Aggressive-class minesweeper

{{Short description|US built ocean minesweepers}}

{{Cleanup|reason=The lists in this article and Agile-class minesweeper should be disentangled.|date=August 2022}}

{{further|Agile-class minesweeper}}

{{Infobox ship begin}}

{{Infobox ship image

|Ship image=USS Constant (AM-427).jpg

|Ship image size=300px

|Ship caption=USS Constant (MSO-427) in 1988

}}

{{Infobox ship class overview

|Name=Aggressive class

|Builders=

|Operators=*{{navy|United States}}

  • {{navy|Republic of China}}
  • {{navy|Belgium}}
  • {{navy|Norway}}
  • {{navy|Netherlands}}
  • {{navy|Philippines|1936}}

|Class before=

|Class after=

|Subclasses= {{sclass|Onversaagd|minesweeper|4}}

|Cost=

|Built range=

|In service range=

|In commission range=1953–Present

|Total ships building=

|Total ships planned=

|Total ships completed=53

|Total ships cancelled=

|Total ships active=1

|Total ships laid up=

|Total ships lost=

|Total ships retired=52

|Total ships preserved=2

}}

{{Infobox ship characteristics

|Hide header=

|Header caption=

|Ship class=

|Ship type=Minesweeper

|Ship displacement= 853 tons (full load)

|Ship length= {{convert|172|ft|m|abbr=on|0}}

|Ship beam={{convert|35|ft|m|abbr=on|0}}

|Ship height=

|Ship draft={{convert|10|ft|m|abbr=on|0}}

|Ship depth=

|Ship power=

|Ship propulsion=*4 × aluminum block Waukesha diesels, {{convert|2,400|bhp|lk=in|abbr=on}}

  • 2 × shafts
  • 2 × controllable pitch propellers

|Ship speed= {{convert|14|kn|lk=in}}

|Ship range=

|Ship endurance=

|Ship boats=

|Ship complement= 7 officers, 70 enlisted

|Ship sensors= AN/SQQ-14 mine hunting sonar

|Ship EW=

|Ship armament=*1 × twin 20 mm gun

|Ship armor=

|Ship notes=

}}

The Aggressive-class minesweepers are a class of US-built minesweepers. They are designated as MSO (Mine Sweeper Ocean), distinguishing them from the smaller coastal MSCs and inshore MSIs. Besides the US Navy, this class of vessels has also been used by the Belgian Navy and the Norwegian Navy, among others.

Background

Minesweeping, or the disposal of naval mines, by these vessels is performed in different ways:

  • Sweeping proper, with an underwater cable cutting the mooring cables of moored mines. The mines then come to the surface and are destroyed by gunfire.
  • Acoustic sweeping, with a towed device producing noise to trigger acoustic mines.
  • Magnetic sweeping, with a towed device producing a magnetic field to trigger magnetic mines. To protect the minesweeper itself against magnetic mines, the hull and superstructure of the ship are made of wood. Other components are made of non-magnetic materials, and any magnetic materials are strictly controlled.

Construction and disposition

Of the 53 constructed for the United States Navy, 10 were built at Higgins Corp., New Orleans, Louisiana, 9 at J.M. Martinac Shipbuilding Corp., Tacoma, Washington, 8 at Wilmington Boat Works Inc., Wilmington, California, 6 at Luders Marine Construction Co. of Stamford, Connecticut, 4 at Broward Marine Inc, Fort Lauderdale, Florida, 4 at Martinolich Shipbuilding Co., San Diego, California, 3 at Burger Boat Company, Manitowoc, Wisconsin, 3 at Colberg Boat Works, Stockton, California, 2 at Fulton Shipyard, Antioch, California, 2 at Norfolk Naval Shipyard and 2 at Seattle Shipbuilding and Drydocking Co., Seattle, Washington.

33 of the class were decommissioned before the mid-1970s. Four ex-USN ships were sold to the Republic of China Navy 1994 and re-classed as {{sclass|Yung Yang|minesweeper|1}}s. They were still in active service in 2012. {{USS|Implicit|MSO-455|6}} was decommissioned 30 September 1994 in Tacoma, Washington and was the last Aggressive-class minesweeper in US Navy active service.

File:USS Conquest (MSO-488) mine detection sonar console.jpg|A crewman monitors a mine detection and classification sonar console aboard the ocean minesweeper USS Conquest

File:USS Conquest (MSO-488) mine detection and classification console.jpg|A crewman monitors a mine detection and classification console aboard the ocean minesweeper USS Conquest

File:Paravane aboard USS Engage (MSO-433).jpg|A paravane used for mine sweeping aboard USS Conquest

File:USS Illusive (MSO-448) lowers an acoustical device during an exercise.jpg|USS Illusive lowers an acoustical device during an exercise.

