Castle-class patrol vessel

BNS Dhaleshwari (ex-HMS Leeds Castle) in 2018
Class overview
Builders	Hall, Russell & Company
Operators	Royal Navy (retired) Bangladesh Navy
Preceded by	Island class
Succeeded by	River class
Built	1979–1981
In commission	1982–Present
Planned	6
Completed	2
General characteristics
Type	Offshore patrol vessel
Displacement	1,570 tons full load
Length	246 ft (75 m) (overall)
Beam	37 ft 9 in (11.51 m)
Draught	11 ft 3 in (3.43 m)
Propulsion	2 shafts, 2 Paxman diesels, 2,820 hp (2,100 kW)
Speed	20 knots (37 km/h)
Range	10,000 nautical miles (19,000 km) at 10 knots (19 km/h)
Complement	40
Sensors and processing systems	Type 1006 radar Simrad RU sidescan sonar (Bangladesh Navy installed Type 360 Radar as the main radar)
Armament	Royal Navy: 1 × Bofors 40 mm gun Mark III, replaced by 1 × 30 mm gun Bangladesh Navy: 1 x 76 mm (3.0 in) main gun 4 × C-704 AShM Small caliber guns or autocannons
Aviation facilities	Flight deck capable of supporting a Sea King helicopter

The Castle class was a class of British offshore patrol vessels of the Royal Navy. Two ships were constructed and after nearly 30 years service were sold to the Bangladesh Navy in 2010. The Bangladesh Navy upgraded these with more armaments including C-704 anti-ship missiles and sensors. These ships are now reclassified as corvettes 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 Island class for insufficient speed, sub-optimal sea-keeping and lack of a flight deck for rescue helicopters.

In the event, only two ships were built, HMS Leeds Castle and HMS Dumbarton Castle. Both vessels were built by Hall Russell in Aberdeen, Scotland. These had significant improvements over the Island-class – they were 300 tonnes larger, more stable in heavy seas, 3 knots (5.6 km/h; 3.5 mph) 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, protecting both the fishing fleets and the oil and gas fields of the North Sea. They could also serve as minelayers, and had detergent spraying facilities on board for dispersing oil slicks.

Operations

After the Falklands War, one ship was kept long-term in the Falkland Islands as a guard ship. 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 River class, HMS Clyde, and both vessels of the class were decommissioned. Originally due to transfer to the Pakistan Maritime Security Agency in 2007, the deal fell through and both ships were sold to the Bangladesh Navy.

Ships in class

Name	Pennant Number	Builder	Laid down	Launched	Commissioned	Fate
Leeds Castle	P258	Hall, Russell & Company, Aberdeen	18 October 1979	29 October 1980	27 August 1981	Sold to Bangladesh Navy, April 2010 as BNS Dhaleshwari
Dumbarton Castle	P265		25 June 1980	3 June 1981	12 March 1982	Sold to Bangladesh Navy, April 2010 as BNS Bijoy

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