View source for Acciaio-class submarine

{{Short description|Italian submarine class}}
{|{{Infobox ship begin}}
{{Infobox ship image
|Ship image= Acciaio_class_submarine.jpg
|Ship caption= Italian ''Acciaio''-class submarine (''Porfido'')
}}
{{Infobox ship class overview
|Name=''Acciaio'' class
|Builders=*[[Oto Melara|Odero Terni Orlando]] (OTO), [[Lerici|Muggiano]]
* [[Cantieri Riuniti dell' Adriatico]] (CRDA), [[Monfalcone]]
* [[Cantieri navali Tosi di Taranto|Tosi]], [[Taranto]]<ref name=conway/><ref name=bagnasco/>
|Operators={{navy|Kingdom of Italy|name=''Regia Marina''}}
|Class before={{sclass|Adua|submarine|4}}
|Class after=end of [[Italian 600 Series submarines|600 series]]
|Subclasses=
|Cost=
|Built range=
|In service range=
|In commission range=1941–1966
|Total ships building=
|Total ships planned=
|Total ships completed=13
|Total ships cancelled=
|Total ships active=
|Total ships laid up=
|Total ships lost=8
|Total ships retired=
|Total ships preserved=
}}
{{Infobox ship characteristics
|Hide header=
|Header caption=<ref name=conway>Conway p310</ref><ref name=bagnasco>Bagnasco p163</ref>     
|Ship type=[[Submarine]]
|Ship displacement=*{{convert|697|LT|t|0}} surfaced
* {{convert|850|LT|t|0}} submerged
|Ship length={{convert|60.18|m|ftin|abbr=on}}
|Ship beam={{convert|6.44|m|ftin|abbr=on}}
|Ship height=
|Ship draught={{convert|4.78|m|ftin|abbr=on}}
|Ship power=
|Ship propulsion=*2 [[diesel engine]]s, {{convert|1400|hp|lk=in|abbr=on}}
* 2 electric motors, {{convert|800|bhp|abbr=on}}
|Ship speed=*{{convert|14|kn|lk=in}} surfaced
* {{convert|7.7|kn|lk=in}} submerged
|Ship range= {{convert|3180|nmi|km|abbr=on|lk=in}} at {{convert|10.5|kn|km/h|abbr=on}} surfaced
|Ship endurance=
|Ship test depth={{convert|80|m|ft|abbr=on}}
|Ship complement=45
|Ship sensors=
|Ship EW=
|Ship armament=*1 × [[Škoda 10 cm K10#OTO 100/47 History|{{convert|100|mm|in|abbr=on|0}} / 47&nbsp;caliber]] [[deck gun]]
* 1-2 × 20mm/70 AA
* 6 × {{convert|533|mm|in|0|abbr=on}} [[torpedo tube]]s (4 forward, 2 aft)
* 12 × torpedoes
|Ship notes=
}}
|}

The '''''Acciaio''-class submarine'''<ref name=conway/><ref name=bagnasco/> (also sometimes called ''Platino'' class<ref name=adamo>C Adamo at [http://www.regiamarina.net regiamarina.net]</ref>) was the fifth subclass of the [[Italian 600 Series submarines|600 Series]] of [[coastal submarine]]s built by the [[Regia Marina]]. They were completed during the early 1940s and saw service in [[World War II]].

==Design and description==
The ''Acciaio''s were a development of the {{sclass|Adua|submarine|5}} and {{sclass|Perla|submarine|5}} designs, with some improvements, such as a lower conning tower to improve stability and reduce the silhouette.<ref name=bagnasco/> Of the 13 vessels in the class, six were built by [[Cantieri Riuniti dell' Adriatico|CRDA]] at [[Monfalcone]], four by [[Oto Melara|OTO]] at [[Muggiano]], and three by [[Cantieri navali Tosi di Taranto|Cantieri Tosi]] in [[Taranto]], the three main Italian shipyards for [[submarine]]s. They were single-hulled with side tanks, and built to a Bernardis design, though the Tosi vessels had more powerful engines (at the expense of the two stern [[torpedo tube]]s), giving a surface speed of {{convert|14.7|kn}}.

The word ''Acciaio'' means "steel", and all vessels in this class were named for metals and minerals.

