FAS | Military | DOD 101 | Systems | Ships ||||
Index | Search |

Submarine Warfare

On the NAUTILUS men's hearts never fail them.
No defects to be afraid of, for the double shell is as firm as iron,
no rigging to attend to, no sails for the wind to carry away;
no boilers to burst, no fire to fear, for the vessel is made of iron, not of wood;
no cove to run short, for electricity is the only power;
no collision to fear, for it alone swims in deep water;
no tempest to brave, for when it dives below the water, it reaches absolute tranquility.
That is the perfection of vessels.

In the midst of significant changes in mission requirements spawned by advances in technology and the threat, the Navy’s attack submarine (SSN) force remains an important multimission component capable of conducting covert operations in forward regions. SSN missions include gathering surveillance data, communicating tactical information, controlling the surface and undersea battlespace, and delivering strike weapons or special operations forces ashore in contingencies. The QDR reinforced the ongoing shift in SSN missions from open-ocean antisubmarine warfare and surveillance toward power projection, support of special operations forces, and littoral ASW, while making a modest reduction in force size by the end of the FYDP.

As directed by the QDR, the ongoing deactivation of older SSNs will decrease the force from 65 units in FY 1998 to 50 units in FY 2003. This force structure reflects continued deactivations of SSN-637 and older 688-class submarines, deliveries of the remaining two Seawolf-class (SSN-21) units through FY 2003, and subsequent deliveries of the New Attack Submarine (NSSN) class starting in FY 2004.

In March of 1998 the Chairman of the Joint Chiefs of Staff ordered a new study of attack Submarine Force levels as a follow-up to the Quadrennial Defense Review (QDR). Its goal is to determine the number of SSNs required for peacetime forward presence, national tasking, and warfighting in the 2015-2025 time frame. In determining this future need, the study will assess the importance of stealth in littoral regions and whether submarines will be required to assume new roles because of the vulnerability of other platforms. It will also build on previous force level analysis and the Defense Science Board’s recent study on the Submarine of the Future. In the context of the total DoD budget, affordability will be a major consideration. The Joint Staff (J8) will lead the study, with participation by the Offices of the Under Secretary of Defense for Acquisition and Technology (A&T), the Under Secretary of Defense for Policy, and the Under Secretary of Defense for Program Appraisal and Evaluation (PA&E). The Defense Intelligence Agency and the Navy – particularly the Submarine Warfare Division (N87) in the Office of the Chief of Naval Operations – will also assist. The results of the study were expected to be briefed to the Secretary of Defense in spring 1999.

The existing DOD guidance calls for a force of 50 attack submarines, although some Navy studies suggest that current operational requirements demonstrate a need for a force of at least 72 submarines. These studies, which included the Joint Staff Submarine forces of the Future Study (1992-93) and the Navy Fleet Commander's Study on SSN requirements (1996-97), concluded that 51-72 SSNs were required and that the peacetime requirement for forward presence was most limiting. Existing plans are sufficient to meet the goal of 50 boats, although higher numbers would require modification to these plans. According to Navy secretary Richard Danzig, as of October 1999 the Joint Chiefs of Staff were studying options for increasing the size and capability of the submarine force. The three options under review include by converting older Ohio-class SSBN submarines to so-called SSGNs at a cost of $420 million; refueling and extending by 12 years the service life of perhaps eight Los Angeles-class (SSN 688) subs at a cost per copy of $200 million; or building new Virginia-class (SSN 774) subs at a rate of at least four over the next five years, at a cost of roughly $2 billion per boat. The FY2000 Defense Authorization bill requires the Navy to study converting four of the oldest Tridents to the new SSGN configuration.

The JCS Submarine Force Structure Study, completed in November 1999, concluded that the optimal force structure would be 68 attack submarines by 2015 and 76 by 2025, with the minimum being at least 55 by 2015 and 62 by 2025. The first would be to refuel some Los Angeles-class submarines previously scheduled to be decommissioned. The report called for at least 18 Virginia-class submarines by 2015. The current Navy acquisition plan calls for ordering one per year through 2006, and two a year after that. The proposal in the Force Structure Study calls for the Navy to go to two a year in 2004, two years early, and to buy three in 2008. A final element would be to convert four older Ohio-class ballistic missile submarines to an attack role.

In June 2000 Rear Adm. Albert Konetzni, commander of submarine forces Pacific, testified that the Pacific fleet now has 26 attack submarines, versus a requirement for 35 subs to provide CVBG support and engagement with allies. Rear Adm. John Padgett, commander of submarine group two and naval region Northeast, said that the Atlantic fleet could easily use 40 submarines to for surveillance, carrier battle group support and engagement with allies to fully support the requirements of the regional commanders-in-chief. Over the previous year the Atlantic submarine force has shrunk from 35 boats to 29.

