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Mine-Warfare Ships and Boats Built Since WWII

Most recent update: December 23, 2011.

After the war, the Navy retained 60 Yard Minesweepers (YMS) and reclassified them as Motor Minesweepers (AMS).  Then, in the early 1950s, the Navy started to build new AMSs but, in 1955, changed the designation to MSC and simultaneously reclassified the 60 ex-YMSs as MSC(O)s , where the O stood for Old.  The basic design of the new boats had a light displacement of 390 tons and was 144 feet long.  In total, 312 were built, all but 24 of them being transferred directly to allied navies, and 59 of them being built by yards in the recipient countries.

The Navy also retained 50 other craft - mostly LCI(L)s and LCTs - after the war and converted them to Coastal Minesweepers (Undersea Locator), or AMCUs: this designation was changed to Mine Hunter (MHC) in 1955. 

In parallel with the MSC program, the Navy also built a series of Ocean Minesweepers (AM): this designation was changed to MSO in 1955.  The basic design of these boats had a light displacement of 630 tons and was 172 feet long.  In total, 101 were built, of which 65 were for the U.S. Navy and 36 were for allied navies: all these boats were built by U.S. yards.

In the late 1950s, the Navy initiated a third program, to build Inshore Minesweepers, (MSI).  The basic design of these boats had a light displacement of 120 tons and was 112 feet long.  In total, 55 were built, all but the first two for allied navies: only the first eight were built in U.S. yards, the remainder being built by yards in the recipient countries.

Also in the 1950s, the Navy built a series of Minesweeping Boats (MSB) and another of Minesweeping Launches (MSL).  There appear to have been at least 54 MSBs and at least 40 MSLs, but the records are very sketchy.  The standard MSB was 44 tons and 57 feet long, while the MSL was 10 tons and 36 feet long.  Any information about these boats would be welcomed.

Following this surge of activity in the 1950s and 60s, there was no new construction activity until the Reagan Administration, when the Navy built 14 Mine Countermeasures Ships (MCM) and 12 Mine Hunters (MHC).  At present, there are no plans for any new mine-warfare ships or boats, the Littoral Combat Ship (LCS) having taken over this role.

