Reprinted with permission from Undersea Warfare Magazine.
The United States was not first to conceive or develop submarine-launched missiles, but it was the first to capitalize on the concept and emerging technology, making it a viable reality. Stealth was always an integral advantage of submarines, but combining that stealth with the reach of missiles made a truly formidable combination. No longer would submarines be limited to seaborne and shoreline targets. While submarine- launched missiles are by their nature offensive weapons, they quickly took on the arguably more important strategic deterrence role of preventing wars between major powers.
America’s first successful submarine-launched missile was the Loon, which was a slightly larger, re engineered version of Germany’s V-1 flying bomb. The Navy didn’t begin experimenting with launching the Loon from a submarine until 1946, but that wasn’t the first missile launch from a submarine.
German scientists began work in the 1930s to develop rockets to be used for space exploration. The German government later funded this research because it came to see that rocket technology could be applied to weaponry. Development of Germany’s first rocket-propelled weapon began in 1941, which eventually led to Germany’s V-1 flying bomb in June 1944 and the V-2 rocket in September 1944, both liquid-fueled. In 1942, British intelligence acquired photos and sketches of a crashed test model, which were shared with the United States.
The V-1 was essentially the first cruise missile, albeit rudi- mentary, able to fly at predetermined altitudes and guided on a given heading by a gyrocompass. A timer an odometer driven by a vane anemometer (measures wind speed) and adjusted for observed prevailing wind conditions determined the point at which the missile would drop from the sky, detonating on contact. The V-2 was a ballistic missile, which followed an arced or ballistic trajectory to its target area. Shortly before Germany was defeated, it had begun using a ground-based radio guidance system to direct V-2s to their intended target areas.
The First Submerged Rocket Launch
The Germans were the first to explore the idea of launching a guided missile from a submarine. In seeking how Germany might strike the U.S. mainland, two brothers, Ernst and Friedrich Steinhoff Ernst a rocket engineer and Director for Flight Mechanics, Ballistics, Guidance Control, and Instrumentation at the Peenemünde Army Research Center who later worked for the U.S. government with Werner von Braun, and Friedrich the CO of U-511 and later U-873 who died of wrist wounds in Boston after surrendering to USS VANCE (DE 387) began discussing the possibility of launching an artillery rocket (aimed but unguided) from the deck of a submerged submarine. This concept was tested on U-511 in May and June of 1942 using a standard army launcher. The tests showed that the rockets could be successfully launched from a depth of 15m below the water’s surface.
Germany never used these weapons against the U.S. mainland because the project was delayed due to concerns with the launcher. Launchers were, however, installed on three U-boats and deployed against the Russians during Germany’s retreat in 1945. The Germans claimed to have used them but there are no records indicating damage inflicted by rockets. German engineers also conceived of placing a V-2 missile inside a watertight tube that could be towed by submarine to a location near the U.S. coast. The tubes could then be trimmed to a vertical position and the missiles launched. The submarine would have to remain on the surface, however. The war ended before the concept could be tested, but the Soviet Union’s Golem submarine-towed missile launcher, produced in the 1950s, was based on captured German plans of this system.
The Allied nations were eager to acquire these rockets, their production facilities, documentation, and the engineers who developed and produced them so as to begin or enhance their own rocket programs. On April 11, 1945, as Allied forces were advancing through Germany toward Berlin from opposite directions, the U.S. Army 3rd Armor Division captured intact the subterranean Mittelwerk V-1 and V-2 production facility at Nordhausen. There they found a treasure trove of V-1 and V-2 parts and rockets in various stages of completion. The Soviet Union, however, had been given jurisdiction over Nordhausen at the Yalta conference. Between May 22 and May 31, the U.S. 144th Motor Vehicle Assembly Company loaded 341 rail cars with rocket-related materials and moved them to Antwerp, Belgium, for removal by ship to the United States, just one day before Soviet troops were scheduled to arrive in Nordhausen. 1 The United States got by far the lion’s share of the hardware, documentation, and engineers, including Dr. Werner von Braun.
