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MSO OCEAN MINESWEEPERS

Here is a list of all of the 102 MSO class Ocean Minesweepers Hull Numbers.

Within five years of the end of the Second World War, the U.S. Navy was designing a new generation of minesweepers. Far from springing from the unhappy experience of the North Korean mining at Wonsan, as is often claimed, the program was, in fact, well underway before the outbreak of the Korean War and was developed in reponse to new technology developed during the Second World War.²

The new sweeper would be the largest all-wood warship in the U.S. Navy. The hull of the MSO was designed by Philip L. Rhodes 1895-1974, (see Developments in Wooden Minesweeper Hull Design Since World War II). The hull form was adapted from the WW2 YMS and incorporated new construction techniques that BuShips eventually claimed saved about 50 percent of hull weight. The new type of hull construction proved so strong that the last ships of this basic design were lengthened from 171 feet to 190 feet (ABILITY Class). The really radical step was to add a variable degaussing system which could compensate automatically for variations in the ships position in the earth’s magnetic field due to roll and pitch as well as to course changes and were built with internal machinery and components of non-ferrous or non-magnetic materials for minimum magnetic signature. The sweeper was considered among the most complex and innovative ships in the navy, only matched in cost per ton by submarines². These new ships were first designated as Minesweepers (AM); they were later reclassified on February 7, 1955 as Minesweeper, Ocean (MSO). Cost $3.5 million in 1951 [$1.6-$6.3 million 1951-1960]. They were capable of sweeping for moored and bottom contact, magnetic and acoustic mines.

These ships served our country well for over 41 years and over 50,000 "Iron Men" proudly served until the last one was decommissioned in 1994 and participated in almost every conflict that occurred during those years including the Lebanon Crisis, The Naval Quarantine of Cuba, 1962, Vietnam (Operation "Market Time" and Operation "End Sweep"), Operation "Earnest Will", and operation Desert Shield/Desert Storm. These ships earned numerous Awards and Campaign Participitation Awards. USS Leader was awarded a PRESIDENTIAL UNIT CITATION, the only MSO [officially] awarded. We think they provided as important a role to insuring United States superiority on the seas and ashore as the Destroyers, Aircraft Carriers, Submarines and Battleships and ought to be remembered in the same fashion.

Since 1950 and up to 2004, fifteen of the nineteen ships either damaged or sunk by hostile weapons have been by enemy mines³.

During the 1987-88 Operation "Earnest Will" (the escort of the reflagged Kuwaiti oil tankers), SIX active and reserve MSO's deployed to the Persian Gulf. Three West Coast MSO's: USS Enhance (MSO-437), USS Conquest (MSO-488), and USS Esteem (MSO-438), and three East Coast MSOs : USS Inflict (MSO-456), USS Fearless (MSO-442), and USS Illusive (MSO-448). Both ships and crews performed extremely well in very demanding conditions, clearing hundreds of mines from the international waterway. The Belgium Navy participated with two MSO's [hull 504 (Breydel M906) & hull 516 (Bovesse M909)]

During the Cold War the U.S. mine warfare concept was designed around a European war scenario which relied on North Atlantic Treaty Organization (NATO) allies to participate substantially in mine warfare operations. The Navy's MCM capabilities in the Persian Gulf War (1990-91) included the surface mine countermeasures capabilities of three 30-year-old minesweepers [USS Impervious (MSO-449), USS Leader (MSO-490), and USS Adroit (MSO-509) (Gulf War Stories)].

All United States ships of this class have been disposed of.
Five ships are still IN SERVICE, four for Taiwan and one for Italy.
Former Crew Members Visit Taiwan Navy Base

This list is the most complete, accurate, detailed and up to date list of MSO information on the internet today.

• Links in NAME column link to Ship Picture OR Ship's Home Page, some ships have multiple home pages.
• Links in NBR column link to the Dictionary of American Naval Fighting Ships.
• Links in BUILDER column link to information of the builder.
• MODERNIZATION: F= full, P= partial, C=canceled
• An Asterisk (*) in the STATUS column means there is NO listing in the NVR.

² Per Norman Friedman's article, The Cold War, Korea and the US Minesweepers, WARSHIP 1994

³ Wooden Ships and Iron Men, Cdr. David D. Bruhn, 2006.

