Albatros-class Corvette (1954)

Built 1954-58: Albatros, Alcione, Airone, Aquila, Bellona*, Diana*, Flora*, Triton*, Lynx*, Pattimura**, Sultan Hasanudin**

The Albatros class was a class of eight corvettes designed and built in Italy in the 1950s, paid for by US funds, and somewhat prsented as NATO standard ASW corvettes. They were operated by Italy, Denmark, Indonesia and the Netherlands. The lastwere retired (in Italy) in 1991 so they soldiered for the entire cold war. They also used US sensors and (partly) armament.

Background

Following the Second World War, the Italian Regia Marina (later Marina Militare after the transition to a republic in 1946) found itself in a more favourable position than its former allies. They were lucky enough to have retained a good number of vessels, even including two battleships that would continue to serve until 1957. Despite this, the Marina Militare still relied on support from the United States and through this support was provided a significant number of ships from the former’s reserve stockpile. It would be in the period of the early 1950s when the Italian military industry started to return to development of domestic equipment, with the Albatros-class being the first natively designed and built ships to be commissioned into the Marina Militare following WWII (disregarding the Capitani Romani-class, which had been rebuilt and recommissioned as the San Giorgio-class destroyers).

The program for the development of the Albatros-class originated out of the American Mutual Defense Assistance Act and Mutual Security Act of 1949 and 1951, which sought to increase the defense capability of allied European nations against the Soviet Union and its satellite states. Eight ships were ordered by the US as anti-submarine corvettes and were built in multiple Italian shipyards: Castellammare di Stabia, Cantieri Navali Breda in Venice, Riva Trigoso, Ansaldo and Cantiere del Tirreno. Interestingly enough, the order for this class saw each ship as the property of the United States Navy during the construction and pre-commissioning process rather than the navies they were destined for. In fact, each ship was given American designations, such as PCE-1919 for Albatros.

Almirante Clemente class pre-launch

Out of the eight ships ordered, four were intended for the Royal Danish Navy while three were for the Marina Militare and only one for the Royal Netherlands Navy. The one Dutch ship, named Lynx, was deemed inadequate and returned to Italy in 1961 and served until 1991 as the Aquila.

Design of the Class

Hull and General Design

2-view plan, src naviecapitani.it/

While the ships might not appear to be of substantial size, they were designed to be effective and modern fleet escorts that were built upon experiences gained during the Second World War. The overall design called for a flush deck with a noticeable sheer that gave them better seakeeping properties, with this sheer and bow shape being the start of a common design within Cold War Italian vessels. The hull was made of hardened steel, which was entirely welded and involved no riveting, and the superstructure was made of an aluminium alloy that saved on weight.

This superstructure was primarily concentrated in the centre of the ship, containing both a quarterdeck and a two-story deckhouse. The quarterdeck contained the officer quarters, mess and heads while the galley was situated in the aft section. As one can expect, the deckhouse situated above the quarterdeck was the location of the command functions of the ship. Fire control and CIC were situated on the first story along with the captain’s quarters, while the second story was the location of the semi-open bridge.

Most noticeable about the superstructure is the mast, which has a unique design that rose out of the rear of the searchlight platform and incorporated a lookout post that also mounted the surface/air search radar. Under the superstructure and throughout the below-deck sections contained the rest of the crew quarters and the enlisted mess, with the quarters being notable for using “fold-down bunks” rather than “camp beds.”
The ships were an overall length of 76.3 m with a 9.6 m beam and draft of 2.79 m. The total weight was 895 tons (normal) and 950 tons at full load. The full crew compliment was 6 officers and 111 NCOs and enlisted.

Powerplant

The ships were equipped with two FIAT M409 9 cylinder diesel engines, which produced 2000 HP each and were situated directly under the centre superstructure. Despite being placed on either side of the ship within said room, the exhaust was snaked from each so that they met within and exited out the rear of the searchlight platform atop the superstructure. Each engine was attached to one shaft that drove one four bladed propeller. The engines were able to propel the ships at a maximum speed of 20 knots (37 kmh) The ship had a total supply of 95 tons of diesel fuel under normal operation, and had a range of 2189.82 nm (4055.5 km) at top speed.

Equipment

Electronics

As of their commissioning, the ships were equipped with a fire control and surface/air search radar as well as sonar equipment for hunting submarines. The fire control radar’s designation is unknown, however the surface/air search radar was the MLN 1.A that was eventually replaced in 1962 due to insufficiencies. The sonar was of the American P.55 type, which was also equipped on the modernised Gabbiano-class corvettes.

