View source for Júpiter-class minelayer

{|{{Infobox ship begin}}
{{Infobox ship image
|Ship image=Minador-JUPITER-AD003761.jpg
|Ship caption=Minelayer ''Júpiter''
}}
{{Infobox ship class overview
|Name=
|Builders= [[Sociedad Española de Construcción Naval|SECN]]|Operators={{navy|Spain|1945}}
|Class before=
|Class after=
|Subclasses=
|Cost=
|Built range=
|In service range=
|In commission range=1935&ndash;1977
|Total ships building=
|Total ships planned=
|Total ships completed=4
|Total ships cancelled=
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|Total ships laid up=
|Total ships lost=
|Total ships retired=4
|Total ships preserved=
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{{Infobox ship characteristics
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|Header caption=
|Ship type=[[Minelayer]]
|Ship displacement=*{{convert|2100|LT|t|lk=in}} standard
*{{convert|2600|LT|t}} full load
|Ship length= {{convert|100|m|ftin|abbr=on}}
|Ship beam= {{convert|12.36|m|ftin|abbr=on}}
|Ship height=
|Ship draught= {{convert|3.6|m|ftin|abbr=on}}
|Ship depth=
|Ship propulsion=*2 shaft Parsons type geared turbines
*2 [[Yarrow boiler]]s
*{{Convert|5000|hp|kW|-2|abbr=on}}
|Ship speed= {{convert|18|kn|lk=in}}
|Ship range= {{convert|3700|nmi|km|abbr=on}} at {{convert|12|kn}}
|Ship endurance=
|Ship boats=
|Ship complement=180
|Ship sensors=
|Ship EW=
|Ship armament=*4 × {{convert|120|mm|in|abbr=on}} guns (4×1)
*2 × 76&nbsp;mm anti-aircraft guns
*3 × 20mm
*264 mines or depth charges
|Ship armour=
|Ship notes=
}}
|}
'''''Júpiter''-class minelayers''' was a group of four vessels of the [[Spanish Republican Navy]]  built during the [[Second Spanish Republic|Spanish Republic]]. Three of them came into service during the [[Spanish Civil War|Civil War]] after joining the [[Nationalist faction (Spanish Civil War)|rebel side]].
== Design and construction ==
The minelayers were commissioned by the Government of the Republic to [[Sociedad Española de Construcción Naval|SECN]] shipyards at [[Ferrol, Spain|Ferrol]]  in 1935, a year before the start of the Spanish Civil War. The construction had been approved by the [[Cortes Generales|Cortes]] on 27 March 1934, after a proposal from the minister of the navy Juan José Rocha García. The warships of the class were designed to protect the [[Balearic Islands|Balearic islands]] in the event of a war between France and Italy.<ref>{{Cite web|url=http://blog.todoavante.es/?p=7929|title=Historia Naval de España: Minador Vulcano|website=Todoavante|language=Spanish|access-date=12 September 2017}}</ref><ref>{{Cite web|url=http://www.armada.mde.es/archivo/mardigitalrevistas/boletininfanteria/2016/01BIM26.pdf|title=La Ocupación de Tánger|date=July 2016|website=Boletín de Infantería de Marina|page=11|language=Spanish|access-date=12 September 2017}}</ref><ref>{{Cite journal|last=Pérez|first=Artemio Mortera|date=2008|title=Los minadores de la clase "Jupiter" (1ª parte)|url=https://dialnet.unirioja.es/servlet/articulo?codigo=2682838|journal=Revista española de historia militar|language=es|issue=93|issn=1575-9059}}</ref>
==Operational history==
===Civil War===
The first three ships of the class were seized by the insurgents and served in the rebel fleet at the very beginning of the war. Their first deployment was the blockade of [[Bilbao]].<ref name="Alboran">Moreno de Alborán y de Reyna, Fernando: ''La  guerra silenciosa y silenciada: Historia de la campaña naval durante la guerra  de 1936–39''. Madrid, 1998, v. 2. {{in lang|es}}</ref><ref name=rastreo/>