A dual crew would enable the submarine to get back to sea quickly after returning its primary crew from a deployment. The Navy uses a dual-crew arrangement to man its 18 ballistic-missile submarines, but those larger ships are designed for quick turnaround. The SSBNs have oversize hatches that speed the replacement of parts and supplies between deployments, features that are not part of the design of the new Virginia-class attack subs. A dual-crew arrangement would not double each attack sub's time on station. With the extra maintenance needed to accommodate dual crews, the ships would be available for duty only about 40 percent more than single-crew subs. Dual crews also would burn up each sub's nuclear fuel more quickly, forcing the Navy to refuel the ships or decommission them well before their hulls reach their 33-year life expectancy. Currently there aren't enough mid-level officers to provide dual crews for three to five subs, and the Navy would need years to recruit and train the extra officers and sailors needed to give each sub an alternate crew.

The changes in the US Submarine Force since the end of the Cold War involve shifts in submarine warfighting concepts and doctrine, from the deterrence of global war to the support of U.S. national interests in regional crises and conflicts; from a primary Anti-Submarine Warfare (ASW) orientation against nuclear powered submarines to taking full advantage of the modern submarine's multi-mission capabilities; from weapon loadouts of primarily MK 48 torpedoes to Tomahawk Land-Attack missiles or other weapons.

The transitions in the submarine force follow directly from the transitions in the world order and the evolving nature of the US Navy. The world order has shifted from a bi-polar superpower alignment to a multi-polar collection of interests. During the Cold War the Soviets, concerned for the safety of their ballistic missile submarines in light of US submarine capability, decided to use a significant percentage of their attack submarines as escorts. While the likelihood of global conflict is greatly reduced, there is an increasing chance of regional conflict. The composition and operational posture of the US Navy reflects this, having changed from a blue water emphasis to a littoral emphasis. For the submarine force this has meant several changes in roles. Prior to the end of the Cold War, Anti-Submarine Warfare was the major role for US Attack Submarines. Now US submarines are more multi-mission oriented. Intelligence gathering has shifted from strategic to tactical reconnaissance.

The primary roles and missions for the U.S. submarine force are:


In peacetime the deployment of submarines in forward areas can demonstrate US interest in the region. Alternatively, submarines are valuable if the President decides that interest should not be visible until a specific time. The long endurance and high transit speeds of nuclear submarines make them particularly attractive for rapid deployments to forward areas in such circumstances. Once on station the attack submarine can be highly visible - in 1991 U.S. submarines conducted more than 200 port visits to 50 cities around the world - or invisible. The submarine can also be used to land small groups of special operations forces, or to conduct surveillance of an area, or carry out electronic surveillance to gain valuable intelligence. These submarines can also operate independently or in direct support of carrier battle groups, surface task forces, or with other submarines.


Submarines have been employed in various forms of surveillance and intelligence collection throughout the Cold War. Although the SSN force has been cut by nearly 40 percent since 1994, the volume of Intelligence, Surveillance, and Reconnaissance [ISR] mission tasking directed to the Submarine Force has more than doubled. The the attack submarine has been a valuable platform for surveillance, intelligence, and warning. This capability comes from the submarine's ability to enter an area to watch, to listen, to collect information without being seen. While satellites and aircraft are used to garner various types of information, their operations are inhibited by weather, cloud cover, and the locations of collection targets. In some situations it is difficult to keep a satellite or aircraft in a position to conduct sustained surveillance of a specific area. And satellites and aircraft are severely limited in their ability to observe or detect underwater activity. Space-based signals interception is critically and uniquely complemented by submarine intercepts. Because submarines are close to the action, they can capture signals that are too elusive or enveloped in background noise for our satellites to detect. Submarines can position themselves to capture line-of-sight transmissions or observe over water tests that would otherwise elude national systems. Submarines also provide sole source “tip-off” information, which enables the intelligence community to optimally allocate other intelligence collection assets. In the future, submarines may also use Autonomous Underwater Vehicles (AUV) or drones to collect intelligence or conduct sustained surveillance of critical regions of the world. These vehicles will be sent out from a submarine to carry sensors into areas where it may not be safe or prudent for the submarine to venture. After fulfilling its mission, the AUV could return to the launching submarine, or transmit the data underwater or to a satellite.


Submarines have long been used for special operations - carrying commandos, reconnaissance teams, and agents on high-risk missions. Most special operations by US submarines are carried out by SEALs, the Sea-Air-Land teams trained for missions behind enemy lines. These special forces can be inserted by fixed-wing aircraft, helicopter, parachute, or surface craft, but in most scenarios only submarines guarantee covert delivery. Once in the objective area, SEALs can carry out combat search-and-rescue operations, reconnaissance, sabotage, diversionary attacks, monitoring of enemy movements or communications, and a host of other clandestine and often high-risk missions. US nuclear powered submarines have repeatedly demonstrated the ability to carry out special operations involving many swimmers. During exercises, which include Army, Air Force, and Marine Corps special operations personnel as well as SEALs, submarines recover personnel who parachute from fixed-wing aircraft and rappel down from helicopters into the sea, take them aboard, and subsequently launch them on missions. These Special Warfare Team Missions include combat swimmer attacks, reconnaissance and surveillance, infiltration and exfiltration across the beach, beach feasibility studies, hydrographic survey, and Surf Observation Teams in support of amphibious landing operations.


