Ailanthus-class net laying ship

The Ailanthus class were a group of 40 wooden-hulled net laying ships of the United States Navy built during World War II as part of the huge building programs of late 1941 and early 1942 for small patrol and mine warfare vessels. Five of the class were transferred to the British Royal Navy under Lend-Lease, and another five were converted while at their shipyards into Auxiliary Fleet Tugs, the ATA-214-class.

Construction
Originally ordered on 30 September 1941 as Yard Net Tenders ("YN"), the first twenty ships (YN 57-76) were to be constructed for the British under Lend-Lease, while a further twenty (YN 77-96) were for the United States. However, after a major redistribution of small combatant contracts this order was cancelled. Finally in May 1942 contracts for twenty vessels were awarded, with orders for YN 57-66 going to the Everett Pacific Shipbuilding & Drydock Company of Everett, Washington, and for YN 67-76 to the Pollock-Stockton Shipbuilding Company of Stockton, California.

In July, 14 more ships were ordered from four shipyards; four (YN 77-80) from the Barbour Boat Works in New Bern, North Carolina, five (YN 81-84 and 86) from Snow Shipyards Inc. in Rockland, Maine, one (YN-85) from the Canuelette Shipbuilding Company of Slidell, Louisiana, and four (YN 87-90) from the American Car and Foundry Company of St. Charles, Missouri.

Finally, in September, the final batch of six ships (YN 91-96) were ordered from the Canuelette Company. On 19 February 1943, after a review of requirements, the first twenty ships were reallocated to the United States. In January 1944 the ships were reclassified as Auxiliary Net Layers, redesignated "AN" and renumbered. Ultimately the British allocation was reduced to five vessels (AN 73-77), and in British service they were called Boom Defence Vessels. On 9 August 1944 five of the ships that were still at their yards were ordered to be converted to Auxiliary Fleet Tugs, and AN-64, 65, and 70-72 were reclassified as ATA 214-218 on 12 August 1944.

Armament
In the original design, in addition to the 3-inch gun mounted forward of the bridge, there were two single 20 mm guns mounted on top of the bridge. In September 1944, as a trial, a third 20 mm gun was installed on a small elevated platform mounted on a pedestal between the bridge and the smokestack on Terebinth (AN-59), but it was found that the arc of fire was restricted, that the platform was too hot to permit the storage of ready ammunition, and that the gun crew became ill from engine fumes. Instead two additional single 20 mm guns were installed at the after end of the deckhouse on AN 39-63 and 66-69. In April 1945 the four single mounts were ordered to be replaced with four twin mounts, but this change does not seem to have been made.

Losses
Two ships of the class were lost during the war;
 * USS Ailanthus (AN-38), was wrecked barely a month after commissioning, running aground in the Aleutians on 26 February 1944, and was declared a total loss on 14 March 1944.
 * USS Snowbell (AN-52), was driven hard aground when Typhoon Louise hit Buckner Bay, Okinawa, on 9 October 1945 and was declared beyond repair. The wreck was blown up in January 1946.

Disposal
In early 1946 six of the ships, Cliffrose (AN-42), Cinnamon (AN-50), Silverbell (AN-51), Torchwood (AN-55), Catclaw (AN-60), and Shellbark (AN-67), were transferred to the Republic of China's Maritime Customs Service at Shanghai, while the remainder were disposed of in 1947 in a Maritime Commission sales program for small vessels.

Ships

 * USS Ailanthus (AN-38) (YN-57/AN-38)
 * USS Bitterbush (AN-39) (YN-58/AN-39)
 * USS Anaqua (AN-40) (YN-59/AN-40)
 * USS Baretta (AN-41) (YN-60/AN-41)
 * USS Cliffrose (AN-42) (YN-61/AN-42)
 * USS Satinleaf (AN-43) (YN-62/AN-43)
 * USS Corkwood (AN-44) (YN-63/AN-44)
 * USS Cornel (AN-45) (YN-64/AN-45)
 * USS Mastic (AN-46) (YN-65/AN-46)
 * USS Canotia (AN-47) (YN-66/AN-47)
 * USS Lancewood (AN-48) (YN-67/AN-48)
 * USS Papaya (AN-49) (YN-68/AN-49)
 * USS Cinnamon (AN-50) (YN-69/AN-50)
 * USS Silverbell (AN-51) (YN-70/AN-51)
 * USS Snowbell (AN-52) (YN-71/AN-52)
 * USS Spicewood (AN-53) (YN-72/AN-53)
 * USS Manchineel (AN-54) (YN-73/AN-54)
 * USS Torchwood (AN-55) (YN-74/AN-55)
 * USS Winterberry (AN-56) (YN-75/AN-56)
 * USS Viburnum (AN-57) (YN-76/AN-57)


 * USS Abele (AN-58) (YN-77/AN-58)
 * USS Terebinth (AN-59) (YN-78/AN-59)
 * HMS Precept (Z266) (YN-79/AN-73), served as HMS Precept (Z266)
 * Boxelder (YN-80/AN-74), served as HMS Precise (Z285)
 * USS Catclaw (AN-60) (YN-81/AN-60)
 * USS Chinaberry (AN-61) (YN-82/AN-61)
 * USS Hoptree (AN-62) (YN-83/AN-62)
 * USS Whitewood (AN-63) (YN-84/AN-63/AG-129)
 * Palo Blanco (YN-85/AN-64/ATA-214)
 * Paloverde (YN-86/AN-65/ATA-215)
 * USS Pinon (AN-66) (YN-87/AN-66)
 * Prefect (YN-88/AN-75), served as HMS Prefect (Z263)
 * Satinwood (YN-89/AN-76), served as HMS Pretext (Z284)
 * Seagrape (YN-90/AN-77), served as HMS Preventer (Z265)
 * USS Shellbark (AN-67) (YN-91/AN-67)
 * USS Silverleaf (AN-68) (YN-92/AN-68)
 * USS Stagbush (AN-69) (YN-93/AN-69)
 * Allthorn (YN-94/AN-70/ATA-216)
 * Tesota (YN-95/AN-71/ATA-217)
 * Yaupon (YN-96/AN-72/ATA-218)