Due to the lack of destroyers in the [[Francisco Franco|Franco]]'s fleet, and the potential of their armament, the main mission of these vessels was not minelaying, but to face Government units in open combat, despite their slow speed.<ref name=Alboran/>
====''Júpiter''====
Along with ''Vulcano'', ''Júpiter'' was one of the main players in the blockade of international shipping in the ports of [[Bay of Biscay|Biscay]], where she took part in the capture of several merchantmen, especially the British ''Candleston Castle'', ''Dover Abbey'' and ''Yorkbrook'', the French ''Cens'' and a number of [[Basque Auxiliary Navy]] trawlers during the second half of 1937.<ref name="Cervera">[http://www.asturiasrepublicana.com/cervera7-2.html#prof Log of insurgent cruiser ''Almirante Cervera''] {{Webarchive|url=https://web.archive.org/web/20081014013322/http://www.asturiasrepublicana.com/cervera7-2.html#prof |date=2008-10-14 }} {{in lang|es}}</ref> She also laid four minefields off [[Santander, Cantabria|Santander]] and [[Gijón]], from April to July 1937. The rebel battleship ''[[Spanish battleship Alfonso XIII|España]]'' was lost on 30 April after hitting by accident one of her mines at Santander. There were only four casualties among ''España''{{'}}s crew.<ref name=rastreo>[http://www.gudontzidia.eu/es/rastreo-de-minas.php?o=5&a=4 El rastreo de minas]{{Dead link|date=February 2020 |bot=InternetArchiveBot |fix-attempted=yes }} {{in lang|es}}</ref>
On 17 July, while on patrol off Gijón, ''Júpiter'' caught two British cargo ships while they were attempting to run the blockade. One of them, ''Sarastone'', managed to reach the harbor despite being fired on. The other steamer, ''Candleston Castle'', stopped after the minelayer fired two shots across her bows. She was handed over by ''Júpiter'' to the auxiliary cruiser ''Ciudad de Palma'', which escorted the captured merchantman to [[Ferrol, Spain|Ferrol]].<ref>''Tres días después, el minador “Júpiter”, de patrulla frente a Gijón, apresaba al “Candlestone Castle”, no pudiendo evitar, pese a cañonearlo, que el “Sarastone” entrara en El Musel. El “Candlestone Castle” y el “Kellwyn”, de pabellón británico como los anteriores, habían salido el día uno de Julio de Santander hacia Francia con refugiados, protegidos por dos destructores y un acorazado ingleses. Después de ese viaje, ambos barcos llevaban varios días esperando para entrar en Santander, dirigiéndose a Gijón ante la imposibilidad de hacerlo en aquel puerto. El “Candlestone Castle” procedía de Burdeos y el “Sarastone”, también en lastre, había salido de Saint Nazaire. El “Candlestone Castle” fue conducido al Ferrol por el crucero auxiliar "Ciudad de Palma".'' [http://www.asturiasrepublicana.com/cervera5.html Asturias Republicana] {{Webarchive|url=https://web.archive.org/web/20201018041725/http://www.asturiasrepublicana.com/cervera5.html |date=2020-10-18 }} {{in lang|es}}</ref><ref>[https://api.parliament.uk/historic-hansard/commons/1937/jul/21/spain Parliamentary debate, 21 July 1937]</ref> A fruitless sortie was launched from the French port of [[Saint Jean de Luz]] by the [[Royal Navy]] battleship {{HMS|Royal Oak|08|6}} and the destroyer {{HMS|Basilisk|H11|6}}.<ref>{{cite web|title=British Vessel is Seized by Spanish Rebels - Battleship and Destroyer Dash from France|url=https://www.nytimes.com/1937/07/19/archives/british-vessel-is-seized-by-spanish-rebels-battleship-and-destroyer.html|work=The New York Times|date=19 July 1937|accessdate=2012-09-23}}</ref>
