Conventional US Submarines

If atomic was soon declined for submarines, the bulk of USN sub fleet in 1970 was still made of conventional submarines. The oldest ones were modernized WW2 mass-produced Gatao/Balao-Tench series (GUPPY), and they provided the meaty part of the sub fleet. However alongside the admiralty multiplied small series of peacetime models: The small Barracuda, the large Tang, the Skate and Barbel classes were all small series and conventional.

Alongside these, scores of experimental boats: USS Darter, the Mackerel, X1, Albacore, were all SSNs. The USN also started its race towards strategic subs through pre-nuclear testing models such as the USS Grayback and USS Growler, now forgotten, or the early nuclear USS Halibut. There were also alongside several specialized models,
They had several nicknames, "fleet snorkels" Not a single boat but a whole serie of radar picket conversions. It concerned ten fleet submarines, all converted into Migraine I to Migraine III class. A radar Picket class, A large boat launched in 1958, first propelled by nuclear power, to solve mainly the problem of slow speed;


The USS Albacore (1952), experimental precursor of the Barbel, was tested in 1954. With its revolutionary shell form, extensively tested in the basin, and its very high capacity batteries, it was able to reach 33 knots underwater.

H.G.Rickover and nuclear era

The great revolution was of course the domestication of atom power to be carried at sea in a closed environment: In that sense, the 4,000 tonnes USS Nautilus (1954) pushed with vigor by Hyman George Rickover, the American father of "nuc-subs", was nothing short of an astonishing technological achievement.

For the USN records, she was still a SSN, with six bow tubes, and soon the concept was confirmed by the even larger USS Seawolf, one year later. They prepared the ground for the Skipjack class SSN, quite small compared to later boats such as the Los Angeles, or the experimental Tullibee, an attempt to produce a coastal minimalistic SSN. However in the 1960s, "Rickover's fleet" was born: The Tresher, Sturgeon, made its bulk while the Los Angeles announced the 70-80 and 90s, certainly the most famous mass-production SSN serie in history. Historically, the Skipjacks are the first class of modern SNAs of the US Navy. Their predecessors in the Skate class (1957) who relied on the design of the Seawolf and Nautilus had indeed a classic hull whose hydrodynamics and acoustic signature were passable, especially with regard to experiments realized in the East with the November. The USS Albacore (1953), although conceived with conventional propulsion, pushed hydrodynamics into its abutments and formed an experimental base upon which the Skipjack relied five years later. The first was launched in 1958 and the fifth and last in 1960. The class included USS Skipjack, Scamp, Scorpion, Sculpin, Shark and Snook.

Thanks to the power of their S5W reactors and their excellent profiling, they literally left the Skate with 10 more knots. They thus arrived to support the comparison with the November RussiSSNs, more massive, noisy and especially much less reliable. The progress brought by this class allowed them not only to remain in service until the years 86-90, but also to inspire widely the design of Washington, as well as subsequent SNA. They remained the fastest attack submarines before the arrival of the Los Angeles in 1974. The USS Scorpion sank well and good in the Azores in 1968.


Skipjack class SSNs

⚙ Characteristics:

Displacement: 3070t standard, 3500t FL
Dimensions: 76.8 x 9.7 x 7.7 m
Propulsion: 1 propeller, 1 turbine coupled to a S5W reactor, 15,000 hp. and 30 knots
Crew: 85
Sensors: Sonar BQS-4
Weaponry: 6TLT 533 mm, 24 torpedoes

The three Barbel class ships (Barbel, Blueback and Bonefish) were the last American attack diesels. They were made from the finely worked hull of the USS Albacore (1953), and were of a higher tonnage. They had only one propeller and their 6 tubes were in the bow. The old rear tube system was only possible due to the conventional use of two side propeller shafts. They were equipped with elevators at the bow, and later on the kiosk. Their internal layout included a single central operating room where all orders and indications were grouped, a novelty taken from later SNAs.

Thanks to their hydrodynamics, they were able to sail 21 knots underwater. Nevertheless these high speeds, as for the Albacore, were valid only for short periods, thanks to the electric motor coupled to the reserves of batteries. This speed was clearly behind the Albacore (15,000 hp for 33 knots), but the habitability had been considerably increased. Moreover this last one was a demonstrative prototype, Barbel of the operational units. They were all three in service in 1959, and the Bonefish was retired active in 1988, the other two in 1990.

⚙ Specifications:

Displacement: 2144t Surface 2639t Dive
Dimensions: 66.8 x 8.8 x 6.3 m
Propulsion: 1 propeller, 3 diesels, 1 electric Westinghouse Engine, 4800/3150 hp. and 15/21 knots max.
Crew: 77
Electronics: Sonar BQS-4
Armament: 6 TLT 533 mm (bow)
USS Tresher

This class of SNA contrasted with 1958 Skipjack: The latter, although very fast, remained cramped and their autonomy limited. To meet these limitations and improvements in electronics and armament, diving capabilities, was developed the Tresher class, which was to be a model of large series (53 units counting the improved class) Sturgeon, from 1960 to 1975, unequaled record). The USS Tresher (launched in 1960) was equipped with a new BQQ-2 active sonar capable of guiding long-range torpedoes, then SUBROC missiles, and the hull was reinforced to allow a 397-meter dive.

