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

Bangladesh Navy The Bangladesh Navy ( bn, বাংলাদেশ নৌবাহিনী, Bangladesh Nou Bahini) is the naval warfare branch of the Bangladesh Armed Forces, responsible for Bangladesh's of maritime territorial area, and the defence of imp ...

. 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 of Bangladesh in the

Bay of Bengal The Bay of Bengal is the northeastern part of the Indian Ocean, bounded on the west and northwest by India, on the north by Bangladesh, and on the east by Myanmar and the Andaman and Nicobar Islands of India. Its southern limit is a line betwee ...

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 s ...

variant and

anti-submarine warfare Anti-submarine warfare (ASW, or in 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 are t ...

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 forms part of the urban core of and is one of 13 urban District (China), districts of the prefecture-level city of Wuhan, the capital of Hubei, Hubei Province, China. It is the oldest of the three cities that merged into modern-day Wu ...

in China. 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 ( bn, ) is a Bangladeshi state owned defense contractor based in Khulna, Bangladesh. It is located on 68.97 acres of land at Labanchara, Khulna, Bangladesh. It is about 45 km north from the Port of Mongla. The shipyar ...

. These ships were constructed in Bangladesh under ToT from China. Keel laying 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 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 are t ...

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 protruding bulb at the bow (or front) of a ship just below the waterline. The bulb modifies the way the water flows around the hull, reducing drag and thus increasing speed, range, fuel efficiency, and stability. Large ships w ...

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 bottom joined to side-forming air tubes that are i ...

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 on 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 displa ...

surface-to-surface missile A surface-to-surface missile (SSM) or ground-to-ground missile (GGM) 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 ins ...

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 em ...

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