The ''Skipjack'' class was a class of

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

nuclear submarine A nuclear submarine is a submarine powered by a nuclear reactor, but not necessarily nuclear-armed. Nuclear submarines have considerable performance advantages over "conventional" (typically diesel-electric) submarines. Nuclear propulsion, ...

s (SSNs) that entered service in 1959-61. This class was named after its lead boat, . The new class introduced the

teardrop hull A teardrop hull is a submarine hull design which emphasizes submerged performance over surfaced performance. It was somewhat commonly used in the early stages of submarine development, but was gradually abandoned in the early 20th century in fav ...

and the S5W reactor to U.S. nuclear submarines. The ''Skipjack''s were the fastest U.S. nuclear submarines until the s, the first of which entered service in 1974.

Design

The ''Skipjack''s' design (project SCB 154)Friedman, pp. 258 was based on the USS ''Albacore'''s high-speed hull design. The hull and innovative internal arrangement were similar to the diesel-powered ''Barbel'' class that were built concurrently. The design of the ''Skipjack''s was very different from the s that preceded the ''Skipjack''s. Unlike the ''Skate''s, this new design was maximized for underwater speed by fully streamlining the hull like a blimp. This required a single screw aft of the rudders and stern planes. Adoption of a single screw was a matter of considerable debate and analysis within the Navy, as two shafts offered redundancy and improved maneuverability.Friedman, pp. 31-35 The so-called "body-of-revolution hull" reduced her surface sea-keeping, but was essential for underwater performance. Also like ''Albacore'', the ''Skipjack''s used

HY-80 HY-80 is a high-tensile, high yield strength, low alloy steel. It was developed for use in naval applications, specifically the development of pressure hulls for the US nuclear submarine program and is still currently used in many naval applicati ...

high-strength steel, with a

yield strength In materials science and engineering, the yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning of plastic behavior. Below the yield point, a material will deform elastically and wi ...

of , although this was not initially used to increase the diving depth relative to other US submarines. HY-80 remained the standard submarine steel through the ''Los Angeles'' class. Skipjack control room

Another ''Barbel''-like innovation was the combination of the conning tower, control room, and attack center in one space. This was continued in all subsequent US nuclear submarines. Combining the functions in one space was facilitated by the adoption of "push-button" ballast control, another feature of ''Albacore''. Previous designs had routed the trim system piping through the control room, where the valves were manually operated. The "push-button" system used hydraulic operators on each valve, remotely electrically operated (actually via toggle switches) from the control room. This greatly conserved control room space and reduced the time required to conduct trim operations. The overall layout made coordination of the weapons and ship control systems easier during combat operations. Skipjack class submarine 3D drawing

Much of the overall internal arrangement was continued in the subsequent ''Thresher''- and ''Sturgeon''-class submarines. The ''Skipjack''s' five compartments were called the Torpedo Room, Operations Compartment, Reactor Compartment, Auxiliary Machinery Space (AMS), and Engine Room. With the addition of a missile compartment, the arrangement of the first 41 US nuclear-powered ballistic missile submarines (

SSBN A ballistic missile submarine is a submarine capable of deploying submarine-launched ballistic missiles (SLBMs) with nuclear warheads. The United States Navy's hull classification symbols for ballistic missile submarines are SSB and SSBN – ...

s) was similar. The design was primarily single-hull, with a double hull around the torpedo room and AMS for ballast tanks. The design was improved on the ''Thresher''s, the one-off , and subsequent attack submarines by relocating the torpedo room into the operations compartment via angled midships torpedo tubes to make room for a large sonar sphere in the bow. The ''George Washington'' class, the first SSBNs, were derived from the ''Skipjack''s, with rebuilt from the incomplete first . The hull of ''Scorpion'' was laid down twice, as the original hull was redesigned to become the ''George Washington''. Also, the material for building was diverted into building , which delayed ''Scamp''s progress. The bow planes were moved to the massive sail to cut down on flow-induced noise near the bow sonar arrays. They were known as sail planes (

fairwater plane Diving planes, also known as hydroplanes, are control surfaces found on a submarine which allow the vessel to pitch its bow and stern up or down to assist in the process of submerging or surfacing the boat, as well as controlling depth when subm ...

s). The ''Skipjack''s were the first class built with sail planes; they were later backfitted on the ''Barbel''s. This design feature would be repeated on all U.S. nuclear submarines until the improved , the first of which was launched in 1988. The small "turtleback" behind the sail was the exhaust piping of the auxiliary diesel generator. The ''Skipjack''s also introduced the

S5W reactor The S5W reactor is a nuclear reactor used by the United States Navy to provide electricity generation and propulsion on warships. The S5W designation stands for: * S = Submarine platform * 5 = Fifth generation core designed by the contractor * ...

to U.S. nuclear submarines. It was known as ASFR (Advanced Submarine Fleet Reactor) during development. The S5W was used on 98 U.S. nuclear submarines of 8 classes and the first British nuclear submarine, , making it the most-used US Navy reactor design to date. The design of the prototype HMS Dreadnought is closely related to the Skipjack class. The entire aft section of HMS Dreadnought was identical to the Skipjack class as the hull was built around the reactor and could not be changed but the fore section was based on earlier British studies into nuclear submarine design, great care had to be taken to marry the two designs alignment.

Service

''Skipjack'' was authorized in the FY 1956 new construction program and commissioned in April 1959. Each hull cost around $40 million. ''Skipjack'' was certified as the "world's fastest submarine" after initial sea trials in March 1959, although the actual speed attained was classified. The ''Skipjack''s remained the fastest US nuclear-powered submarines until the first of the ''Los Angeles'' class entered service in 1974. This was due to the increased size of the ''Thresher'' and ''Sturgeon'' classes, which retained ''Skipjack''s S5W power plant, plus the introduction of the ''skewback'' screw, which was quiet but mechanically inefficient. The ''Skipjack''s saw service during the

Vietnam War The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vie ...

and most of the

Cold War The Cold War is a term commonly used to refer to a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term '' cold war'' is used because the ...

. The ''Skipjack''-class submarines were withdrawn from service in the late 1980s and early 1990s except for , which sank on 22 May 1968 southwest of the

Azores ) , motto =( en, "Rather die free than subjected in peace") , anthem= ( en, "Anthem of the Azores") , image_map=Locator_map_of_Azores_in_EU.svg , map_alt=Location of the Azores within the European Union , map_caption=Location of the Azores wi ...

while returning from a

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...

deployment, with all 99 crewmembers lost.On Eternal Patrol postwar page including ''Scorpion''
/ref>

Ships in class

The gap in the hull-number sequence was taken by the two one-of-a-kind submarines and .

Design

Service

Ships in class

References

Further reading

External links

See also