View source for Trento-class cruiser

{{Short description|Heavy cruiser class of the Italian Royal Navy}}
{{good article}}
{|{{Infobox ship begin}}
{{Infobox ship image
|Ship image=Italian cruiser Trento NH 86592.jpg
|Ship caption=''Trento'' early in her career
}}
{{Infobox ship class overview
|Name=
|Builders=
* [[Cantiere navale fratelli Orlando]]
* [[Stabilimento Tecnico Triestino]]
|Operators={{navy|Kingdom of Italy|name=''Regia Marina''}}
|Class before=None
|Class after= {{sclass|Zara|cruiser|4}}
|Built range=1925–1929
|In commission range=1928–1943
|Total ships completed=2
|Total ships lost=2
}}
{{Infobox ship characteristics
|Hide header=
|Header caption= 
|Ship type=[[Heavy cruiser]]
|Ship displacement=[[Full load]]: {{convert|13334|LT|sp=us|lk=on}}
|Ship length={{convert|196.96|m|ftin|abbr=on}} [[length overall|o/a]]
|Ship beam={{convert|20.6|m|ftin|abbr=on}}
|Ship draft={{convert|6.8|m|ftin|abbr=on}}
|Ship power=
*12 × [[Yarrow boiler]]s
*{{cvt|150000|shp|lk=on}}
|Ship propulsion=
*4 × [[Parsons Marine Steam Turbine Company|Parsons]] [[steam turbine]]s
*4 × [[screw propeller]]s
|Ship speed=
*Trials: {{convert|35.65|kn|abbr=on}}
*Service: {{convert|31|kn|abbr=on}}
|Ship range={{convert|4160|nmi|abbr=on|lk=in}} at {{convert|16|kn|abbr=on}}
|Ship complement=
*Peacetime: 723
*Wartime: 781
|Ship EW=
|Ship armament=
*4 × 2 - [[203 mm /50 Model 1924|{{convert|203|mm|in|abbr=on|0}} / 50&nbsp;]] [[Caliber#Caliber as measurement of length|caliber]] guns
*8 × 2 - [[Škoda 10 cm K10#OTO 100.2F47 History|{{convert|100|mm|in|abbr=on|0}} / 47&nbsp;caliber]] guns
*4 × 1 - [[QF 2-pounder naval gun|{{cvt|40|mm}} / 39&nbsp;caliber]] [[anti-aircraft warfare|anti-aircraft guns]] (early)
*4 × 2 - [[Cannone-Mitragliera da 37/54 (Breda)|{{convert|37|mm|in|abbr=on|0}} / 54&nbsp;caliber]] anti-aircraft guns (late)
*4 (''Trento'') or 8 (''{{ship|Italian cruiser|Trieste||2}}'') × 1 - [[Breda Model 35|{{convert|20|mm|abbr=on}} / 65&nbsp;caliber]] anti-aircraft guns (late)
*4 × 2 - [[Breda Model 1931 Machine Gun|{{convert|13.2|mm|in|abbr=on}}]] [[machine gun]]s (early)
*4 × 2 - {{convert|533|mm|in|abbr=on|0}} [[torpedo tube]]s
|Ship armor=
*[[Belt armor|Belt]]: {{convert|70|mm|in|abbr=on}}
*[[Deck (ship)|Deck]]: {{convert|20|to|50|mm|in|abbr=on}} deck
*[[Gun turret|Turrets]]: {{convert|100|mm|in|abbr=on}}
*[[Conning tower]]: {{convert|100|mm|in|abbr=on}}
|Ship aircraft=2 × [[IMAM Ro.43]] [[seaplane]]s
|Ship aircraft facilities=
|Ship notes=
}}
|}

The '''''Trento'' class''' was a group of two [[heavy cruiser]]s built for the Italian ''[[Regia Marina]]'' (Royal Navy) in the late 1920s, the first such vessels built for the Italian fleet. The two ships in the class&mdash;{{ship|Italian cruiser|Trento||2}} and {{ship|Italian cruiser|Trieste||2}}, were named after the [[Irredentism|redeemed]] cities of [[Trento]] and [[Trieste]] annexed from the [[Austro-Hungarian empire]] after the victory in [[World War I]]. The ships were very lightly armored, with only a {{convert|70|mm|abbr=on}} thick [[armored belt]], though they possessed a high speed and heavy [[main battery]] of eight {{cvt|203|mm|0}} guns. Nominally built under the restrictions of the [[Washington Naval Treaty]], the two cruisers nevertheless exceeded the [[Displacement (ship)|displacement]] limits imposed by the treaty.

