they not only protected Narraganset Bay, but interdicted the main channels into Buzzards Bay and the east end of Long Island Sound. By late 1943, the threat of a naval attack on the United States had diminished, and with two or four 16-inch guns in most harbor defenses, construction and arming of further batteries was suspended. As 16-inch guns and a companion improved 6-inch gun were emplaced, older weapons were scrapped. With the war over in 1945, most of the remaining coast defense guns, including the recently emplaced 16-inch weapons, were scrapped by 1948. Surviving examples All but four of these guns were scrapped by 1950. One remaining piece is a Mark 3 (Bethlehem Steel No. 138) at Aberdeen Proving Ground, Aberdeen, Maryland, . Another is a Mark 2 (Naval Gun Factory No. 111) at the former Naval Gun Factory at the Washington Navy Yard, part of the Naval Historical Center museum collection. Two Mark 2 guns (Nos. 96 and 100) remain at the Naval Surface Warfare Center Dahlgren Division, Dahlgren, Virginia. Project HARP used some 16-inch, Mark II, Mod 1 barrels for high altitude projectile research. At least two of these barrels can be found at the abandoned Project HARP research site in Barbados, near the eastern end of Grantley Adams International Airport. Another complete HARP gun, made of two 16-inch barrels, is at Yuma Proving Ground, Arizona. Another survivor is the Fort Miles 16 inch mark 2 guns. Gallery See also 16"/50 caliber Mark 7 gun : successor 16"/50 caliber M1919 gun : purpose-built United States Army coast defense gun List of the largest cannon by caliber Seacoast defense in the United States References Bibliography FM 4-85, Service of the Piece, 16-inch gun and howitzer Journals External links DiGiulian, Tony, United States of America 16"/50 (40.6 cm) Mark 2 and Mark 3 DiGiulian, Tony, United States of America 16"/45 (40.6 cm) Mark 1 400 mm artillery Abandoned military projects of the United States Artillery of the United States World War II artillery of the United States Coastal artillery Naval guns of the United States Military equipment introduced in the 1920s