Auxiliary floating drydock

At the start of World War II, the US Navy had only three steel auxiliary floating dry docks: To reduce travel time for repair work, over 150 auxiliary floating dry docks of different sizes were built during World War II between 1942 and 1945. These newly built floating dry docks had a lift capacity of 400 to 100,000 tons. Without these forward repair bases, ships would have had to return to the US for repairs. Between 1 October 1944 and 17 October 1945, 7,000 ships were repaired in auxiliary floating dry docks. After World War II some auxiliary floating dry docks were sold for private use and others were scrapped. In addition to auxiliary floating dry docks, timber floating dry docks were built for use in World War II. Timber floating dry docks had a lift capacity of 400 to 20,000 tons. They were not towed across the open ocean and were not given a US Navy class. ==Role==

During wartime, ships in continuous use need repair both from wear and from war damage such as from naval mines, kamikaze attacks, dive bombs and torpedoes. Rudders and propellers are best serviced on dry docks. Without remote on-location dry docks, months could be lost if a ship returned to a home port for repair. Most auxiliary floating drydocks had provisions for the repair crew, including bunk beds, meals, and laundry. Most had power stations, ballast pumps, repair shops, machine shops, and mess halls to be self-sustaining. Some auxiliary floating drydocks also had provisions for the ship under repair, but when possible, the crew of the damaged ship remained on ship while repairs were done. Many had cranes able to lift tons of material and parts to remove damaged parts and to install new parts. ==Armament==

Most auxiliary floating drydocks had only anti-aircraft guns for defense, as space would not allow for large guns. Typical armaments included 40 mm and 20 mm machine guns. Japanese pilots sometimes mistook empty auxiliary floating drydocks for aircraft carriers. ==US Dry Docks==

Large Auxiliary Floating Dry Docks (AFDB) with rail traveling 15-ton crane Auxiliary Floating Docks, Big (AFDB), also known as Advance Base Sectional Docks (ABSD), came in sections, long and 3,850 tons each. Each section had a beam, a molded depth, and 10,000 tons of lifting capacity. Sections could be put together to lift larger ships. AFDB were needed to repair battleships, aircraft carriers, cruisers, and large auxiliary ships. The AFDB-1 Artisan had 10 sections (A to J) for a total lift of 100,000 tons, and was long with all 10 sections installed. AFDB-1 to 7 were built between 1943 and 1945 and towed to remote navy bases. An AFDB would have a crew of 600 to 1,000 men, a fresh-water distilling plant and was otherwise self-sustaining. They had a rail traveling 15-ton capacity crane with an radius and two or more support barges. To pump water from the tanks, there were two discharge pumps on each section, each pump rated per minute. For electricity, there were two 350-kw diesel AC generators on each section, producing 440 volts 3-phase 60-cycle power. AFDBs had steam plants to run the pumps. Each section could store of fuel oil to supply the ships under repair. Crew lived in barracks ships, called APL, that docked next to the AFDB. • USS Artisan (ABSD-1) (A-J), built by Everett-Pacific and others • (A-J), built