In the [[interwar period]], the two cruisers served in the Cruiser Division, frequently alternating as the divisional [[flagship]]. ''Trento'' made two extensive trips abroad, the first was a tour of South American countries in mid to late-1929 and the second was a deployment to China to protect Italian nationals during the [[Chinese Civil War]]. In 1938, ''Trieste'' assisted in the repatriation of Italian volunteer soldiers who had fought in Spain during the [[Spanish Civil War]]. Both ships saw extensive action in [[World War II]], including the battles of [[Battle of Calabria|Calabria]], [[Battle of Cape Spartivento|Cape Spartivento]], and [[Battle of Cape Matapan|Cape Matapan]]. ''Trieste'' was damaged by a British submarine in November 1941 and therefore missed the [[First Battle of Sirte|First]] and [[Second Battle of Sirte|Second Battles of Sirte]], where at the latter action ''Trento'' damaged a British [[destroyer]].

''Trento'' was torpedoed and sunk by a British torpedo bomber and a submarine in June 1942 with heavy loss of life. In April 1943, ''Trieste'' was also sunk in port at [[La Maddalena]] during an attack by United States [[heavy bomber]]s. Salvage operations began in 1950, and after it was determined that the ship's engines had been preserved by leaked fuel oil, the hull was sold to the [[Spanish Navy]], which planned to convert the vessel into a light [[aircraft carrier]]. The plan was eventually cancelled in 1956 due to rising costs of the project, and ''Trieste'' was [[ship breaking|broken up]] for scrap in 1959.

== Design ==
In the early 1920s, the ''[[Regia Marina]]'' began design studies for [[cruiser]]s that would adhere to the limitations of the [[Washington Naval Treaty]], which limited cruisers to a [[Displacement (ship)|displacement]] of {{convert|10000|LT|lk=on|-1}} and an armament of {{convert|203|mm|adj=on|0|sp=us}} guns. The design for what became the ''Trento'' class was prepared by General [[Filippo Bonfiglietti]] in 1923.<ref>Brescia, p. 72&ndash;73</ref> In 1924, the [[French Navy]] laid down the first of two {{sclass|Duquesne|cruiser|1}}s, prompting the ''Regia Marina'' to order two vessels to match their rival.<ref>Marriott, p. 50</ref> The designers emphasized very high speed, which required a significant reduction in armor protection to keep the ships within the displacement limit.<ref name=GC291/> In addition, they were designed with a narrow [[beam (nautical)|beam]] to help them reach high speeds, which reduced their stability. This would be the general pattern for Italian cruisers and [[destroyer]]s built in the 1920s and 1930s, with the exception of the later {{sclass|Zara|cruiser|1}}s and some of the later {{sclass2|Condottieri|cruiser|1}}s.<ref>Gardiner & Chesneau, p. 283</ref>

While the ships were still on the [[slipway]]s, officers in the ''Regia Marina'' expressed concerns that the thin armor protection of the ''Trento''s would leave the vessels poorly equipped for combat. As a result, the navy ordered the more balanced ''Zara''-class, which featured a significantly thicker scale of armor protection.<ref>Brescia, p. 76</ref> The lightly-built ''Trento'' design nevertheless provided the basis for the {{sclass|Veinticinco de Mayo|cruiser|1}}s built by [[OTO Melara|Odero Terni Orlando]] for the [[Argentine Navy]]; the Argentine vessels were scaled down slightly, with thinner armor and {{convert|190|mm|adj=on}} guns.<ref name="Friedman 263">Friedman, p. 263</ref> Another derivative design built for the Italian fleet, {{ship|Italian cruiser|Bolzano||2}}, started construction in 1930 and was commissioned in 1933; though the ''Bolzano'' was quite different from the other two vessels, she is sometimes considered a member of the ''Trento'' class.<ref>Marriott, p. 156</ref>

