Pattimura class Corvette (1956)

Indonesian Navy: KRI Pattimura, KRI Sultan Hasanudin

The Pattimura class of the 1950s, not the Parchim class Frigates of the 1990s, were Italian-designed Albatros-class corvette, including KRI Pattimura. The class was designed and built in Italy by Ansaldo during the mid-1950s using United States funding (MDAP) as part of a NATO plan to have a standard anti-submarine warfare (ASW) corvette program. This “Euro Corvette” was also operated by the navies of Italy, the Netherlands, Denmark, and Indonesia. The Indonesian Navy operated two ships of this 1950s group, KRI Pattimura and KRI Sultan Hasanudin, both from Ansaldo, Livorno. KRI Pattimura was launched on July 1, 1956, and entered service on January 28, 1958 and her sister KRI Sultan Hasanudin was launched on 24 March 1957 and commissioned on 8 March 1958. Bot wree stricken in 1985. They diverged from those built for Denmark, Netherlands and Italy by details. Indonesian ships were ordered together with the fast frigates of the Bondjol class and were modernized in 1976-77.

KRI Sultan Hasanudin

Development

Back in WW2, the Gabbiano class corvettes designed in Italy, in 59 vessels built for the Regia Marina in various yards proved a simple, cost-effective and effective design for mass-production. Its anti-submarine records proved it could be quite deadly as well, claiming many British submarines. Larger and better designed on purpose than British Flower class which suffered in the Atlantic, the Gabbianos were perfectly adapted to the Mediterranean conditions and this was still in the mind of NATO planners postwar, when working on a plan for a standard ASW Corvette for European waters, an austere ship, with limited capabilities in other areas unlike escort destroyers or frigates, but specialized in its role and cost-effective for a possible mass production in case of war. Several yards took part in the contest, and Ansaldo proposed a modernized version of the Gabbiano essentially. It was examined by the commission and accepted as standard. Under the under the Mutual Defense Assistance Program, four ships would be built for Italy (The Albatros class), four for Denmark and later one Italian ship was transferred to the Netherlands. The very last were for Indonesia, also benefiting from US help to stem communism in Asia.

The Italian Albatros, F543

These last ships were ordered both at Ansaldo, Livorno, a paradox as they were the last in class built in the yard that provided the plans for Navalmeccanica, Castellammare di Stabia, Breda Marghera Yard, Venice and Cantiere del Tirreno, Riva, Trigoso which build the others earlier. Indeed the lead ship Alabtros was launched in July 1954.
KRI Pattimura and Sultan Hasanudin received the pennants 257 and 253 when ordered as yard number 270 and 275, laid down both the same day on 8 January 1956. They were launched in 1 July 1956 and 24 March 1957 respectively and completed both in 1958. Alonsgide these were received the two Bondjol class as seen above, also from Ansaldo, built 1956-58, designed and built earlier for Venezuela as Almirante Clemente class. They will be the object of a separate post in the future.
They were soon eclipsed in the 1960s after Indonsia turned to USSR anyway and received from the USSR in 1963-65 a number of former Soviet light frigates of Project 50 (JOS SUDARSO class),
To mark the difference with the modern Corvettes, this 1950s class is often referred to as the “Pattimura” class when the Parchim 1990 class is referred as the “Kapitan Pattimura” class.

Design of the class

These vessels were generally identical to the Italian Albatros class corvettes, with diesel engines. They only varied in details but were similar overall, having also US equipments, sensors and armaments.

Hull and general design

As standard these ships displaced 800 t and full load 950 t. Indonesian vessels were heavier at 950 tons standard and 1200 tons fully loaded however. They were indeed longer at 75 meters between perpendiculars and 82.4 meters overall (versus 69.5 m pp and 76.3 m oa) for a superior beam of 10.4 meters (versus 9.7 m (31 ft 10 in)) but reduced draught, light at 2.7 meters versus 2.8 m (9 ft 2 in) FL.
Now, for their general outlook, they were flush deck with a raised deck amidship, beam to beam, on which was installed the central island, followed by the main funnel. The hull had a peculiar bow shape, with an inverted stem (curved outwards rather than inwards like the clipper bow) and a robust tip.