File:USS Illusive (MSO-448) lowers an acoustical device for training 2.jpg|USS Illusive lowers a different acoustical device for training.

File:USS Illusive (MSO-448) deploys a mineweeping cable.jpg|USS Illusive deploys a mineweeping cable.

File:USS Constant (MSO-427) deploying the mag-tail.jpg|USS Constant deploying the "mag-tail", used to simulate the magnetic field of a vessel, are towed behind the ship to trigger magnetic mines.

File:Super Sea Rover aboard USS Conquest (MSO-488).jpg|A remote control mine-seeking system, Super Sea Rover, aboard USS Conquest

File:USS Esteem (MSO-438) deploys a marker.jpg|USS Esteem deploys a marker, for marking mines or mine fields.

{{-}}

Units

class="wikitable"
Ship Name

!Hull no.

!Builder

!Commission–
Decommission

!Fate

!Link

{{USS|Aggressive|MSO-422|2}}{{Naval Vessel Register URL|id=MSO422|title=AGGRESSIVE (MSO 422)}}

|422

|Luders Marine Construction Co. of Stamford, Connecticut

|1953–1971

|Sold for scrap 1980

|

{{USS|Avenge|MSO-423|2}}

|423

|Luders Marine Construction Co. of Stamford, Connecticut

|1954-1970

|Destroyed by fire, sold for scrapping 1969

{{USS|Bold|MSO-424|2}}{{Naval Vessel Register URL|id=MSO424|title=Naval Vessel Register}}424Norfolk Naval Shipyard1953-1971Sold for scrap 1981
{{USS|Bulwark|MSO-425|2}}{{Naval Vessel Register URL|id=MSO425|title=Naval Vessel Register}}

|425

|Norfolk Naval Shipyard

|1953-1971

|Sold for scrap 1980

|

{{USS|Conflict|MSO-426|2}}{{Naval Vessel Register URL|id=MSO426|title=Naval Vessel Register}}