She engaged the [[Basque Auxiliary Navy]] destroyer [[Churruca-class destroyer|''Císcar'']] on 10 August off Gijón. During this exchange of fire, ''Júpiter''{{'}}s gunfire accidentally straddled the British destroyer {{HMS|Foxhound|H69|6}}.<ref>[[Peter Gretton (Royal Navy officer)|Gretton, Peter]] (1984). ''El Factor Olvidado: La Marina Británica y la Guerra Civil Española''. Editorial San Martín, p. 385. {{ISBN|84-7140-224-6}}. {{in lang|es}}</ref><ref>Foreign Office: ''Index to the correspondence of the Foreign Office for the year 1937, Part 4.'' Kraus-Thomson, 1937, page 545</ref> Occasionally, she also provided support fire for the rebel troops inland.<ref name=Cervera/> On 24 August 1937, after the fall of the port of [[Santoña]], ''Júpiter'', along with other naval units was called from [[Bilbao]] to watch the British steamer ''Seven Seas Spray'', taken in custody by Nationalist troops while attempting to evacuate Basque troops as part of the ill-fated [[Santoña Agreement]] between the Italian [[Corpo Truppe Volontarie]] and the [[Basque Nationalist Party]].<ref>Moreno de Alborán y de Reyna, Fernando: ''La guerra silenciosa y silenciada: Historia de la campaña naval durante la guerra de 1936–39''. Madrid, 1998, p. 278. {{ISBN|84-923691-2-4}} {{in lang|es}}</ref>
[[File:HMS-Resolution.jpg|thumb|left|250px|Battleship HMS ''Resolution'']]
On 5 October, while she was escorting the seized freighters ''Dover Abbey'' and ''Yorkbrook'' to [[Ribadeo]], the former vessel sent a distress message to {{HMS|Resolution|09|6}}, giving the position and course of the convoy and claiming that her capture had taken place outside territorial waters. Actually, they have been caught by armed trawlers {{convert|2|nmi|km}} off shore, well inside Spanish [[maritime boundary|maritime boundaries]]. ''Júpiter'' successfully outran the British battleship and the convoy reached destination without incident.<ref>''Ordené reunir las presas para ser conducidas por el “Tito” a Ribadeo, ya que este bou debía de ser relevado por la tarde por el “Tritonia”. Al “Júpiter” le ordené escoltar los bous hasta verlos entrar en Ribadeo y al “Fantástico” le ordené continuar la vigilancia frente a Avilés.''
''A mediodía se sorprendieron unos radios que el “Dover Abhey” dirigía al “Resolution”, dándole su situación 6 millas al NW de cabo Peñas. Indebidamente continuaron confundiendo cabo Vidio con cabo Peñas. Le decían habían sido obligados a parar en esa situación y que, aparentemente, eran conducidos a Ferrol.''
''Como el “Resolution” contestó que se dirigía a su encuentro, arrumbé nuevamente al encuentro del convoy desde el N de cabo Peñas, donde me encontraba en aquellos momentos.''
''A las 2h. 30m., los buques se encontraban a la altura del cabo Busto y navegaban sin novedad hacia Ribadeo. No viendo cerca el acorazado inglés, regresé nuevamente al cabo Peñas y las 15h. encontré al “Resolution” a la altura de Avilés. Dicho buque me pasó el siguiente despacho:''
De “Resolution” a “Cervera”.– Ruego me diga si tiene usted alguna información del barco mercante inglés “Dover Abhey”.
