Known by her crews as "Alpha Boats," Assault Support Patrol Boats, participated in the Vietnam War, as part of the Brown Water Navy. The boats were utilized for escort duty, gunboats, interdiction and surveillance craft, and minesweepers. Fifty feet in length, the steel and aluminum craft had armament including a 20mm cannon, .50-caliber machine guns, and MK-19 grenade launchers. The craft also carried a straight drag chain to sever the wires of water mines. The first two boats arrived in September 1967, providing escort protection during troop transport of riverine assaults. Problems with seaworthiness in early 1968, and with the boat's armor, led the U.S. Navy to utilize the craft for Task Force 117 (Mobile Riverine Task Force) primarily as minesweepers and base defense craft. Despite these shortcomings, the boats proved effective while clearing Viet Cong mines placed in the river bottom mud.
A model of an ASPB is on display in the America's Wars in Vietnam: 1961-1975 exhibit in the south end of the Cold War Gallery, Bldg. 70, Washington Navy Yard.
War in the Shallows: U.S. Navy Coastal and Riverine Warefare in Vietnam
Image: 80-G-K-42552: Assault Support Patrol Boat (ASPB), November 1967. Patrols a Mekong Delta canal. Note the U.S. Army CH-17 "Chinook" helicopter above.