OCEAN MINESWEEPERS
Name	Nbr	Builder	Keel Laid	Launch Date	Commis- sioned	Moder- nized	Decomm- issioned	Fleet Reserve	Status Date & Status	Additional Information
Agile	421	Luders Marine Construction Co., Stamford, Conn.	2/22/54	11/19/55	6/21/56 Commissioning	P	7/28/72		11/1/79 Disposed	Converted to Flagship, The Naval Quarantine of Cuba, 1962 Scrapped by Union Minerals & Alloy Corp., N.Y.,N.Y. $25,000. Removal date: 10/18/79
Aggressive	422	Luders Marine	5/25/51	10/4/52	11/25/53		7/2/71		5/1/80 Disposed	Shock Test The Naval Quarantine of Cuba, 1962 Sold to Rbt.E. Williams, Torrance, CA $44,000. Removal date:4/23/80 Ship Model Pictures
Avenge	423	Luders Marine	8/1/51	3/15/53	5/13/54		1/31/70		10/6/69 Fire*	Shipyard Fire Scrapped by Steve B. Clemens, Miami Shores, FL $2,789. Removal date: 3/1/71
Bold	424	Norfolk Naval Shipyard, Norfolk, Va.	12/12/51	3/14/53	9/25/53		7/2/71		6/1/81 Disposed	Scrapped by Tuscon One Hour Inc., Cincinnati, OH. $45,000. Removal date: 9/6/81 [Reported Taiwan transfer did not take place]
Bulwark	425	Norfolk Naval Shipyard	12/12/51	3/14/53	11/12/53		7/2/71		5/1/80 Disposed	Scrapped by Rbt E. Williams, Torrance, CA $44,000. Removal date: 4/23/80
Conflict More Pictures	426	Fulton Shipyard, Antioch, Calif.	8/13/51	12/16/52	3/23/54		6/9/72 at 1730Z time		12/1/73 Disposed	Scrapped by Al Kidman, Wilmington, CA $32,501. Removal date: 1/22/74 from San Diego under tow of Beverly Gene to L.A., Calif
Constant Constant More Pictures	427	Fulton Shipyard	8/16/51	2/14/52	9/8/54	P	9/30/92 San Diego, CA Decommissioning Ceremony 9/30/92	7/72	4/1/01 Disposed	Scrapped by Crowley Marine Removal date: 9/29/99, NO scrapping pictures available
Dash	428	Astoria Marine Construction Co., Astoria, Oreg.	7/2/51	9/20/52	8/14/53	P	10/1/82 Charleston, SC Decommissioning Ceremony 10/1/82	y	12/1/83 Disposed	Scratch built model by Jim White 26-Jan-84 Scrap Sale, Wayne Hobbs, Huntington Beach, Calif, $22,229
Detector More pictures	429	Astoria Marine	10/1/51	12/5/52	1/26/54	P	10/1/82 Charleston, SC Decommissioning Ceremony 10/1/82	y	12/1/83 Disposed	26-Jan-84 Scrap Sale, Wayne Hobbs, Huntington Beach, Calif, $22,229
Direct	430	C. Hiltebrant Dry Dock Co., Kingston, N.Y.	2/2/52	5/27/53	7/9/54		10/1/82 Charleston, SC Decommissioning	7/71	12/1/83 Disposed	26-Jan-84 Scrap Sale, Wayne Hobbs, Huntington Beach, Calif, $22,229
Dominant	431	Hiltenbrant Drydock	4/23/52	11/5/53	11/8/54	P	10/1/82 Charleston, SC Decommissioning	y	12/1/83 Disposed	26-Jan-84 Scrap Sale, Wayne Hobbs, Huntington Beach, Calif, $22,229
Dynamic More Pictures	432	Colberg Boat Works, Stockton, Calif.	10/31/51	12/17/52	12/15/53	P	7/1/71		8/1/74 Foreign Military Sale	Scratch built model by Doug Gramp Loaned to Spain 7/1/71 as Guadalete
To Spain as Guadalete	M41				7/1/71		1998		Unknown	Sold to Spain 7/7/74 Modernisation completed 1984-86
Engage ex- Elusive More Pictures	433	Colberg Boat Works	11/7/51	6/18/53	6/29/54	F	12/30/91 Mayport, FL Decommissioning	8/74	5/17/02 Disposed	Operation "End Sweep" Scrapped January 2002 by Baltimore Marine, Baltimore MD Mothball pictures, Additional info
Embattle	434	Colberg Boat Works	11/14/51	8/27/53	11/16/54		7/24/72 or 9-22-72 Long Beach		11/1/76 Disposed	Scrapped by Glenn Dobkins, Miami, Fla $32,769. Removal date: 12/21/76 Not transferred to Peru or Pakistan as reported FORMERLY IN PRIVATE HANDS
Endurance More Pictures	435	J. M. Martinac Shipbuilding Corp., Tacoma, Wash.	1/28/52	8/9/52	5/19/54	P	7/1/72		12/1/73 Disposed	Collision with HMS Rorqurl 27-Jan-74, Scrap Sale, Al Kidman, Wilmington, CA, $32,501
Energy	436	J.M. Martinac Shipbuilding	3/3/52	2/13/53	7/16/54 Commissioning		7/5/72		1972 Foreign Military Sale	Scratch built model by Ron Perkins Loaned to Philippines 7/5/72
To Philippines as Davao Del Norte	PM91								6/1/77 Disposed	Returned 1-Jul-77, 8-Jul-77, Scrap Sale, Ming Hing & Co, Rowloon, Hong Kong, $26,100
Enhance	437	Martinolich Shipbuilding Co., San Diego, Calif.	7/12/52	10/11/52	4/16/55 & 8/27/71	F	10/30/701 & 12/31/91	7/74	8/1/00 Disposed	Operation "End Sweep" Operation "Ernest Will" Scrapped by Crowley Marine, Removal date: 3-20-2000 Fire Damage Fire pictures Scrap Pictures PiggyBack Minesweepers
Esteem	438	Martinolich Shipbuilding Co.	Award Date 8/7/51 9/1/52	12/20/52	9/10/55 Commissioning & 8/1/71 Recommissioning	F	9/30/701 & 9/30/91	10/72	8/1/00 Disposed	Operation "End Sweep" Operation "Ernest Will" Scrapped by Crowley Marine, removal date:3-20-2000 Scrap Pictures Significant Firsts
Excel More Pictures	439	Higgins Corp., New Orleans, La.	2/9/53	9/25/53	2/24/55 Commissioning	P	9/30/92 San Francisco, CA	7/72	4/1/00 Disposed	Scrapped by Crowley Marine in January, 2000. Fire pictures Scrapping pictures
Exploit More Pictures	440	Higgans	12/28/51	4/10/53	3/31/54 Commissioning	P	12/16/93 Little Creek, VA Decommissioning Ceremony 12/15/93	7/73	5/17/02 Disposed	Equipped with prototype SSN-2 precise-navigation system in 1975 for new MCM class Scrapped January 2002 by Baltimore Marine, Baltimore MD Mothball pictures
