Tripartite-class (Éridan)

The Tripartite class originated from a joint agreement between the navies of Belgium, France, and the Netherlands to develop a successor to the French Circé-class minehunters. Construction occurred between 1977 and 1995. The program utilized a work-sharing arrangement where France provided minehunting and electronic systems, the Netherlands supplied main propulsion systems, and Belgium produced minehunting propulsion and electrical generating systems.

The vessels feature fiberglass hulls molded within steel shells. The design incorporates two independent propulsion systems: a conventional diesel engine for transit and a specialized system for minehunting operations. The latter employs active rudders and a bow thruster powered by gas turbine alternators. Both systems are operable from the bridge or a soundproof control center above the main deck. For mine detection and neutralization, the class initially used retractable hull-mounted sonar and remotely operated underwater vehicles (ROVs). Later modernizations replaced original sensors with updated sonar packages, combat data systems, and newer ROV models. While primarily configured for minehunting, certain variants include mechanical, acoustic, or magnetic minesweeping gear.

The three founding nations commissioned the majority of the vessels, designated as the Éridan class in France, the Alkmaar class in the Netherlands, and the Aster or Flower class in Belgium. Operational roles include minehunting, minesweeping, and ammunition transport. Pakistan acquired three vessels beginning in 1992, operating them as the Munsif class. Indonesia purchased two modified ships, the Pulau Rengat class, which serve as minehunters, minesweepers, and patrol vessels.

Secondary markets and donations have extended the service life of the class across several navies. Latvia acquired five former Dutch vessels between 2007 and 2009. Bulgaria integrated former Belgian and Dutch units into its fleet starting in 2009, with additional transfers scheduled through 2028. Following the Russian invasion of Ukraine, the Netherlands and Belgium authorized the transfer of vessels to the Ukrainian Navy, with the first units renamed and transferred in 2025 and a third, the former HNLMS Makkum, renamed Henichesk on 15 June 2026. None of the three has reached the Black Sea: all remain based in the United Kingdom because Türkiye applies the wartime provisions of the Montreux Convention to belligerent warships transiting the Straits. Replacement of the class in Belgian and Dutch service is currently underway through a joint procurement of new mine countermeasure vessels.