Lo USS Halibut (SSGN-587) era un sottomarino lancia missili da crociera (SSGN) a propulsione nucleare

Lo USS Halibut (SSGN-587) era un sottomarino lancia missili da crociera (SSGN) a propulsione nucleare. Unico della sua classe e varato nel 1959, ha servito come sottomarino lancia missili tra il 1960 e il 1965. Nel 1965 venne convertito in sottomarino d'attacco e ridesegnato SSN-587. A partire dal 1968 venne modificato per svolgere operazioni di intelligence sottomarina.

Storia

Prima del definitivo avvento dei sottomarini lancia missili balistici a propulsione nucleare (SSBN), la marina degli Stati Uniti realizzò diversi esemplari di sottomarini per il lancio di missili da crociera RGM-6 Regulus, tra cui l'USS Halibut. Finanziato nel 1956 come sottomarino a propulsione diesel-elettrica (SSG), poco dopo l'approvazione del budget il progetto fu convertito alla propulsione nucleare (SSGN) con l'adozione di un reattore nucleare ad acqua pressurizzata R3W. La costruzione dell'Halibut cominciò nel 1957 presso i cantieri navali di Mare Island, il varo ebbe luogo il 9 gennaio 1959 e fu preso in carico dalla marina il 4 gennaio 1960 sotto il comando del Tenente comandante Walter Dedrick. L'USS Halibut era il secondo sottomarino nucleare al mondo dotato di armamento missilistico (il primo fu l'SSBN USS George Washington) ad entrare in servizio e il primo SSGN in assoluto L'armamento era costituito da 5 missili Regulus I (o in alternativa 2 Regulus II) collocati in un hangar a prua e lanciati in emersione tramite un'apposita rampa. Oltre l'armamento missilistico, l'Halibut era dotato di 6 tubi lanciasiluri da 533 mm (4 a prua e 2 a poppa). Dal punto di vista costruttivo, l'Halibut presentava ancora le tipiche caratteristiche del design ereditato dai sommergibili tedeschi U-Boot Tipo XXI, che ancora prediligevano la navigazione in emersione, e che avevano caratterizzato tutti i battelli prodotti dopo la fine della Seconda guerra mondiale. Tuttavia, queste caratteristiche cominciavano a risultare obsolete in un periodo in cui venivano impostati nuovi battelli secondo le soluzioni innovative introdotte dal sottomarino sperimentale USS Albacore (AGSS-569) ed impersonate dai nuovi sottomarini d'attacco della Classe Skipjack.

Missioni di deterrenza (1960-1965)

Le prove in mare dell'Halibut furono condotte nell'Oceano Pacifico tra l'11 marzo e il 18 giugno 1960, in questa occasione divenne il primo sottomarino nucleare ad effettuare con successo il lancio di un missile da crociera. Dopo il ritorno ai cantieri navali di Mare Island, fu assegnato alla Flotta del Pacifico e stanziato a Pearl Harbor. Tra il 1961 e il 1964, l'Halibut portò a termine sette missioni di deterrenza in occasione delle quali condusse diversi lanci di prova. Tuttavia, il programma Regulus era stato cancellato già nel 1958 in favore del missile balistico Polaris. Questo, comportò, alla metà degli anni '60, la fine degli SSGN come l'Halibut in favore dei più grandi SSBN di cui l'USS George Washington rappresentava il capostipite.

Operazioni speciali (1965-1976)

Venuto meno il ruolo di SSGN, l'Halibut venne riconvertito in sottomarino nucleare d'attacco con la nuova denominazione di SSN-587. Dopo un periodo di servizio in pattuglie ASW, l'Halibut manifestò la sua inadeguatezza a rivestire un ruolo per cui non era stato concepito e in cui era abbondantemente superato da battelli di nuova concezione. Per evitare di radiare un battello con pochi anni di servizio alle spalle e ancora in piena efficienza, la Marina decise di convertirlo in un sottomarino per operazioni di intelligence sotto la copertura di operazioni di ingegneria sottomarina. Per questo, nel 1968 l'Halibut tornò ai cantieri navali di Mare Island per essere dotato di una serie di equipaggiamenti speciali necessari al nuovo ruolo che doveva ricoprire. Questi equipaggiamenti comprendevano: eliche laterali per manovre di precisione; camera stagna; camera di decompressione per immersioni in saturazione; sonar per lo studio del fondale; apparecchiature di registrazione audio e video; computer mainframe; pattini per posarsi sul fondale; un drone filoguidato per l'esplorazione delle profondità marine e altre apparecchiature oceanografiche di vario genere. In questa configurazione, l'Halibut ha prestato servizio presso la Flotta del Pacifico tra il 1970 e il 1976 conducendo diverse operazioni di spionaggio ai danni dell'Unione Sovietica. 

La recente declassificazione di documenti riservati ha portato alla luce le due missioni più celebri dell'Halibut:

• il ritrovamento del relitto del sottomarino sovietico K-129 scomparso nel maggio 1968 e mai ritrovato dai sovietici;
• intercettazioni telefoniche sulla linea militare sottomarina che collegava le basi sovietiche in Kamčatka alla terraferma, nel Mare di Ochotsk, tra il 1971 e il 1980 (Operazione Ivy Bells).


ENGLISH

USS Halibut (SSGN-587), a unique nuclear-powered guided missile submarine-turned-special operations platform, later redesignated as an attack submarine SSN-587, was the second ship of the United States Navy to be named after the halibut.

