U.S. Navy Submarines

WWI Era

USS Holland
Plunger-class
B-class
C-class
D-class
E-class
F-class
G-class
K-class
L-class
USS M-1
AA-1-class
N-class
O-class
R-class

Inter-War Era

V-Boats

The "V-Boats" were a group of nine U.S. Navy submarines which were authorized by Congress in 1916 as large, high speed "fleet boats" to follow the AA-1 class. Only the three V-1 class boats were actually high speed designs; V-4 was instead a large minelaying submarine, the two V-5 boats were cruiser submarines, and V-7 onwards were attempts at a "medium" submarine.

V-1 ⁄ Barracuda-class

V-1 ⁄ USS Barracuda (SS-163)
V-2 ⁄ USS Bass (SS-164)
V-3 ⁄ USS Bonita (SS-165)

V-4 ⁄ USS Argonaut (SM-1)

V-5 ⁄ Narwhal-class

V-5 ⁄ USS Narwhal (SS-167)
V-6 ⁄ USS Nautilus (SS-168)

V-7 ⁄ USS Dolphin (SS-169)

V-8 ⁄ Cachalot-class

V-8 ⁄ USS Cachalot (SS-170)
V-9 ⁄ USS Cuttlefish (SS-171)

Fleet Submarines

Porpoise-class
Salmon-class
Sargo-class
Mackerel-class

World War II Era

Fleet Submarines

Tambor ⁄ Gar-class

The Tambor ⁄ Gar class submarines are considered the U.S. Navy's first truly successful fleet submarines.

Gato-class

The Gato class submarines were the U.S. Navy's first mass produced class of fleet submarines, with a combined total of 77 ships produced by four shipyards: the Electric Boat Company, Portsmouth Naval Shipyard, Mare Island Naval Shipyard, and Manitowoc Shipbuilding Company. The U.S. Navy ordered "only" 73 Gato-class, but the Manitowoc yard producecd an additional four Gato due to delays in the transition to the improved Balao-class.

The Gatos were virtually identical to the Tambors, primarily differing in being five feet longer in order to accccomodate an additional watertight bulkhead dividing the engine room into two seperate compartments. Diving depth was increased from 250 feet to 300 feet, but this was primarily because the Bureau of Construction and Repair decided that it had calculated the diving depth too conservatively; there were no actual changes to the pressure hull.

Balao-class

The Balao-class submarines were a further improvement over the the Gato-class. One hundred thirty-two ships of this class were built, with an additional sixty-two units cancelled.

The Balaos were (again) virtually identical in design to previous fleet submarine classes, but with a thicker and stronger pressure hull of new High-Tensile Steel (HTS) alloy enabling an increase in rated depth to 450 feet. This was initially reduced to 400 feet due to the limited capacity of the trim pump, an issue which was resolved with a new pump by 1944. In addition, the Balaos incorporated all of the various superstructure reduction modifications being performed as refits on the older classes.

Tench-class

The Tench-class submarines were an further improvement over the Balao-class. Eighty ships of this class were ordered, but due to the end of the war only twenty-nine were built and the remaining fifty-one were cancelled.

The Tenches were (again, again!) virtually identical in design to the previous fleet submarine classes, but the ballast tanks were rearranged in order to eliminate the vulnerable vent riser pipes for the #1 and #7 tanks. This also enabled the #7 tank to be converted from a ballast tank to a fuel ballast tank for increased range, and freed up enough space to allow for four additional torpedo reloads.

Cold War Era

War Prizes

The U.S. Navy took as war prizes the German Type XXI Elektroboot U-Boats U-2513 and U-3008. These boats were fully overhauled and extensively tested, but unlike other Allied nations, the United States never commissioned them into its own service.

