Assault Support Patrol Boat
ASPB in South Vietnam c.1968
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Class overview | |
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Name | ASPB (Assault Support Patrol Boat) |
Operators | |
Completed | 86 |
General characteristics | |
Type | Riverine patrol boat |
Length | 50 ft (15 m) |
Propulsion | 2 × 430hp General Motors 12V71 diesel engines |
Speed | 14.8 knots |
Range | 130 nautical miles (240 km; 150 mi) |
Complement | 5 |
Armament |
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The Assault Support Patrol Boat (ASPB) (also known as the Alpha Boat), was a heavily armed and armored riverine patrol boat developed by the United States Navy for use in the Vietnam War from late 1967.
History
The ASPB was approximately 50 feet (15 m) long, its hull was constructed of 7⁄32 inch (5.6 mm) steel, from the
The first ASPBs arrived at
On 21 December 1967, ASPB 111-4 hit a 75-pound mine 2 miles (3.2 km) northwest of Đồng Tâm Base Camp. Although the mine detonated right against the ASPB, the charge failed to puncture the hull, and the ASPB was able to return to base on its own power with only moderate damage.[2]: 182
These boats were followed by another fifty craft ordered on 24 January 1968, however within months of their deployment, the boats began revealing some shortcomings. Between February and March 1968 four ASPBs sank due to noncombat reasons. In one event, on 2 March two passing ASPBs swamped ASPB 91–1, causing the boat to sink in less than a minute and drowning a sailor who became trapped in a berthing compartment. A Navy investigation of all four sinkings concluded that the primary faults were the lack of seaworthiness caused by inadequate compartmentalization and marginal buoyancy, coupled with excessive weight and a low freeboard. As a quick fix, Naval Forces Vietnam tried to improve the ASPB's seaworthiness by removing engine-compartment armor to reduce top weight. The armor also never lived up to its promise. Engineers had difficulty developing a hard, lightweight armor that was not brittle. On the first generation boats, a 75mm recoilless rifle round aimed at the cockpit could break off an entire piece of armor and propel it through the cockpit. By late 1969 most ASPBs were being used only for minesweeping and base security duties.[2]: 181
Mark II prototypes
Stewart Seacraft built an ASPB Mark II prototype at Berwick, Louisiana.[7] The Stewart Mark II had three gun turrets and a mortar well in the extreme bow and bar armor around midships superstructure.[8]
Operators
- United States – U.S. Navy
- South Vietnam – Republic of Vietnam Navy
- Khmer Republic – Khmer National Navy
See also
References
- ^ ]
- ^ .
- ^ "NH 95973 50-foot assault support patrol boat (ASPB)". Naval History and Heritage Command. 17 August 1967. Retrieved 2 May 2020.
- ^ Wells II, William R. (August 1997). "The United States Coast Guard's Piggyback 81mm Mortar/.50 cal. machine gun". Vietnam Magazine. Retrieved 16 January 2012.
- ^ Bob Stoner. "Notes on Mk 2 Mod 0 and Mod 1 .50 Caliber MG/81mm Mortar".
- ^ a b "US Naval Forces Vietnam Monthly Historical Supplement September 1967". Department of the Navy. 2 January 1968. Retrieved 2 May 2020. This article incorporates text from this source, which is in the public domain.
- ^ "NH 95845 Assault support patrol boat (ASPB), Mark II". Naval History and Heritage Command. Retrieved 2 May 2020.
- ^ "NH 95981 Assault support patrol boat (ASPB), Mark II". Naval History and Heritage Command. Retrieved 2 May 2020.
- ^ "NH 95842 Assault support patrol boat (ASPB), Mark II". Naval History and Heritage Command. Retrieved 2 May 2020.
- ^ "Gunboat". Sikorsky Archives. Retrieved 2 May 2020.