by Mare Island Naval Shipyard in Vallejo, California (E, F, H & I in use) • USS AFDB-3 (A-I), saw fighting action in Guam, and was sold to Croatia in 2000. • (A-G), built by Mare Island Naval Ship Yard (NSY). Attacked by air on April 27, 1945. Partially sunk 1989 as a reef. • (A-G), built by Chicago Bridge in Morgan City, Louisiana. Scrapped in 1997. • (A-G), built by Mare Island NSY. Scrapped 1976. • USS Los Alamos (AFDB-7) (A-G), built by Chicago Bridge. Sold to a private shipyard in 1995. Post WW2 • AFDB-8 Machinist, built by Seebeckwerft in Germany. Sold to Guam in 1997. • AFDB-9 (A-B), built by Sun Shipbuilding in Chester, Pennsylvania. Sold to private owners in Galveston in 1985. Medium Auxiliary Floating Dry Docks (AFDM) center section floated through the Panama Canal on its side. Towed by USS Alarka (YTB-229) (center) and USS Umpqua (ATA-209) (left) in 1945. Navy SeaBees turned it on its side with many pontoons to fit through the canal AFDM are from 6,800 to 8,000 tons and are from long. An AFDM has a crew of 140 to 200 men. An AFDM had a lift capacity 18,000 tons and was armed with two 40 mm and four 20 mm guns. It also had two -ton cranes with 16 ballast tank compartments. AFDMs were built in three pieces, a long center section and two shorter sections, one at each end. All AFDM also had Yard Floating Docks (YFD) class numbers. • USS AFDM-1 Chicago Bridge, YFD 3. Was floated through the Panama Canal on it side, and scrapped in 1986. • Alabama DD, YFD 4. Sold to private users in 1999. • USS AFDM-3 Chicago Bridge, through the Panama Canal on it side to Naval Base Trinidad, YFD 6. Sold to private users. • USS AFDM-4 Chicago Bridge, YFD 10. Sold to private users in 1948. • USS Resourceful (AFDM-5) Everett-Pacific, YFD 21. Sold to private users in 1999. • USS Competent (AFDM-6) Everett-Pacific, YFD 62. Sold to private users in 1997. • USS Sustain (AFDM-7) Everett-Pacific, YFD 63. Leased to BAE Systems Southeast Shipyards in 1997. • USS Richland (AFDM-8) Chicago Bridge, YFD 64, scrapped in 2016 • USS AFDM-9 Chicago Bridge, YFD 65. Sold to private users in 1989. • USS Resolute (AFDM-10) Chicago Bridge, YFD 67. Destroyed in 1947. • USS AFDM-11 Chicago Bridge, YFD 68. Sold to private users in 2004. • USS AFDM-12 – Kaiser Shipyards in Vancouver, Washington, YFD 69. Scrapped in 1990. • USS AFDM-13 – See YFD 70 Columbia Const. in Vancouver, WA. Sold to private users in 1969. • USS Steadfast (AFDM-14) in floating drydock Steadfast Pollock-Stockton in Stockton, California, YFD 71. Sold to private users in 1998. Medium Auxiliary Repair Docks (ARDM) Auxiliary repair dock Mobile (ARDM) are 5,200 tons and long. ARDs had a ship form hull and lifting capacity of 3,500 tons. ARDMs were used to repair destroyers, submarines, and small auxiliaries. ARDMs had a crew of 130 to 160 men. • USS Endeavor AFD-1/AFDL-1 By Chicago Bridge • USS AFD-2 By Chicago Bridge • USS AFD-3/AFDL-3 By Chicago Bridge • USS AFD-4/AFDL-4 By Chicago Bridge • USS AFD-5/AFDL-5 By Chicago Bridge • USS Dynamic (AFD-6)/AFDL-6 By Chicago Bridge • USS Ability (AFD-7)/AFDL-7 By Chicago Bridge • USS AFD-8/AFDL-8 By Chicago Bridge • USS AFD-9/AFDL-9 By Chicago Bridge, stationed at Naval Base Noumea • USS AFD-10/AFDL-10 By Chicago Bridge • USS AFD-11/AFDL-11 By Chicago Bridge • USS AFD-12/AFDL-12 • USS AFD-13/AFDL-13 Typhoon Ida