U.S. attack submarines carry Tomahawk Land-Attack Missiles (TLAM), which provide the capability for long-range, precision strike with conventional warheads against shore targets. First used in combat in the 1991 Gulf War, US Navy surface ships and submarines fired 288 land-attack variants of the Tomahawk during the Gulf War. Battleships, cruisers, and destroyers launched 276 of the missiles and 12 were launched from submarines - the USS LOUISVILLE (SSN 724), operating in the Red Sea launched eight missiles and the USS PITTSBURGH (SSN 720), operating in the eastern Mediterranean, launched four missiles. These launches demonstrated the ability of the submarine to operate as part of an integrated strike force, with targets and related strike data being communicated to them at sea.


Attack submarines are integrated into Navy battle group operations. Typically, 2 attack submarines are assigned to each battle group. These submarines particpate with the battle group in all pre-deployment operational training and exercises. While operating with the battle group, tactical control or command of the submarines is routinely shifted to amphibious group commanders, battle group commanders, destroyer squadron commanders, or even NATO commanders. Likewise, tactical control of NATO submarines is routinely shifted to U.S. commanders.


Stopping enemy surface ships and submarines from using the seas is an important mission for submarines. Attack submarines can perform sea denial missions in a variety of scenarios, from general war against a major maritime power, to blockages of enemy ports. Attacks against enemy surface ships or submarines can be part of a war of attrition, where the object is to destroy as much of the opposing naval fleet or merchant shipping as possible, or such attacks can be directed against specific targets. An example of the attrition campaign was the U.S. submarine operations against the Imperial Japanese merchant marine in World War II, with US undersea craft sinking more than half of Japan's merchant vessels, as well as a large number of warships. During the Falklands War in 1982, the sinking of the Argentine cruiser GENERAL BELGRANO by the British nuclear-powered submarine CONQUEROR caused the remainder of the Argentine surface fleet, including its aircraft carrier, to return to port. There were no further sorties by Argentine surface warships during the conflict because of the demonstrated threat from British nuclear-powered submarines. The principal US submarine weapon for attacking enemy surface ships or submarines is the MK 48 torpedo, with the improved ADCAP (Advanced Capability) variant now entering service. This is a heavy-weight torpedo, with a long range and a large warhead. Advanced guidance allows it to be used against both surface ships and submarines, with the ability to engage high-speed, maneuvering targets. Attack submarines also carry anti-ship missiles that can engage enemy surface ships at ranges beyond those of torpedoes. The Tomahawk Anti-Ship Missile (TASM), has a range of more than 250 nautical miles and is launched while the submarine is completely submerged. The Tomahawk can be carried in place of torpedoes and can be launched from torpedo tubes. Half of the submarines in the LOS ANGELES (SSN 688) class are also fitted with 12 vertical tubes that can launch TLAMs and TASMs. Submarines also carry mines to deny sea areas to enemy surface ships or submarines. Two types of mines are used by submarines, the enCAPsulated TORpedo (CAPTOR) and the Submarine-Launched Mobile Mine (SLMM). The CAPTOR can be used against submarines in deep water, while the SLMM is a torpedo-like weapon that, after being launched by the submarine, can travel several miles to a specific point, where it sinks to the sea floor and activates its mine sensors. It is particularly useful for blockading a harbor or a narrow sea passage.

Submarine Communications

Submarines communicate via multiple, complementary RF systems, covering nearly all the military communications frequencies. No one communications system or frequency band can support all submarine communications requirements. Submarine shipboard communications systems consist of RF antennas and radio room equipment, both RF transmitters/receivers and baseband suites. Submarines require a suite of antennas to provide the necessary communications, navigation, and Identification, Friend or Foe (IFF) capabilities. Submarine antennas, as compared to surface ship antennas, are unique in design, shape, materials, and performance due to a submarine’s space and weight limitations, extreme environmental conditions, and stealth considerations. UHF SATCOM provides a relatively high data rate but requires the submarine to expose a detectable mast-mounted antenna, degrading its primary attribute — stealth. Conversely, extremely low frequency (ELF) and VLF broadcast communications provide submarines a high degree of stealth and flexibility in speed and depth, but are low data rate, submarine-unique and shore-to-submarine only.

One of the immediate tasks delineated by the Navy in “From the Sea” is to continue the full integration of SSNs into expeditionary task forces. To be effective units of a Naval Task Group within a joint, Tailored Forward Element (TFE), submarines must be fully interoperable with both Naval and Joint communication systems. Submarines must be capable of tailoring on-board capabilities to optimize their support for the Joint Task Force (JTF) and Naval Component Commanders.

Sources and Resources

FAS | Military | DOD 101 | Systems | Ships ||||
Index | Search |

Maintained by Webmaster