Avenger-class

The United States Navy developed the Avenger-class mine countermeasures ships in the early 1980s. Peterson Shipbuilders and Marinette Marine constructed 14 vessels between 1987 and 1994 to replace the Ability-class minesweeper. The class is designed to find, classify, and destroy moored and bottom mines.

The hulls are constructed of oak, Douglas fir, and Nootka Cypress with an external fiberglass coating. This wooden construction allows the hull to withstand nearby explosions and maintains a low magnetic signature. For mine detection, the ships utilize the AN/SQQ-32 advanced minehunting sonar, which consists of search and classification sonars fitted in a submersible pod towed under the ship. Neutralization is performed by remotely operated vehicles, such as the AN/SLQ-48 and EX116 Mod 0. These tethered units use high-frequency sonar, low-light television, cable cutters, and explosive charges to dispose of mines. Propulsion consists of four diesel engines—either Waukesha-Pearce or Isotta-Fraschini units—designed for low magnetic and acoustic signatures. The ships use electric motors for stationkeeping and an Omnithruster hydrojet for precision maneuvering.

Operational history includes mine countermeasures in the Persian Gulf during the Iran-Iraq War and Operations Desert Shield and Desert Storm. By 2012, eight vessels were forward-based in Sasebo, Japan, and Manama, Bahrain. Four additional units were deployed to Bahrain in 2012 to monitor the Strait of Hormuz. One vessel, USS Guardian, was lost in 2013 following a grounding on Tubbataha Reef. The United States Navy began decommissioning the class in 2014, with several units retired in 2020. The Freedom and Independence-class littoral combat ships are designated to replace the class. Current active units are scheduled for decommissioning through 2027.