Crew Equipment

Along with the primary diesel engines, the ships were equipped with auxiliary diesel generators aft of the engine room. These generators were used for the ship’s general electrical needs, such as lighting and the air conditioning. The air conditioning system was used for the belowdeck compartments due to the complete lack of portholes along the hull and wasplaced at the very aft section of the hull and was funneled throughout the rooms.

Weaponry

The 76mm S.M.P.-3 Automatic Mount

The most unique aspect of the ships was certainly their primary armament, which was the origin of what would become the world-famous OTO 76mm naval gun that has seen service with over 60 navies around the world. This gun mount was named the S.M.P.-3, which stood for “Stabilimenti Meccanici di Pozzuoli – cannone da 3 pollici” (Pozzuoli Mechanical Plants – 3 inch cannon) and had a calibre of 76mm.

As mentioned previously, following the Second World War the United States had provided a multitude of surplus weaponry and equipment to allied nations to bolster their capability for defense. Many of these provided weapons included the American 76/50 Mk 27/33 and Bofors 40mm naval guns, which were ubiquitous on American ships. During this postwar period, the Marina Militare had expressed displeasure with the American 76mm guns and reportedly preferred the Italian 102/46 that had been previously produced by OTO. However, it was decided that the 76mm calibre was more economical, and certainly more powerful than a 40mm gun, but would need improvement and therefore requested the creation of a 76mm gun with a length of 62 calibres. This is where SMP stepped in, reportedly because civilian contracts had been relatively scarce following the end of the war.

The SMP-3, on paper, embodied exactly what the Marina Militare was looking for in a new light weapon: it was a fully automatic gun that was capable of a burst fire mode with an impressive elevation of 90 degrees while also being fully autoloaded. The autoloader was a rotating drum design that contained 14 rounds with average rate of fire of 50 RPM. When the drum was depleted, the entire mount would go to its maximum elevation in order to allow for replenishment of the system and then return to its original firing position – the entire process took only 3 seconds. The 6 kg projectile fired by the gun had a range of 16 km with an initial velocity of 959 m/s.

The SMP-3 mount was exclusively used on the Albatros-class, primarily due to the issues that came about during its short service life in the late 1950s. The system was significantly complex and with this was sensitive to errors, with the Dutch discovering on the Lynx that the reload speed of the drum would cause an “inertia” that led to a potential of catastrophic error. This error was encountered on the Lynx, when a shell was in the process of reloading from the drum and had become caught between the rollers that moved the shell and the hitch that would bring it to the gun. After becoming caught, the shell was heated by the friction of the rollers and eventually detonated – leading to an unknown amount of casualties. This explosion combined with the general unreliability and weight of the entire system would lead to its downfall and complete replacement on the ships. Despite the SMP-3 being a failure, OTO Melara would introduce the 76/62 “Allargato” and “Sovrapposto” mounts that would start the ubiquitous OTO 76 family of autocannons.

On the Albatros-class, the Marina Militare replaced the SMP-3 with Breda 40/70 mounts (based on the Bofors 40mm) and the Danish with American 3″/50 Mk.34s.

Other Weaponry

The ships were also equipped with a twin Breda 40/70 mount towards the rear of the superstructure, mounted just above the aft 76mm mount. This mount would have its own independent fire control, which consisted of simply a rangefinder placed on a platform just behind the guns. Following the removal of the SMP-3s, this mount would remain and augment the new all-40mm calibre armament.

Being anti-submarine escorts, the ships naturally were equipped with ASW weaponry – however their method of delivery was relatively antiquated by the late 1950s. Forward of the deckhouse were two Mk 11 Hedgehog launchers on either side, armed with 24 mortars and with storage for extra stored in a magazine just forward of the mounts. The aft of the ships contained the majority of the anti-submarine weaponry, with the ships at commissioning being equipped with 4 Menon depth charge launchers and one “Gatteschi 6 discharger” mounted centreline on the transom. The Menon launchers were mounted in groups of two on either side and were of a “double barrel” design, but were found to be heavy and cumbersome and were removed in 1960 in favour of simpler dischargers. The “Gatteschi” device was also replaced in favour of a “double-decker IMN Mk 6” that held 12 depth charges.

