Avenger-Class Mine Countermeasures Ship

The Avenger-class mine countermeasures ship USS Ardent transits the Arabian Sea. Photo by Petty Officer 2nd Class Cassandra Thompson

Avenger-class mine countermeasures ships are a class of 14 ships constructed for the United States Navy from 1987 to 1994. The ships are designed to clear mines from vital waterways. The ships have the hull designator MCM.

Builders: Peterson Shipbuilders
Marinette Marine
Preceded by: Ability-class minesweeper
Succeeded by: Littoral combat ship
In commission: 1987
Completed: 14
Active: 13
Lost: 1
General characteristics
Type: Mine countermeasures ship
Displacement: 1,312 tons
Length: 224 ft (68 m)
Beam: 39 ft (12 m)
Draft: 15 ft (4.6 m)
Propulsion: 4 × Waukesha Diesel engines (first two ships) or 4 × Isotta-FraschiniDiesel engines (600 hp (450 kW) ea.)
2 × 200 hp (150 kW) electric propulsion motors
2 × shafts with controllable pitch propellers
1 × 350 hp (260 kW) Omnithruster waterjet bow thruster
Speed: 14 knots (26 km/h; 16 mph)
Complement: 8 officers, 76 enlisted
Armament: Mine neutralization system,
2 × .50 caliber machine guns



Shock trial of USS Avenger

The hulls of the Avenger-class ships are constructed of wood with an external coat of glass-reinforced plastic. 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.

Mine countermeasures systems

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 1,070 metres (3,510 ft) cable and under control of the vessel.

The ATK/Raytheon ROV is a similar system, but has a 1,500 metres (4,900 ft) tether cable, and also carries cable cutters for dealing with tethered or moored mines, and explosive charges to detonate the mines.

Sensor systems

The ships employ the AN/SQQ-32 advanced mine hunting 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 Motors Co. 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 600 horsepower (447.4 kW) (combined 1.79 MW) sustained power, providing a cruising speed of 14 knots (26 km/h; 16 mph) with controllable pitch propellers. For station keeping the ship uses two Hansome electric motors rated at 294 kW. Precision maneuvering capability is provided by a 257 kW Omnithruster hydrojet.


Ship Hull No. Commissioned Decommissioned Builder Home Port NVR Page
Avenger MCM-1 12 September 1987 Peterson Shipbuilders Sasebo, Japan MCM01
Defender MCM-2 30 September 1989 Marinette Marine Sasebo, Japan MCM02
Sentry MCM-3 2 September 1989 Peterson Shipbuilders San Diego, California MCM03
Champion MCM-4 8 February 1991 Marinette Marine San Diego, California MCM04
Guardian MCM-5 16 December 1989 15 February 2013
Peterson Shipbuilders Sasebo, Japan MCM05
Devastator MCM-6 6 October 1990 Peterson Shipbuilders San Diego, California MCM06
Patriot MCM-7 18 October 1991 Marinette Marine Sasebo, Japan MCM07
Scout MCM-8 15 December 1990 Peterson Shipbuilders Manama, Bahrain MCM08
Pioneer MCM-9 7 December 1992 Peterson Shipbuilders San Diego, California MCM09
Warrior MCM-10 7 April 1993 Peterson Shipbuilders San Diego, California MCM10
Gladiator MCM-11 18 September 1993 Peterson Shipbuilders Manama, Bahrain MCM11
Ardent MCM-12 18 February 1994 Peterson Shipbuilders Manama, Bahrain MCM12
Dextrous MCM-13 9 July 1994 Peterson Shipbuilders Manama, Bahrain MCM13
Chief MCM-14 5 November 1994 Peterson Shipbuilders San Diego, California MCM14


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