A sea-going metal-hulled ship or submarine, by its very nature, develops a magnetic signature as it travels due to a magneto-mechanical interaction with the Earth's magnetic field. This signature can be exploited by magnetic mines, or facilitate the detection of a submarine by ships or aircraft with magnetic anomaly detection (MAD) equipment. Navies use the deperming procedure, in conjunction with degaussing, as a countermeasure against this.
Specialized deperming facilities, such as the United States Navy's Lambert's Point Deperming Station are used to perform the procedure. Heavy gauge copper cables are wrapped around the hull and superstructure of the vessel, and very high electrical currents (as high as 4000 amps) are pulsed through the cables. This has the effect of "resetting" the ship's magnetic signature. It is also possible to assign a specific signature that is best suited to the particular area of the world in which the ship will operate. Over time the deperm will begin to degrade and the procedure must be redone periodically to maintain the desired effect.
During World War II the United States Navy commissioned a specialized class of degaussing ships that were capable of performing this function. One of them, USS Deperm (ADG-10), was named after the procedure.
- ^ Payne, Craig M. (2006). Principles of Naval Weapon Systems. Naval Institute Press. p. 208. ISBN 9781591146582. http://books.google.com/books?id=F3q59-hcGDoC&lpg=PA208&dq=Deperming&pg=PA208#v=onepage&q=Deperming&f=false. Retrieved January 3, 2011.
- ^ Holmes, John J. (2008). Reduction of a Ship's Magnetic Field Signatures - Volume 23 of Synthesis lectures on computational electromagnetics. Morgan & Claypool Publishers. p. 19. ISBN 9781598292480. http://books.google.com/books?id=28PCgAGjXCwC&lpg=PA19&dq=Deperming&pg=PA19#v=onepage&q=Deperming&f=false. Retrieved January 3, 2011.
Wikimedia Foundation. 2010.
Look at other dictionaries:
deperming — v. neutralize a magnetic field, demagnetize … English contemporary dictionary
Lambert's Point Deperming Station — is a United States Navy deperming facility located in the Elizabeth River just off Lambert s Point, Norfolk, Virginia. It was built in the mid 1940 s and services the U.S. Atlantic Fleet. The station, which is administered by Naval Station… … Wikipedia
Naval Station Norfolk — Norfolk, Virginia Naval Station Norfolk in June 2009 Type … Wikipedia
Naval Amphibious Base Little Creek — Virginia Beach, Virginia NAB Little Creek insignia Type … Wikipedia
Degaussing — Degausser redirects here. For the song by Brand New, see Degausser (song). Degaussing is the process of decreasing or eliminating an unwanted magnetic field. It is named after Carl Friedrich Gauss, an early researcher in the field of magnetism.… … Wikipedia
List of ships of Russia by project number — The list of ships of Russia by project number includes all Russian ships by assigned project numbers. Ship descriptions are Russian assigned classifications when known. (The Russian term проект can be translated either as the cognitive project or … Wikipedia
Norfolk, Virginia — Norfolk Independent city Downtown Norfolk skyline, Chrysler Museum of Art, Ocean View Fishing Pier, The Tide light rail … Wikipedia
Norfolk Naval Shipyard — Portsmouth, Virginia Type Shipyard Built 1767 as Gosport Shipyard (Royal Navy; current name since 1862 (US Navy) In use 1767 … Wikipedia
Hampton Roads — Coordinates: 36°58′N 76°22′W / 36.967°N 76.367°W / 36.967; 76.367 … Wikipedia
Marine Corps Base Quantico — Quantico, Virginia MCB Quantico logo … Wikipedia