===General characteristics===
[[File:Тяжелый крейсер типа Trento 2.jpg|thumb|left|Plan and profile drawing of the Trento class]]

The ships of the ''Trento'' class were {{convert|190|m|ftin|sp=us}} [[length between perpendiculars|long between perpendiculars]] and {{convert|196.96|m|ftin|abbr=on}} [[length overall|long overall]]. They had a beam of {{convert|20.6|m|ftin|abbr=on}} and a [[draft (hull)|draft]] of {{convert|6.8|m|ftin|abbr=on}}. They had a design displacement of {{convert|10339|to|10344|LT}} and they displaced up to {{convert|13334|LT}} at [[full load]], though their displacement was nominally within the 10,000-long-ton restriction set in place by the Washington Naval Treaty.<ref name=GC291/> Their [[hull (watercraft)|hulls]] had a [[flush deck]] and a [[bulbous bow]], the first time the latter feature was employed on an Italian warship.<ref>Brescia, p. 73</ref> The ships were completed with a pair of tripod masts, though on trials they were found to vibrate excessively, and the foremast was strengthened with two extra legs. They had a crew of 723 officers and enlisted men, though during the war this increased to 781. They carried a pair of [[IMAM Ro.43]] [[seaplane]]s for aerial reconnaissance; the hangar was located under the [[forecastle]] and a fixed [[aircraft catapult|catapult]] was mounted on the [[:wikt:centerline|centerline]] at the bow.<ref name=GC291>Gardiner & Chesneau, p. 291</ref><ref name=B72>Brescia, p. 72</ref>

The ''Trento''-class cruisers' power plant consisted of four [[Parsons Marine Steam Turbine Company|Parsons]] [[steam turbine]]s powered by twelve oil-fired [[Yarrow boiler]]s, which were trunked into two funnels [[amidships]]. The boilers were divided into three [[Fire room|boiler rooms]] with four each; two powered the forward engines that drove the outboard propellers and the remaining four were allocated to the turbines that drove the center shafts. The engines were rated at {{convert|150000|shp|lk=in}} for a top speed of {{convert|36|kn|lk=in}}, with projected service performance of {{convert|120000|shp|abbr=on}} for {{convert|34|kn}} at normal displacement. On [[sea trials]], ''Trieste'' only reached {{convert|35.65|kn}} and ''Trento'' managed slightly less than that; these speeds could only be reached on a very light displacement, and in service, her practical top speed was only {{convert|31|kn}}. The ships had a storage capacity of {{convert|2214|MT|sp=us}} of [[fuel oil]], which provided a cruising range of {{convert|4160|nmi|lk=in}} at a speed of {{convert|16|kn}}. During refits in early 1940, funnel caps were added to reduce smoke interference with the masts.<ref>Brescia, pp. 72, 74</ref><ref name="Gardiner Chesneau 291 292">Gardiner & Chesneau, pp. 291&ndash;292</ref>

===Armament and armor===
[[File:Italian cruiser Trento NH 82418.jpg|thumb|upright|Bow view of ''Trento''; note the very close mounting of the turret guns]]
''Trento'' and ''Trieste'' were armed with a [[main battery]] of eight [[203 mm /50 Model 1924|{{cvt|203|mm|0}} Mod 24]] 50-[[caliber (artillery)|caliber]] guns in four [[gun turret]]s;<ref name=GC291/> each turret carried the guns in a single cradle rather than independent mounts.<ref name="Friedman 263"/> The turrets were arranged in [[superfire|superfiring pairs]] forward and aft, and allowed for elevation to 45&nbsp;degrees, for a maximum range of {{convert|30000|yd|m|order=flip|sp=us}}. They had a [[rate of fire]] of three rounds per minute,<ref name=GC291/> and the guns had to reset to 15&nbsp;degrees to reload. The turrets were electrically operated, including the training and elevation gear and the ammunition hoists.<ref>Campbell, p. 328</ref> The guns suffered from excessive shell dispersion, like many other Italian guns of the period. Initially supplied with {{convert|125|kg|adj=on|sp=us}} shells fired at a [[muzzle velocity]] of {{convert|905|m/s|sp=us}}, the shells and propellant charges were reduced&mdash;to {{convert|118|kg|abbr=on}} at {{convert|840|m/s|abbr=on}}&mdash;in an unsuccessful attempt to tighten shell grouping. The problem was in large part due to poor quality control in Italian munition factories, which failed to ensure tight manufacturing tolerances necessary for accurate shells.<ref>Friedman, p. 310</ref> In addition, the single cradle mounts required the guns to be very close together; this caused the shells to interfere with each other in flight and contributed to the dispersion problem.<ref>Brescia, pp. 73&ndash;74</ref> Fire control was provided by a pair of [[Barr & Stroud]] {{convert|5|m|abbr=on}} [[coincidence rangefinder]]s.<ref>Friedman, pp. 263&ndash;264</ref>