De “Cervera” a “Resolution”.– Sí, vapores “Dover Abhey” y “Yorkbrook” fueron capturados esta mañana 2 millas al NE cabo Vidio y son conducidos a Ribadeo. ''[http://www.asturiasrepublicana.com/cervera7-2.html#prof Log of insurgent cruiser ''Almirante Cervera''] {{Webarchive|url=https://web.archive.org/web/20081014013322/http://www.asturiasrepublicana.com/cervera7-2.html#prof |date=2008-10-14 }} {{in lang|es}}''</ref>
At least five minor vessels carrying refugees and soldiers of the Republican army where seized by the minelayer after the fall of the last government's strongholds on northern Spain by the end of October.<ref>[http://www.asturiasrepublicana.com/cervera10.html ''Relación de buques capturados por los nacionales''] {{Webarchive|url=https://web.archive.org/web/20090923192822/http://www.asturiasrepublicana.com/cervera10.html |date=2009-09-23 }} {{in lang|es}}</ref>
On Christmas Day 1937 ''Júpiter'' shelled the port  of [[Burriana]], near [[Castellón de la Plana|Castellon]], in the Mediterranean coast, where the British freighter ''Bramhill'' was at anchor. The merchant was hit by several rounds, specially on her bow, and had to withdraw to [[Marseille]] to undergo repairs.<ref>Heaton, Paul Michael: ''Welsh Blockade Runners in the Spanish Civil War.'' Starling  Press, 1985. Page 74. {{ISBN|0-9507714-5-7}}</ref><ref>Foreign Office: ''Index to the correspondence of the Foreign Office for the year 1938, Part 4.'' Kraus-Thomson, 1969, page 81</ref><ref name=cast>[http://www.aulamilitar.com/gncas.hts#prof  Guerra Naval en Castellón] {{in lang|es}}</ref>
Towards the end of the war, along with the auxiliary cruiser ''[[Mar Negro]]'', she supported the landing of an [[infantry division]] on [[Mahón]], [[Menorca]], after the Republican surrender of this island, on 9 February 1939.<ref>[[Ramón Salas Larrazábal|Salas Larrazábal, Ramón]] & Jesús: ''Historia general de la Guerra de España.'' Rialp, 1986, page 393. {{ISBN|84-321-2340-4}} {{in lang|es}}</ref> She was one of the units involved in the blockade of [[Alicante]], where thousands of refugees gathered in order to flee Spain when Franco's victory was in sight. Assisted by her sister ships, ''Júpiter'' entered the port on 31 March, the day before the official end of the conflict, in order to land the 121st and 122nd [[Galicia (Spain)|Galician]] Regiments.<ref name=":0">{{Cite web|url=http://www.diarioinformacion.com/alicante/2014/03/30/final-guerra-civil-alicante/1485474.html|title=El final de la Guerra Civil en Alicante|last=INFORMACION|website=www.diarioinformacion.com|language=Spanish|access-date=2016-04-23}}</ref>
After the Spanish Civil War, in December 1940, ''Júpiter'' carried out an undercover [[reconnaissance]] mission around [[Gibraltar]] with [[Wilhelm Canaris|Admiral Canaris]], [[Joachim-Friedrich Lang|General Lang]] and a Spanish officer aboard. The goal was to gather intelligence about the British fortifications and boom defenses as a first step toward the proposed [[Operation Felix]].<ref>Suárez Fernández, Luis (2005). ''Franco''. Ariel, p. 188. {{ISBN|84-344-6781-X}}</ref>
====''Vulcano''====
[[File:Jupiter-2.jpg|thumb|200px|Minelayer ''Vulcano'' during World War II, displaying neutrality marks on her bow]]
''Vulcano'' temporarily  blocked the entrance to [[Gijon]] of the British merchants ''Stanray''<ref>''A mediodía, encontrándome a 18 millas al N de Tazones, recibí un radio en claro del “Vulcano” en el que me decía salía un destructor de Gijón. Arrumbé a cabo Peñas y avisté al “Vulcano” con un vapor inglés y un destructor.''