==Ships==
{| class="wikitable sortable plainrowheaders"  style="font-size:97%;"
|+ List of ''Acciaio''-class submarines
|-
! scope="col" | Ship
! scope="col" | Builder<ref name=conway/>
! scope="col" | Launched<ref name=conway/>
! scope="col" | Fate<ref name=conway/>
|-
! scope="row" | {{ship|Italian submarine|Acciaio||2}}
| OTO
| 20&nbsp;July 1941
| data-sort-value="13 July 1943" | torpedoed 13&nbsp;July 1943 by {{HMS|Unruly|P49|6}}
|-
! scope="row" | {{ship|Italian submarine|Alabastro||2}}
| CRDA
| 18&nbsp;December 41
| data-sort-value="14 September 1942" | bombed 14&nbsp;September 1942 by Allied aircraft
|-
! scope="row" | {{ship|Italian submarine|Argento||2}}
| Tosi
| 22&nbsp;February 1942
| data-sort-value="3 August 1943" | sunk 3&nbsp;August 1943 by {{USS|Buck|DD-420|6}}
|-
! scope="row" | {{ship|Italian submarine|Asteria||2}}
| CRDA
| 25&nbsp;June 1941
| data-sort-value="17 February 1943" | sunk 17&nbsp;February 1943 by {{HMS|Easton}}, {{HMS|Wheatland}},
|-
! scope="row" | {{ship|Italian submarine|Avorio||2}}
| CRDA
| 6&nbsp;September 1941
| data-sort-value="8 February 1943" | sunk 8&nbsp;February 1943 by {{HMCS|Regina|K234|6}}
|-
! scope="row" | {{ship|Italian submarine|Bronzo||2}}
| Tosi
| 28&nbsp;September 1941
| data-sort-value="12 July 1943" | captured 12&nbsp;July 1943 by British destroyers
|-
! scope="row" | {{ship|Italian submarine|Cobalto||2}}
| OTO
| 20&nbsp;July 1941
| data-sort-value="12 August 1942" | rammed 12&nbsp;August 1942 by {{HMS|Ithuriel|H05|6}}
|-
! scope="row" | {{ship|Italian submarine|Giada||2}}
| CRDA
| 10&nbsp;July 1941
| data-sort-value="September 1943" | surrendered at armistice September 1943
|-
! scope="row" | {{ship|Italian submarine|Granito||2}}
| CRDA
| 7&nbsp;August 1941
| data-sort-value="9 November 1942" | torpedoed 9&nbsp;November 1942 by {{HMS|Saracen|P247|6}}
|-
! scope="row" | {{ship|Italian submarine|Nichelio||2}}
| OTO
| 12&nbsp;April 1942
| data-sort-value="September 19433" | surrendered at armistice September 1943
|-
! scope="row" | {{ship|Italian submarine|Platino||2}}
| OTO
| 1&nbsp;June 1941
| data-sort-value="September 1943" | surrendered at armistice September 1943
|-
! scope="row" | {{ship|Italian submarine|Porfido||2}}
| CRDA
| 23&nbsp;August 1941
| data-sort-value="6 December 1942" | torpedoed 6&nbsp;December 1942 by {{HMS|Tigris|N63|6}}
|-
! scope="row" | {{ship|Italian submarine|Volframio||2}}
| Tosi
| 9&nbsp;November 1941
| data-sort-value="September 1943" | scuttled at armistice September 1943; raised by Germans, sunk in Allied air raid 1944
|}

==Service==
Of the 13 vessels completed, eight were lost in action. The submarines served in the [[Mediterranean]].

==See also==
* [[Italian submarines of World War II]]

== References ==
===Notes===
{{reflist|30em}}

=== Bibliography ===
* {{cite book|last=Bagnasco |first=Erminio |title=Submarines of World War Two |year=1977 |publisher=Naval Institute Press |location=Annapolis, Maryland |isbn=0-87021-962-6}}
* {{cite book|last=Brescia|first=Maurizio|title=Mussolini's Navy: A Reference Guide to the Regina Marina 1930–45|year=2012|publisher=Naval Institute Press|location=Annapolis, Maryland|isbn=978-1-59114-544-8}}
* {{cite book |editor-last=Chesneau |editor-first=Roger |year=1980 |title=Conway's All the World's Fighting Ships 1922–1946 |location=London |publisher=[[Conway Publishing|Conway Maritime Press]] |isbn=0-85177-146-7}}
* {{cite book |last1=Dodson |first1=Aidan |last2=Cant |first2=Serena |title=Spoils of War: The Fate of Enemy Fleets after Two World Wars |date=2020 |publisher=Seaforth Publishing |location=Barnsley, UK |isbn=978-1-5267-4198-1|name-list-style=amp}}
* {{cite journal|last1=Frampton |first1=Viktor|year=2010 |title=Question 22/44: HMS X-2|journal=Warship International|volume=XLVII|issue=3|page=218|issn=0043-0374}}

==External links==
* [http://www.regiamarina.net/ship_info.asp?class=Platino&nid=154&lid=1 ''Acciaio'' class at regiamarina.net]
* [https://www.marina.difesa.it/noi-siamo-la-marina/mezzi/mezzi-storici/Pagine/sommergibili.aspx Sommergibili] Marina Militare website

{{Portal bar|Italy|Engineering}}
{{Acciaio-class submarine}}
{{Italian 600 Series submarines}} 
{{WWII Italian ships}}

[[Category:World War II submarines of Italy|Acciaio]]
[[Category:Italian 600 Series submarines|Acciaio]]
[[Category:Acciaio-class submarines| ]]
[[Category:Submarines of the Regia Marina|Acciaio]]
[[Category:Ships built by Cantieri navali Tosi di Taranto]]
[[Category:Ships built by Cantieri Riuniti dell'Adriatico]]
[[Category:Ships built by OTO Melara]]