Avenger-class mine countermeasures ship

In the early 1980s, the U.S. Navy began development of a new mine countermeasures (MCM) force, which included two new classes of ships and minesweeping helicopters. The vital importance of a state-of-the-art mine countermeasures force was strongly underscored in the Persian Gulf during the eight years of the Iran–Iraq War, and in Operations Desert Shield and Desert Storm in 1990 and 1991 when Avenger and Guardian conducted MCM operations.

Avenger-class ships are designed as mine hunter-killers capable of finding, classifying, and destroying moored and bottom mines. The last three MCM ships were purchased in 1990, bringing the total to 14 fully deployable, oceangoing Avenger-class ships. These ships use sonar and video systems, cable cutters and a mine-detonating device that can be released and detonated by remote control. They are also capable of conventional sweeping measures.

As of 2012, eight Avengers were forward-based: four at Sasebo, Japan with standing crews, and four at Manama, Bahrain, with ten ships' companies on rotational deployments.{{cite journal |last=Tringham |first=Kate |date=16 March 2012 |title=US to double the number of minesweepers in the Persian Gulf |journal=Jane's Navy International |publisher=Jane's Information Group}} In March 2012, the USN announced plans to deploy another four MCMs to Bahrain to counter potential Iranian threats to mine the Strait of Hormuz reflecting increasing tensions between the United States and Iran over the latter's nuclear program.

File:USS Avenger;Shocktrial.jpg

The hulls of the Avenger-class ships are constructed of wood with an external coating of fiberglass. The wood used is oak, Douglas fir and Nootka Cypress because of their flexibility, strength and low weight. This construction allows the hull to withstand a nearby blast from a mine, and also gives the ship a low magnetic signature.

The ships use AN/SLQ-48 remotely operated mine disposal system supplied by Alliant Techsystems (ATK) and the EX116 Mod 0 remotely operated vehicle (ROV) mine neutralization system supplied by ATK and Raytheon. The AN/SLQ-48 detects, locates, classifies, and neutralizes moored mines and mines resting on the seabed. The vehicle uses high-frequency, high-resolution sonar, low light level television (LLLTV), cable cutters, and explosive charges to detect and dispose of mines, while remaining tethered to the vessel by a {{convert|1070|m|ft|adj=on|order=flip}} cable and under control of the vessel.

The ATK/Raytheon ROV is a similar system, but has a {{convert|1500|m|ft|adj=on|order=flip}} tether cable, and also carries cable cutters for dealing with tethered or moored mines, and explosive charges to detonate the mines.

The ships employ the AN/SQQ-32 advanced minehunting and classification sonar from Raytheon and Thales Underwater Systems (formerly Thomson Marconi Sonar). The system has two sonars fitted in a small submersible pod towed under the ship. When not deployed the submersible is housed in a trunk below the deck of the ship. The sonars are a Raytheon search and detection sonar and a Thales high-resolution, high-frequency, target-classification sonar. The deployment and retrieval system for the submersible was designed by the Charles Stark Draper Laboratory in Massachusetts.

The Avenger class employ the AN/SPS-55 surface-search and navigation radar supplied by Cardion, Inc. of New York. The ships have been equipped with CMC Electronics LN66 or Raytheon AN/SPS-66 navigation radars, but are slated to be upgraded with the AN/SPS-73.

The Avenger-class ships are equipped with four Waukesha-Pearce diesel engines (MCM 1 and 2) or Isotta-Fraschini ID 36SS6V diesel engines (remainder), which are designed to have very low magnetic and acoustic signatures. Each engine develops {{convert|600|hp|kW}}, with a combined power of {{convert|2400|hp|MW}}, providing a cruising speed of {{convert|14|kn}} with controllable pitch propellers. For stationkeeping the ship uses two Hansome electric motors rated at {{convert|294|kW|hp|order=flip}}. Precision maneuvering capability is provided by a {{convert|257|kW|hp|order=flip}} Omnithruster hydrojet (powered by Solar (Caterpillar Inc) Magnetic Marine Gas Turbine Generator).{{cite web|url=http://magazines.marinelink.com/Magazines/MaritimeReporter/198407/content/diesel-power-review-203686|title=DIESEL POWER REVIEW – Magazines|website=magazines.marinelink.com}}{{cite web|url=http://www.trucktrend.com/cool-trucks/1206dp-avenger-class-navy-mine-hunters/|title=Avenger Class Navy Mine Hunters – Diesel Power Magazine|date=1 June 2012}}

A fictional Avenger-class MCM is the vessel at the center of the 2023 film The Caine Mutiny Court-Martial. While no scenes appear on board the ship, it is shown in a photo posted in the courtroom, and much of the dialog involves the typical missions and capabilities of Avenger-class MCMs.

Image:USS Sentry (MCM-3);11120302.jpg|USS Sentry and USS Kingfisher

Image:USS guardian H.jpg|USS Guardian

Image:USS Gladiator MCM-11.jpg|USS Gladiator in the Persian Gulf

Image:USS AVENGER at Yokosuka.jpg|USS Avenger at the Port of Yokosuka

• List of mine warfare vessels of the United States Navy
• Osprey-class coastal minehunter – smaller vessels formerly in service with the USN
• Sandown-class minehunter – British contemporary
• Tripartite-class minehunter – numerous 1980s class in service in many European countries

{{reflist}}

• [https://web.archive.org/web/20050527204206/http://www.navy.mil/navydata/fact_display.asp?cid=4200&tid=1900&ct=4 United States Navy Fact File: Mine Countermeasures Ships – MCM]
• [http://www.globalsecurity.org/military/systems/ship/mcm-1.htm Globalsecurity.org MCM-1 Avenger Mine Countermeasures Ships]
• [http://www.globalsecurity.org/military/systems/ship/mcm-1-specs.htm Globalsecurity.org MCM-1 Avenger Mine Countermeasures Ships]
• [http://www.naval-technology.com/projects/avenger/ Naval-Technology.com: Avenger Class Mine Countermeasures Vessel]
• [http://www.fas.org/man/dod-101/sys/ship/mcm-1.htm Federation of American Scientists: MCM-1 Avenger Mine Countermeasures Ships]
• {{Naval Vessel Register|https://web.archive.org/web/20110503180210/http://www.nvr.navy.mil:80/nvrships/s_MCM.htm}}

{{commons category|Avenger class mine countermeasures ships}}

• [http://www.globalsecurity.org/military/systems/ship/mcm-1-schem.htm Globalsecurity.org: Plans and schematics of the Avenger class]
• [http://www.globalsecurity.org/military/systems/ship/mcm-1-gallery.htm Globalsecurity.org: Photo gallery]

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Category:Mine warfare vessel classes

Category:Naval ships of the United States