''Según me comunicó más tarde, a mediodía intentaron entrar los vapores ingleses “Mydol” y “Stanray”. Al entrar dentro del límite de las aguas jurisdiccionales este último, disparó y le ordenó parar, viendo que este barco metía a una banda, lo creyó capturado, pero como, al parecer, no paró las máquinas, el almirante inglés no concedió captura, diciendo que el barco había metido para escapar.'' [http://www.asturiasrepublicana.com/cervera7-1.html#prof Log of insurgent cruiser ''Almirante Cervera''] {{Webarchive|url=https://web.archive.org/web/20081014150630/http://www.asturiasrepublicana.com/cervera7-1.html#prof |date=2008-10-14 }} {{in lang|es}}</ref> and ''Stangrove''.<ref>''El “Vulcano” comunicó que a 1h. había encontrado al vapor inglés “Stangrove” que se dirigía a Gijón con luces apagadas. Al ser reconocido, se alejó hacia el N.'' [http://www.asturiasrepublicana.com/cervera7-3.html#prof Log of insurgent cruiser ''Almirante Cervera''] {{Webarchive|url=https://web.archive.org/web/20180613122334/http://www.asturiasrepublicana.com/cervera7-3.html#prof |date=2018-06-13 }} {{in lang|es}}</ref> At the end of the war in the north she joined a naval squadron which drove back the steamers ''Hillfern'', ''Bramhill'', ''Stanhill'' and ''Stanleigh'' off Cape Peñas, seizing a number of small Republican vessels crowded with refugees in the process.<ref name="ins">[http://www.asturiasrepublicana.com/cervera7-3.html#prof Log of insurgent cruiser ''Almirante Cervera''] {{Webarchive|url=https://web.archive.org/web/20180613122334/http://www.asturiasrepublicana.com/cervera7-3.html#prof |date=2018-06-13 }} {{in lang|es}}</ref> During this period she  shelled, without success, the British ''Thorpebay'' when this steamer entered the port of the Musel.<ref>[http://www.asturiasrepublicana.com/cervera7-2.html Log of insurgent cruiser ''Almirante Cervera''] {{Webarchive|url=https://web.archive.org/web/20081014013322/http://www.asturiasrepublicana.com/cervera7-2.html |date=2008-10-14 }} {{in lang|es}}</ref> Between the last months of 1937 and 1939 ''Vulcano'' was active in the  Mediterranean, where she was part of the rebel fleet which bombarded Castellon, Burriana and [[Vinaròs]] on Christmas Day 1937.<ref name="cast"/> She played a key role, along with her sisters ships, in ferrying troops after Franco's army reach the coast between [[Valencia, Spain|Valencia]] and [[Barcelona]] [[Aragon Offensive|in April 1938]].<ref name="Alboran22"/>
On 17 October 1938, she seized the [[USSR|Soviet]] cargo ship ''Katayama'', of 3,200 tons. She also played a secondary role in the capture of the Greek merchant ''Victoria'' by the [[Armed merchantman|auxiliary cruiser]] ''Mar  Cantábrico'' and the British ''Stangrove'' by the gunboat ''Dato'',  in the final months of the civil  war. All these  freighters joined the Spanish merchant fleet at the end of the conflict.<ref name="Alboran22">Moreno de Alborán y de Reyna, Fernando: ''La  guerra silenciosa y silenciada: Historia de la campaña naval durante la guerra  de 1936–39''. Madrid, 1998, v. 4, part 2. {{in lang|es}}</ref>
Perhaps the most famous action of ''Vulcano'' is the chase and capture of the Republican {{sclass|Churruca|destroyer|1}} {{ship|Spanish destroyer|José Luis Díez||2}} off Gibraltar, in the course of a battle fought as close as {{convert|50|m|ft}} between the ships involved. ''José Luis Diez'' eventually became stranded in [[Catalan Bay]], in the territory of Gibraltar, the last day of 1938. The destroyer was turned over to Franco's government after its recognition by Britain as the legitimate authority in Spain.<ref>[http://www.ciere.org/CUADERNOS/art%2062/Art.%203.htm The ''José Luis Diez'' issue] {{Webarchive|url=https://web.archive.org/web/20080315210156/http://www.ciere.org/CUADERNOS/art%2062/Art.%203.htm |date=2008-03-15 }}, a lecture by Dennis D. Beiso, Gibraltar, 2002</ref>
