{{short description|United States Navy's second bathyscaphe}} {{More citations needed|date=June 2023}} {{Infobox ship |display_title=ital |section1={{Infobox ship/image |image= Bathyscaphe Trieste II.jpg |image_caption=''Trieste II'' }}
|section2={{Infobox ship/career |hide_header= |country=United States |flag={{shipboxflag|United States|1980}} |name= ''Trieste II'' |ordered= |awarded= |builder=Mare Island Naval Shipyard |original_cost= |laid_down= |launched= |sponsor= |christened= |completed= 1964 |acquired= |commissioned= |recommissioned= |decommissioned= |maiden_voyage= |in_service=1 September 1969 |out_of_service=1980 |renamed= |reclassified=*X-1, 1 September 1969 *DSV-1, 1 June 1971 |refit= |struck= |reinstated= |homeport= |identification= |nickname= |fate= Preserved at the Naval Undersea Museum |status= |notes= |badge= }}
|section3={{Infobox ship/characteristics |hide_header= |header_caption= |type=Deep-submergence vehicle |tonnage= |displacement= {{convert|46|LT|t|lk=in|abbr=on}} |length= {{convert|67|ft|m|abbr=on}} |beam= {{convert|15|ft|m|abbr=on}} |draft={{convert|12|ft|5|in|m|abbr=on}} |power= |propulsion= |speed= |range= |endurance= |test_depth= {{convert|20000|ft|m|abbr=on}} |complement=2 |sensors= |armor= |notes= }} }} alt=A white-colored submarine with black painted bands.|thumb|''Trieste II'' on display at the Naval Undersea Museum, 2023 '''''Trieste II''''' '''(DSV-1)''' is the United States Navy's first bathyscaphe purchased from its Swiss designers, and the successor to ''Trieste''.
==History== The original ''Trieste'' design was heavily modified by the Naval Electronics Laboratory in San Diego, California and built at the Mare Island Naval Shipyard. ''Trieste II'' incorporated the original Terni, Italian-built sphere used in ''Trieste'', after it was made redundant by the new high-pressure sphere cast by the German Krupp Steelworks. The ''Trieste'' sphere was suspended from an entirely new float, more seaworthy and streamlined than the original, but operating on identical principles. Completed in early 1964, ''Trieste II'' was placed on board USNS ''Francis X. McGraw'' (T-AK241) and shipped, via the Panama Canal, to Boston.<ref>{{Cite web |date=September 23, 2016 |title=Trieste II (DSV 1) |url=https://navalunderseamuseum.org/trieste-ii/ |access-date=October 1, 2024 |website=United States Naval Undersea Museum}}</ref>
Commanded by Lt Comdr. John B. Mooney Jr., with co-pilot Lt. John H. Howland and Capt. Frank Andrews, ''Trieste II'' conducted dives in the vicinity of the loss site of {{USS|Thresher|SSN-593|2}} – operations commenced by the first ''Trieste'' the year before. She recovered bits of wreckage, positively fixing the remains as that of the lost ''Thresher'', in September 1964.
Between September 1965 and May 1966, ''Trieste II'' again underwent extensive modification and conversion at Mare Island Naval Shipyard, but there is no clear record that she was ever operated in that new configuration, i.e., the addition of skegs or outriggers on both sides of the sphere.<ref>{{Cite web |last=Curator |first=USNUM |date=2016-09-23 |title=Trieste II (DSV 1) |url=https://navalunderseamuseum.org/trieste-ii/ |access-date=2025-01-05 |website=U. S. Naval Undersea Museum |language=en-US}}</ref>
thumb|''Trieste II'' in its third configuration. During that same time period, work was under way on a third configuration of the bathyscaphe. This work resulted in yet a new appearance for the ''Trieste II'', and included the installation of a new pressure sphere, designed for operation to {{convert|20,000|ft|m}}.
As the bathyscaphe continued her operations as a test vehicle for the deep submergence program, she qualified four officers as "hydronauts" – the beginning of a burgeoning oceanographic operation. ''Trieste II'''s valuable experience in deep submergence operations has helped in the design and construction of other deep-diving submersibles which could be used in rescuing crews and recovering objects from submarines in distress below levels reachable by conventional methods.
300px|thumb|Equipment configuration. This unique craft was listed only as "equipment" in the Navy inventory until the autumn of 1969. On 1 September 1969, ''Trieste II'' was placed in service, with the hull number X-1. She was reclassified as a deep submergence vehicle (DSV) on 1 June 1971.
On 25 April 1972, ''Trieste II'' recovered a satellite package called a "bucket" weighing several hundred pounds from a depth of greater than {{convert|16000|ft|||}}, a record at the time.<ref>{{cite book|last=Polmar|first=Norman|author-link=Norman Polmar|title=Project Azorian: the CIA and the Raising of the K-129|year=2010|publisher=Naval Institute Press|location=Annapolis, Md.|isbn=978-1-59114-690-2|edition=null|author2=White, Michael }}</ref> ''Trieste II'' (DSV-1) continued her active service in the Pacific Fleet into 1980.
The Trieste class DSV were replaced by the Alvin class DSV, as exemplified by the famous ''Alvin'' (DSV-2). The ''Alvin''s are more capable, more maneuverable, less fragile, but also can not dive as deep, reaching only a maximum of 20,000 feet (6,100 m) (for the ''Sea Cliff'' (DSV-4)).{{citation needed|date=October 2021}}
''Trieste II'' is now preserved as a museum ship at the Naval Undersea Museum, Keyport, Washington.
==Awards== *Navy Unit Commendation with star<ref name=":0">{{Cite web |title=History of the Bathyscaph Trieste |url=https://www.bathyscaphtrieste.org/#:~:text=After%20completion%20of%2015%20dives,Unit%20Commendation%20after%20this%20deployment. |access-date=2024-11-21 |website=www.bathyscaphtrieste.org}}</ref> *Meritorious Unit Commendation with star<ref name=":0" />
==See also== * {{annotated link|Deep-submergence vehicle}} * {{annotated link|Deep-submergence rescue vehicle}} * {{annotated link|DSV Alvin|DSV ''Alvin''}} (DSV-2)
==References== {{Reflist}}
==External links== {{Commons category|Trieste_II_(submarine,_1964)}} {{Commons category|Underwater Ice Station Zebra - Trieste II (CIA)}} * [https://www.cia.gov/static/ebe9fc2c883aa1e90651116bc996b52c/An-Underwater-Ice-Station-Zebra.pdf An Underwater Ice Station Zebra: Recovering a Secret Spy Satellite Capsule from 16,400 Feet Below the Pacific Ocean] * [https://web.archive.org/web/20040308155258/http://www.history.navy.mil/danfs/t8/trieste_ii.htm ''Trieste II''] * [http://www.bathyscaphtrieste.org/ History of the Bathyscaph ''Trieste''] * [http://college.hmco.com/history/readerscomp/ships/html/sh_034900_fnrs2.htm FNRS-2] * [https://web.archive.org/web/20070922212645/http://www.hnsa.org/ships/triesteii.htm HNSA Ship Page: RV ''Trieste''] * [https://www.navalunderseamuseum.org/wp-content/uploads/2016/01/Trieste-Dive-Log-2014_020_001-low-res.pdf Trieste Program Dive Log from the Collection of the Naval Undersea Museum]
{{Underwater diving|other}} {{authority control}} {{coord|47.70024|-122.62381|type:landmark_region:US-WA|display=title}}
Category:Submarines of the United States Navy Category:Trieste-class deep-submergence vehicle Category:Museum ships in Washington (state) Category:1964 ships