The United States began development of its first jet bomb in 1943, the JB-1, which used a flying wing design. Over 17 days in July 1944, the United States succeeded in reverse-engineering Germany’s pulse-jet engine using crashed V-1 duds sent from Britain. This engine was used in a redesigned missile modeled after the V-1 and dubbed the JB-2, or Loon, which had a range of 50 nautical miles (NM) as limited by the guidance signal from the launching submarine, or 135 NM if a second submarine were in position downrange to continue broadcasting guidance information. The Loon’s design was identical to the V-1 except for being 60cm longer at 8.25m and having a 5.4m wingspan, 6.35cm wider than that of the V-1.
America developed an improved guidance system for the Loon using radio command, which enabled a Circular Error Probable (CEP) 5 of about 5,500m (¼ NM cross range and ½ NM downrange). While this accuracy was better than that of the V-1, it was quite poor by today’s standards. The radio command operator could also execute simple in-flight maneuvers such as changing the approach course to avoid enemy forces directing counterat tacking aircraft down the Loon’s bearing. The next step was to figure out how to launch the Loon from a submarine.
A Triad of Strategic Deterrence
After World War II, a new era, the Cold War, began. Rising tensions between the West and the Eastern bloc nations led to increased development and production of nuclear weapons. The first means of delivering these weapons were bombers, followed by intermediate-range and intercontinental ballistic missiles (ICBMs). The final piece of what would be known as the Triad was the submarine-launched ballistic missile (SLBM). While heavy bombers provide advance notice that action is being taken and the ability to be reassigned or recalled, and land-based missiles assure prompt first-strike capability, the SLBM would complete the equation. Nearly undetectable, the submarine-based capability offers stealth, survivability, and assured second-strike capability, thus upping the ante of true strategic deterrence. They could be deployed in such sufficient numbers that not all of them could be targeted.
In 1946, the U.S. Navy began work on a submarine-launched version of the Loon. USS CUSK (SS 348) became the first submarine to launch a guided missile on February 12, 1947 and was the first to be re-designated as a guided missile submarine (SSG) on January 20, 1948. The missile was carried in a hangar attached to the deck behind the conning tower and would have to be maneuvered onto a ramp to be launched. The submarine had to remain surfaced for this procedure, making it vulnerable to attack if spotted.
Entering the 1950s, the Cold War was just heating up. The U.S. government’s highest strategic priority was to develop a strong deterrent against a potential first strike by the Soviet Union. It was in this atmosphere that the developments in submarines, the atomic bomb, and missiles converged.
Even while testing the Loon aboard CUSK and later USS CARBONERO (SS 337), the Navy was already working with Chance Vought Aircraft Industries on specifications for its next guided missile, the subsonic Regulus, later named Regulus I. The Regulus was about 3½m longer than the Loon and had a 1m longer wingspan when its wings were in the deployed position. It was nearly twice as fast as the Loon, had a greater range of 500 NM, and carried a larger and nuclear warhead. Like the Loon, however, the Regulus required the submarine to be surfaced for launching, had to be launched from a ramp, and was guided by radio command, requiring a second submarine to act as a guidance relay to direct it to its target. It was also, like the Loon, liquid- fueled. Liquid rocket fuel had to be stored outside the missile and loaded into the missile immediately before launching. In addition to prolonging exposure on the surface, storing and handling the highly flammable fuel was dangerous in the sealed environment of a submarine.
