which the liner Kaiser Wilhelm II was able to enter harbor twenty-two hours before the fog at the Weser river mouth cleared and other vessels could enter port. By using the submarine signals of the entrance lightvessel the ship was able to enter the fog clear harbor to discharge passengers and cargo. [4]
The Admiralty conducted tests in October 1906 using a bell such as was used by U.S. lightvessels. The tests were successful with the Admiralty recommending their use as a coastal navigation aid with notes on the possible ship-to-ship use to warn and establish direction of another ship in fog. There was also notation of use between submarines and "parent ships" with some of the submarine results withheld from publication as purely military in application. [13] Experience of U.S. Navy battleships in fog off Nantucket Shoals proved the fleet could, under reduced speed, safely navigate and maintain formation by using the signals. [14]
On March 3, 1905 an act in the United States had authorized funding for aids including submarine signals. The U.S. lighthouse authorities were by the summer of 1906 installing signals, specifically at lightvessels stationed at Boston, Pollock Rip, Nantucket, Fire Island, and Sandy Hook. [15] The United States and Canada were placing the signals at important locations. The U.S. Lighthouse Board was ordering systems for the Gulf of Mexico and Britain had adopted the system for all its aids to navigation. In 1910 the report of the United States Department of Commerce showed forty-nine signals established by June 30, most on lightvessels. [16] Extension into the Great Lakes revealed a problem with the forepeak receiver installation for seagoing ships operated in light condition in fresh water. The forepeak was almost out of the water thus reducing the effectiveness requiring a solution by the Submarine Signal Company. [9]
By 1907 the signals were in common use with most large ships equipped with the receiving apparatus. The receiving apparatus had evolved from a simple receiver on the ship's bottom to two hydrophones in water-filled sea chests on each side of the ship enabling the ship to determine the direction from which the signal came. [6] [17] [18] The Submarine Signal Company, with branches in Bremen, Liverpool, London, and New York, was both manufacturing the apparatus and collecting data from shipping companies and individual ships on the operation of the signals. [17] [18]
The utility of the signals became evident as more stations and ships were equipped. Prominent ship captains, such as James Watt, master of Lusitania, strongly endorsed the system. Marine underwriters needed information on which ships were equipped to adjust risk for vessel and cargo insurance. [19] The American Bureau of Shipping included whether a vessel was equipped with submarine signal apparatus as a part of the registry information along with wireless. [20] Registers making note of navigation equipment of yachts and ships listed "Submarine Signal system" or "Sub.Sig." as seen in the yacht Noma and Lloyd's Register, column two, "Special surveys" for ships. [21] [22]
The Submarine Signal Company was the first company engaged in underwater acoustics becoming the national underwater sound experts and producing acoustical aids to navigation. It also became the major sonar supplier to the U.S. Navy in later years. [23]
A technique termed synchronous signaling combined bell signals with coordinated radio dot signals for direct distance to the signal without use of stopwatches. The radio dots would follow a bell strike sequence and the number of dots received before the next bell signal would indicate the distance in half miles. [24] The stations with the capability and precise method to use the combined radio, including stations transmitting radio direction finding signals, and submarine signal were published in nautical notices and tables. [25]
The Fessenden oscillator, invented by Submarine Signal Company's consulting engineer Reginald Fessenden in 1913 and developed and manufactured in 1914, was a transducer that was easier to install and maintain, could both send and receive, and also allowed coded communication between any two installations, including submarines. Bells were quickly phased out and transducer equipped installations remained active until World War II. [6] [7] [26] [27] The bells had been adequate to send signals, even coded strikes for identification, but the company had been seeking a method of acoustical communications. The oscillator accomplished that and led to further developments in underwater acoustics. [28] The company acted quickly to replace the bells with the transducers and began working on use in submarine telegraphy, but it was slow to recognize or take advantage of the sonic distance measurement of interest to Fessenden so that others took the lead in SOund NAvigation Ranging, now generally simply known as sonar. [26] [27]
Submarine Signal Company's focus with the Fessenden device was on submarine telegraphy with a beginning in submarine telephones. With marine radio gaining usage the expensive submarine version faded. Despite Fessenden's demonstration in June 1914 of the effectiveness of his device in telegraphy that aspect faded and the "sensing" potential, first crudely applied to locating icebergs, became critical with World War I and submarine warfare. [29]
Full focus came to underwater acoustics and the potential to detect submarines by sound, either passively or actively. The existing receivers, designed to detect intentional signals, proved unable to detect the incidental sounds of submarines. Harold J. W. Fay of Submarine Signal Company was invited to meet with the Chief, Bureau of Steam Engineering 20 March 1917 to discuss establishing an acoustical research station at East Point, Nahant, Massachusetts. Fay gave assurances property would be made available. As implemented Submarine Signal Company would be joined by Western Electric Company and General Electric Company to work on the project. On 8–9 May representatives of the companies met in Washington to establish working relationships. [30] [31]
To meet concerns of the Naval Consulting Board that naval interests might not be met in general research a Navy Special Board on Anti-Submarine Devices would oversee the work. Commander Clyde Stanley McDowell was secretary of the board and later filled the same function at the Naval Experimental Station, New London, Connecticut. The Nahant Antisubmarine Laboratory, completed April 7, 1917, was the first anti-submarine, acoustical laboratory of the Navy. The laboratory, a cluster of buildings behind guarded security fencing, was where "submarine signals" research entered the new field of anti-submarine acoustics. [30] [31] [note 2]
The submarine signals as navigational aids, just as many lights went dark, were stopped so as not to aid enemy submarines or become gathering points for target ships. [32]
During World War I and after the Submarine Signal Company had expanded into fathometers and other marine electronics including radio direction finders and radiotelephones as the acoustic aids faded in importance with radio navigation gaining importance and users. In 1946 the company was acquired by and merged with the American Appliance Company, later Raytheon, to become that company's Marine Division responsible for all products with marine applications. [23] [33]
Sonar is a technique that uses sound propagation to navigate, measure distances (ranging), communicate with or detect objects on or under the surface of the water, such as other vessels.