Type # Old Type Old # Original Name Shipbuilder LDT Feet Original Delivery Date Conversion Delivery Date Built for New Type New # Disposition
Minesweepers Ocean (AM/MSO)
MSO 421 AM 421 Agile Luders Marine 630 172 21-Jun-56   U.S. Navy     Scrapped 1979
MSO 422 AM 422 Aggressive Luders Marine 630 172 25-Nov-53   U.S. Navy     Scrapped 1980
MSO 423 AM 423 Avenge Luders Marine 630 172 13-May-54   U.S. Navy     Destroyed by fire 1970
MSO 424 AM 424 Bold Norfolk NSY 630 172 25-Sep-53   U.S. Navy     Scrapped 1980
MSO 425 AM 425 Bulwark Norfolk NSY 630 172 12-Nov-53   U.S. Navy     Scrapped 1980
MSO 426 AM 426 Conflict Fulton Shipyard 630 172 23-Mar-54   U.S. Navy     Scrapped 1973
MSO 427 AM 427 Constant Fulton Shipyard 630 172 8-Sep-54   U.S. Navy     Scrapped 2001
MSO 428 AM 428 Dash Astoria Marine 630 172 14-Aug-53   U.S. Navy     Scrapped 1983
MSO 429 AM 429 Detector Astoria Marine 630 172 26-Jan-54   U.S. Navy     Scrapped 1983
MSO 430 AM 430 Direct Hiltebrant DD 630 172 9-Jul-54   U.S. Navy     Scrapped 1983
MSO 431 AM 431 Dominant Hiltebrant DD 630 172 8-Nov-54   U.S. Navy     Scrapped 1983
MSO 432 AM 432 Dynamic Colberg BW 630 172 7-Feb-54   U.S. Navy     To Spain 1974 as Guadalete (M 41): struck 1998
MSO 433 AM 433 Engage Colberg BW 630 172 29-Jun-54   U.S. Navy     Scrapped 2002
MSO 434 AM 434 Embattle Colberg BW 630 172 16-Nov-54   U.S. Navy     Scrapped 1976
MSO 435 AM 435 Endurance Martinac SB 630 172 19-May-54   U.S. Navy     Scrapped 1973
MSO 436 AM 436 Energy Martinac SB 630 172 16-Jul-54   U.S. Navy     To Philippines 1972 as Davao del Norte (PM 91): scrapped 1977
MSO 437 AM 437 Enhance Martinolich SB 630 172 16-Apr-55   U.S. Navy     Scrapped 2000
MSO 438 AM 438 Esteem Martinolich SB 630 172 10-Sep-55   U.S. Navy     Scrapped 2000
MSO 439 AM 439 Excel Higgins Industries 630 172 24-Feb-55   U.S. Navy     Scrapped 2000
MSO 440 AM 440 Exploit Higgins Industries 630 172 31-Mar-54   U.S. Navy     Scrapped 2002
MSO 441 AM 441 Exultant Higgins Industries 630 172 22-Jun-54   U.S. Navy     Scrapped 2002
MSO 442 AM 442 Fearless Higgins Industries 630 172 22-Sep-54   U.S. Navy     Scrapped 1992
MSO 443 AM 443 Fidelity Higgins Industries 630 172 19-Jan-55   U.S. Navy     Scrapped 2000
MSO 444 AM 444 Firm Martinac SB 630 172 12-Oct-54   U.S. Navy     To Philippines 1972 as Davao del Sur (PM 92): scrapped 1977
MSO 445 AM 445 Force Martinac SB 630 172 4-Jan-55   U.S. Navy     Sunk 1972
MSO 446 AM 446 Fortify Seattle SB 630 172 16-Jul-54   U.S. Navy     Scrapped 2002
MSO 447 AM 447 Guide Seattle SB 630 172 15-Mar-55   U.S. Navy     Scrapped 1973
MSO 448 AM 448 Illusive Martinolich SB 630 172 14-Nov-53   U.S. Navy     Scrapped 1993
MSO 449 AM 449 Impervious Martinolich SB 630 172 15-Jul-54   U.S. Navy     Scrapped 2002
MSO 450 AM 450 Berneval Bellingham SY 630 172 23-Dec-53   France M 613 Struck 1987
MSO 451 AM 451 Bir Hacheim Bellingham SY 630 172 24-Feb-54   France M 614 Returned 1970: to Uruguay as Maldonado (MS 33): scrapped 1979
MSO 452 AM 452 Garigliano Bellingham SY 630 172 29-Apr-54   France M 617 Sunk as target 1996
MSO 453 AM 453 Alencon Bellingham SY 630 172 23-Jun-54   France M 612 Struck 1983
MSO 454 AM 454 Dompaire Bellingham SY 630 172 23-Jun-54   France M 616 Struck 1983
MSO 455 AM 455 Implicit Wilmington BW 630 172 10-Mar-54   U.S. Navy     To Taiwan 1995 as Yung Ky: active
MSO 456 AM 456 Inflict Wilmington BW 630 172 11-May-54   U.S. Navy     Scrapped 1992
MSO 457 AM 457 Loyalty Wilmington BW 630 172 11-Jun-54   U.S. Navy     Scrapped 1973
MSO 458 AM 458 Lucid Higgins Industries 630 172 14-May-55   U.S. Navy     Sold for scrap 1976 but laid up, to be museum in Stockton CA
MSO 459 AM 459 Nimble Higgins Industries 630 172 11-May-55   U.S. Navy     Scrapped 1981
MSO 460 AM 460 Notable Higgins Industries 630 172 8-Jun-55   U.S. Navy     Scrapped 1971