Russia’s SLBM threat
Beginning in 1958, our Cold War enemy, the Soviet Union, began commissioning its Golf II-class diesel-electric ballistic missile submarines, followed in 1959 by the Hotel I-class nuclear ballistic missile submarines. Each of these was designed to carry the Soviet Union’s new R-11FM (Scud-A) missile, which could be launched from a surfaced submarine in about 12 minutes. Three silos were placed aft of the sail and the sail was extended to enclose the silos. The Scud-A had a range of about 80 NM when armed with a 50 kiloton nuclear warhead. From 1958 through 1962, the Soviet Union produced 22 Golf II-class and 8 Hotel I-class submarines, averaging about six boats per year.
While CUSK and CARBONERO each carried a single Loon missile, two other fleet boats were converted to SSGs, USS TUNNY (SS 282) and USS BARBERO (SS 317), each carrying two Regulus missiles in their missile hangars. On July 15, 1953, TUNNY became the first submarine to launch a Regulus missile. A month before this test launch, Chance Vought had begun development of an improved guided missile, the Regulus II.
In 1954, the Navy began building its second generation of guided missile submarine. The purpose-built USS GRAYBACK (SSG 574), USS GROWLER (SSG 577), and the first nuclear-powered guided missile submarine (SSGN), USS HALIBUT (SSGN 587) were each designed with two missile hangars. Each missile hangar could carry either two Regulus I missiles or one of the in-development Regulus II missiles for a total of two to four missiles per boat. GRAYBACK, GROWLER, and HALIBUT were launched in 1957, 1958, and 1959, respectively.
Even as the Regulus II was being developed, Navy leaders recognized its shortcomings. The most significant hurdle to overcome was the one that the Navy most wanted addressed: a missile that could be launched from a submerged submarine. This would require not only a new missile and launching mechanism, but a new type of submarine as well. As early as 1955, the Navy committed to developing this new missile, the Polaris.
The Regulus II was successfully test launched in 1956, but the program was ended in 1958 because of progress being made on the Polaris. The Regulus II was never deployed, but the Regulus I was deployed on U.S. submarines from 1958 to 1964. During that time, U.S. submarines made 41 strategic deterrent patrols armed with the Regulus I. The number 41 was soon to have great significance to the U.S. Submarine Force and the nation’s security.
While the Loon and Regulus were cruise missiles, the Polaris A1, developed by Lockheed Missiles & Space Co., was America’s first true submarine-launched ballistic missile (SLBM). In addition to using solid fuel, Polaris more than doubled the range of the Regulus I, was more than twice as accurate, was nearly 10 times as fast, and carried a warhead more than 12 times as powerful. Polaris, while becoming operational a year later than the Soviets’ first SLBM and having a range less than the 1,500 NM desired by the Navy, was nonetheless a game changer.
Heading up the newly established Special Programs Office (now called Strategic Systems Programs) and the Polaris Program was Rear Adm. William “Red” Raborn, who was given exception- al authority and latitude to make the Polaris a near term reality. His team included the inventive and persistent Dr. John Craven, whose job it was to figure out how to launch the massive new missile from a submerged submarine.
There were other advancements that came together at this time to make the Polaris a success. There were breakthroughs in reducing the size of atomic warheads, thus improving range, and in solid rocket fuel making it more reliable, responsive, and safe. The Massachusetts Institute of Technology developed an inertial guidance system, which eliminated the need for radio guidance and the need for a second submarine to guide the missile to its target area. Inertial guidance also brought a significant improvement in accuracy.
The Navy’s development of the nuclear-powered ballistic missile submarine, or SSBN, took place concurrently with development of the Polaris. The advent of the SSBN in America was undertaken with a real sense of urgency due to the threat of a Soviet first strike. The first SSBN was originally laid down as a fast attack submarine (SSN) of the SKIPJACK class in 1958, three years after the Soviets conducted their first successful surfaced test launch of an SLBM. The vessel’s partially constructed hull was cut across the middle to make room for a 40m-long section containing two rows of eight launch tubes to house 16 Polaris A1 missiles and other associated equipment.