Exultant	441	Higgans	5/22/52	6/6/53	6/22/54	F	6/30/93 Charleston, SC Decommissioning Ceremony 6/25/93	7/72	5/17/02 Disposed	Fire In Memory of Five Fallen Shipmates Scrapped January 2002 by Baltimore Marine, Baltimore MD Mothball pictures
Fearless	442	Higgans	7/23/52	7/17/53	9/22/54	F	10/31/90	7/74	12/1/92 Disposed	Operation "Ernest Will" 4-Dec-92, Scrapped 11/93, Seawitch Salvage, Baltimore, MD, $6,000
Fidelity	443	Higgans	12/15/52	8/21/53	1/19/55	F	5/19/89 Decommissioning		8/16/90 Disposed	Test ship for the SQQ-30 sonar Scrap Sale, Wyns Hoggs, $13,775
Firm More Pictures	444	J. M. Martinac Shipbuilding Corp., Tacoma, Wash.	4/16/52	4/15/53	10/12/54 Commissioning		7/5/72		1972 Foreign Military Sale	Converted to Flagship in 1955 Loaned to Philippines 7/5/72 On June 3 the Philippine Navy crews assigned to USS FIRM and USS ENERGY for transfer arrived in Long Beach for four week’s training before taking possession. During this period, FIRM’s crew trained the allied crew in ship operation, minehunting and minesweeping. On July 5, USS FIRM was decommissioned and trans­ferred to the Philippine Navy. Lieutenant Commander LINTAG, P.N. assumed command and renamed the ship the RPS DAVAO DEL SUR, which is a province in the Philippine Islands. R.P.S. DAVAO DEL SUR departed Long Beach on July 17, 1972 for her new home in the Philippines.
To Philippines as Davao Del Sur	PM92								6/1/77 Disposed	Returned 1-Jul-77 8-Jul-77, Scrap Sale, Ming Hing & Co, Kowloon, Hong Kong, $21,100
Force Force	445	J.M. Martinac Shipbuilding	8/26/52	6/26/53	1/4/55	F	4/24/73		4/24/73 Sunk	Force Sinking Operation "End Sweep" Fire & Sunk
Fortify	446	Seattle Ship Building and Drydocking Co., Seattle, Wash.	11/30/51	2/14/53	7/16/54 Commissioning	F	8/31/92 Little Creek, VA Decommissioning	8/74	5/17/02 Disposed	Operation "End Sweep" Scrapped January 2002 by Baltimore Marine, Baltimore MD Mothball pictures
Guide More Pictures	447	Seattle Ship Building	2/20/53	4/17/54	3/15/55		6/9/72 at 1730Z time		12/1/73 Disposed	Scrapped by Al Kidman, Wilmington, CA $32,501. Removal date: 1/22/74 from San Diego under tow of Beverly Gene to L.A., Calif
Illusive	448	Martinolich Ship Building Co., San Diego, Calif.	10/23/51	7/12/52	11/14/53 & ???	F	11/30/701 & 3/30/90 Mayport, FL		2/9/93 Disposed	Operation "End Sweep" Operation "Ernest Will" 12-May-93, Scrapped 6/95, SeaWitch Salvage, Baltimore, MD, $12,000 SCRAP PICTURES
Impervious More Pictures	449	Martinolich	11/18/51	8/29/52	7/15/54	F	12/12/91 Decommissioning Little Creek, VA	8/74	5/17/02 Disposed	Operation "End Sweep" Scrapped January 2002 by Baltimore Marine, Baltimore MD Mothball pictures, More info, Desert Storm
Name	Nbr	Builder	Keel Laid	Launch Date	Commis- sioned		Decomm- issioned		Date Status	Additional Information
France Berneval	450 M613	Bellingham Shipyards Co., Bellingham, Wash.	1/16/52	10/15/52	1/19/54		1988		1987 Struck
France Bir Hacheim	451 M614	Bellingham Shipyard	3/21/52	1/10/53	3/16/54		9/70		To Uruguay 4/9/70
To Uruguay as Maldonado	MS 33				To Uruguay 4/9/70		Stricken 1979		9/18/79 Scrapped	Scrap sale $80,000
France Garigliano	452 M617	Bellingham Shipyard	8/15/52	8/20/53	5/19/54		12/8/88		7/3/96 Disposed Target
France Alencon	453 M612	Bellingham Shipyard	11/1/52	4/11/53	7/16/54		Unk		Storage	Struck in 1983 Now in a ships-cemetery in "Landevennec" near by "Brest" in France
France Dompaire	454 M616	Bellingham Shipyard	1/15/53	6/5/53	9/01/54		1/20/88		9/28/86 Disposed
Name	Nbr	Builder	Keel Laid	Launch Date	Commis- sioned	Moder- nized	Decomm- issioned	Fleet Reserve	Date Status	Additional Information
Implicit More Pictures	455	Wilmington Boat Works Inc., Wilmington, Calif.	10/29/51	8/1/53	3/10/54	P	9/30/94 (Last MSO in Commission) Tacoma, WA Decommissioning Ceremony 9/30/94 This decommissioning marks THE END OF AN ERA. With IMPLICIT's passing goes the last of the U.S. MSOs.	7/72	9/30/94 Foreign Military Sale	*** PRESIDENTIAL UNIT CITATION *** Fire Sold to Taiwan ExcessDefenseArticles sale 19 Aug 1994 $2,412,812
To Taiwan as Yung Yang	M1306				03/01/95 Kaohsiung, Taiwan		Active		ACTIVE	Extensively overhauled following transfer STILL IN SERVICE as of 12/2001 and have been re-planked Former Crew Members Visit Taiwan Navy Base
Inflict	456	Wilmington Boat	10/29/51	10/6/53	5/11/54	F	3/30/90 Little Creek, VA Decommissioning Ceremony	8/74	12/1/92 Disposed	Operation "End Sweep" Operation "Ernest Will" Stayed in commission during rebuild 12/30/68-2/10/71. Scrap sale 4-Dec-92, Scrapped 11/93, Seawitch Salvage, Baltimore, MD, $12,000
Loyalty More Pictures	457	Wilmington Boat	11/9/51	11/22/53	6/11/54		Scheduled for decommissioning 7/1/72 Striken 7-1-72 Still in commission 3-72		12/1/73 Disposed	15-Jan-74, Scrap Sale, Robert D. Perry, Valleajo, CA, $32,223
Lucid	458	Higgans	3/16/53	11/14/53	5/4/55	P	12/23/701 San Diego		11/1/76 Disposed	30-Dec-76, Scrap Sale, W. Dean Kirkpatrick, San Francisco, CA, $40,250 IN PRIVATE HANDS LUCID MSO-458 FOUNDATION
Nimble	459	Higgans	4/27/53	8/6/54	5/11/55		11/24/701 Charleston		6/1/81 Disposed	6-Sep-81, Scrap Sale, Tuscon One Hour Inc., Cincinnati, OH, $45,002