The Italian ships would see their final armament change in 1966 when they became training vessels, seeing the Menon dischargers removed entirely and replaced by two Mk 32 anti-submarine torpedo launchers just aft of the stern 40mm mount.

Careers of the Ships

All of the Italian ships of the class would not have exciting careers, primarily being regulated to exercises around Italy or training duties. Each ship would undergo armament refits during the early 1960s until 1966, which would see the last refit for purely training duties. Interestingly enough, there remain two members of the class still in existence in Augusta, Sicily, however both unfortunately sank around 2016 and remain partially sunk. It has been confirmed that these ships are Airone (GT-06) and Alcione (GT-05), with Airone sinking due to a storm and breach in the hull that caused her to capsize. Many thanks to Phoenix_jz for helping identify and providing a Marina Militare document regarding the ships!

Albatros, named after the bird, was the first unit of the class and commissioned into the Marina Militare on June 1, 1955 after her construction as Catellammare di Stabia. After commissioning, the ship was assigned to the 10. Squadriglia Antisom (10th Anti-Submarine Squadron) from 1955 and joined the 2. Divisione Navale (2nd Naval Division) in 1958 and primarily took part in regular exercises with her sisters and Gabbiano-class corvettes. In November of 1960, she was chosen to take part in experiments utilising self-guiding torpedoes and would partake in other experimental exercises until December of 1962 when she was assigned to the Flottiglia della Scuola Comando (Command School Flottila). The purpose of this flotilla was for the training of command crews, especially new captains, so that they could become adapted to their future positions and learn tactics for the modern era. She would remain as a training ship until 1985, when she was decommissioned and became an accomidations hulk. She would be stricken in 1989.

Alcione, named after the kingfisher, was built alongside her sister at the Catellammare di Stabia and joined the Marina Militare in October of 1955. She would join Albatros and Airone in the 10. Squadriglia Antisom and also had a relatively uneventful first few years of service, primarily operating around the Italian peninsula but did see port calls in Monaco, Toulon and Malta. She would have a nearly identical career from 1958 to 1960 as Albatros, however was not chosen for experimental duties and in 1961 was transferred to the Scuola Comando to serve as a training ship. She would serve until being decommissioned in the late 1980s and ultimately was stricken in 1991.

Airone, named after the heron, was also built at Catellammare di Stabia and would be commissioned in July of 1956. Unlike her sisters whom immediately joined the 10. Squadriglia Antisom, she would instead head to Monaco after commissioning before returning to Taranto and joining her sisters. Like her sisters, she was assigned to the Scuola Comando, albeit later in 1963, and would continue as a training ship until being decommissioned in the late 1980s and stricken in 1991.

Although she was identical to her sisters, Lynx would start her life being built in the Cantieri Navali Breda in Venice rather than at CdS. She would be completed in 1955 and be delivered to the Royal Danish Navy by the USN as the only member of the class delivered. She would serve from 1955 to 1960, however during this period of time the Dutch found many inadequacies with the ship, with remarks that her design was more suited to the Mediterranean rather than the North Sea, and with the previously mentioned explosion in her SMP-3 turret, it was decided that she would be returned to the USN. After a short period with the Americans, Lynx would be given back to Italy and she was renamed Aquila at her commissioning in October of 1961. She would make the journey from the Netherlands to Italy through the English Channel, visiting port towns such as Brest, El Ferrol, Gibraltar and Palma de Mallorca along the way. Almost immediately after arriving in Italy, she was put into the reserves due to maintenance and would stay at La Spezia until the end of 1962. She would immediately be transferred to be with her sisters at the Scuola Comando and serve as a training ship until the late 1980s and was stricken in 1991.

Src, Read More

Blackman, Raymond V. B. Jane’s Fighting Ships 1960–61. London: Sampson Low, Marston & Company, 1962.
Blackman, Raymond V. B. Jane’s Fighting Ships 1971–72. London: Sampson Low, Marston & Company, 1971.
Couhat, Jean Labayle and A.D. Baker III. Combat Fleets of the World 1986/87. NIP
Gardiner, Robert and Stephen Chumbley. Conway’s All The World’s Fighting Ships 1947–1995. NIP
Grove, Eric J. NATO Major Warships – Europe. London: Tri-Service Press, 1990.
Prézelin, Bernard and A.D. Baker III. Combat Fleets of the World 1990/1991. NIP