Sank off of Okinawa, Japan on 16 September 1945. • USS AFD-14/AFDL-14 served Espiritu Santo. • USS AFD-15/AFDL-15 served at Enewetak Atoll • USS AFD-16/AFDL-16 • USS AFD-17/AFDL-17 served at Kwajalein Atoll • USS AFD-18/AFDL-18 • USS AFD-19/AFDL-19 By The Auchter Company served in Dunstaffnage a Scottish village, sold moved to Jacksonville, Florida • USS AFD-20/AFDL-20 By Auchter Company served American Samoa • USS AFD-21/AFDL-21 By Auchter Company • USS AFD-22/AFDL-22 By Auchter Company • USS Adept (AFD-23)/AFDL-23 Auchter Company • USS AFD-24/AFDL-24 By Doullot & Ewin in Mobile, Alabama • USS AFD-25/AFDL-25 By Doullot & Ewin • USS AFD-26/AFDL-26 By Doullot & Ewin • USS AFD-27/AFDL-27 By Doullot & Ewin • USS AFD-28/AFDL-28 By Doullot & Ewin • USS AFD-29/AFDL – AFDL-29 By Doullot & Ewin • USS AFD-30/AFDL-30 By Foundation Co. Scrapped in 1979. • USS AFD-31/AFDL-31 By Foundation Co. Later YFD 83. To US Coast Guard 1947. After war moved to Singapore. • USS AFD-32/AFDL-32 By Foundation Co. • USS AFD-33/AFDL-33 By Foundation Co. To Peru 1959 as AFD 106. Active. • For AFDL-34 to AFDL-46 see: Auxiliary Repair Dock, Concrete Auxiliary Repair Docks (ARD) under tow by USS Bridge 28 October 1934 , Alaska with Sub USS S-46 for repair 1944 Auxiliary Repair Docks were built by Pacific Bridge Company in Alameda, California. ARD are long, have a beam of , a draft of , and a displacement of 4,800 tons. The crew complement is 6 officers and 125 enlisted. ARD have an armament of two single Oerlikon 20 mm cannons, a bow and are sea worthy. They are self-sustaining with rudders to help in tow moving and have two cranes with a five-ton capacity. ARD also have a stowage barge for extra space. They were used to repair destroyers and submarines. Class 2 could repair Landing Ship, Tank (LST). The stern of the ship is open to allow a ship in need of repair to enter. • Displacement of 2,200 tons. Built in 1933. Only one in class. • USS ARD-2 stationed at Naval Base Noumea Sold in 1963. • USS ARD-3 Sold in 1999. • USS ARD-4 Sold in 1961. • ARD-2-class long, wide, ARD-5 to 11: • USS Waterford (ARD-5) • USS ARD-6 Sold in 1961. • USS West Milton (ARD-7) Scrapped in 1992. • USS ARD-8 Sold in 1961. • Sold 1977 • Sold, scrapped in 2014 • USS ARD-11 Sold 1977 • ARD-2-class wide: , to wide, ARD 12 to 32: • USS ARD-12 Sold in 1987. • USS ARD-13 Sold in 1977. • USS ARD-14 Sold in 1980. • USS ARD-15 Sold in 1971. • USS ARD-16 By Pacific Bridge. Sold and moved to Mobile, AL. • Sold in 1971. • USS Endurance ARD-18 ARDM 3. Laid up at Charleston Naval Shipyard. • USS Oak Ridge ARD-19 ARDM 1. To United States Coast Guard in 2002. • USS White Sands ARD-20 By Pacific Bridge Co., (changed to AGDS-1). Sold in 1974. • USS ARD-21 Reserve • USS Windsor (ARD-22) Sold in 1976 • USS ARD-23 Transferred to Argentine Navy in 1961, redesignated ARA Y-1. Sold in 1991 • USS ARD-24 Sold in 1982. • USS ARD-25 Sold in 1973. • USS Alamogordo ARD-26 Sold in 2000. • USS ARD-27 Scrapped in 1974. • USS ARD-28 Sold and renamed Capitan Rodriguez Zamora. • Sold to Iran in 1971. • USS San Onfre (ARD-30) By Pacific Bridge Co. • USS ARD-31 To US Air Force in 1974. • USS ARD-32 Sold in 1960. • USS ARD-33 By Dravo Corp. Renamed AFDL 47 Reliance. Auxiliary Repair Dock, Concrete (ARDC) , An Auxiliary Repair Dock, Concrete Auxiliary Repair Dock, Concrete were mobile