[[anti-aircraft warfare|Anti-aircraft defense]] was provided by a battery of sixteen [[Škoda 10 cm K10#OTO 100.2F47 History|{{convert|100|mm|in|abbr=on|0}}]] 47-cal. guns in twin mounts, four [[QF 2-pounder naval gun|Vickers-Terni 40 mm/39]] guns in single mounts and four {{convert|12.7|mm|abbr=on}} [[machine gun]]s. The 100&nbsp;mm guns were copies of Austro-Hungarian guns designed in 1910 by [[Škoda Works|Škoda]] that were placed in newly designed dual-purpose mounts that elevated to 85&nbsp;degrees for a maximum range of {{convert|15240|m|abbr=on}}. In addition to the gun armament, they carried eight {{convert|533|mm|abbr=on}} [[torpedo tube]]s in four [[deck (ship)|deck]] mounted twin launchers.<ref name=GC291/><ref name=B72/><ref>Campbell, p. 339</ref> The ships' [[secondary armament|secondary batteries]] were revised several times during their careers. Both ships had their 100&nbsp;mm guns replaced with newer Mod 31 versions of the same caliber. In 1937&ndash;1938, the two aft-most 100&nbsp;mm guns were removed, along with all four 12.7&nbsp;mm machine guns; eight {{convert|37|mm|abbr=on}} 54-cal. [[Cannone-Mitragliera da 37/54 (Breda)|Breda M1932 guns]] and eight {{convert|13.2|mm|abbr=on}} [[Breda Model 1931 Machine Gun|Breda M1931 machine guns]], all in twin mounts, were installed in their place. In 1942, ''Trento'' received four [[Breda Model 35|{{convert|20|mm|abbr=on}} 65-cal. Breda M1940 guns]] in single mounts, with ''Trieste'' receiving eight of those guns the following year.<ref name="Gardiner Chesneau 291 292"/><ref>Campbell, pp. 345&ndash;347</ref>

Both vessels were protected with an [[armored citadel]] that covered the ships' vitals, including the machinery spaces and ammunition [[magazine (artillery)|magazines]]. The vertical [[belt armor|armor belt]] was {{convert|70|mm|abbr=on}} thick and ran from {{convert|8|m|abbr=on}} forward of the fore main battery turrets to {{convert|5|m|abbr=on}} aft of the rear turrets. Either end of the belt was capped with armored [[bulkhead (partition)|bulkheads]] {{convert|60|mm|abbr=on}} thick on the upper portion; the forward bulkhead had a lower section that was reduced to {{cvt|50|mm|0}}, and the aft bulkhead's lower portion was reduced to {{convert|40|mm|abbr=on}}. Their armor deck was 50&nbsp;mm thick in the central portion of the ship and reduced to {{convert|20|mm|abbr=on}} aft, with {{convert|30|mm|abbr=on}} thick sloped sides. The armor deck did not extend forward of the citadel. The gun turrets had {{convert|100|mm|abbr=on}} thick plating on the faces and the supporting [[barbette]]s they sat in were 70&nbsp;mm thick above the armor deck and 60&nbsp;mm thick below. The main [[conning tower]] had 100&nbsp;mm thick sides and a 50&nbsp;mm thick roof; above the tower was a fire control director with {{convert|80|mm|abbr=on}} thick sides and a 60&nbsp;mm thick roof.<ref name=GC291/>