In a little over a year and a half, USS GEORGE WASHINGTON (SSBN 598) went from a nearly completed nuclear-powered SSN to being commissioned into service at the very end of 1959 as an SSBN. She successfully test-launched a Polaris A1 in July 1960 and began her first strategic deterrent patrol in November 1960. Before USS GEORGE WASHINGTON returned from her maiden 67-day patrol, the second SSBN, USS PATRICK HENRY (SSBN 599) set sail on December 30, 1960 on its first strategic deterrent patrol. Thus began the rapid SSBN building program known as 41 for Freedom the timing was profoundly fortuitous.
41 for Freedom
The GEORGE WASHINGTON was the first of 41 SSBNs, referred to as the 41 for Freedom, authorized from 1957 through 1963, the last of which, USS WILL ROGERS (SSBN 659), was commissioned into service in 1967. The first five SSBNs, comprising the GEORGE WASHINGTON class, were modified Skipjack-class SSN designs lengthened to accommodate the missiles. The Ethan Allen class was the first class of submarine designed from the outset to be an SSBN. As missile technology continued to advance and new missiles were developed, earlier boats were backfitted to carry the newer missiles.
Cuban Missile Crisis
In October 1962, President Kennedy was informed that the Soviet Union had been staging SS-4 medium-range nuclear ballistic missiles in Cuba, which led to the tense Cuban Missile Crisis. For 13 days, from the 16th to the 28th of October, 1962, the whole nation feared that a nuclear exchange with the Soviet Union could begin at any moment. It is arguably the closest we have ever come to nuclear war.
At the time the standoff began, there were already nine U.S. SSBNs in commission, six of which were known to be on station in the Norwegian and Mediterranean Seas, one of which had departed on patrol on October 10th, and another that was preparing to depart. 6 No doubt Soviet Premier Nikita Khrushchev was aware of the more than 100 Polaris missiles lurking beneath the surface within reach of major Soviet cities, which must have factored into his decision to remove Soviet missiles from Cuba. In addition, USS TUNNY (SSG 282), USS BARBERO (SSG 317), and USS GRAYBACK (SSG 574) were on station near the Soviet Pacific coast carrying eight Regulus I missiles.
Well before the Polaris A1 became operational in 1960, the Navy knew that it was an evolutionary step toward getting a sufficient sea-based strategic deterrent in place. Even before the Polaris A1 went on patrol, the Navy and Lockheed Missiles & Space Co. began development of its successor, the Polaris A2. The A2 was first successfully test launched from a submerged submarine, USS ETHAN ALLEN (SSBN 608), in October 1961, and it became operational in June 1962.
The Polaris A2 met the Navy’s original desired range of 1,500 NM and was more accurate and more reliable due to improved electronics. The five Ethan Allen class submarines were designed to carry the Polaris A2, which was almost a meter longer than the A1 but with the same diameter. As with the Polaris A1, the Navy didn’t stop development with the A2. Just two years after the A2 became operational, newer U.S. SSBNs began deploying with the Polaris A3.
The first successful Polaris A3 test launch from a submerged submarine took place aboard USS ANDREW JACKSON (SSBN 619) in October 1963, and the first A3 patrol began in September 1964 aboard USS DANIEL WEBSTER (SSBN 626).
While the Polaris A3’s name implies that it was an improved A2, that’s not entirely accurate. The Polaris A3 was really a new missile design that had to fit into the A2 launch tubes. The A3 offered a greater range of 2,500 NM, significantly expanding SSBN operating areas and enabling full coverage of the Europe- an/Asian continent with the first Polaris patrols in the Pacific. USS DANIEL BOONE (SSBN 629) conducted the first Polaris patrol in the Pacific beginning in December 1964.
Aside from its greater range, the Polaris A3 was the first missile to have multiple re-entry vehicles (or bodies) (MRVs). The first A3s each carried a single nuclear warhead. Beginning in the 1970s, the A3 carried three separate and smaller nuclear warheads. 7 These would be ejected over the target area to improve target coverage and reduce the effectiveness of missile defenses. The three smaller warheads delivered greater destruction than the single large-yield warhead while maintaining the missile’s original throw weight.