dry docks made of concrete, due to the shortage of steel during World War II. ARDC had a 2,800 ton lifting capacity. ARDC were long, wide, and deep. ARDC has a crew of five officers and 84 enlisted men. Each had a 5-ton crane, with a reach. Eight were built at Wilmington, North Carolina, and five at San Pedro in Los Angeles, California. • ARDC 4 – Changed to AFDL-37. Scrapped in 1981. • ARDC 5 – Changed to AFDL-38. Placed out of service, date unknown. Final Disposition, transferred to San Francisco Maritime National Historical Park and leased to Bay Ship and Yacht shipyard at Alameda, CA. • ARDC 6 – Changed to AFDL-39. Sold to Brazil in 1980 Cidade de Natal. • ARDC 7 – Changed to AFDL-40. Sold to the Philippines in 1990. • ARDC 8 – Changed to AFDL-41. Sold in 1983 to North Florida Shipyard • ARDC 9 – Changed to AFDL-42. Sold to Hurley Marine Works in 1945. Scrapped in 1975. • ARDC 10 – Changed to AFDL-43. Scrapped in 1979. • ARDC 11 – Changed to AFDL-44. Sold to the Philippines in 1969. • ARDC 12 – Changed to AFDL-45. Sold to Todd Seattle 1945. Sold 1981 to Puglia Engineering. • ARDC-13 – Changed to AFDL-46. Destroyed at Bikini in 1946. Yard Floating Dock (YFD) The first Yard Floating Dock built in 1901, arriving Pearl Harbor 23 Oct. 1940 from New Orleans Naval Yard Yard Floating Dock (YFD) was used for many types of floating docks, mostly used for harbor or shipyard use. YFDs normally had little-to-no crew space and were serviced from shore. Some auxiliary Repair Docks were converted to YFDs. Types of YFDs were: 400-ton concrete docks, 1,000-ton, 3,000-ton and 5,000-ton wood docks; sectional wood docks from 7,000 to 20,000 tons lifting capacity and a three-piece self docking steel sectional docks with 14,000 to 18,000 tons lifting capacity. All Medium Auxiliary Floating Dry Docks were converted to YFDs after World War II. • • . A medium auxiliary floating dry dock. Retired in 2003. • USS YFD-3 • USS YFD-4 • USS YFD-5 • USS YFD-6 • USS YFD-7 • USS YFD-8 • USS YFD-9 • USS YFD-10 • USS YFD-11 • USS YFD-12 • USS YFD-13 • USS YFD-14 • USS YFD-15 • USS YFD-16 • USS YFD-17 • USS YFD-18 • USS YFD-19 • USS YFD-20 • USS YFD-21 • USS YFD-22 • USS YFD-23 • USS YFD-24 • USS YFD-25 • USS YFD-26 • USS YFD-27 • USS YFD-28 • USS YFD-29 • USS YFD-30 • USS YFD-31 • USS YFD-32 • USS YFD-33 • USS YFD-34 • USS YFD-35 • USS YFD-36 • USS YFD-37 • USS YFD-38 • USS YFD-39 • USS YFD-40 • USS YFD-41 • USS YFD-42 • USS YFD-43 • USS YFD-44 • USS YFD-45 • USS YFD-46 • USS YFD-47 • USS YFD-48 • USS YFD-49 • USS YFD-50 • USS YFD-51 • USS YFD-52 • USS YFD-53 • USS YFD-54 • USS YFD-55 • USS YFD-56 • USS YFD-57 • USS YFD-58 • USS YFD-59 • USS YFD-60 • USS YFD-61 • USS YFD-62 • USS YFD-63 • USS YFD-64 • USS YFD-65 • USS YFD-66 • USS YFD-67 • USS YFD-68 • USS YFD-69 • USS YFD-70 • USS YFD-71 • USS YFD-72 • USS YFD-73 • USS YFD-74 • USS YFD-75 • USS YFD-76 • USS YFD-77 • USS YFD-78 • USS YFD-79 • USS YFD-80 • USS YFD-81 • USS YFD-82 ==Image gallery==