==Ships==
{| class="wikitable plainrowheaders"
|+ Construction data
|-
! scope="col" | Name
! scope="col" | Builder<ref name=GC291/>
! scope="col" | [[keel laying|Laid down]]<ref name=GC291/>
! scope="col" | [[Ship naming and launching|Launched]]<ref name=GC291/>
! scope="col" | Completed<ref name=GC291/>
|-
! scope="row" | {{ship|Italian cruiser|Trento||2}}
| [[Cantiere navale fratelli Orlando]]
| 8 February 1925
| 4 October 1927
| 3 April 1929
|-
! scope="row" | {{ship|Italian cruiser|Trieste||2}}
| [[Stabilimento Tecnico Triestino]]
| 22 June 1925
| 20 October 1926
| 21 December 1928
|}

==Service history==
[[File:Italian cruiser Trieste NH 86003.jpg|thumb|''Trieste'' in 1930]]

''Trento'' and ''Trieste'' were named for the two largest [[Irredentism|unredeemed]] cities taken from [[Austria-Hungary]] in the aftermath of [[World War I]].<ref>Brescia, p. 74</ref> They frequently served as the [[flagship]] of the Cruiser Division throughout the 1930s. During the pre-war period, ''Trento'' made lengthy trips abroad, including a tour of South America from May to October 1929 and a deployment to China from January to June 1932 to protect Italian nationals during the [[Chinese Civil War]]. Both vessels took part in numerous [[naval review]]s held for visiting foreign leaders in the 1930s, including [[Adolf Hitler]] of [[Nazi Germany]] and [[Miklós Horthy]], the [[Regent of Hungary]]. In 1938 ''Trieste'' helped transport soldiers of the ''[[Corpo Truppe Volontarie]]'' (Corps of Volunteer Troops), which had been sent to Spain to fight in the [[Spanish Civil War]], back to Italy.<ref>Hogg & Wiper, pp. 2, 10</ref>

After Italy entered [[World War II]] in June 1940, ''Trento'' and ''Trieste'' saw extensive action against British forces in the [[Mediterranean Sea]], including at the battles of [[Battle of Calabria|Calabria]], [[Battle of Cape Spartivento|Cape Spartivento]], and [[Battle of Cape Matapan|Cape Matapan]] in July and November 1940 and March 1941, respectively. ''Trento'' was present at Calabria, where she battled British cruisers but did not sustain any damage.<ref>Hogg & Wiper, pp. 2&ndash;3, 11</ref> At the Battle of Cape Spartivento, either ''Trento'' or ''Trieste'' scored a hit on the British cruiser {{HMS|Berwick|65|6}},<ref>Greene & Massignani, p. 119</ref><ref>O'Hara, pp. 70&ndash;71</ref> and ''Trieste'' was briefly engaged but not seriously damaged by the [[battlecruiser]] {{HMS|Renown|1916|6}}.<ref>Stern, p. 62</ref> At Cape Matapan, the two cruisers engaged several British cruisers at very long range, with neither side scoring any hits.<ref>Greene & Massignani, pp. 150–151</ref>

In November 1941, ''Trieste'' was torpedoed by the [[submarine]] {{HMS|Utmost}}; she spent most of the next year under repair. In the meantime, ''Trento'' was also present during the inconclusive [[First Battle of Sirte|First]] and [[Second Battle of Sirte|Second Battles of Sirte]], and at the latter she severely damaged a British destroyer. Both cruisers were also frequently tasked with escorting convoys to supply Italian forces in North Africa as well as interdicting British convoys to the island of [[Malta]] in the central Mediterranean. During one of the latter missions to attack the British [[Operation Harpoon (1942)|Operation Harpoon]] convoy in June 1942, ''Trento'' was torpedoed twice, first by a [[Bristol Beaufighter]] [[torpedo bomber]] and then sunk by the submarine {{HMS|Umbra}} with very heavy loss of life on 15 June;<ref>Hogg & Wiper, p. 3, 10&ndash;11</ref> out of a wartime complement of 51&nbsp;officers and 1,100&nbsp;enlisted men, 549 were killed in the sinking, and a further 21 later died of wounds.<ref>Fioravanzo, p. 312</ref>