Notable	460	Higgans	6/8/53	10/15/54	6/8/55	C	5/14/701		2/1/71 Disposed*	30-Aug-71, Scrap Sale, Charles, Gural, Rahway, NJ, $2,800
Observer	461	Higgans	7/20/53	10/19/54	8/31/55		7/1/72 7/28/72 Charleston		4/1/79 Disposed	21-Jul-79, Scrap Sale, Union Minerals & Alloys Corp, NY,NY $20,250
Pinnacle	462	Higgans	8/24/53	1/3/55	10/21/55		11/24/701 Charleston		2/1/78 Disposed	INACTSHIPFAC, Orange, Texas accepted custody 04-Mar-71. Ship Moored at facility Pier Nine. 1-May-78, Scrap Sale, C.B.Herter Jr., Hopewell, VA, $26,491
Pivot More Pictures	463	Wilmington Boat	3/31/52	1/9/54	7/12/54	P	7/1/71 6/19/71		8/1/74 Foreign Military Sale	Loaned 7/1/71 to Spain as GUADALMEDINA M42
To Spain as Guadalmedina	M42				7/1/71		1999		unknown	Sold to Spain 8/1/74
Pluck More Pictures	464	Wilmington Boat	3/31/52	2/6/54	8/11/54	P	11/29/90 Decommissioning Ceremony 11/29/90	7/72	9/2/92 Disposed	Test ship in the mid-1970s for the SSN-2 precise navigation system for the MCM & MHC classes. Scrap sale 25-Sep-92, Scrapped 5/94, NorthWest Demolition, Inc., Wilsonville, OR, $19,000. Parts For Sale: 503-638-6900
Prestige	465	Wilmington Boat	4/15/52	4/30/54	9/11/54		8/23/58		8/23/58 Grounded*
Prime More Pictures	466	Wilmington Boat	12/30/52	5/27/54	10/11/54		11/6/701		11/1/76 Disposed	Thailand, Planned but Cancelled 7-Jan-77, Scrap Sale, Edward Hixson, Los Alamitos, CA, $26,769
Reaper	467	Wilmington Boat	5/15/52	6/25/54	11/10/54		9/22/72		11/1/76 Disposed	Thailand, Planned but Cancelled 7-Jan-77, Scrap Sale, Edward Hixson, Los Alamitos, CA, $26,769
Rival	468	Luders Marine	2/1/52	8/15/53	9/3/54	C	6/10/701		2/1/71 Disposed*	The Naval Quarantine of Cuba, 1962 31-Aug-71, Scrap Sale, Charles Gural, Rahway, NJ, $2,700
Sagacity	469	Luders Marine	10/6/52	2/20/54	1/20/55		10/1/701		10/1/70 Grounded*	1-Mar-71, Scrap Sale, Steve B. Clemens, Miami Shores, Fl, $7,890
Salute	470	Luders Marine	3/17/53	8/14/54	5/4/55	C	5/14/701		2/1/71 Disposed*	The Naval Quarantine of Cuba, 1962 30-Aug-71, Scrap Sale, Charles Gural, Rahway, NJ, $1,700
Skill	471	Luders Marine	Award Date= 11/2/51 8/17/53	4/23/55	11/7/55		12/15/701 Charleston		4/1/79 Disposed	INACTSHIPFAC, Orange, Texas accepted custody 04-Mar-71. Ship Moored at facility Pier Nine. The Skill was cut up in Kearny, NJ in the 1983. Scrap Info
Valor	472	Burger Boat Co., Manitowoc, Wis.	4/28/52	5/13/53	7/29/54	C	7/16/701		2/1/71 Disposed*	8/30/71, Scrap Sale, Charles Gural, Rahway, NJ $1,400
Vigor	473	Burger Boat Co.	6/16/52	6/24/53	11/8/54		4/4/72		8/1/74 Foreign Military Sale	Sold 4/4/72 to Spain as GUADIANA M44
To Spain as Guadiana	M44				4/4/72		11/1/1999		Scrapped	Modernisation completed 1984-86
Vital	474	Burger Boat	10/31/52	8/12/53	6/9/55		9/27/72 or 9-22-72 Charleston		4/1/79 Disposed	Fire 21-Jul-79, Scrap Sale, Union Minerals & Alloys Corp, NY,NY, $25,250
Name	Nbr	Builder	Keel Laid	Launch Date	Commis- sioned		Decomm- issioned		Date Status	Additional Information
France Mytho	475 M618	Bellingham Shipyard	3/3/53	9/25/53	10/20/54		1/20/88		9/28/89 Disposed	classified as a tender in 1965
France Cantho	476 M615	Bellingham Shipyard	4/15/53	9/26/53	2/16/55				Unk	Converted to A769 in 1976
France Vinh Long	477 M619	Bellingham Shipyard	6/10/53	2/5/54	4/15/55		6/1/88		1992 Scrapped
Portugal Sao Jorge	478 M415	Bellingham Ship Yard	8/26/53	4/30/54	4/24/55		1973		unk	discarded in 1973
Portugal Pico	479 M416	Bellingham Ship Yard	10/1/53	6/18/54	6/1/55		1974		1974 To Belgium	Transfered to Belgium Navy in 1974 for spare parts only.
To Belgium as Spare parts	479				Spare parts only 1974				Sunk	Transfered to Belgium Navy in 1974 for spare parts only, Then sold in 1984 to the Sea Scouts, Currently (11/2001) sunk and laying in Ostend harbor, Belgium
Netherlands Onversaagd	480 M884	Astoria Marine	9/24/52	4/11/53	5/27/54		6/23/76		7/31/79 Disposed	Reclassified in 1966 A854 Sold as refitted hydrographic ship in 1979 Sold to Liguria Martime Ltd, Sittingbourne for UK P 47,150 for scrapping
Netherlands Onbevreesd	481 M885	Astoria Marine	12/8/52	11/7/53	9/21/54		5/28/82		3/17/89 Disposed	Reclassified in 1966 A855 Sold to Heuvelman Staal, Veenendaal for US$111,000 for scrapping in Sgravendeel, Holland
Netherlands Onvervaard	482 M888	Astoria Marine	4/11/52	3/6/54	1/31/55		Stricken 5/15/82		11/14/84 Disposed	Reclassified in 1966 A858 1/18/1985 towed from Vlissingen where she had been laid up for years. Sold to Deans Marine Ltd, Kent, England for UK P 51,555 for scrapping.
Netherlands Onverschrokken USS 483 (Paul Haaze's site) Mercuur Museum Web Site Second Mercuur Museum Web Site	483 M886	Peterson Builders Inc., Sturgeon Bay, Wisc.	2/19/52	1/17/53	7/22/54		3/1/72		4/24/93 Museum	Reclassified 1966 A 856 Converted to Torpedo Tender ship and renamed Mercuur in 1972 Mercuur transferred to the Nautisch Kwartier museum in Amsterdam. Due to bankrupty the Mercuur was returned to the Dutch Navy on 10/13/1991. The ship was acquired again by a museum and is now on display in Holland.