Type XXI Elektroboot

Greater Underwater Propulsive Power (GUPPY) Program

GUPPY I: The first GUPPY conversions were performed on the Tench-class fleet submarines USS Odax and USS Pomodom, and involved extensive streamlining of the upper superstructure, the removal of all deck guns, and the replacement of the entire bow with a new, rounded "Guppy bow" optimized for underwater performance.
GUPPY II: The GUPPY II (Project SCB 47) conversions were the first "production" GUPPY conversions, performed on thirteen Balao-class and eleven Tench-class fleet submarines (including the two GUPPY I subs). GUPPY II incorporated all of the GUPPY I modifications, plus a new snorkel system and an enlarged sail with sufficient space to accomodate both original periscopes alongside new masts for the ESM system, and the snorkel system's air intake and exhaust.
GUPPY IA: The GUPPY IA (Project SCB 47B) conversions were the second batch of GUPPY conversions, performed on nine Balao-class and one Tench-class fleet submarines. GUPPY IA was a slightly reduced-cost version of GUPPY II with Sargo II batteries in the original wells.
Fleet Snorkel: Due to the high cost of GUPPY IA fleet submarine conversions, the "Fleet Snorkel" program was developed as a cost effective basic upgrade option. Eight Tench-class submarines were retrofitted with this upgrade, of which one was immediately transferred to Pakistan and the other seven were retained by the U.S. Navy.
GUPPY IIA: The GUPPY IIA (Project SCB 47C) program was essentailly a repeat of GUPPY IA, but with one of the two forward diesels removed to relieve overcrowding. Four Tench-class were refitted to this standard from 1952-1954.
GUPPY IB: GUPPY IB was an informal designation for the "export version" of the GUPPY IA upgrade package, which included the snorkel and battery upgrades but not the new sonar, fire control, and ESM. Two Gato-class submarines were refitted to this standard for Italy, and two Balao-class were refitted to this standard for the Netherlands.
GUPPY III: The GUPPY III program (SCB 223) was a further upgrade of GUPPY II boats, with a taller, unstepped "North Atlantic" sail and the addition of a 12.5-foot (3.8 m) expansion section to the main hull just forward of the control room. This new space accomodated a seperate sonar room as well as additional berthing, electronics and storage spaces. In addition, one of the forward diesels wwas removed as in GUPPY IIA. The Navy wanted to upgrade all 24 GUPPY II boats to GUPPY III, but was only able to budget nine.

Fleet Submarines (SS ⁄ SSN)

Tang-class: The Tang-class submarines (Project SCB 2) were the U.S. Navy's first postwar fleet submarines, incorporating lessons from both the GUPPY conversions and the German Type XXI U-boats which had been handed over as war prizes.
USS Darter: The USS Darter (Project SCB 116) was a further development of the Tang-class. This was originally intended to be a three ship class, but the second and third ships were modified during construction into cruise missile submarines (see Greyback-class below).
USS Nautilus
USS Seawolf
Skate-class: The Skate class submarines (Project SCB 121) were the first production run of nuclear powered fleet submarines, essentially an evolution of the Tang-class combined with a scaled-down version of the Nautilus nuclear propulsion. They were intended as "budget" nuclear submarines due to concerns with the high cost of the Nautilus.

Hunter-Killer Submarines (SSK ⁄ SSKN)

Gato-class (modified): Seven Gato-class fleet submarines were converted to hunter-killer configuration with a snorkel added, both forward diesel engines removed, and sonar equipment added.
Barracuda-class: The Barracuda-class submarines were purpose built for the low-cost, high-volume "hunter-killer" role. However, only three were built and all were retired after only eight years of service (1951 to 1959).
USS Tullibee: The one-off Tullibee (Project Nobska) was an attempt to miniaturize nuclear propulsion down to the level of the "hunter-killer" concept as opposed to a fleet or fast attack boat. While the ASW-oriented features introduced in her design -- a large bow sonar, angled torpedo tubes mounted amidships, and nuclear turbo-electric drive -- were highly successful, making her smaller and less capable than the contemporary Thresher ⁄ Permit class fast attack submarine did not yield the hoped-for cost savings. As a result, the "hunter-killer" submarine concept was permanently abandoned and Tullibee was redesignated from SSKN-597 to SSN-597.