While the first five SSBNs comprising the George Washing- ton class were never retrofitted to carry the Polaris A2, they were retrofitted to carry the A3, with conversions taking place between 1966 and 1971. The last A3 was removed from service in October 1982.
Beginning in the late 1960s, the U.S. government became concerned that the Soviet Union would begin moving strategic assets into hardened underground bunkers to protect them from U.S. missiles. To counter this, the Navy and Lockheed Missiles & Space Co. began development of a penetrator warhead to breach the bunker before detonating and an upgraded missile to deliver it. The A3 was not accurate enough for this task, so work began on an upgrade to the A3. As different warhead and re-entry body options were considered, the nomenclature for this new missile changed, from A3A to B3 to C3 and finally, in January 1965, to a new name altogether: Poseidon.
The Poseidon C3, as it became known, was a half meter wider than the Polaris, but it still had to fit into the Polaris launch tubes. The Polaris launch tubes had a liner that could be removed to accommodate the larger missile. What really distinguished the Poseidon is that it had multiple independently targetable re-entry vehicles (MIRVs), enabling a single missile to hold multiple targets at risk.
The Poseidon C3 was first tested in 1968, and the first test launch from a submerged submarine took place in 1970 aboard USS JAMES MADISON (SSBN 627). USS JAMES MADISON set sail on the first Poseidon patrol in March 1971. Poseidon incorporated substantial improvements in accuracy and resistance to countermeasures over previous missiles, but its principal advantage was its targeting flexibility. Poseidon could deliver multiple warheads on multiple targets in multiple widely spaced target groupings (footprints). Greater accuracy allowed smaller warheads to be employed while achieving the target effects of larger, less accurate warheads.
Although the Department of Defense was working on a far more accurate, stellar inertial, guidance system during the Poseidon’s development in the latter half of the 1960s, 8 it decided not to use this on the Poseidon. Had Poseidon’s accuracy been improved significantly, it could have been viewed by the Soviets as a first-strike weapon capable of destroying Soviet missiles and related military targets. 9 The DoD’s position was that Poseidon SLBMs would be strictly for second-strike retaliation after a Soviet first strike. 10 The missile’s small improvement in accuracy 11 over the Polaris A3 was more than sufficient for that task.
The last Poseidon was offloaded in September 1992. Stellar- inertial guidance fully matured in the 1970s for use in Poseidon’s successor, the Trident.
The Soviet Union lagged behind the United States in missile and submarine technology and development. The Soviets were deploying liquid-fueled missiles aboard submarines until 1980 when they deployed their first solid-fueled missile, the R-31 Snipe (NATO designation SS-N-17), which had a range of 2,100 NM. 12 What they lacked in technology, however, they made up for in the number of nuclear bombs, land-based intercontinental ballistic missiles (ICBMs), and SLBMs produced through the 1970s and 1980s. In the words of Marxist doctrine, “Quantity has a quality all its own.” The Navy’s answer to this Soviet nuclear build-up was the Trident SLBM.
The first version was the Trident I C4. The Navy and Lock- heed Missiles & Space Co. commenced development in 1973, and the missile became operational in 1979. It was developed in conjunction with a new class of ballistic missile submarine to carry it, the Ohio class. Six Lafayette-class 13 and six Benjamin Franklin-class boats, however, were backfitted between 1976 and 1981 to carry it as well. Each Ohio class boat can carry up to 24 missiles, eight more than previous SSBNs. The Ohio-class launch tubes were made 3m longer than the Poseidon launch tubes to accommodate a larger missile that was then in the planning stages, which was the Trident I’s successor. The Trident I first went on patrol aboard USS FRANCIS SCOTT KEY (SSBN 657) in October 1979.