Netherlands Onvermoeid	484 M887	Peterson Builders	2/27/52	5/2/53	1/31/55		10/1/71		1/8/75 Disposed	Reclassified in 1966 A857 Towed 1/18/1973 from Den Heller Navy Base to Scotland. Sold to Ross & Son, Girvan, Scotland for US$39,000 for scrapping.
Netherlands Onverdroten	485 M889	Peterson Builders	2/17/52	8/22/53	11/22/54		Stricken 5/15/82		9/18/84 Disposed	Reclassified in 1966 A859 Sold to W. Mantel, Amsterdam for DFL 333,564 for scrapping.
Portugal Graciosa	486 M417	Burger Boat Co.	5/16/53	11/19/53	8/15/55				1973 Disgarded
Portugal Corvo	487 M418	Burger Boat Co.	8/18/53	7/28/54	11/23/55				1973 Disgarded
Name	Nbr	Builder	Keel Laid	Launch Date	Commis -sioned	Moder -nized	Decomm -issioned	Fleet Re- serve	Date Status	Additional Information
Conquest More Pictures	488	J.M. Martinac Shipbuilding	Award Date= 12/29/52 3/26/53	5/20/54	7/20/55 & 10/21/71	F	10/30/701 & 6/29/94 Decommissioning Ceremony 6/30/70	9/72	8/3/94 Foreign Military Sale	Operation "End Sweep" Operation "Ernest Will" Sold to Taiwan EDA sale 19 Aug 1994 $4,143,779
To Taiwan as Yung Tzu	M1307				03/01/95 Kaohsiung, Taiwan		Active		ACTIVE	Extensively overhauled following transfer STILL IN SERVICE as of 12/2001 and have been re-planked Former Crew Members Visit Taiwan Navy Base
Gallant	489	J.M. Martinac Shipbuilding	Award Date= 12/29/52 5/21/53	6/4/54	9/14/55 Commissioning	P	4/29/94 Treasure Is.,CA Decommissioning Ceremony 4/29/94	7/72	8/3/94 Foreign Military Sale	Sold to Taiwan EDA sale 19 Aug 1994 $2,161,307
To Taiwan as Yung Ku	M1308				03/01/95 Kaohsiung, Taiwan		Active		ACTIVE	Extensively overhauled following transfer STILL IN SERVICE as of 12/2001 and have been re-planked Former Crew Members Visit Taiwan Navy Base
Leader More Pictures	490	J.M. Martinac Shipbuilding	Award Date= 12/29/52 9/22/53	11/15/54	11/16/55 & 2/11/72	F	11/30/70 & 3/18/92(NVR) or 12/12/91 Decommissioning Little Creek, VA		4/15/94 Disposed	*** PRESIDENTIAL UNIT CITATION *** Operation "End Sweep" 18-Aug-94, Scrapped 7/96, NR Acquisition, N.Y., Wilmington Resources, Wilmington, NC for $28,880 Piggyback Minesweepers, Desert Storm
Persistent More Pictures	491	J.M. Martinac Shipbuilding	6/17/54	4/23/55	2/3/56	P	7/1/71 4/26/71		8/1/74 Foreign Military Sale	Loaned 7/1/71 to Spain as GUADALQUIVIR M43
To Spain as Guadalquivir	M43				7/1/71		2001		unk	Sold to Spain 8-1-74 Modernisation completed 1984-86
Pledge	492	J.M. Martinac Shipbuilding	Award Date= 12/29/52 6/24/54	7/20/55	4/20/56	P	1/31/94 Bremerton, WA Decommissioning Ceremony 1/31/94	7/72	8/3/94 Foreign Military Sale	Sold to Taiwan EDA sale 19 Aug 1994 $2,161,307
To Taiwan as Yung Teh	M1309				03/01/95 Kaohsiung, Taiwan		Active		ACTIVE	Extensively overhauled following transfer STILL IN SERVICE as of 12/2001 and have been re-planked Former Crew Members Visit Taiwan Navy Base
Stalwart More Pictures	493	Broward Marine Inc., Fort Lauderdale, Fla.	6/22/54	12/3/55	4/23/57		8/24/66 Fire 6/25/66		6/66 Fire*	Final Personnel Diary Entry Sank at pier from fire, raised, Scrapped 16-Dec-68 Scrap Sale $unk
Sturdy More Pictures	494	Broward Marine	10/15/54	1/28/56	Preliminary Acceptance Trials 10/23/57 Commissioning		7/1/71 Charleston		4/1/78 Disposed	Custody transferred to USS Salinan 13-JUL-71 for tow from Chasn to INACTSHIPFAC NORVA. ETA NORVA 16-JUL-71 1-May-78, Scrap Sale, C.B. Herter Jr., Hopewell, VA, $27,019 1959 Med Cruise Travel Log
Swerve More Pictures	495	Broward Marine	12/20/54	11/1/55	7/27/57		7/1/71 Charleston		2/1/78 Disposed	Custody transferred to USS Salinan 13-JUL-71 for tow from Chasn to INACTSHIPFAC NORVA. ETA NORVA 16-JUL-71 Sold for scrapping
Venture	496	Broward Marine Broward Marine news article	1/11/55	11/27/56	2/3/58 Ft. Lauderdale	P	8/2/71 Charleston		2/1/78 Disposed	Custody of Venture accepted upon arrival INACTSHIPFAC NORVA 01-NOV-71. Berthed Pier "A", South, Southgate Annex, 1-May-78, Scrap Sale, C.B. Herter Jr., Airports Rd., Hopewell, VA. $27,019
Cancelled	497	Never Awarded							Cancelled	Cancelled
Name	Nbr	Builder	Keel Laid	Launch Date	Commis- sioned		Decomm- issioned		Date Status	Additional Information
Norway Lagen	498 M950	Bellingham Shipyard	2/11/54	8/13/54	9/27/55		04/14/66		Belgium	Lagen and Namsen, which were classified as sea-going minesweepers, got approximately ll years of duty in the Norwegian Navy. In May of 1966 both vessels were transferred to the Belgian Navy in exchange for three coast-going minesweepers. Then to Belgium 4/14/66 as A.F. Dufour
To Belgium as A.F. Dufour	M903				04/14/66		1999		Jan/Feb 2007 Scrapped	Converted to MHSO in 1974
Norway Namsen	499 M951	Bellingham Shipyard	4/25/54	10/15/54	11/1/55		04/14/66		Belgium	Lagen and Namsen, which were classified as sea-going minesweepers, got approximately ll years of duty in the Norwegian Navy. In May of 1966 both vessels were transferred to the Belgian Navy in exchange for three coast-going minesweepers. Transfered to Belgium 4/14/66 as De Brouwer
To Belgium as De Brouwer	M904				04/14/66		07/93		Jan/Feb 2007 Scrapped	Converted to MHSO in 1973
France Berlaimont	500 M620	Bellingham Shipyard	6/23/54	1/7/55	1/31/56		1989		1989 Struck