File:USS Pennsylvania (ACR-4) in Drydock Dewey.jpg|USS Pennsylvania (ACR-4) in dry dock Dewey, c. 1906–1907 File:USS Maryland (ACR-8) in Drydock Dewey.jpg|USS Maryland (ACR-8) in dry dock Dewey, c. 1907 File:USS Chauncey in Drydock Dewey c. 1910.jpg|USS Chauncey (DD-3) in dry dock Dewey, c. 1910 File:USS Chauncey in Drydock Dewey c. 1910, stern view.jpg|USS Chauncey (DD-3) in dry dock Dewey, stern view, c. 1910 File:Drydock Dewey with submarines.jpg|US Navy submarines in dry dock Dewey, c. 1912 File:Submarines in Drydock Dewey, c. 1912.jpg|US Navy submarines in dry dock Dewey, c. 1912 File:USS Galveston (CL-19) in Drydock Dewey, c. 1916.jpg|USS Galveston (CL-19) in dry dock Dewey, c. 1916 File:Dewey Drydock with USS Jason 1928 NARA 19-LC-19C.jpg|Aerial view of dry dock Dewey with USS Jason (AV-2) nearby, October 1928 File:USS Jason (AV-2) in the drydock USS Dewey (YFD-1), at Olongapo, Philippine Islands, on 9 March 1932 (80-CF-22672-1).jpg|Aerial view of USS Jason (AV-2) in dry dock Dewey, 8 March 1932 File:USS Jason (AV-2) in drydock USS Dewey (YFD-1), at Olongapo, Philippine Islands, on 8 March 1932 (80-CF-22672-3).jpg|Side view of USS Jason (AV-2) in dry dock Dewey, 9 March 1932 File:USS Octans (AF-26) drydocked in YFD-18 at San Francisco, California (USA), 15 June 1943.jpg| in YFD-18 at San Francisco on 15 June 1943 File:USS Columbia (CL-56) docked in ABSD-1 at Espiritu Santo, in January 1944.jpg|Cruiser Columbia (CL-56) docked in Artisan (ABSD-1) at Espiritu Santo in January 1944 File:USS Columbia (CL-56) docks in ABSD-1 at Espiritu Santo, in January 1944.jpg|Columbia docked in Artisan ABSD-1 at Espiritu Santo in January 1944 File:ABSDsectionUnderTowwingsup.jpg|One Advance Base Sectional Dock (ABSD) section under tow with float wings up in 1944 File:USS Artisan ABSD-1 04.jpg|AFDB-1 with USS West Virginia (BB-48) high and dry in the dock November 1944 File:USS Iowa Floating Drydock.jpg| floating in dry dock at Manus Island, Admiralty Islands, 28 December 1944 File:G379472.jpg|USS LST-646 and in ABSD-6, in Apra Harbor, Guam, 29 May 1945 File:USS Makin Island (CVE-93) enters floating drydock ABSD-6 at Guam on 8 June 1945 (NH 99118).jpg|USS Makin Island (CVE-93) halfway into USS ABSD-6, at Guam, 8 June 1945 File:ABSD5repairingUSSMississippiBB41.jpg| at Manicani Island, Philippines repairing USS Mississippi in July 1945 File:Seeadler USN drydock 1945.jpg|USS AFDB-2 at Seeadler Harbor in 1945 File:ABSD6underTowSectionD.jpg|ABSD-6's Section D and one crane under tow to Guam. Pontoons are folded down to reduce wind resistance and lower center of gravity File:ABSD6assemblingApraHarbor1945.jpg|USS ABSD-6 being assembled at Apra Harbor, Guam in 1945 File:ABSD-3 repairing small ship at the same time.jpg|ABSD-3 repairing small ships (likely Admirable-class minesweepers or PCE-842-class patrol craft) at the same time at Guam in 1945 File:ABSD3GuamMarianasIslandsUSSPennsylvaniaBB-38.jpg| at Guam ca. September 1945 repairing USS Pennsylvania (BB-38), to the rear right of ABSD-3 is the land base that supported the ABSD-6 and ABSD-3 crews File:USS Abraham Lincoln (SSBN-602) in USS AFDB-7.jpg| in USS AFDB-7 at Holy Loch, Scotland, on 19 March 1963 File:USS Los Alamos (AFDB-7).JPEG| at Holy Loch, Scotland, on 1 December 1985 File:Arco (ARDM-5) Badge.gif|Official crest of Arco (ARDM-5) File:US Navy 070425-N-6357K-002 Los Angeles-class fast attack submarine USS Asheville (SSN 758), nicknamed The Ghost of the Coast, enters the floating dry dock Arco (ARDM 5) for a scheduled maintenance period aboard Naval Base Point.jpg|USS Asheville (SSN-758) enters the floating dry dock of Arco (ARDM-5) for scheduled maintenance at Naval Base Point Loma, California, on 25 April 2007 ==See also==