The ''Durjoy'' class is a class of large patrol craft of the

Bangladesh Navy The Bangladesh Navy () is the naval warfare branch of the Bangladesh Armed Forces, responsible for the defence of Bangladesh's of maritime territorial area from any external threat, the security of sea ports and exclusive economic zones of Ban ...

. A total of four are serving the Bangladesh Navy as of 2021.

History

The ''Durjoy class'' is a class of large patrol crafts of the Bangladesh Navy, designed to meet the longer patrolling and surveillance needs in the vast

EEZ An exclusive economic zone (EEZ), as prescribed by the 1982 United Nations Convention on the Law of the Sea, is an area of the sea in which a sovereign state has exclusive rights regarding the exploration and use of marine natural resource, reso ...

of Bangladesh in the

Bay of Bengal The Bay of Bengal is the northeastern part of the Indian Ocean. Geographically it is positioned between the Indian subcontinent and the Mainland Southeast Asia, Indochinese peninsula, located below the Bengal region. Many South Asian and Southe ...

as well as to perform limited offensive roles. The ships of this class are of two variants,

anti-surface warfare Anti-surface warfare (ASuW or ASUW) is the branch of naval warfare concerned with the suppression of surface combatants. More generally, it is any weapons, sensors, or operations intended to attack or limit the effectiveness of an adversary's ...

variant and

anti-submarine warfare Anti-submarine warfare (ASW, or in the older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations ar ...

variant. The primary characteristics of the two variants are same but they differ in armaments and sensor suite. Initially, a contract was signed in 2009 for two ships to be built at

Wuchang Shipyard Wuchang Shipbuilding Industry Group (WS), commonly called Wuchang Shipyard or Wuhan Shipyard, is a major state-owned in-land shipyard in Wuchang, Wuhan, China. It was founded in 1934. It is part of the China Shipbuilding Industry Corporation. The ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. The ships were of

variant. The first, (P 811), was launched on 26 August 2012, while the second, (P 813), was launched on 27 September 2012. Both ships arrived in Bangladesh in February 2013. The ships were commissioned on 29 August 2013. On 30 June 2014 the Bangladesh Navy signed a contract for the next two ''Durjoy''-class vessels with

Khulna Shipyard The Khulna Shipyard Limited () is a Bangladeshi state-owned defense contractor based in Khulna, Bangladesh. It is located on of land at Labanchara, Khulna, Bangladesh. It is about 45 km north from the Port of Mongla. The shipyard has the c ...

. These ships were constructed in Bangladesh under ToT from

Keel laying Laying the keel or laying down is the formal recognition of the start of a shipbuilding, ship's construction. It is often marked with a ceremony attended by dignitaries from the shipbuilding company and the ultimate owners of the ship. Keel l ...

of the ships was done on 6 September 2015. The first two vessels made at Khulna Shipyard were commissioned on 8 November 2017. These ships were of

Anti-submarine warfare Anti-submarine warfare (ASW, or in the older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations ar ...

variant.

Design

These ships are long, wide and have a draught with a displacement of 648 tonnes. The ships have a

bulbous bow A bulbous bow is a streamlined flaring or protruding bulb at the bow (or front) of a ship just below the waterline. The flare or bulb modifies the way the water flows around the hull, reducing drag and thus increasing speed, range, fuel effici ...

shape, which suggests they are designed to sustain heavy sea states. The ships have speed and range to support long missions. The large patrol crafts are powered by SEMT Pielstick 12PA6 diesel engines driving three screws for a top speed of for anti-surface warfare variant and for anti-submarine warfare variant. The range of the ships is for anti-surface warfare version and for anti-submarine warfare version with an endurance of 15 days. The anti-surface warfare ships can carry 60 personnel while anti-submarine warfare ships can carry 70 personnel. They can carry one

Rigid-hulled inflatable boat A rigid inflatable boat (RIB), also rigid-hull inflatable boat or rigid-hulled inflatable boat (RHIB), is a lightweight but high-performance and high-capacity boat constructed with a rigid hull (watercraft), hull bottom joined to side-forming a ...

and has the support system to launch it.

Electronics

;Anti-surface variant The primary sensor of these ships is a ''SR47AG'' surface and air search radar. The ship carries a Chinese TR47C fire control radar for main gun. The ships also have an ''ESS-3'' bow mounted sonar with an effective range of about for underwater detection. A JRCSS combat management system (CMS) with at least three multifunction consoles is also fitted in the ships. ;Anti-submarine variant The primary sensor of these ships is a ''SR47AG'' surface and air search radar. They carries a Chinese TR47C fire control radar for main gun. For navigation, the ships use the Japanese ''JMA 3336'' radar. To help the navigational radar, the ''Vision Master'' chart radar is used. These ships have an ''ESS-2B'' bow mounted

sonar Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects o ...

with an effective range of about for underwater detection.

Armament

;Anti-surface variant The large patrol crafts of this variant are armed with a H/PJ-26 naval gun and four

C-704 The C-704 is a Chinese anti-ship missile. The missile was developed by the third research institute of the Chinese Aerospace Group, also the manufacturer of the C-701. Design This anti-ship missile is designed specifically for targets with displ ...

surface-to-surface missile A surface-to-surface missile (SSM) is a missile designed to be launched from the ground or the sea and strike targets on land or at sea. They may be fired from hand-held or vehicle mounted devices, from fixed installations, or from a ship. They ar ...

s (SSM) mounted aft. Besides, these ships have two dual

Oerlikon 20 mm cannon The Oerlikon 20 mm cannon is a series of autocannons based on an original German Becker Type M2 20 mm cannon design that appeared very early in World War I. It was widely produced by Oerlikon Contraves and others, with various models empl ...

mounted amidships which can be used for anti-aircraft role. For ASW role they have two forward-mounted 6-tube ''EDS-25A'' 250 mm ASW rocket launchers and decoy launchers. ;Anti-submarine variant The ships of this variant uses a Chinese origin single NG 16-1 naval gun as the primary gun. Besides, they have one ''CS/AN2'' single-barrel naval gun mounted amidships used as the secondary gun. For

role, these ships are armed with two triple torpedo tubes for ET-52C torpedo. This torpedo has a range of 9.4 km and speed of 42 knots.

Ships in class

References