USS F-2 (SS-21)

USS F-2 (SS-21)
Shipname	USS F-2 (SS-21)
Country	United States
Shipyard	Union Iron Works
Launched	1909
Commissioned	1912
Decommissioned	1919
Struck	1922
Displacement	330 tons surfaced
Length	142 ft
Beam	15 ft
Draft	12 ft
Propulsion	Diesel and electric
Speed	14 kn surfaced
Armament	1 × 18 in (450 mm) torpedo tube
Complement	21 officers and men

USS F-2 (SS-21) was an United States Navy submarine of the F-class submarine built for coastal defense in the early 20th century. Laid down by Union Iron Works in San Francisco, California, she served in experimental and training roles during the period encompassing the Taft administration, the World War I era, and the immediate postwar years. F-2's career intersected with major developments in naval architecture, submarine warfare, and undersea technology as the United States expanded its undersea fleet.

Design and construction

Designed under the supervision of designers influenced by the Bureau of Construction and Repair and contemporary European practices, F-2 reflected transitional concepts between pioneering boats like USS Holland (SS-1) and later R-class submarine developments. Built at Union Iron Works in San Francisco, California, her construction paralleled other early American submarine programs overseen by the Navy Department and contractors like Electric Boat Company and Fore River Shipyard. Keel-laying and assembly used steel hull techniques compatible with plans reviewed by figures associated with the Office of the Supervisor of Shipbuilding, while propulsion machinery procurement involved suppliers familiar to the United States Naval Observatory procurement networks. Launched in 1909 and commissioned in 1912, F-2 entered service amid debates in the United States Congress over naval appropriations and strategic posture articulated by the Great White Fleet proponents.

Service history

After commissioning, F-2 was assigned to the Pacific Fleet and operated from bases including San Pedro, California and San Diego, California, participating in trials alongside contemporaries such as USS F-1 (SS-20), USS E-2 (SS-25), and other early 20th-century submarines. Her peacetime duties emphasized training between naval districts, cooperation with Destroyer Squadron units, and experimental exercises directed by officers who had served under leaders tied to the Office of Naval Intelligence and the Naval War College. With the American entry into World War I, F-2 performed coastal patrols, anti-submarine training, and development work supporting doctrines debated at Admiralty equivalents and in coordination with the United States Coast Guard on harbor defense. Postwar, she contributed to evaluations informing later classes like the S-class submarine before decommissioning movements influenced by the Washington Naval Treaty-era naval reductions and Congressional mandates.

Armament and performance

F-2's primary offensive armament consisted of torpedo tubes compatible with Whitehead torpedo-type designs standard in the era, reflecting ordnance developments shared in exchanges with organizations such as the Naval Torpedo Station, Newport and manufacturers tied to Washington Navy Yard contracts. Her torpedo delivery systems and control gear were contemporary with fire-control discussions at the Naval Ordnance Laboratory and were tested in exercises with surface units from the Pacific Fleet. Performance metrics—surface speed near 14 knots, submerged endurance suitable for coastal operations, and displacement around 330 tons surfaced—placed her between experimental craft like USS Porpoise (SS-7) and later operational boats such as USS K-1 (SS-32). Mechanical systems included diesel engines for surface running and electric motors for submerged propulsion, reflecting propulsion debates examined by committees linked to the Bureau of Steam Engineering.

Crew and accommodations

Complemented by a small complement drawn from personnel assigned through Naval Training Stations and warrant officers promoted from service aboard earlier submarines, F-2 typically carried about 21 officers and enlisted men. Living quarters and habitability on board resembled those of sister boats, with constrained berthing, galley facilities overseen by petty officers, and watch rotations influenced by doctrines taught at the United States Naval Academy and the Submarine School, New London in its formative discussions. Crew training incorporated tactics and procedures promulgated in pamphlets from the Chief of Naval Operations staff and in coordination with fleet exercises led by commanders associated with the Fourth Naval District and other operational commands.

Modifications and refits

Throughout her service life, F-2 underwent periodic overhauls at navy yards including maintenance by Mare Island Naval Shipyard personnel and contractors with links to the Bethlehem Steel enterprise for hull work. Modifications addressed improvements in ballast systems, battery capacity monitored by standards from the Bureau of Ordnance, and updates to periscopes and signaling gear procured under specifications influenced by the Naval Communications Service. These refits paralleled broader fleet modernization efforts that informed later submarine design choices advocated by planners inside the Office of the Chief of Naval Operations and committees reviewing postwar naval posture.

Decommissioning and fate

Decommissioned in 1919 during a reduction of older classes and struck from the Naval Vessel Register in 1922, F-2 was disposed of in accordance with policies shaped by legislative actions of the United States Congress and administrative guidance from the Navy Department. Her materials and salvage operations involved yards experienced with dismantling early submarines, with components sometimes repurposed in shore establishments such as the Naval Shipyard facilities or transferred to training commands for instructional use. The decommissioning of F-2 reflected the transitional period between pioneering submarine efforts and the emergence of modern undersea forces that would serve in later conflicts.

Category:United States submarines