|426

Fulton Shipyard, Antioch, California

|1954-1973

|Sold for scrap 1973

|

{{USS|Constant|MSO-427|2}}427Fulton Shipyard., Antioch, California1954-1992Sold for scrap 2001{{Naval Vessel Register URL|id=MSO427|title=Naval Vessel Register}}
colspan=6|428 - 431 were US Dash-class minesweepers
{{USS|Dynamic|MSO-432|2}}432Colberg Boat Works., Stockton, California1953-1971Sold or loaned to Spain as Guadalete M41, 1971.{{Naval Vessel Register URL|id=MSO432|title=Naval Vessel Register}}
{{USS|Engage|MSO-433|2}}433Colberg Boat Works., Stockton, California1953-1991Scrapped 2002{{Naval Vessel Register URL|id=MSO433|title=Naval Vessel Register}}
{{USS|Embattle|MSO-434|2}}434Colberg Boat Works., Stockton, California1954-1972Sold to be scrapped 1976, privately held until scrapped by USACE in 1993.{{Naval Vessel Register URL|id=MSO434|title=Naval Vessel Register}}
{{USS|Endurance|MSO-435|2}}435J. M. Martinac Shipbuilding Corp., Tacoma, Washington1954-1972Sold for scrap 1973{{Naval Vessel Register URL|id=MSO435|title=Naval Vessel Register}}
{{USS|Energy|MSO-436|2}}436J. M. Martinac Shipbuilding Corp., Tacoma, Washington1954-1972Loaned to Philippines 1972
Sold for scrap 1977
{{Naval Vessel Register URL|id=MSO436|title=Naval Vessel Register}}
{{USS|Enhance|MSO-437|2}}437Martinolich Shipbuilding Co., San Diego, California1955-1970
1971-1991
Sold for scrap 2000{{Naval Vessel Register URL|id=MSO437|title=Naval Vessel Register}}
{{USS|Esteem|MSO-438|2}}438Martinolich Shipbuilding Co., San Diego, California1955-1970
1971-1991
Sold for scrap 2000{{Naval Vessel Register URL|id=MSO438|title=Naval Vessel Register}}
{{USS|Excel|MSO-439|2}}439Higgins Corp., New Orleans, Louisiana1955-1992Sold for scrap 2000{{Naval Vessel Register URL|id=MSO439|title=Naval Vessel Register}}
{{USS|Exploit|MSO-440|2}}440Higgins Corp., New Orleans, Louisiana1954-1993Sold for scrap 2002{{Naval Vessel Register URL|id=MSO440|title=Naval Vessel Register}}
{{USS|Exultant|MSO-441|2}}441Higgins Corp., New Orleans, Louisiana1954-1993Sold for scrap 2002{{Naval Vessel Register URL|id=MSO441|title=Naval Vessel Register}}
{{USS|Fearless|MSO-442|2}}442Higgins Corp., New Orleans, Louisiana1954-1990Sold for scrap 1992{{Naval Vessel Register URL|id=MSO442|title=Naval Vessel Register}}
{{USS|Fidelity|MSO-443|2}}443Higgins Corp., New Orleans, Louisiana1955-1989Sold for scrap 1990{{Naval Vessel Register URL|id=MSO443|title=Naval Vessel Register}}
{{USS|Firm|MSO-444|2}}444J. M. Martinac Shipbuilding Corp., Tacoma, Washington1954-1972Loaned to Philippines 1972
Scrapped 1977
{{Naval Vessel Register URL|id=MSO444|title=Naval Vessel Register}}
{{USS|Force|MSO-445|2}}445J. M. Martinac Shipbuilding Corp., Tacoma, Washington1955-1973Sunk after a fire{{Naval Vessel Register URL|id=MSO445|title=Naval Vessel Register}}
{{USS|Fortify|MSO-446|2}}446Seattle Shipbuilding and Drydocking Co., Seattle, Washington1954-1992Scrapped 2002{{Naval Vessel Register URL|id=MSO446|title=Naval Vessel Register}}
{{USS|Guide|MSO-447|2}}447Seattle Shipbuilding and Drydocking Co., Seattle, Washington1955-1972Sold for scrap 1973{{Naval Vessel Register URL|id=MSO447|title=Naval Vessel Register}}
{{USS|Illusive|MSO-448|2}}448Martinolich Shipbuilding Co., San Diego, California1953-1990Sold for scrap 1993{{Naval Vessel Register URL|id=MSO448|title=Naval Vessel Register}}
{{USS|Impervious|AM-449|2}}449Martinolich Shipbuilding Co., San Diego, California1954-1991Scrapped 2002{{Naval Vessel Register URL|id=MSO449|title=Naval Vessel Register}}
colspan=6|450 - 454 built at Bellingham Shipyards Co., Bellingham, Washington for France, not necessarily Aggressive-class ships.
{{USS|Implicit|AM-455|2}}455Wilmington Boat Works Inc., Wilmington, California1954-1994Sold to Taiwan 1994{{Naval Vessel Register URL|id=MSO455|title=Naval Vessel Register}}
{{USS|Inflict|AM-456|2}}456Wilmington Boat Works Inc., Wilmington, California1954-1990Sold for scrap 1992{{Naval Vessel Register URL|id=MSO456|title=Naval Vessel Register}}
{{USS|Loyalty|AM-457|2}}457Wilmington Boat Works Inc., Wilmington, California1954-1972Sold for scrap 1973{{Naval Vessel Register URL|id=MSO457|title=Naval Vessel Register}}
{{USS|Lucid|MSO-458|2}}458Higgins Corp., New Orleans, Louisiana1955-1970Sold for scrap 1976
Currently being restored by the [http://www.stocktonhistoricalmaritimemuseum.org/ Stockton Historical Maritime Museum] as a museum ship
{{Naval Vessel Register URL|id=MSO458|title=Naval Vessel Register}}
{{USS|Nimble|AM-459|2}}459Higgins Corp., New Orleans, Louisiana1955-1970Sold for scrap 1981{{Naval Vessel Register URL|id=MSO459|title=Naval Vessel Register}}
{{USS|Notable|MSO-460|2}}