The Soviet Union greatly improved its anti-submarine warfare capabilities during the 1970s, thanks in no small part to the spy John Walker. Trident I’s 1,500 NM increase in range over the Poseidon, however, meant that Trident-armed submarines had far more ocean in which to operate and still be able to reach their targets, thus making them harder to locate. The increase in range was due to technological advances in microelectronics and propulsion, the use of lighter-weight graphite epoxy materials, and something called an aerospike.
The third-stage rocket motor was placed between the missile’s eight warheads in the nose fairing to make more space for other components, thus spreading the warheads farther from the missile’s axis. Combined with the unchanged launch tube height in the backfitted Lafayette-class and Benjamin Franklin-class boats, this necessitated a wider, flatter nose, which increased drag. To compensate, the aerospike was added to the missile’s tip. After the first-stage rocket motor ignited, the aerospike extended from the nose of the missile. At the tip of the spike is a small disc that, at supersonic speed, creates an inclined shockwave behind it. This provides a lower-pressure area for the missile to move through. The effect improved range by making the missile aerodynamically more slender, thus reducing drag by about 50 percent.
Also housed in the Trident’s nose was the new and more accurate stellar-inertial guidance system. The stellar portion included a sensor to conduct a star sighting. This capability keeps SLBMs independent of external positioning signals (e.g., GPS). Stellar-inertial guidance improved the Trident I’s accuracy more than two-fold over the Poseidon. When USS MARIANO G. VALLEJO (SSBN 658) returned from her last patrol on April 2, 1994, it marked not only the last patrol of the 41 for Freedom boats, but also the last patrol of the Benjamin Franklin-class boats backfitted to carry the Trident I. The last Trident I patrol ended after 26 years of service with the return of USS ALABAMA (SSBN 731) (G) from its 67th patrol on September 2, 2005. The Trident I had been deployed on the first eight Ohio-class boats until the Trident II became operational.
Continued improvements led to the next generation of missile, the Trident II D5, the backbone of today’s U.S. strategic deterrence forces and one leg of the nuclear triad. Further use of lighter graphite epoxy and filament-wound Kevlar led to a further increase in payload capacity. This, in addition to retaining the aerospike, gave the larger missile greater throw weight and range than the Trident I. Improved accuracy also provided better performance against hardened targets.
Development of the Trident II began in October 1983. The Navy conducted eight Production Evaluation Missile (PEM) test flights. PEMs 1 and 3, early in the testing phase, were failed launches. From December 1989 to March 2016, however, the U.S. and UK navies have conducted 160 successful Trident II D5 test flights. This record of success is unsurpassed by any other large- diameter rocket program. The first successful test launch from a submerged submarine occurred on August 2, 1989 aboard USS TENNESSEE (SSBN 734). The three most recent of these Trident II test launches test launches 158, 159, and 160 were conducted March 14-16, 2016 by an SSBN assigned to Submarine Group 10 out of Kings Bay, Ga.
The new missile became operational on March 29, 1990, with 24 Trident II D5s aboard USS TENNESSEE as she left port for her maiden strategic deterrence patrol. This was nine months after the Polish elections that signaled the beginning of the end of the Cold War and five months after the fall of the Berlin wall. While the Trident II is capable of carrying its MIRVs over 4,000 NM to their targets, the New START treaty limits the number of warheads deployable by the Navy to 1,550, which would mean an average of four or five MIRVs per SLBM.
Strategic Arms Treaties
In November 1969, U.S. and Soviet negotiators met in Finland to discuss limiting the number of nuclear weapons in each nation’s arsenal. These became known as the Strategic Arms Limitation Talks, or SALT. The SALT Treaty (later called SALT I) and the Anti-Ballistic Missile (ABM) Treaty were signed two and a half years later in May 1972. At issue were two technologies of primary concern: MIRV warheads and ABM capability. When negotiations began, the Soviets were more advanced in ABM technology and had deployed an ABM system around Moscow, and the United States was rapidly developing MIRV warheads. The Soviets were concerned that MIRV capability would both render their cities and ballistic missiles vulnerable to a U.S. first strike that would overwhelm their ability to intercept the incoming warheads. The United States was concerned that Soviet ABM technology could be advanced enough to intercept all or most of its MIRVs, which would negate its superior submarine- based advantage. If the Soviets were confident in their ability to intercept incoming warheads, the United States feared that the Soviet Union could initiate a first strike with impunity.