France Origny	501 M621	Bellingham Shipyard	8/17/54	2/25/55	2/14/56		7/1/82		1/14/85 Disposed	Renumbered A 640 1961-62
France Autun	502 M622	Bellingham Shipyard	10/15/54	5/6/55	4/4/56		7/27/79		1985 Disposed scrapped
Belgium Belgium MSO's Web Site M907 Artevelde Artevelde	503 M907	Tacoma Boatbuilding Co. 1840 Marine View Dr Tacoma, WA 98421	10/15/53	6/19/54	12/15/55		2/1/85		unknown	Removed from duty Feb 1, 1985 Scrapped in Amsterdam, Holland
Belgium Breydel Breydel	504 M906	Tacoma Boatbuilding Co.	11/25/54	3/25/55	1/24/56		7/1993		4/2006 Scrapped	Converted to MHSO in 1976 Removed from duty January, 1993. Scrapped in Boom Belgium
France France Baccarat	505 M623	Tacoma Boatbuilding Co.	6/25/54	8/6/55	4/4/56		Unk		Storage	Struck in 1993 Now in a ships-cemetery in "Landevennec" near by "Brest" in France
Italy Storione	506 M5431	Martinolich Shipbuilding Co.	8/18/53	11/13/54	2/22/56		Stricken 3/1/97		ACTIVE	Converted to fisheries patrol craft duty. STILL IN SERVICE
Italy Salmone	507 M5430	Martinolich Shipbuilding Co.	9/16/53	2/19/55	6/5/56		Stricken 3/31/96		1996 Struck
Name	Nbr	Builder	Keel Laid	Launch Date	Commis -sioned	Moder -nized	Decomm -issioned	Fleet Re- serve	Date Status	Additional Information
Acme	508	Frank L. Sample Jr., Inc., Shipyard, Boothbay Harbor, Maine	11/16/54	6/23/55	9/27/56	P	11/6/70		11/1/76 Disposed	6-Jan-77, Sold, Oskco Edwards, Capistrano Beach, CA, $30,000
Adroit More Pictures	509	Frank L. Sample	Award Date= 6/25/54 11/18/54	8/20/55	3/4/57	P	5/8/92(NVR) or 12/12/91 Decommissioning Little Creek, VA	7/73	4/15/94 Disposed	Scratch built model by Al Hines 18-Aug-94, Scrapped 5/95, Wilmington Resources, Inc.,Wilmington, N.C. $44,950 PiggyBack Minesweepers, Desert Storm
Advance	510	Frank L. Sample	6/28/55	7/12/57	6/16/58	P	12/23/70 Long Beach, CA Decommissioning Ceremony 12/23/70		11/1/76 Disposed	6-Jan-77, Sold, Oskco Edwards, Capistraniso Beach, CA, $40,010 IN PRIVATE HANDS For Sale(5/2007)
Affray	511	Frank L. Sample	Award Date= 6/25/54 8/24/55	12/18/56	12/8/58	P	12/20/92 Newport, RI Decommissioning Ceremony 12/10/92 Ceremony	7/73	5/17/02 Disposed	Mothball pictures, Taiwan sale cancelled in 1993 Scrapped January 2002 by Baltimore Marine, Baltimore MD
Name	Nbr	Builder	Keel Laid	Launch Date	Commis- sioned		Decomm- issioned		Date Status	Additional Information
France France Narvik	512 M609	Peterson Builders	9/1/54	4/23/55	04/23/56		1988		1989 Struck	Renumbered A769 in 1976
France Ouistreham	513 M610	Peterson Builders	10/21/54	7/30/55	9/21/26		Unk		Storage	Converted to A640 in 1962 Now in a ships-cemetery in "Landevennec" near by "Brest" in France
France France Colmar	514 M624	Peterson Builders	4/30/55	10/29/55	4/21/57		2/27/76		1985 Scrapped
Belgium Belgium MSO's Web Site Truffaut	515 M908	Tampa Marine Co., Tampa, Fla.	2/1/55	11/1/55	9/21/56		Decommed		Jan/Feb 2007 Scrapped	Converted to MHSO in 1976 Trials ship for Thomson Marconi Sterne multi-influence sweep for the new minesweeper class.
Belgium Belgium MSO's Web Site Bovesse	516 M909	Tampa Marine	4/1/55	2/8/56	1/25/57		3/93		Jan/Feb 2007 Scrapped	Converted to MHSO in 1976
Italy Sgombro	517 M5432	Tampa Marine	6/15/55	6/21/56	2/22/57		10/03/2000		unknown	To reserve status 9/10/90. Decommissioned 10/03/2000
Italy Squalo	518 M5433	Tampa Marine	6/15/55	12/3/56	6/13/57		Active		ACTIVE	Converted for offshore patrol duty 1992-93, All minesweep gear removed, New bridge fitted. STILL IN SERVICE as of 9-2000. Scheduled to be paid off in late 2000.
Name	Nbr	Builder	Keel Laid	Launch Date	Commis -sioned	Moder -nized	Decomm -issioned	Fleet Re- serve	Date Status	Additional Information
Ability	519	Peterson Builders	3/5/56	12/29/56	8/4/58	C	6/70		2/1/71 Disposed*	Flagship, The Naval Quarantine of Cuba, 1962 3-Jan-72, Scrap Sale, Union Minerals & Alloys, NY,NY, $17,688
Alacrity More Pictures	520	Peterson Builders	3/5/56	6/8/57	10/1/58		9/30/77 Charleston, SC Decommissioning		7/1/78 Disposed	Flagship, Modified for sonar test activities and redesignated as (AG) on June 1, 1973 Minesweeping gear was removed, AN/SQR-15 TASS sonar system installed, fuel tanks modified, and habitability improved. The ship performed tests in the Caribbean. 27-Dec-79, Scrap Sale, Ampol Wrecking & Dismantling Corp, 274 Communipaw Ave., New Jersey City, NJ 07304 $50,475
Assurance	521	Peterson Builders	1/28/57	8/31/57	11/21/58		9/30/77 Charleston, SC Decommissioning		7/1/78 Disposed	Flagship, Modified for sonar test activities and redesignated as (AG) on March 1, 1973 Minesweeping gear was removed, AN/SQR-15 TASS sonar system installed, fuel tanks modified, and habitability improved. The ship performed tests in the Caribbean. 27-Dec-79, Scrap Sale, Ampol Wrecking & Dismantling Corp, 274 Communipaw Ave., New Jersey City, NJ 07304
Name	Nbr	Builder	Keel Laid	Launch Date	Commis- sioned		Decomm- issioned		Date Status	Additional Information
Belgium Van Haverbeke M902 Belgium MSO's Web Site	522	Peterson Builders	3/2/59	10/25/59	11/7/60		unk		2002 scrapped	Converted to MHSO in 1975 Scrapped in 2002 in Amsterdam, Holland