A hydrophone is a microphone designed to be used underwater for recording or listening to underwater sound. Most hydrophones are based on a piezoelectric transducer that generates an electric potential when subjected to a pressure change, such as a sound wave.
Reginald Aubrey Fessenden was a Canadian-born inventor, who did a majority of his work in the United States and also claimed U.S. citizenship through his American-born father. During his life he received hundreds of patents in various fields, most notably ones related to radio and sonar.
A buoy is a floating device that can have many purposes. It can be anchored (stationary) or allowed to drift with ocean currents.
Echo sounding or depth sounding is the use of sonar for ranging, normally to determine the depth of water (bathymetry). It involves transmitting acoustic waves into water and recording the time interval between emission and return of a pulse; the resulting time of flight, along with knowledge of the speed of sound in water, allows determining the distance between sonar and target. This information is then typically used for navigation purposes or in order to obtain depths for charting purposes.
The Naval Undersea Warfare Center (NUWC) is the United States Navy's full-spectrum research, development, test and evaluation, engineering and fleet support center for submarines, autonomous underwater systems, and offensive and defensive weapons systems associated with undersea warfare. It is one of the corporate laboratories of the Naval Sea Systems Command. NUWC is headquartered in Newport, Rhode Island and has two major subordinate activities: Division Newport and Division Keyport in Keyport, Washington. NUWC also controls the Fox Island facility and Gould Island. It employs more than 4,400 civilian and military personnel, with budgets over $1 billion.
(Acoustic homing) is the process in which a system uses the sound or acoustic signals of a target or destination to guide a moving object. There are two types of acoustic homing: passive acoustic homing and active acoustic homing. Objects using passive acoustic homing rely on detecting acoustic emissions produced by the target. Conversely, objects using active acoustic homing make use of sonar to emit a signal and detect its reflection off the target. The signal detected is then processed by the system to determine the proper response for the object. Acoustic homing is useful for applications where other forms of navigation and tracking can be ineffective. It is commonly used in environments where radio or GPS signals can not be detected, such as underwater.
A fishfinder or sounder (Australia) is an instrument used to locate fish underwater by detecting reflected pulses of sound energy, as in sonar. A modern fishfinder displays measurements of reflected sound on a graphical display, allowing an operator to interpret information to locate schools of fish, underwater debris, and the bottom of a body of water. Fishfinder instruments are used both by sport and commercial fishermen. Modern electronics allow a high degree of integration between the fishfinder system, marine radar, compass and GPS navigation systems.
Project Artemis was a United States Navy acoustics research and development experiment from the late 1950s into the mid 1960s to test a potential low-frequency active sonar system for ocean surveillance. The at sea testing began in 1960 after research and development in the late 1950s. The project's test requirement was to prove detection of a submerged submarine at 500 nmi. The experiment, covering a number of years, involved a large active element and a massive receiver array.
Underwater acoustics is the study of the propagation of sound in water and the interaction of the mechanical waves that constitute sound with the water, its contents and its boundaries. The water may be in the ocean, a lake, a river or a tank. Typical frequencies associated with underwater acoustics are between 10 Hz and 1 MHz. The propagation of sound in the ocean at frequencies lower than 10 Hz is usually not possible without penetrating deep into the seabed, whereas frequencies above 1 MHz are rarely used because they are absorbed very quickly.