The ABM Treaty limited each side to no more than 100 interceptor missiles and launchers located at no more than two deployment areas. 15 The Interim Agreement on the Limitation of Strategic Offensive Arms (SALT I) froze the number of nuclear ballistic missiles, both land-based and aboard submarines. Later in 1972, follow-on negotiations began to replace the interim SALT I agreement with a longer-term and more comprehensive agreement, known as SALT II. SALT II established numerical limits on the total number of strategic nuclear delivery vehicles with additional numerical limits on MIRVs. Delivery vehicle refers to heavy bombers, ICBMs, and SLBMs. SALT II was signed by President Jimmy Carter in 1979, but it was never ratified by the Senate. Both sides, however, voluntarily met some of the agreement’s terms.
The follow-on agreement to SALT II was the result of the Strategic Arms Reduction Talks, or START, begun in 1982 and signed in 1991. Whereas SALT I and II focused on limiting strategic weapon systems, START would seek to actually begin reducing their numbers in three phases. By the end of the third phase in 2001, each side would have to reduce its number of attributable warheads from about 11,000 to no more than 6,000 and its number of delivery vehicles to no more than 1,600. Attribution refers to the number of warheads that may be on any of the three types of delivery vehicles. No more than 4,900 of the 6,000 warheads permitted could be mounted on deployed ICBMs and SLBMs at any time. START also limited the number of MIRV warheads resulting in no more than eight warheads attributable to an SLBM. START expired in December 2009.
START was to be followed by START II, negotiations for which got underway in 1992. START II would have banned all MIRVs in ICBMs and halved the number of warheads each side could deploy, but it never entered into force. The Senate approved it in 1996, but the Russians repeatedly delayed Duma approval due to its frustration with U.S. involvement in the Persian Gulf and the Balkans. The day following U.S. withdrawal from the ABM Treaty on June 13, 2002, Russia ceased its efforts to bring START II into force.
A month before both sides ceased efforts on START II in 2002, the Strategic Offensive Reductions Treaty (SORT), also known as the Moscow Treaty, was signed by both the United States and Russia. SORT, which entered into force in June 2003, would limit the number of operationally deployed nuclear warheads to between 1,700 and 2,200 per side by December 2012. The parties also agreed that the terms of START would remain in force. SORT was superseded by the New START Treaty (NST) in February 2011.
NST is the current strategic arms reduction treaty in force between the United States and Russia. The Senate ratified NST in December 2010 and the Duma in January 2011. It went into force on February 5, 2011, replacing START and superseding SORT, and will expire 10 years later. NST limits each side to no more than 1,550 deployed warheads on up to 700 deployed delivery vehicles and no more than 800 total delivery vehicles. Of those 1,550 warheads on the U.S. side, approximately 70% are planned for SLBMs. U.S. plans are for no more than 240 deployed SLBMs at any given time. These reductions are about 30 percent lower than the levels set by SORT. These reductions must be accom- plished by February 2018.
While the reduction in the number of Ohio-class SSBNs from 18 to 14 due to the conversion of four to SSGNs, the number of Ohio Replacement submarines slated at 12, reduction of the number of launchers per SSBN from 24 to 20, and the reduction in the number of warheads may appear to reduce our deterrence posture, they don’t as long as both sides reduce their nuclear forces accordingly.
