The Mark 48 and its improved Advanced Capability (ADCAP) variant are American heavyweight submarine-launched torpedoes. They were designed to sink deep-diving nuclear-poweredsubmarines and high-performance surface ships.
History
The Mark 48 was initially developed as REsearch TORpedo Concept II (RETORC II), one of several weapons recommended for implementation by Project Nobska, a 1956 summer study on submarine warfare.[9] The Mk-48 torpedo was designed at the end of the 1960s to keep up with the advances in Sovietsubmarine technology. Operational since 1972, it replaced the Mk-37, Mk-14 and Mk-16 torpedoes as the principal weapon of U.S. Navy submarines.[3] With the entry into service of the new Soviet Alfa-class submarine in 1977, the decision was made to accelerate the ADCAP program, which would bring significant modifications to the torpedo. Tests were run to ensure that the weapon could keep up with the developments and the weapon was modified with improved acoustics and electronics. The new version of the weapon, also known as Mk-48 Mod 5, was extensively tested and production started in 1985, with entry into service in 1988. From then on, various upgrades have been added to the torpedo. As of 2012[update] Mk-48 Mod 6 was in service; a Mod 7 version was test fired in 2008 in Exercise RIMPAC. The inventory of the U.S. Navy in 2001 was 1,046 Mk-48 torpedoes.[7] In 2017 Lockheed's production was approximately 50 per year.[10]
Mk-48 and Mk-48 ADCAP torpedoes can be guided from a submarine by wires attached to the torpedo. They can also use their own active or passive sensors to execute programmed target search, acquisition, and attack procedures. The torpedo is designed to detonate under the keel of a surface ship, breaking the keel and destroying its structural integrity. In the event of a miss, it can circle back for another attempt.[11]
The torpedo's seeker has an active electronically steered "pinger" (2D phased array sonar) that helps avoid having to maneuver as it approaches the target. Unconfirmed reports[by whom?] indicate that the torpedo's sensors can monitor surrounding electrical and magnetic fields. This may refer to the electromagnetic coils on the warhead (at least from 1977 to 1981), used to sense the metallic mass of the ship's hull and detonate at the proper stand-off distance.
The torpedo has been the subject of continued improvement over its service lifetime.
In the 1990s, a Mod 6 variant of the ADCAP provided much improved noise isolation for the engine, which makes this torpedo more difficult to detect for a potential target.
The Mk48 Mod 7 Common Broadband Advanced Sonar System (CBASS) torpedo is optimized for both the deep and littoral waters and has advanced counter-countermeasure capabilities. The MK48 ADCAP Mod 7 (CBASS) torpedo is the result of a Joint Development Program with the Royal Australian Navy and reached Initial Operational Capability in 2006.[8] The modular Mod 7 variant increases sonar bandwidth, enabling it to transmit and receive pings over a wider frequency band, taking advantage of broadband signal processing techniques to greatly improve search, acquisition, and attack effectiveness. This version is much more resistant to enemy countermeasures.[12]
On July 25, 2008 a MK 48 Mod 7 CBASS torpedo fired by an Australian Collins-class submarine, HMAS Waller, successfully sank a test target during the Rim of the Pacific 2008 (RIMPAC) exercises.[13][14]
In 2015 the USN announced plans to restart production and seek a more modular design.[15]Lockheed Martin is to upgrade existing Mark 48s to include a new guidance-control system known as the Common Broadband Advanced Sonar System (CBASS), in addition to improving propulsion and resistance to electronic countermeasures.[16]
Starting in 2003, the US Navy began the Stealth Torpedo Enhancement Program which aims to upgrade the capability of the existing Mk 48 design by implementing alternative fuel sources including electric fuel cells, and a "swim out" capability, a capability that allows a torpedo to leave the tube under its own power without using a torpedo tube's noisier compressed air launch system. The program is ongoing, with many details yet classified.[17]
^ abcdefThomas, Vincent C. The Almanac of Seapower 1987. Navy League of the United States (1987). ISBN0-9610724-8-2. p. 190.
^ abcd"Mk 48 ADCAP". Jane's Naval Forces News. www.janes.com. Archived from the original on April 1, 2001. Retrieved 2011-04-06.((cite web)): CS1 maint: unfit URL (link)
^"Aussie sub sinks US Warship". The Sydney Morning Herald. 25 July 2008. Archived from the original on 26 July 2008. An Australian submarine has fired a new heavy torpedo for the first time and sunk a US warship. But, rest easy, the dramatic event was part of an exercise and not a sudden deterioration in relations with the US. [...] The new heavyweight torpedo, jointly developed by Australia and the US, was fired yesterday during the Rim of the Pacific 2008 (RIMPAC 08) exercise. Multiple navies are taking part in the exercise off the coast of Hawaii, which featured the planned sinking of a retired US warship. The MK 48 Mod 7 Common Broadband Advanced Sonar System (CBASS) torpedo is considered the world's premier submarine-launched torpedo.
^Mizokami, Kyle (December 27, 2016). "The U.S. Navy is Getting a More Lethal Torpedo". Popular Mechanics. Archived from the original on December 28, 2016. Defense contractor Lockheed Martin is upgrading existing Mark 48s to a new standard. A new, upgraded torpedo will run quieter, have an improved propulsion system, be more resistant to electronic countermeasures, and have an all-new guidance control system known as Common Broadband Advanced Sonar System, or CBASS. The new system should allow for locking onto enemy vessels at even longer ranges. In addition to upgrading older torpedoes, Lockheed will deliver 250 more brand new Mark 48s to the U.S. Navy.
^Gady, Franz-Stefan (September 9, 2016). "US Agrees to Supply Taiwan With Advanced Torpedoes". The Diplomat. After many years of delay, the United States will finally approve the sale of advanced MK-48 heavyweight torpedoes to Taiwan, an unnamed official of Taiwan's Ministry of National Defense told Defense News. According to local Taiwanese media reports, the "problem" over the purchase of the MK-48 has "now been resolved" and the MK-48 is included in this year's military budget request, currently being debated in Taiwan's Legislative Yuan. The sale of the torpedoes was first requested during the presidency of George W. Bush. Neither the United States nor Taiwan has officially confirmed the deal. It is also unclear how many torpedoes will be sold and under what timeframe. Once procured, the MK-48 Mod 6 Advanced Technology (AT) heavyweight torpedoes will be installed aboard the two Hai Lung-class (improved Dutch Zwaardvis-class) submarines, according to the source.