Fast Attack Submarines (SS ⁄ SSN)

USS Argonaut
Barbel-class: The Barbel-class (Project SCB 150) were the USN's first modern attack submarines with an Albacore hull layout and its also its last diesel-electric combat submarines.
Skipjack-class: The Skipjack-class (Project SCB 154) were nuclear-powered counterparts of the Barbel-class, and the world's first nuclear fast attack submarines.
Thresher ⁄ Permit-class
Sturgeon-class
USS Narwhal: Project SCB 245.
USS Glenard P. Lipscomb
Los Angeles-class
Seawolf-class

Radar Picket Submarines (SSR ⁄ SSRN)

Radar picket submarines were developed as a less vulnerable alternative to the effective but dangerously exposed radar picket destroyers which were used to counter kamikaze attacks during World War II.

Wartime Radar Pickets

SV Radar Boats: The earliest radar picket boats were wartime interim conversions of the USS Grouper (SS-214) and USS Finback with a modified version of the standard SV air-search radar fitted on the periscope so that it could operate from shallow depth. A slightly more extensive version of this conversion, including the creation of a rudimentary combat information center, was initiated on four more boats before VJ-Day.
SR-2 Radar Boats: The Navy had originally ordered 24 "full" wartime picket conversions to support the planned invasion of Japan, but only two were brought to completion after the war, on the Tench-class USS Requin (SS-481) and USS Spinax (SS-489). This conversion involved mounting an SR-2 search radar and SV-2 height finder radar on the afterdeck, with corresponding electronics and a combat information center taking over the aft torpedo room. In addition, homing beacons were mounted on the forward decks to provide a reference point for friendly aircraft being guided by the picket.

Project MIGRAINE

Migraine I: The " Migraine I" program consisted of radar picket conversions of the Tench-class USS Spinax (SS-489) and USS Requin (SS-481). The SR-2 search radar was now mounted on the aft portion of the sail, and the SV-2 height finder was installed on a tower on the aft deck. Two forward torpedo tubes were sacrificed to make room for supporting electronics, the crew mess and galley were sacrificed for a combat information center, and all four aft torpedo tubes were removed to make the entire aft torpedo room into a replacement berthing and storage space.
Migraine II: The " Migraine II" program (SCB 12) consisted of radar picket conversions of the USS Burrfish and USS Tigrone plus equivalent upgrades of the already converted Requin and Spinax. As with Migraine I, the aft torpedo tubes were removed for berthing and storage, but now the radar equipment was fitted in the aft battery well, with high capacity GUPPY batteries installed in the forward battery well to compensate. SR-2 and SV-2 radars were both mounted on raised masts.
Migraine III: The " Migraine III" program (Project SCB 12A) was the final set of radar picket submarine conversions, with six Gato-class submarines being used (SS-269 through -272, and -274). These had the same radar equipment as Migraine II, but a 24-foot hull extension enabled the addition of a CIC without repurposing existing compartments and the sail was extended to enable it to house both the SR-2 and SV-2 radars.

Sailfish-class

The Sailfish-class (Project SCB 84) submarines were the first purpose-built radar picket submarines.

USS Triton

USS Triton (Project SCB 132) was the first and only nuclear-powered radar picket submarine, as well as the only U.S. Navy submarine ever with two reactors and the last U.S. Navy submarine with the "traditional" fleet boat pattern of a surface-optimized hull, twin screws, aft torpedo room, and a seperate conning tower compartment in the sail.

Guided Missile Submarines (SSG ⁄ SSGN)

Balao-class (Modified): Two Balao-class fleet submarines, USS Tunny (SSG-282) and USS Barbero (SSG-317) were converted into guided missile submarines with a massive external missile hangar for two SSM-N-8 Regulus nuclear cruise missiles on the aft deck.
Greyback-class: The Greyback-class missile submarines (Project SCB 161) were originally laid down as Darter-class fleet submarines, but were converted into guided missile submarines during construction. These submarines had an expanded bow section with an internal missile hangar for two SSM-N-9 Regulus II nuclear cruise missiles. USS Greyback made a single successful test launch of a prototype Regulus II missile prior to the program's cancellation, after which both submarines were modified to instead carry four of the older SSM-N-8 Regulus. These conversions were done in lieu of a more expensive purpose-built Regulus II SSG class, Project SCB 137.
USS Halibut (SSGN-587): The one-off USS Halibut (Project SCB 137A) was a nuclear powered counterpart to the Greyback-class guided missile submarines, designed for two SSM-N-9 Regulus II nuclear cruise missiles and subsequently modified to carry five SSM-N-8 Regulus. After the Regulus cruise missiles were replaced by Polaris ballistic missiles, Halibut was officially redesignated as an attack submarine, but in reality secretly modififed into a dedicated underwater espionage vessel.
Ohio-class (Modified): From 2002 to 2008, the four oldest Ohio-class SSBNs were converted into SSGNs. Twenty-two of their Trident ballistic missile tubes were modified to load seven-tube cluster launchers for Tomahawk cruise missiles, and the other two were converted into swimmer lockout chambers for SEAL naval commandos.