Life Extension of the Trident II
Today the Navy and the nation have in the Trident II a reliable SLBM that does everything required of it and is limited by treaty, not capability. It may at some point be limited by age, however. Trident IIs were expected to have a service life of 25 years, 20 and they have reached that point. The Navy’s first Ohio Replacement SSBNs are expected to begin service in the early 2030s, but they will be carrying Trident IIs that first came online 40 years prior with warheads that were expected to have a service life of 10 years. To ensure that these missiles were kept safe, reliable, and effective, the Navy began the D5 Life Extension (LE) Program (D5 LE).
D5 LE was begun in 2002 to identify and replace aging Tri- dent II missile components, some with upgraded components based on new technology. The goal of D5 LE is to ensure that the fleet of Trident II SLBMs remains operational for another 25 years, into the first decade or so of the Ohio Replacement submarines’ patrols. Sometime after the first Ohio Replacement submarine is commissioned, the Navy may consider replacing the Trident II with a new missile.
SSBN Conversions to SSGN
Although START II was agreed to in 1992, it was never ratified. Both parties nevertheless verbally agreed to abide by its terms, one of which was a limit in the number of SSBNs to 14. 22 To avoid decommissioning four of the 18 SSBNs to meet this requirement, the first four of the Navy’s Ohio-class SSBNs— USS OHIO (SSBN 726), USS MICHIGAN (SSBN 727), USS FLORIDA (SSBN 728), and USS GEORGIA (SSBN 279)—underwent conversions between 2002 and 2007 to SSGN configuration. 23 In addition to retaining their capability to fire Mk 48 ADCAP torpedoes, the modern SSGNs were designed to be multi-mission platforms. The two forward-most launch tubes became lockout chambers and docking stations for the Advanced SEAL Delivery System or Dry Deck Shelters for Special Operations Forces missions. The other 22 launch tubes can now accommodate mission-specific equipment or canisters that each hold seven Tomahawk cruise missiles for a maximum of 154 per boat.
USS FLORIDA successfully launched an unmanned under- sea vehicle (UUV) from a modified Trident launch tube in 2003. 24 General Dynamics’ Electric Boat Division has developed the Universal Launch and Recovery Module (ULRM) for use on the four SSGNs as well as with the Virginia Payload Module. The ULRM can launch and retrieve UUVs and deploy other payloads. ULRM prototype testing on SSGNs is scheduled to begin later this year.
The Only Constant Is Change
As the U.S.-Soviet arms race was gathering steam, the U.S. Navy, under the leadership of a handful of prescient and extraordinarily capable men, quickly outpaced America’s Cold War adversary with technological advances in missile and submarine design and rapid building programs such as the 41 for Freedom. Despite the sense of tranquility that came with the collapse of the Soviet Union, thus ending the Cold War, and the last commissioning of an SSBN taking place in 1997, U.S. Submariners have remained vigilant, keeping the watch, as life went on stateside without much thought given to the need for maintaining our strong strategic deterrent.
Leading up to 2000, the United States faced a decreasing number of challenges from nation-states. Beginning in 2000, America saw a sharp rise in asymmetric threats from non-state actors, against which a nuclear deterrence force has little deterrent effect, further reducing the apparent need for a strong strategic deterrence force. With alarming suddenness, however, America now finds itself again facing challenges from nuclear-capable major power nation-states. With all the proverbial lines in the sand being drawn and redrawn, making for a shifting and uncertain future, it would seem that, despite whatever appearances may suggest to the contrary, maintaining a strong deterrence capability and posture is the wise course.
Navy personnel will soon bear on their collective shoulders nearly three-quarters of the nation’s strategic deterrence assets. U.S. Submariners on the Ohio-class boats the first two of which have entered the Ohio class’ own life-extended period currently have the nation covered. As our nation’s survivable and effective at-sea strategic deterrent, the Trident II D5 weapon system is out there day after day to quietly prevent major power war and provide extended deterrence to our non-nuclear-capable allies.