The increase in tonnage, based on the same Skipjack S5W reactor, resulted in a loss of speed (27 knots), partially offset by a minimalist kiosk. The USS Tresher was conducting his tests in April 1963 when he sank body and soul. The Tresher renamed Permit class (second unit) initially counted 5 units, and 5 others were extended to 90.5 meters to accommodate the new BQQ-5 sonar installed on all later buildings. The USS Jack (SSN-605, 1963, first of the elongated series) served to remain a contra-rotative propeller, remained without continuation. All these units were removed from service between 1988 and 1992.


USS tresher, author's illustration

⚙ Characteristics

Displacement: 84.9 x 9.7 x 7.7 m
Dimensions: Standard 3705t Surface, 4311t Dive
Propulsion: 1 propeller, 1 turbine coupled to a S5W reactor, 15,000 hp. and 27 knots
Crew: 94
Sensors: Sonar BQQ-2 or BQQ-5
Armament: 4 TLT 533 mm lateral, 20 torpedoes, 4 missiles SUBROC Harpoon, then Tomahawk

These buildings were the first SNLE designed as such in the USA. The previous Georges Washington were indeed derived from the SNA Skipjack class. They themselves took over many elements of the Tresher, quieter. However, they were too small to receive the new Poseidon missiles, and were effectively withdrawn from service as SNLEs. They were built at Newport News and Electric Boat between 1959 and 1963, including USS Ethan Allen, Sam Houston, Thomas Edison, John Marshall and Thomas Jefferson. In 1980-81 they lost their SNLE ("SSBN") designation for SNA ("SSN"), with their Polaris control system removed and concrete poured into their silos. The Ethan Allen was set aside in 1983, the Jefferson in 1985, while the Houston and Marshall were equipped with bunkers to accommodate each of 67 SEAL (marine commandos) equipped in 1984. They were set aside in 1991-92

⚙ Characteristics:

Displacement: 2144 surface 2639t dive
Dimensions: 66.8 x 8.8 x 6.3 m
Propulsion: 1 propeller, 3 diesels FM, 1 word. elect. Westinghouse, 4800/3150 cv. and 15/21 knots max. s/p.
Crew: 77
Embedded Electronics: Sonar BQS-4
Armament: 6 x 533 mm TTs (bow)

This new generation of SSNs, contemporary Lafayette, was largely based on the Tresher/Permit of 1960. They were even comparable to this first class, although enjoying many improvements. Their hull was identical, though enlarged to reach 89 meters and 92 from the late USS Archerfish (1971). The last in service was Richard B Russel (1975). They formed, with 42 units, the largest class of SSNs ever deployed. The habitability thanks to a cylindrical hull had been improved, as well as the stealth, using the same S5W thruster, simply improved version of the S5W of the Skipjack, with consequently a clear withdrawal of the speed (26-27 knots). Their kiosk in particular was first reduced with the Tresher, then slightly increased.

As with previous SSNs, the torpedo tubes had been moved to the flanks, and the large room for the Sturgeon left them with a wider range of weapons, the conventional medium and long-range torpedoes, the nuclear Mk45s, the very long-range SUB-ROC which were later converted into Harpoon and Tomahawk encapsulated. In order to simplify this choice, the Mk 45 and the medium and long range models were removed in favor of the single Mk 48.

An attempt was also made to improve the speed of the units with a counter-rotating propeller test on the USS Jack (Tresher type, abandoned due to excessive cavitation), the Narwhal (SSN-671, 1966) testing the natural circulation S5G reactor, lengthened to 97 meters, and finally the Glenard P. Liscomb, lengthened to 111 meters to receive a turbo-electric thruster. The latter measured 6480 tons in diving, against 4777 in standard on the other units. Before the arrival of the Los Angeles, their withdrawal from service began in 1990, and continued until 1999. Only 7 units were reconverted for special operations (including SEALS) in the 80s-90s, and remain in service.

Sturgeon class SSNs

⚙ Characteristics:

Displacement: 7325t, 8250t FL
Dimensions: 129.6 x 10.1 x 8.5 m
Propulsion: 1 shaft turbine coupled to a S5W reactor, 15,000 hp. and 20 knots.
Crew: 140
Sensors: BQS sonars 4, 7, 15 and 19.
Armament: 16 LP Poseidon missiles, 4 TLT 533 mm.

The Lafayettes were not a revolutionary design, since they completely echoed the design of the previous Ethan Allen, themselves closely derived from Washington. The main differences were dictated by the more massive silos adapted to the new Poseidon vectors, the hull being lengthened by a few meters. because of savings, the series continued until 1966 with a total of 31 units, the largest series of SNLE companies in the west. These buildings formed until the arrival of the very high-capacity Ohio, the spearhead of the naval deterrent force of the United States and even of NATO.