Fleet Ballistic Missile Submarines (SSBN)

Collectively known as the "41 for Freedom", the George Washington, Ethan Allen, Lafayette, James Madison, and Benjamin Franklin classes of fleet ballistic missile submarines were all armed with UGM-27 Polaris missiles and built in rapid succession from 1959 to 1967. All thirty-one of the combined Lafayette, James Madison, and Benjamin Franklin classes were subsequently retrofitted with multiple warhead capable UGM-73 Poseidon missiles, and six each of the James Madison and Benjamin Franklin classes were further retrofitted with UGM-96 Trident I missiles.

After the "41 for Freedom", construction of additional SSBNs was restricted by the Strategic Arms Limitations Talks II agreement. As a result, only eighteen of the next generation Ohio-class SSBNs were built and the George Washington and Ethan Allen classes were withdrawn from strategic role as the Ohios entered service. The remainder of the "41 for Freedom" were retired at the end of the Cold War.

George Washington-class
Ethan Allen-class: Project SCB 180.
Lafayette-class: Project SCB 216 ⁄ 216A.
James Madison-class
Benjamin Franklin-class
Ohio-class

Modern Era

Fast Attack Submarines (SSN)

Virginia-class

The Virginia class attack submarine was developed as the "New SSN" program, previously "Centurion". It was intended to produce a smaller and less expensive but still highly capable alternative to the Seawolf-class, with a substantial design emphasis on multi-mission capability against asymmetric opponents in near-shore littoral waters.

The Navy placed an initial order for eighteen submarines and the USS Virginia was commissioned in 2004. As of 2023, a total of thirty-eight Virginia-class submarines have been ordered; twenty-one are in active service, three are in trials, ten are under construction, and four are pending. The Virginia-class is intended to fully replace the remaining units of the Los Angeles-class.

In March 2023, it was announced that Australia intended to purchase three Virginia-class submarines with an option for two more in order to cover the gap between the retirement of its Collins-class diesel electric submarines and the development of the joint "SSN-AUKUS" class (intended as a next-generation SSN for both the Royal Navy and the Royal Australian Navy, with substantial commonality with the Virginia class). This was subsequently clarified to be the purchase of two of the U.S. Navy's existing Block III or Block IV Virginias, followed by one new Virginia from future production.

Block I

First four submarines built, using modular "raft" construction of internal equipment spaces.

USS Virginia (SSN-774)
USS Texas (SSN-775)
USS Hawaii (SSN-776)
USS North Carolina (SSN-777)

Block II

Six submarines built, no design changes from Block I but utilizing improved construction techniques with four sections rather than ten.

USS New Hampshire (SSN-778)
USS New Mexico (SSN-779)
USS Missouri (SSN-780)
USS California (SSN-781)
USS Mississippi (SSN-782)
USS Minnesota (SSN-783)

Block III

Eight boats built, with revised bow featuring new Large Aperture Bow (LAB) horseshoe sonar array and two 87-inch Virginia Payload Tubes in place of twelve 21-inch Mark 45 vertical launch tubes. The Payload Tubes are a slightly downsized adaptation of the 88-inch payload modules from the Ohio-class SSGNs, containing six rather than seven Tomahawk cruise missiles.

USS North Dakota (SSN-784)
USS John Warner (SSN-785)
USS Illinois (SSN-786)
USS Washington (SSN-787)
USS Colorado (SSN-788)
USS Indiana (SSN-789)
USS South Dakota (SSN-790)
USS Delaware (SSN-791)

Block IV

Ten boats ordered; as of 2023, three commissioned, three launched, and four under construction.

