Durjoy-class

The Durjoy class is a group of large patrol craft in service with the Bangladesh Navy. The class was designed for patrolling and surveillance within the Bangladesh Exclusive Economic Zone in the Bay of Bengal, as well as for limited offensive operations. The vessels were developed in two phases. An initial contract for two ships was signed in 2009 for construction at Wuchang Shipyard in China. A subsequent contract for two additional ships was signed in 2014 with Khulna Shipyard, where the vessels were built in Bangladesh under a transfer of technology agreement.

The class utilizes a hull design with a bulbous bow to facilitate operations in heavy sea states. Propulsion is provided by SEMT Pielstick 12PA6 diesel engines driving two shafts. The ships are produced in two distinct configurations: an anti-surface warfare variant and an anti-submarine warfare variant. While sharing a common hull, the variants are equipped with different sensor suites and internal systems. Both versions feature surface and air search radar, fire control radar, and a bow-mounted sonar. The anti-submarine variant is further equipped with navigational and chart radars. All vessels in the class utilize a combat management system with multifunction consoles and carry a rigid-hulled inflatable boat with a dedicated launch system.

Four ships of the class are active: Durjoy, Nirmul, Durgam and Nishan. The first two vessels, BNS Durjoy and BNS Nirmul, were launched in 2012 and commissioned in August 2013. The second pair, BNS Durgam and BNS Nishan, were commissioned in November 2017. These ships are designed for 15-day missions, with crews ranging from 60 to 70 personnel depending on the variant. The Keris-class littoral mission ship is a subclass of the Durjoy design.