She was the leading unit of an aborted landing at [[Cartagena, Spain|Cartagena]] on 7 March 1939, after the withdrawal of the Republican fleet from its bases and its [[internment]] at [[Bizerte]]. The operation was mounted on the belief that anti-communist Republicans had taken over  the port once the Government navy fled. However, loyalist forces retook control of the coastal batteries around the harbour. All the ships received the order of aborting the operation, but two transports, {{SS|Castillo de Olite||2}} and ''Castillo Peñafiel'', deprived of radio, continued toward Cartagena undeterred. They were the former Soviet steamers ''Postishev'' and ''Smidovich'', of 3,545 and 2,485 tons respectively, which had been seized by the Nationalists at high seas.<ref>González Etchegaray, Rafael : ''La Marina Mercante y el Trafico Maritimo en la Guerra Civil''. Editorial San Martin, Madrid, 1977, Appendix II. {{ISBN|84-7140-150-9}}</ref> ''Castillo de Olite'' was sunk by a {{convert|381|mm|in|abbr=on|0}} [[Coastal artillery|battery]] close to the docks, with a loss of life of almost 1,500. Meanwhile, ''Castillo Peñafiel'' had a narrow escape, harassed by Republican aircraft. In a letter to General Franco, Admiral Francisco Moreno put the blame on ''Vulcano''{{'}}s commander for his failure to prevent the departure of the freighters, as ordered by Moreno himself. ''Vulcano'' apparently gave a green light to the transports after receiving contradicting orders from the high command to proceed.<ref>De la Cierva, Ricardo: ''La victoria y el caos: a los sesenta años del 1 de abril de 1939''. Fénix, 1999, pp. 512-518. {{ISBN|84-88787-25-1}} {{in lang|es}}</ref>
Along with her sister ships, ''Vulcano'' landed two infantry battalions at Alicante on 31 March, the day before the official end of hostilities.<ref name=":0" />
==== ''Marte'' ====
''Marte'' was the last minelayer of the class to be commissioned before the end of the civil war. ''Neptuno'', the last of the batch, was not completed until November 1939, seven months after the war was over.<ref>{{Cite web|url=http://www.todoavante.es/index.php?title=Neptuno_(1943)|title=Neptuno (1943)|last=|first=|date=|website=Todoavante.es|publisher=|language=Spanish|access-date=22 April 2016|archive-date=9 May 2016|archive-url=https://web.archive.org/web/20160509095012/http://www.todoavante.es/index.php?title=Neptuno_(1943)|url-status=dead}}</ref> ''Marte'' was released to the Nationalist navy on 11 November 1938. The minelayer departed from [[Ferrol, Galicia|El Ferrol]] in December 1938 to take part in the chase of the Republican destroyer ''José Luis Díez'', which had taken shelter in Gibraltar. Given the inexperience of her crew, ''Marte'' didn't play any major role in the neutralization of the Republican warship. Later, in January 1939, while based at the [[Palma, Majorca|port of Palma]], ''Marte'' participated in gunnery trials off [[Majorca]] and in blockade activities along the Catalan coast and the [[Gulf of Lion]]. In February, she relieved her sister ''Júpiter'' from her blockade duties off Catalonia, and on 21 February she attended a naval parade at [[Salou]]. On 7 March 1939, during the ill-fated landing on Cartagena, ''Marte'' loaded troops and cargo at [[Castellón de la Plana|Castellon]] before the operation was cancelled.<ref>{{Cite web|url=http://www.todoavante.es/index.php?title=Marte_(1938)|title=Marte (1938)|last=|first=|date=|website=Todoavante.es|publisher=|language=Spanish|access-date=22 April 2016}}</ref> Along with her sisters, she patrolled the Republican waters off Alicante in the waning days of the war. ''Marte'' took part in one of the last international maritime incidents of the war on 19 March 1939, when she prevented the British steamer ''Stanbrook'' from entering Alicante. The ship, chartered by the Republican government, went back to [[Oran]], [[Algeria]].