¹ Per Personnel Diary Entry: "Final Diary, No personnel remain on board".

If ANYBODY has ANYTHING they would like to add to this list please email me.
Thank you,

Dick Lewis

SHIP CLASSES

OCEAN MINESWEEPERS (MSO) : PROPOSED

A new class of minesweeper was proposed (Ship Characteristics Board No. 501)combining the capabilities of Ocean Minesweepers (MSO) and Coastal Minehunters (MHC) using Shadowgraph/Sea Nettle and SQQ-14 sonar.

Similar in design to the "Ability" class but larger. Four ships authorized in the Fiscal Year 1964 shipbuilding program, five in FY 1967, and seven in FY 1968. Estimated cost per ship was $8.7 million.

They were to be built in FY'68 by Stowman SB Corp., but was cancelled. However the money appropriated for their construction was reallocated and rescinded by Congress in FY 69 because of difficulties encountered in design and contracting procedures. The Department of Defense planned to request funding for the 16 minesweepers in the FY 1971 thru 1973 shipbuilding programs. Estimated cost per ship was increased to $9.0 million. (see Developments in Wooden Minesweeper Hull Design Since World War II). The program was ended about 1971 when Admiral Elmo Zumwalt decided that future assault sweeps would be conducted by helicopters.

During June of 1979, several alternative program approaches were being evaluated in replacing the aging MSO 422/508 ocean minesweeper fleet. The Chief of Naval Operations approved the basic MSO 523 ship design as a candidate for the new Mine Countermeasures (MCM 1) class ship and directed that variations of the MSO 523 design be investigated. In consideration of operational and mission requirements, the most appropriate alternative was selected in countering the open ocean mine threat. This "trade off" analysis, completed during March of 1980, was in lieu of a formal preliminary design effort. MSO class ships were never built and were superseded by new designs. MCM, and later the MSH (unsuccessful),and MHC class.

The MCM contract design was completed in February 1982, and the leadship (AVENGER MCM 1) construction contract was awarded in June 1982.

The MHC class ships have all been decommissioned. The U.S. Navy does not plan to replace the ships. New technology and changing war strategies have led the Navy to create another type of ship, the Littoral Combat Ship, which will take over the mine warfare duties of the coastal mine hunters.

MODERNIZATION:

Estimated cost and schedule per ship were $5 million and ten months in the shipyard. However, some of the early modernization's took as long as 26 months which, coupled with changes in mine countermeasure techniques and with the shift of emphasis to minesweeping helicopters, led to cancellation of the entire modernization program after only 13 ships had been fully modernized.

Ships Fully Modernized (SCB# 502): MSO-
433,437,438,441,442,443,445,446,448,449,456,488,490.

The modernization provided improvements in mine detection, AN/SQQ-14 (nicknamed "Squeaky 14") sonar made by General Electric, with mine classification as well as detection capability provided, engines, [four Waukesha Motors Co. diesel engines installed to replace the Packard engines that were originally in some of the ships, (plus two or three diesel generators for sweep gear)], advanced communications equipment fitted, and habitability improved [retrofitted with Chill water Air conditioning. The Chill water coolers and compressors were located off the Main deck close to amidships....Allen Black ENC (Ret.) Nimble, Exultant] , twin 20 mm gun or combination .50 caliber mg/81 mm mortar in some ships (replacing single 40 mm gun because of space requirements for sonar hoist mechanism)[The Fortify we had both the 40MM and SQQ-14,about six feet between the two...Jim Van Ry USS Fortify.],[some? ships modernized after 1970? had guns removed (MSO 437,439,490)]. Bridge structure in modernized ships extend around mast and aft to funnel. Complement in modernized ships is 6 officers and 70 enlisted men.