Submarine navigation underwater requires special skills and technologies not needed by surface ships. The challenges of underwater navigation have become more important as submarines spend more time underwater, travelling greater distances and at higher speed. Military submarines travel underwater in an environment of total darkness with neither windows nor lights. Operating in stealth mode, they cannot use their active sonar systems to ping ahead for underwater hazards such as undersea mountains, drilling rigs or other submarines. Surfacing to obtain navigational fixes is precluded by pervasive anti-submarine warfare detection systems such as radar and satellite surveillance. Antenna masts and antenna-equipped periscopes can be raised to obtain navigational signals but in areas of heavy surveillance, only for a few seconds or minutes; current radar technology can detect even a slender periscope while submarine shadows may be plainly visible from the air.
Underwater acoustic communication is a technique of sending and receiving messages in water. There are several ways of employing such communication but the most common is by using hydrophones. Underwater communication is difficult due to factors such as multi-path propagation, time variations of the channel, small available bandwidth and strong signal attenuation, especially over long ranges. Compared to terrestrial communication, underwater communication has low data rates because it uses acoustic waves instead of electromagnetic waves.
A fog bell is a navigation mark used as an audible aid to navigation in seafaring, especially in fog and poor visibility. Floating navigation signs with bells are called bell buoys. On ships, the ship's bell is used for sound signals. Due to more suitable sound generators, but also the development and spread of radar, satellite navigation and electronic charting systems, fog bells have lost their importance for maritime navigation.
An underwater acoustic positioning system is a system for the tracking and navigation of underwater vehicles or divers by means of acoustic distance and/or direction measurements, and subsequent position triangulation. Underwater acoustic positioning systems are commonly used in a wide variety of underwater work, including oil and gas exploration, ocean sciences, salvage operations, marine archaeology, law enforcement and military activities.
A short baseline (SBL) acoustic positioning system is one of three broad classes of underwater acoustic positioning systems that are used to track underwater vehicles and divers. The other two classes are ultra short baseline systems (USBL) and long baseline systems (LBL). Like USBL systems, SBL systems do not require any seafloor mounted transponders or equipment and are thus suitable for tracking underwater targets from boats or ships that are either anchored or under way. However, unlike USBL systems, which offer a fixed accuracy, SBL positioning accuracy improves with transducer spacing. Thus, where space permits, such as when operating from larger vessels or a dock, the SBL system can achieve a precision and position robustness that is similar to that of sea floor mounted LBL systems, making the system suitable for high-accuracy survey work. When operating from a smaller vessel where transducer spacing is limited, the SBL system will exhibit reduced precision.
A long baseline (LBL) acoustic positioning system is one of three broad classes of underwater acoustic positioning systems that are used to track underwater vehicles and divers. The other two classes are ultra short baseline systems (USBL) and short baseline systems (SBL). LBL systems are unique in that they use networks of sea-floor mounted baseline transponders as reference points for navigation. These are generally deployed around the perimeter of a work site. The LBL technique results in very high positioning accuracy and position stability that is independent of water depth. It is generally better than 1-meter and can reach a few centimeters accuracy. LBL systems are generally employed for precision underwater survey work where the accuracy or position stability of ship-based positioning systems does not suffice.
GPS sonobuoy or GPS intelligent buoy (GIB) are a type of inverted long-baseline (LBL) acoustic positioning devices where the transducers are installed on GPS-equipped sonobuoys that are either drifting or moored. GIBs may be used in conjunction with an active underwater device, or with a passive acoustic sound source. Typically the sound source or impact event is tracked or localized using a time of arrival (TOA) technique. Typically several GIBs are deployed over a given area of operation; with the total number determined by the size of the test area and the accuracy of the results desired. Different methods of GPS positioning may be used for positioning the array of GIBs, with accuracies of cm to meter level in realtime possible.
A Fessenden oscillator is an electro-acoustic transducer invented by Reginald Fessenden, with development starting in 1912 at the Submarine Signal Company of Boston. It was the first successful acoustical echo ranging device. Similar in operating principle to a dynamic voice coil loudspeaker, it was an early kind of transducer, capable of creating underwater sounds and of picking up their echoes.
Radio acoustic ranging, occasionally written as "radio-acoustic ranging" and sometimes abbreviated RAR, was a method for determining a ship's precise location at sea by detonating an explosive charge underwater near the ship, detecting the arrival of the underwater sound waves at remote locations, and radioing the time of arrival of the sound waves at the remote stations to the ship, allowing the ship's crew to use true range multilateration to determine the ship's position. Developed by the United States Coast and Geodetic Survey in 1923 and 1924 for use in accurately fixing the position of survey ships during hydrographic survey operations, it was the first navigation technique in human history other than dead reckoning that did not require visual observation of a landmark, marker, light, or celestial body, and the first non-visual means to provide precise positions. First employed operationally in 1924, radio acoustic ranging remained in use until 1944, when new radio navigation techniques developed during World War II rendered it obsolete.
{{cite book}}
: CS1 maint: location missing publisher (link)