The Castle class was a

class Class, Classes, or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used d ...

of British

offshore patrol vessel A patrol boat (also referred to as a patrol craft, patrol ship, or patrol vessel) is a relatively small naval vessel generally designed for coastal defence, border security, or law enforcement. There are many designs for patrol boats, and th ...

s of the

Royal Navy The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom ...

. Two ships were constructed and after nearly 30 years service were sold to 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 ...

in 2010. The Bangladesh Navy upgraded these with more armaments including

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 ...

anti-ship missiles An anti-ship missile (AShM or ASM) is a guided missile that is designed for use against ships and large boats. Most anti-ship missiles are of the sea-skimming variety, and many use a combination of inertial guidance and active radar homing. ...

and sensors. These ships are now reclassified as

corvette A corvette is a small warship. It is traditionally the smallest class of vessel considered to be a proper (or " rated") warship. The warship class above the corvette is that of the frigate, while the class below was historically that of the sloo ...

s by the Bangladesh Navy.

Design

The Castle class was designed by David K. Brown and was intended as a series of six offshore patrol vessels for the Royal Navy, designed in response to criticism of the previous for insufficient speed, sub-optimal sea-keeping and lack of a

flight deck The flight deck of an aircraft carrier is the surface on which its aircraft take off and land, essentially a miniature airfield at sea. On smaller naval ships which do not have aviation as a primary mission, the landing area for helicopters ...

for rescue

helicopter A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), hover, and ...

s. In the event, only two ships were built, and . Both vessels were built by Hall Russell in

Aberdeen Aberdeen ( ; ; ) is a port city in North East Scotland, and is the List of towns and cities in Scotland by population, third most populous Cities of Scotland, Scottish city. Historically, Aberdeen was within the historic county of Aberdeensh ...

, Scotland. These had significant improvements over the Island-class – they were 300 tonnes larger, more stable in heavy seas, faster and fitted with a large flight deck capable of supporting a Sea King helicopter. For brief periods, the ships could accommodate up to 120 troops. Their primary mission was to serve with the

Fishery Protection Squadron The Overseas Patrol Squadron (known as the Fishery Protection Squadron until 2020) is a front-line squadron of the Royal Navy with responsibility for patrolling the UK's Extended Fisheries Zone, both at home and around British Overseas Territori ...

, protecting both the fishing fleets and the oil and gas fields of the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

. They could also serve as

minelayer A minelayer is any warship, submarine, military aircraft or land vehicle deploying explosive mines. Since World War I the term "minelayer" refers specifically to a naval ship used for deploying naval mines. "Mine planting" was the term for ins ...

s, and had

detergent A detergent is a surfactant or a mixture of surfactants with Cleanliness, cleansing properties when in Concentration, dilute Solution (chemistry), solutions. There are a large variety of detergents. A common family is the alkylbenzene sulfonate ...

spraying facilities on board for dispersing

oil slick An oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially the marine ecosystem, due to human activity, and is a form of pollution. The term is usually given to marine oil spills, where oil is released into th ...

Operations

After the

Falklands War The Falklands War () was a ten-week undeclared war between Argentina and the United Kingdom in 1982 over two British Overseas Territories, British dependent territories in the South Atlantic: the Falkland Islands and Falkland Islands Dependenci ...

, one ship was kept long-term in the

Falkland Islands The Falkland Islands (; ), commonly referred to as The Falklands, is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and from Cape Dub ...

as a

guard ship A guard ship is a warship assigned as a stationary guard in a port or harbour, as opposed to a coastal patrol boat, which serves its protective role at sea. Royal Navy In the Royal Navy of the eighteenth century, peacetime guard ships were usual ...

. ''Leeds Castle'' and ''Dumbarton Castle'' rotated the role on a three-yearly basis, although the ship's crew usually did a six-month rotation.

Replacement

The Castle class was replaced in the Falklands by a unique vessel based on the , , and both vessels of the class were decommissioned. Originally due to transfer to the

Pakistan Maritime Security Agency The Pakistan Maritime Security Agency (reporting name: PMSA) () is a branch of the Pakistan Navy. It is a Navy-managed and Navy-controlled Law enforcement in Pakistan, Marine law enforcement agency whose mission is to provide protection to Pakis ...

in 2007, the deal fell through and both ships were sold to the

Ships in class

References

* Conway's ''All The World's Fighting Ships 1947–1995'' * D.K. Brown, "The Design of the Castle Class", a personal view in ''Warship 2006'', Conway's Maritime Press * ''Janes Fighting Ships 2007'' {{Castle class opv Patrol ship classes Patrol vessels of the Royal Navy Patrol vessels of the United Kingdom Ship classes of the Royal Navy Corvettes of the Bangladesh Navy Ships built by Hall, Russell & Company