''Trieste'' returned to action in August 1942 for an operation that was cancelled following the torpedoing of another Italian cruiser by a British submarine. ''Trieste'' was moved to [[La Maddalena]], Sardinia, where she was later sunk by United States [[heavy bomber]]s on 10 April 1943. Salvage work on ''Trieste'' began in 1950. Her [[superstructure]] was cut away and she was refloated and towed to [[La Spezia]]; an inspection revealed that fuel oil had leaked into the machinery spaces, protecting them while the ship had been submerged. The [[Spanish Navy]] purchased the hull in 1952 and had her towed to [[Ferrol, Galicia|Ferrol]], with plans to convert the vessel into a light [[aircraft carrier]]. The project ultimately came to nothing due to the growing costs of the project, forcing its cancellation in 1956. She was ultimately [[ship breaking|broken up]] by 1959.<ref>Hogg & Wiper, p. 11</ref>

==Notes==
{{Reflist|20em}}

==References==
* {{cite book|last=Brescia|first=Maurizio|title=Mussolini's Navy: A Reference Guide to the Regia Marina 1930&ndash;1945|year=2012|publisher=Seaforth|location=Barnsley|isbn=978-1-84832-115-1}}
* {{cite book|last=Campbell|first=John|title=Naval Weapons of World War II|year=1985|publisher=Naval Institute Press|location=Annapolis|isbn=0-87021-459-4}}
* {{cite book|last=Fioravanzo|first=Giuseppe|title=La Marina Italiana Nella Seconda Guerra Mondiale. 5, Le Azioni Navali in Mediterraneo. Dal 1. Aprile 1941 all'8 Settembre 1943|publisher=Ufficio Storico della Marina Militare|location=Rome|year=1970|oclc=955692918}}
* {{cite book|last=Friedman|first=Norman|title=Naval Firepower: Battleship Guns and Gunnery in the Dreadnought Era|publisher=Naval Institute Press|location=Annapolis|year=2008|isbn=978-1-59114-555-4}}
* {{cite book|editor-last1=Gardiner|editor-first1=Robert|editor-last2=Chesneau|editor-first2=Roger|title=Conway's All the World's Fighting Ships 1922–1946|location=Annapolis|publisher=Naval Institute Press|year=1980|isbn=0-87021-913-8  |name-list-style=amp}}
* {{cite book|last1=Greene|first1=Jack|last2=Massignani|first2=Alessandro|year=1998|title=The Naval War in the Mediterranean, 1940–1943|publisher=Chatham Publishing|location=London|isbn=1-86176-057-4  |name-list-style=amp}}
* {{cite book|last1=Hogg|first1=Gordon E.|last2=Wiper|first2=Steve|others=Flowers, T. A. (illustrator)|title=Warship Pictorial 23: Italian Heavy Cruisers of World War II|year=2004|location=Tucson|publisher=Classic Warships Publishing|isbn=0-9710687-9-8  |name-list-style=amp}}
* {{cite book|last=Marriott|first=Leo|title=Treaty Cruisers: The First International Warship Building Competition|publisher=Pen & Sword|location=Barnsley|year=2005|isbn=1-84415-188-3}}
* {{cite book|last=O'Hara|first=Vincent P.|year=2009|title=Struggle for the Middle Sea: The Great Navies At War In The Mediterranean Theater, 1940&ndash;1945|publisher=Naval Institute Press|isbn=978-1-59114-648-3|location=Annapolis}}
* {{cite book|last=Stern|first=Robert C.|year=2015|title=Big Gun Battles: Warship Duels of the Second World War|publisher=Seaforth Publishing|isbn=978-1-4738-4969-3}}

==Further reading==
* {{cite book
  |last1=Brescia
  |first1=Maurizio
  |last2=de Toro
  |first2=Augusto
  |title=Italian Heavy Cruisers: From Trento to Bolzano 
  |year=2022
  |location=Barnsley
  |publisher=Seaforth Publishing
  |isbn=978-1-68247-871-4
  }}

==External links==
* [https://www.marina.difesa.it/noi-siamo-la-marina/mezzi/mezzi-storici/Pagine/TUVZ/trento.aspx Trento] Marina Militare website

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{{Trento-class cruiser}}
{{Italian heavy cruisers}}
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