USS Vermont (SSN-792)
USS Oregon (SSN-793)
USS Montana (SSN-794)
USS Hyman G Rickover (SSN-795)
USS New Jersey (SSN-796)
USS Iowa (SSN-797)
USS Massachusetts (SSN-798)
USS Idaho (SSN-799)
USS Arkansas (SSN-800)
USS Utah (SSN-801)

Block V

See SSGN section.

Block VI ⁄ Block VII

Due to procurement of the next generation SSN(X) class being pushed back from 2025 to ~2033, it is speculated that the Navy may order five "Block VI" and five "Block VII" Virginias.

SSN(X) Program

The U.S. Navy's next class attack submarine is currently being developed as the "Next Generation Attack Submarine" (SSN[X]) project, previously "Improved Virginia-class". This design is projected to return to the size range and open ocean submarine warfare focus of the Seawolf class, although the Navy specifictions decclare that it will also retain the littoral multi-mission capabilities of the Virginia. SSN(X) submarines would start being constructed in place of additional Virginia-class submarines in the mid to late 2030s, most likely at the same rate of two per year.

Guided Missile Submarines (SSGN)

Virginia-class Block V

While not officially designated as SSGNs, the upcoming Block V Virginia-class submarines will have a total of six 87-inch Payload Tubes capable of carrying 36 vertically launched Tomahawk cruise missiles, plus additional Tomahawks as part of the "up to 37 torpedo-sized weapons" for its four 533 mm (21") torpedo tubes. Moreover, they are officially slated to cover the planned retirement of the four Ohio-class SSGN conversions, and the Payload Tube approach retains the ability of the Ohio SSGN to be easily refitted with future missile types that would not fit in a submarine torpedo tube.

Block V

Ten boats planned; as of 2023, six under construction. These ships are built with an 80-foot hull extension (the "Virginia Payload Module") to accomodate an amidships missile compartment with four 87-inch Virginia Payload Tubes.

USS Oklahoma (SSN-802)
USS Arizona (SSN-803)
USS Barb (SSN-804)
USS Tang (SSN-805)
USS Wahoo (SSN-806)
USS Silversides (SSN-807)
USS John H. Dalton (SSN-808)
Unnamed (SSN-809)
Unnamed (SSN-810)
Unnamed (SSN-811)

Fleet Ballistic Missile Submarines (SSBN)

In 1994, the U.S. government concluded that its strategic needs could be fully met by fourteen SSBNs; as a result, four Ohios were removed from the strategic role. A further reduction down to 280 missile tubes was agreed to as part of the "New START" nuclear arms reduction treaty, which was implemented by the deactivation of four tubes on each of the active Ohios, bringing them down to twenty active missile launch tubes. The agreement further dictates that no more than 240 of these 280 missile tubes may be in a deployed status at any time, corresponding to a maximum of twelve fully loaded Ohio-class at sea, but the actual count at the last "treaty check" was 212, representing ten Ohios actually at sea and one or two in the process of loading ⁄ unloading.

The Navy has currently stated that it will be constructing "at least twelve" next generation Columbia-class SSBNs, which will be slightly larger than the Ohio-class but carry only sixteen missiles each. This would be a substantial voluntary reduction in deployed missiles, as the New START numbers would allow up to seventeen Columbias built with up to fifteen at sea at any time. It is also a massive reduction from the Cold War numbers; the SALT I treaty agreement had specified that the United States would limit itself to no more than 710 sea-launched ballistic missiles on up to 44 submarines, while the Soviet Union would have no more than 950 SLBMs on up to 62 submarines.

Columbia-class

The Columbia-class ballistic missile submarines are currently being developed as the "Future Follow-On Submarine" (SSBN[X]) project, previously "Ohio Replacement Submarine". They are slated to replace the Ohio-class starting in 2031. They will carry sixteen UGM-133 Trident II missiles each, with the first eight Columbias expected to carry the D5 Life Extension Program (D5LE) upgrade of the missile and subsequent vessels carrying the D5 Life Extension Program 2 (D5LE2) upgrade.

USS District of Columbia (SSBN-826)
USS Wisconsin (SSBN-827)