Ships fitted with AN/SQQ-14 sonars have a massive external hoist forward of the bridge, in place of the single 40mm gun formerly mounted there. Some ships have a single 20mm gun forward, some have two .50 Caliber machine guns, some are unarmed.

MSO	Converted At	Awarded Date	Started	Decommissioned	Re-Commissioned
423	Bethlehem Steel Corp. Baltimore, MD	5/7/68	8/31/68	unknown	Caught fire on October 6, 1969 and was later stricken
433	Dillingham Shipyard Honolulu, Hawaii	5/15/68	10/31/68	Stayed in Commission	8/14/70
437	Harbor Boat Building	6/30/70	10/30/70	10/30/70	8/27/71
438	Harbor Boat Building	6/30/70	9/30/70	9/30/70	8/1/71
441	Beth., Baltimore, MD	5/7/68	8/31/68	Stayed in commission	6/8/70
442	Beth., Baltimore	5/7/68	9/30/68	Stayed in commission	10/19/70
443	Beth., Baltimore	5/7/68	9/30/68	Stayed in commission	12/9/70
445	Dillingham	5/15/68	12/31/68	Stayed in commission	4/7/71
446	Dillingham	5/15/68	10/31/68	Stayed in commission	9/28/70
448	Harbor Boat Building	6/30/70	11/30/70	11/30/70	unknown
449	Dillingham	5/15/68	11/30/68	Stayed in commission	12/4/71
456	Dillingham	5/15/68	11/30/68	Stayed in commission	2/10/71
457	Replaced by 445, 1/69
460				5/14/70	Cancelled 10/16/1970 and the hulk was scrapped
468				6/10/70	Cancelled 10/16/1970 and the hulk was scrapped
470				5/14/70	Cancelled 10/16/1970 and the hulk was scrapped
472				7/16/70	Cancelled 10/16/1970 and the hulk was scrapped
488	Harbor Boat Building	6/30/70	10/30/70	10/30/70	10/21/71
490	Harbor Boat Building	6/30/70	11/30/70	11/30/70	2/11/72
519				6/70	Cancelled 10/16/1970 and the hulk was scrapped

From an examination of the personnel diary's of MSO 437 thru MSO 490 it appears that most of the ships stayed in commission, with reduced crew size during modernization.

All of the 64-65 then in service were not modernized. Modernization of five (MSO 460,468,470,472,and 519) were cancelled 10/16/1970 and the hulks were scrapped. MSO-423 while in the shipyard undergoing modernization, caught fire on October 6, 1969 and was later stricken.

Ships Partially Modernized: MSO
427,428,429,431,432,435,439,440,455,458,463,464,489,491,492,496,508,509,510,511.

Some MSO's received AN/SQQ-14 sonar but not full modernization.

Panel on Undersea Warfare,Committee on Technology for Future Naval Forces, Naval Studies Board:(1997)

The panel believes that MCM systems, concepts, and technologies that are available in the near term, when integrated with present capabilities, will provide the Navy and Marine Corps team with the ability to clear mines in stride.

Anticipating the inevitable retirement of the Avenger-class MCM ship, consideration should be given to a next-generation MCM ship, substantially smaller and lighter than the current classes, capable of operating with improved effectiveness in sea state 4 conditions, and carried on a mother ship capable of transporting up to 10 of the improved MCM units. This support vessel should also carry up to eight of the latest MCM vertical takeoff and landing (VTOL) aircraft; it would include the command, control, and communications capabilities of the current MCM command ship.

Although the Navy's current MCM force may be the most capable in the world, it is inadequate for the challenges of the future. This is a result of the refocusing of the Navy's strategy on the littorals, the lack of a sufficiently aggressive and focused research and development program, and the failure to view MCM as a complete system and provide it with sufficient sustained support from research and development through fleet introduction and operations.

The Navy's newest minehunter The SWATH Mine Hunter (MHS-1)

Technology Update 2001

August 13, 2001

Report: U.S. Navy Must Focus On Mine Warfare Capabilities By Tom Canahuate, DefenseNews.com Staff Writer

WASHINGTON - The U.S. Navy needs to replace its single and aging mine countermeasures ship, the USS Inchon, with a new hull in the near-term and consider for the long term building several ships dedicated to mine warfare in the littoral areas of the world's oceans, according to a draft report from the U.S. National Research Council.

The report recommended the Navy make mine warfare a major focus and increase the budget for this specialty by 30 percent, according to an executive summary of the study, "Naval Mine Warfare: Operational and Technical Challenges," obtained by DefenseNews.com Aug. 13. The Navy plans to spend approximately $4.6 billion during the next seven years on its mine warfare capabilities.

Acknowledging the Navy's shortcomings in this area, a Navy official told DefenseNews.com Aug. 13, "The Navy is working hard to improve its mine warfare capabilities." The official said the service has seven mine warfare programs under way to address the shortcomings.

The study, conducted at the request of Adm. Vernon Clark, chief of naval operations, urged the Navy and Marine Corps "to establish mine warfare as a major naval warfare area ... and should review the allocation of funds by warfare area in the future year defense program, with a view to finding ways to increase funding in the mine warfare area."

Dave Steigman, naval analyst with Teal Group, Fairfax, Va., told DefenseNews.com Aug. 13, "Mine warfare continues to be the stepchild of the U.S. Navy, although some capabilities have improved since the 1991 Gulf War."

The study, which will be published later this year, said the Navy needs to apply more resources toward developing intelligence, surveillance and reconnaissance (ISR) capabilities, saying they are "at the heart of mine warfare."

Given the Navy's shift to conducting operations in littoral areas of the world, the report concluded the service needs to be able to both counter mines and conduct mine warfare operations anywhere in the world. The National Research Council said the service is ill prepared for mine warfare in littoral waters.

The National Research Council is an arm of the National Academy of Sciences, Washington, and conducts research projects at the request of the U.S. government.