<ref>Moreno de Alborán y de Reyna, Fernando: ''La  guerra silenciosa y silenciada: Historia de la campaña naval durante la guerra  de 1936–39''. Madrid, 1998, v. 4, part 2, [https://books.google.com/books?id=1YdpAAAAMAAJ&q=%2219+al+barco+mercante+contrabandista+ingl%C3%A9s+Stanbrook%22 p. 144]. {{in lang|es}}</ref><ref>Arias, Fernando: ''La Valencia de los años 30. Entre el paraiso y el infierno''. Carena Editors, S.l., 1999, page 235. {{ISBN|84-87398-35-9}} {{in lang|es}}</ref> The ''Stanbrook'' eventually reached the Spanish port on 27 March,<ref name="Asturias2">[http://www.sbhac.net/Republica/Colabora/Harmonie.htm ''Republicanos. De Alicante hacia África.1939''] {{in lang|es}}</ref> after the Nationalist side displayed some indulgency toward the evacuation of refugees in return for the British recognition of Franco's legitimacy.<ref>"The British government assumed that Franco would overlook the activities of the occasional merchant ship." Graham, Helen: ''The Spanish Republic at war, 1936-1939''. Cambridge University Press, 2002, page 422. {{ISBN|0-521-45932-X}}</ref> Two days later, ''Stanbrook'' left Alicante bound for Oran, crowded with at least 2,000 people, one of the last ships to either enter or flee Republican Spain. Her [[Wales|Welsh]] skipper, Captain Archibald Dickson, later killed during the sinking of his ship in World War II, is today remembered as a hero in Alicante.<ref>[http://www.elpais.com/articulo/Comunidad/Valenciana/Alicante/recuerda/gales/salvo/miles/republicanos/elpepuespval/20090330elpval_9/Tes ''Alicante recuerda al galés que salvó a miles de republicanos''] {{in lang|es}}</ref>
===Refurbishment===
Of the four vessels, only ''Júpiter'' and ''Vulcano'' took part in a modernization program after the agreements between Spain and the United States in the 1950s, and were reclassified as frigates. The modernization was held in [[Cartagena, Spain|Cartagena]] from 1958 to 1961. The antisubmarine and antiaircraft weapons were updated by adding a [[Squid (weapon)|squid multiple mortar]] and [[Bofors 40 mm Automatic Gun L/60|Bofors 40 mm gun]]s. The units were also fitted with radar. Both ships joined the frigate squadron along with those units of the first ''Pizarro'' class. ''Júpiter'' was written off the Navy List on 23 November 1974, and ''Vulcano'' was used as a store ship from 12 March 1977 until her final decommissioning on 30 April 1978, this being the last warship to be removed from service of those who participated in the Civil War.<ref name="asamblea">Asamblea de Capitanes de Yate:''La armada española''. Editorial San Martín, 1978. Page 77. {{ISBN|84-7140-172-X}} {{in lang|es}}</ref>
''Marte'' and ''Neptuno'' remained unchanged until their decommissioning in 1971 and 1972 respectively.<ref name=asamblea/>
==Units of the class==
{|border="1" align="center" cellpadding="2" cellspacing="0"
|- !align="center"
| Name
| Number
| Commissioned
| Scrapped
|- !align="center"
| ''Marte''
|F-01
| 1938
| 1971
|- !align="center"
| ''Neptuno''
|F-02
| 1939
| 1972
|- !align="center"
| ''Júpiter''
|F-11
| 1937
| 1974
|- !align="center"
| ''Vulcano''
|F-12
| 1937
| 1977
|}
==References==
{{reflist|30em}}
{{SpanishCivilWarShips}}
{{DEFAULTSORT:Jupiter Class Minelayer}}
[[Category:Mine warfare vessels of the Spanish Navy]]
[[Category:Ships built in Spain]]
[[Category:Military units and formations of the Spanish Civil War (National faction)]]
[[Category:Minelayers]]
[[Category:Spanish Civil War ships]]
[[Category:Spanish Republican Navy]]