MSO 461 AM 461 Observer Higgins Industries 630 172 31-Aug-55   U.S. Navy     Scrapped 1979
MSO 462 AM 462 Pinnacle Higgins Industries 630 172 21-Oct-55   U.S. Navy     Scrapped 1978
MSO 463 AM 463 Pivot Wilmington BW 630 172 12-Jul-54   U.S. Navy     To Spain 1974 as Guadalmedina (M 42): active
MSO 464 AM 464 Pluck Wilmington BW 630 172 11-Aug-54   U.S. Navy     Scrapped 1992
MSO 465 AM 465 Prestige Wilmington BW 630 172 11-Sep-54   U.S. Navy     Scrapped 1971
MSO 466 AM 466 Prime Wilmington BW 630 172 11-Oct-54   U.S. Navy     Scrapped 1976
MSO 467 AM 467 Reaper Wilmington BW 630 172 10-Nov-54   U.S. Navy     Scrapped 1976
MSO 468 AM 468 Rival Luders Marine 630 172 3-Sep-54   U.S. Navy     Scrapped 1971
MSO 469 AM 469 Sagacity Luders Marine 630 172 20-Jan-55   U.S. Navy     Scrapped 1971
MSO 470 AM 470 Salute Luders Marine 630 172 4-May-55   U.S. Navy     Scrapped 1971
MSO 471 AM 471 Skill Luders Marine 630 172 7-Nov-55   U.S. Navy     Scrapped 1979
MSO 472 AM 472 Valor Burger Boats 630 172 29-Jul-54   U.S. Navy     Scrapped 1971
MSO 473 AM 473 Vigor Burger Boats 630 172 8-Jul-54   U.S. Navy     To Spain 1974 as Guadiana (M 44): active
MSO 474 AM 474 Vital Burger Boats 630 172 9-Jun-55   U.S. Navy     Scrapped 1979
MSO 475 AM 475 My Tho Bellingham SY 630 172 Dec-53   France M 615 Struck 1989
MSO 476 AM 476 Can Tho Bellingham SY 630 172 Oct-54   France M 618 Struck 1987
MSO 477 AM 477 Vinh Long Bellingham SY 630 172 5-Jan-55   France M 619 Scrapped 1992
MSO 478 AM 478 Sao Jorge Bellingham SY 630 172 30-Apr-54   Portugal M 415 Discarded 1973
MSO 479 AM 479 Pico Bellingham SY 630 172 18-Jun-54   Portugal M 416 Discarded 1973, sunk in Ostend harbor
MSO 480 AM 480 Onversaagd Astoria Marine 630 172 19-May-54   Netherlands M 884 Scrapped 1979
MSO 481 AM 481 Onvevreesde Astoria Marine 630 172 21-Sep-54   Netherlands M 885 Scrapped 1989
MSO 482 AM 482 Onverschrokken Astoria Marine 630 172 18-Jan-55   Netherlands M 886 Torpedo trials ship 1972
MSO 483 AM 483 Onvermoeid Peterson Builders 630 172 18-Jun-54   Netherlands M 887 Museum in the Netherlands
MSO 484 AM 484 Onvervaard Peterson Builders 630 172 12-Aug-54   Netherlands M 888 Scrapped 1985
MSO 485 AM 485 Onverdrotten Peterson Builders 630 172 22-Nov-54   Netherlands M 889 Struck 1982
MSO 486 AM 486 Gracioso Burger Boats 630 172 19-Nov-53   Portugal M 417 Discarded 1973
MSO 487 AM 487 Corvo Burger Boats 630 172 28-Jul-54   Portugal M 418 Discarded 1973
MSO 488 AM 488 Conquest Martinac SB 630 172 20-Jul-55   U.S. Navy     To Taiwan 1995 as Yung Tzu (M 1307), active
MSO 489 AM 489 Gallant Martinac SB 630 172 14-Sep-55   U.S. Navy     To Taiwan 1995 as Yung Der (M 1308), active
MSO 490 AM 490 Leader Martinac SB 630 172 16-Nov-55   U.S. Navy     Scrapped 1994
MSO 491 AM 491 Persistent Martinac SB 630 172 3-Feb-56   U.S. Navy     To Spain 1971 as Guadalquivir (M 43): active
MSO 492 AM 492 Pledge Martinac SB 630 172 20-Apr-56   U.S. Navy     To Taiwan 1995 as Yung Yang (M 1309), active
MSO 493 AM 493 Stalwart Broward Marine 630 172 23-Apr-57   U.S. Navy     Scrapped 1971
MSO 494 AM 494 Sturdy Broward Marine 630 172 23-Oct-57   U.S. Navy     Scrapped 1978
MSO 495 AM 495 Swerve Broward Marine 630 172 27-Jul-57   U.S. Navy     Scrapped 1978
MSO 496 AM 496 Venture Broward Marine 630 172 3-Feb-58   U.S. Navy     Scrapped 1978
MSO 497 AM 497     630 172           Number not used
MSO 498 AM 498 Lagen Bellingham SY 630 172 27-Sep-55   Norway M 950 To Belgium 1966 as A.F. Dufour (M 903), scrapped 2002
MSO 499 AM 499 Nansen Bellingham SY 630 172 1-Nov-55   Norway M 951 To Belgium 1966 as De Brouwer (M 904), scrapped 2002
MSO 500 AM 500 Berlaimont Bellingham SY 630 172 12-Dec-55   France M 620 Struck 1989
MSO 501 AM 501 Origny Bellingham SY 630 172 23-Jan-56   France M 621 Converted to A 640 in 1962
MSO 502 AM