The improvements in the series were significant and led to two subclasses, James Madison (SSBN 627-639) and Benjamin Franklin (SSBN 640-659). The last, USS Will Rodgers, came into service in 1967. From 1979, they began to be converted to the Trident I, and all received eight tubes launch countermeasures in the 80s. From 1988, the SALT II agreements resulted in the retirement of the oldest units, and progressively, until 1995, all were decommissioned, except two, Kamehameha and James Polk, converted to SNA and carrying SEAL commandos for secret missions. The latter operated in particular in Lebanon. These two buildings are the only ones currently active.

⚙ Characteristics:

Displacement: 7325t, 8250t FL
Dimensions: 129.6 x 10.1 x 8.5 m
Propulsion: 1 shaft turbine coupled to a S5W reactor, 15,000 hp. and 20 knots.
Crew: 140
Sensors: BQS sonars 4, 7, 15 and 19.
Armament: 16 LP Poseidon missiles, 4 TLT 533 mm.

This last great SNA class of the Cold War was developed after the Sturgeon and brought the genre to a point never before reached. Because of their size, their electronics, their stealth, their range of action, they are still the best performing SSNs in the world. They were defined in order to regain the speed of the Skipjack of 1958 (and to align with the Soviet SNA, always very fast), while keeping the progress made with the Tresher, then the Sturgeon, until the beginning of the years 70.

In fact, the USS Los Angeles was started in January 1972, just three months after the last Sturgeon, USS Richard B Russel, at Newport News. The hull elongation and its greater diameter was due to the adaptation of a new S6G reactor developing double the power. On the other hand, the speed obtained (31 knots), was at the expense of the solidity of the double hull, at the price of a very significant decrease in the diving operational depth.

A new, stronger steel hull was also designated for them, but it was not approved in the credits, and likewise the new computerized fire control system was not ready for the first units, keeping the old system of fire. Shooting Mk.112: The new Mk.117 did not arrive with the USS Dallas (1979). It was anticipated in the first studies in 1968 to equip them with 20 vertical tubes for anti-ship missiles in the Soviet fashion, but the complexity of the system and the cost per unit (which would have jumped to 13,700 tons) made this plan rejected by Admiral Zumwalt. We returned to a more standard SNA, equipped with SUBROC / Harpoon, with a further study of hydroacoustic stealth. In total, the width of the torpedo room carried its capacity to 26 vectors.

In 1981, the USS La Jolla was the first to launch Tomahawk missiles encapsulated by its torpedo tubes, but this system only became operational with the USS Atlanta in 1983. From the USS Providence in 1985, 12 silos equipped with Tomahawk had been installed at the front of the kiosk. From the USS San Juan (1986) the Los Angeles were equipped with the new integrated BSY-1 combat system and retractable bow fins. Finally, from the USS Hartford (SSN-768, 1993), their rear drift was modified on the model of the new generation Seawolf. A total of 42 units went into service until 1990, and another 19 thereafter, constituting the world's largest series of SSNs in twenty years. Symbols of the Cold War, the former are currently placed in reserve. They look like pachyderms in comparison to the new, very stealthy SNAs developed as a result of the Seawolf.

⚙ Specifications:

Displacement: 6000t standard, 6900t FL
Dimensions: 109.8 x 10.1 x 9.8 m
Propulsion: 1 shaft turbine coupled to a S6G reactor, 30,000 cv. and 31 knots.
Crew: 127
Sensors: Sonar BQQ-5
Armament: 4 TLT 533 mm lateral, 26 torpedoes, including 12 SUBROC Harpoon, 8-20 Tomahawk missiles.

At the same time that the Lafayette were converted to trident missiles, a new type of SSBN was launched with Ohio. The long design time between that of the Lafayette (1961-64) and the Ohio (1975), allowed to define a model with greater offensive capacity, with 24 vectors instead of 16, which allowed to reduce the number of units in service, and hence their cost. They were by far the largest submarines in the west, overshadowed only by the huge contemporary Soviet Typhoons. Their turbo-electric propulsion and the almost gummed vibrations of the new S8G reactor gave them, together with the excellence of their hydroacoustic signature, a much greater stealth and speed than their predecessors, benefiting from studies conducted in concert on the Los Angeles attack. Their automation and centralization further allowed them a smaller crew, to the benefit of habitability.



Finally, their maximum cruising depth was 300 meters. The ohio are deemed to perform 70-day sea rotations, with only 25 days of docking, and a dry refit every 12 years, giving them a higher effectiveness rate than the Lafayette-type submarines. The ohio, started in 1976, suffered from development delays that delayed its testing until June 1981. Subsequently, 17 others entered into service until 1999. 10 were in service when the wall fell. They are currently the only naval nuclear deterrent force in the US.


Ohio class SSBNs - Author's illustration

⚙ Specifications

Displacement: 16,000t standard, 18,700t FL
Dimensions: 170.7 x 12.8 x 10.8 m
Propulsion: 1 propeller, 1 turbine coupled to an S8G reactor, 35,000 hp. and 25 knots.
Crew: 133
Sensors: BQQ-6 bow sonar.
Armament: 24 Trident missiles, 4 TLT 533 mm.

Armament, propulsion and sensors of USN Submarines

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