|460

|Higgins Corp., New Orleans, Louisiana

|1955-1970

|Sold for scrap 1971

|{{Naval Vessel Register URL|id=MSO460|title=Naval Vessel Register}}

{{USS|Observer|MSO-461|2}}

|461

|Higgins Corp., New Orleans, Louisiana

|1955-1972

|Sold for scrap 1979

|{{Naval Vessel Register URL|id=MSO461|title=Naval Vessel Register}}

{{USS|Pinnacle|MSO-462|2}}462Higgins Corp., New Orleans, Louisiana1955-1970Sold for scrap 1978{{Naval Vessel Register URL|id=MSO462|title=Naval Vessel Register}}
{{USS|Pivot|MSO-463|2}}463Wilmington Boat Works Inc., Wilmington, California1954-1971Initially loaned then sold to Spain as Guadalmedina M42, 1974. Decommissioned by Spain 2001.{{Naval Vessel Register URL|id=MSO463|title=Naval Vessel Register}}
{{USS|Pluck|MSO-464|2}}464Wilmington Boat Works Inc., Wilmington, California1954-1990Sold for scrap 1992{{Naval Vessel Register URL|id=MSO464|title=Naval Vessel Register}}
{{USS|Prestige|MSO-465|2}}465Wilmington Boat Works Inc., Wilmington, California1954-1958Grounded and sunk, 1958 in the Naruto Strait
{{USS|Prime|AM-466|2}}466Wilmington Boat Works Inc., Wilmington, California1954-1970Sold for scrap 1976{{Naval Vessel Register URL|id=MSO466|title=Naval Vessel Register}}
{{USS|Reaper|MSO-467|2}}467Wilmington Boat Works Inc., Wilmington, California1954-1972Sold for scrap 1976{{Naval Vessel Register URL|id=MSO467|title=Naval Vessel Register}}
{{USS|Rival|MSO-468|2}}468Luders Marine Construction Co. of Stamford, Connecticut1954-1970Sold for scrap 1971{{Naval Vessel Register URL|id=MSO468|title=Naval Vessel Register}}
{{USS|Sagacity|MSO-469|2}}469Luders Marine Construction Co. of Stamford, Connecticut1955-1970Grounded at Charleston Harbor then sold for scrap 1970.
{{USS|Salute|AM-470|2}}470Luders Marine Construction Co. of Stamford, Connecticut1955-1970Sold for scrap 1971{{Naval Vessel Register URL|id=MSO470|title=Naval Vessel Register}}
{{USS|Skill|MSO-471|2}}471Luders Marine Construction Co. of Stamford, Connecticut1950-1970Sold for scrap 1979, scrapped 1983.{{Naval Vessel Register URL|id=MSO471|title=Naval Vessel Register}}
{{USS|Valor|AM-472|2}}472Burger Boat Company, Manitowoc, Wisconsin1954-1970Sold for scrap 1971{{Naval Vessel Register URL|id=MSO472|title=Naval Vessel Register}}
{{USS|Vigor|AM-473|2}}473Burger Boat Company, Manitowoc, Wisconsin1954-1972Sold to Spain as Guadiana M44, 1972. Scrapped by Spain after 1999.{{Naval Vessel Register URL|id=MSO473|title=Naval Vessel Register}}
{{USS|Vital|MSO-474|2}}474Burger Boat Company, Manitowoc, Wisconsin1955-1972Sold for scrap 1979{{Naval Vessel Register URL|id=MSO474|title=Naval Vessel Register}}
colspan=6|475 - 487 built for France, Portugal, Spain, Belgium and the Netherlands, not necessarily Aggressive-class ships.
{{USS|Conquest|AM-488|2}}

|488

|J. M. Martinac Shipbuilding Corp., Tacoma, Washington

|1955-1970
1971-1994

|Sold to Taiwan 1994 and decommissioned in 2020.

|{{Naval Vessel Register URL|id=MSO488|title=Naval Vessel Register}}

{{USS|Gallant|MSO-489|2}}

|489

J. M. Martinac Shipbuilding Corp., Tacoma, Washington

|1955-1994

|Sold to Taiwan 1994 and decommissioned in 2013.

|{{Naval Vessel Register URL|id=MSO489|title=Naval Vessel Register}}

{{USS|Leader|MSO-490|2}}

|490

|J. M. Martinac Shipbuilding Corp., Tacoma, Washington

|1955-1970
1971-1991/92

|Sold for scrap 1994

|{{Naval Vessel Register URL|id=MSO490|title=Naval Vessel Register}}

{{USS|Persistent|MSO-491|2}}

|491

J. M. Martinac Shipbuilding Corp., Tacoma, Washington

|1956-1971

|Initially loaned in 1971 then sold to Spain as Guadalquivir M43

|{{Naval Vessel Register URL|id=MSO491|title=Naval Vessel Register}}

{{USS|Pledge|MSO-492|2}}{{Naval Vessel Register URL|id=MSO492|title=Naval Vessel Register}}

|492

|J. M. Martinac Shipbuilding Corp., Tacoma, Washington

|1956-1994

|Sold to Taiwan 1994 and decommissioned 2021.

|{{Naval Vessel Register URL|id=MSO492|title=Naval Vessel Register}}

{{USS|Stalwart|MSO-493|2}}493Broward Marine Inc, Fort Lauderdale, Florida1956-1966Caught fire pier side at San Juan, Puerto Rico, sunk 1966. Later raised and sunk as an artificial reef.
{{USS|Sturdy|MSO-494|2}}494Broward Marine Inc, Fort Lauderdale, Florida1957-1971Sold for scrap 1978{{Naval Vessel Register URL|id=MSO494|title=Naval Vessel Register}}
{{USS|Swerve|MSO-495|2}}495Broward Marine Inc, Fort Lauderdale, Florida1957-1971Sold for scrap 1978{{Naval Vessel Register URL|id=MSO495|title=Naval Vessel Register}}
{{USS|Venture|MSO-496|2}} {{Naval Vessel Register URL|id=MSO496|title=Naval Vessel Register}}

|496

|Broward Marine Inc, Fort Lauderdale, Florida

|1958-1971

|Sold for scrap 1978

|

MSO-497

|497

|colspan=4 |Cancelled, never built

See also

References

{{Reflist}}