Bluebird class minesweeper

Broadside view of Bluebird off south end of Mare Island on 29 September 1953.
Class overview
Name:	Adjutant class
Builders:	Various builders
Operators:	United States Navy  Belgian Marine Component  Royal Danish Navy  Republic of Fiji Navy  French Navy  Hellenic Navy  Indonesian Navy  Islamic Republic of Iran Navy  Marina Militare  Republic of Korea Navy  Japan Maritime Self-Defense Force  Royal Moroccan Navy  Royal Netherlands Navy  Royal Norwegian Navy  Pakistan Navy  Philippine Navy  Portuguese Navy  Royal Saudi Navy  Spanish Navy  Republic of Singapore Navy  Royal Thai Navy  Turkish Navy  Republic of China Navy  National Navy of Uruguay  Republic of Vietnam Navy
Preceded by:	YMS-1 class
Succeeded by:	Avenger class
Subclasses:	Bluebird class Redwing class Falcon class MSC-218 class MSC-268 class MSC-292 class MSC-294 class Albatross class
Built:	1952–1978
In service:	1953–present
Planned:	214
Completed:	202
Cancelled:	12
Lost:	4
Preserved:	2
General characteristics
Type:	Minesweeper
Displacement:	330 long tons (340 t) light 390 long tons (400 t) full load
Length:	138 ft (42 m) p/p 144 ft (44 m) o/a
Beam:	27 ft (8.2 m)
Draft:	9 ft (2.7 m)
Installed power:	4 × Packard 300 hp (220 kW) diesel engines or, 2 × General Motors 440 hp (330 kW) 8-268A diesel engines or, 2 × MAN 625 hp (466 kW) V6V 22/30 diesel engines or, 4 × General Motors 238 hp (177 kW) 6-71 diesel engines or, 2 × Waukesha Engine L-1616 diesel engines
Propulsion:	Snow and Knobstedt single reduction gear 2 × variable pitch propellers
Speed:	13 knots (24 km/h; 15 mph)
Complement:	36–43
Sensors and processing systems:	Varies by nation SPS-53 radar Decca 45 radar Decca 707 radar Decca TM626 radar Decca RM914 radar UQS-1 sonar UQS-10 sonar
Armament:	Varies by nation 2 × twin 20 mm (0.8 in) Oerlikon cannons anti-aircraft (AA) mounts 2 × single 20 mm Oerlikon cannon (AA) mounts 1 × 40 mm (1.6 in) Bofors (AA) mount 2 × caliber .50 in (12.7 mm) machine guns 1 × 81 mm mortar

The Adjutant-class Auxiliary Motor Minesweepers were built for the United States Navy throughout the 1950s and 1960s, even as late as 1978. Most were loaned to foreign countries under the Military Defense Assistance Pact, with only 24 actually commissioned by the US Navy, with 13 of those being transferred to foreign nations as well. Initially classified as auxiliary motor minesweeper (AMS), on 7 February 1955, they were reclassified as coastal minesweeper (minesweeper, coastal) (MSC).

The Adjutant-class minesweepers were of a wooden construction with brass and stainless steel fittings to reduce magnetic attraction. The rated displacement was 330 long tons (340 t) light and 390 long tons (400 t) at full load, though the ships of the Redwing class show a displacement of 412 long tons (419 t) and the Albatross class show a displacement of 320 long tons (330 t). They were 138 ft (42 m) between the perpendiculars with an overall length of 144 ft (44 m). They had a beam of 27 ft (8.2 m) with a 8 ft 6 in (2.59 m) draft.

Half of the US ships used four Packard 300 hp (220 kW) diesel engines the rest and most of the ships built for use by foreign nations used two General Motors 440 hp (330 kW) 8-268A diesel engines.

The first ship of the class was to be USS Adjutant (AMS-60), however, the name Adjutant was canceled and the ship was transferred to the Portuguese Navy as Ponta Delgada (M 405). The first ship commissioned by the US Navy was Bluebird, this is where the US ships got their class name. With slight changes in design, some of the ships are referred to by other class names, such as Falcon class, Redwing class, Albatross class, or even under Adjutant class.