Operational history

Halibut's keel was laid down by Mare Island Naval Shipyard at Vallejo, California, on 11 April 1957. She was launched on 9 January 1959, sponsored by Mrs. Chet Holifield, wife of Congressman Chet Holifield of California, and commissioned on 4 January 1960 with Lieutenant Commander Walter Dedrick in command.

Regulus deterrence patrols, 1960 – 1965

Halibut began as a diesel-electric submarine, but was completed with nuclear power. She was the first submarine initially designed to launch guided missiles. Intended to carry the Regulus I and Regulus II nuclear cruise missiles, her main deck was high above the waterline to provide a dry "flight deck." Her missile system was completely automated, with hydraulic machinery controlled from a central control station.

Halibut departed on her shakedown cruise 11 March 1960. On 25 March, underway to Australia, she became the first nuclear-powered submarine to successfully launch a guided missile. She returned to Mare Island Naval Shipyard on 18 June 1960, and after short training cruises sailed 7 November for Pearl Harbor to join the Pacific Fleet. During her first deployment she successfully launched her seventh consecutive Regulus I missile during a major Southeast Asia Treaty Organization weapons demonstration. Returning to Pearl Harbor on 9 April 1961, Halibut began her second deployment 1 May. During subsequent cruises, she participated in several missile firing exercises and underwent training.

Halibut deployed for the third time to the Western Pacific in late 1961, establishing a pattern of training and readiness operations followed through 1964. On 4 May 1964 Halibut departed Pearl Harbor for the last Regulus missile patrol to be made by a submarine in the Pacific. In total, between February 1961 and July 1964, Halibut undertook a total of seven deterrent patrols before being replaced in the Pacific by Polaris-equipped submarines of the George Washington class. From September through December 1964, Halibut joined eight other submarines in testing and evaluating the attack capabilities of the Permit-class submarine.

According to the documentary Regulus: The First Nuclear Missile Submarines the primary target for Halibut in the event of a nuclear exchange would be to eliminate the Soviet naval base at Petropavlovsk-Kamchatsky. The patrols made by Halibut and its sister Regulus-firing submarines represented the first ever deterrent patrols in the history of the submarine navy, preceding those made by the Polaris missile firing submarines.

Special operations missions, 1965 – 1976

In February 1965 Halibut entered Pearl Harbor Naval Shipyard for a major overhaul, and on 15 August was redesignated as an attack submarine and given the hull classification symbol SSN-587. She sailed from Pearl Harbor on 6 September for the West Coast, arriving at Keyport, Washington, on 20 September. On 5 October she departed Keyport for Pearl Harbor and, after an eight-day stop over at Mare Island, California, arrived 21 October. Halibut then began ASW operations in the area, continuing until August 1968 when she transferred to Mare Island for overhaul and installation of: side thrusters; hangar section sea lock; anchoring winches with fore and aft mushroom anchors; saturation diving (mixed gas) habitat; long and short range side-look sonar; video and photographic equipment; mainframe computer; induction tapping and recording equipment; port and starboard, fore and aft seabed skids ("sneakers"); towed underwater search vehicle ("fish") and winch; and other specialized oceanographic equipment. She returned to Pearl Harbor in 1970 and operated with the Pacific Fleet and Submarine Development Group One (SubDevGruOne) out of Naval Submarine Support Facility San Diego (present day Naval Base Point Loma / Ballast Point) with attachment offices at Mare Island until decommissioning in 1976.

Halibut was used on underwater espionage missions by the US against the Soviet Union. Her most notable accomplishments include:

• The underwater tapping of a Soviet communication line running from the Kamchatka peninsula west to the Soviet mainland in the Sea of Okhotsk (Operation Ivy Bells)
• Surveying sunken Soviet submarine K-129 in August 1968, prior to the CIA's Project Azorian.
• The latter mission is profiled in the 1996 book, Spy Sub – A Top Secret Mission to the Bottom of the Pacific, by Dr. Roger C. Dunham, although Dunham was required to change the name of Halibut to that of the non-existent USS Viperfish with a false hull number of SSN-655 to pass Department of Defense security restrictions for publication.

Final disposition

Halibut was decommissioned on 30 June 1976. She was "mothballed" at Keyport/Bangor Trident Base, Washington in 1976, struck from the Naval Vessel Register on 30 April 1986, and disposed of through the Ship-Submarine Recycling Program at Puget Sound Naval Shipyard, Bremerton, Washington, on 9 September 1994.

Awards and commendations

In April 1997, officers and men of Halibut and the other four US Navy submarines that conducted strategic deterrent patrols in the Western Pacific between 1959 and 1964 were awarded the right to wear the Navy's SSBN Deterrent Patrol insignia.

Presidential Unit Citation – 1968

Citation:

• For exceptional meritorious service on support of National Research and Development efforts while serving as a unit in the Submarine Force, U.S. Pacific Fleet. Conducting highly technical submarine operations, over an extended period of time, USS HALIBUT (SSN-587) successfully concluded several missions of significant scientific value to the Government of the United States. The professional, military, and technical competence, and inspiring devotion to duty of HALIBUT's officers and men, reflect great credit upon themselves and the United States Naval Service.

Citation was given for the search and discovery of the wreck of a Soviet submarine K-129 in three miles of water during Project Azorian.

Presidential Unit Citation – 1972

Citation:

• For extraordinary heroism and outstanding performance of duty as a unit in the Submarine Force, United States Pacific Fleet during 1972, USS HALIBUT successfully accomplished two highly productive and complex submarine operations of immeasurable value to the Government of the United States. The superb professional competence, extremely effective teamwork and exemplary devotion to duty displayed by the officers and men of USS HALIBUT reflect great credit upon themselves, the Submarine Force and the United States Naval Service.

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