The half-moon of the chin transitioned smoothly to the flat keel, causing the ship smoothier rocking. The stern was a narrow transom, typical of the 1950s. They had counterkels and a single rudder. the Propellers were protected by guard bars aft. The “funnel” however was “mack” carrying the ensors and with a few exhaust high up to vent out the diesel fumes. The forward gun was protected by a wave breaker. The bridge was typical with an enclosed level (with portholes, more resistant than windows) and an open deck behind. The ASW suite was very much in the WW2 style, with a pair of hedgehog forward and classic depht charge throwers and a single rack aft. There were, for their crew of 110, two motor cutters under davits amidships and four rubber boats. The ships were not protected NBC but there was some redundancy in the powerplant to separate and stagger the diesels and with some longitudinal protection. But no armour.

Powerplant

The Pattimura class Corvette had three shafts powered directly by three 3 Ansaldo-Fiat diesels, each capable of delivering 2,300 bhp for a total of 6,900 bhp. There was no gearbox. The diesels were in direct drive. These three power units enabled flexibility and range, not speed, as intended for their ASW role. When designed, the worst they could hunt down were the Whiskey class of the Black Sea Fleet. There were also 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, especially important in that area. Top speed was 22 knots on trials, but in service it was limited to 20 knots (37 kmh). They had a diesel oil stowage of 100 tonnes versus 95 on the standard Albatros, for an Endurance of 2,400 nautical miles (4,450 km) at 18 knots versus 2,200 nm (4,000 km) for the standard Albatros.

Armament

This was Italian in origin, same as the regular Alabtro class. Two DP 76mm (3 inches)/62 SMP3 fore and aft under shields, two twin 40mm/70 Breda (bofors licenced) type 64 also fore and aft, and two 24-tubes 178mm Hedgehog Mk 11 ASW rocket launchers forward, plus 4 DC thowers, one DC rack. It was “modernized” in 1976-77 completely put to Soviet standards, with two 85mm/52 90K main guns fore and aft, two twin 25mm/80 2M-3M replacing the Breda-Bofors and two twin 14.5mm/95 DhSk HMG mounts.

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.
This 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. However it had a fatal flaw: The reload speed of the drum would cause an “inertia” that led to a potential of catastrophic error. Unreliability and weight led to replacement on all Albatros class.

Breda 40mm

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.

Mk 11 Hedgehog

Standard allied late war models. Armed with 24 mortars and with storage for extra stored in a magazine just forward of the mounts.

Depth Charges

The Pattimura had four 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.

Sensors

These ships carried the NWS-1, CWS-1 radars, and QCU-2 sonar.
The 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. Its possible that in the late 1970s the fire control and radars were als put to Soviet standards.

⚙ specifications
Displacement	950 tons stanbdard, 1200 tons fully loaded
Dimensions	75m pp, 82.4m oa x 10.4m beam x 2.70 m draught
Propulsion	3 shafts Diesels Ansaldo Fiat 2,300 bhp: 6,900 bhp (5,150 Kw) total
Speed	22 knots trials (40.7 kph)
Range	100t fuel oil, 2,400 nautical miles (4,450 km)
Armament	2x 76mm/62 SMP3, 2×2 40m/70 Breda type 64, 2x Hedgehog Mk 11 ASWRL, 4 DCT, 1 DCR
Sensors	NWS-1, CWS-1 radars, QCU-2 sonar
Crew	110

Career of the Pattimura class

KRI Pattimura (257)

KRI Pattimura was ordered under the pennant 257 at yard 270 at Ansaldo, Livorno, in Italy laid down on 8.1.1956, launched on 1.7.1956 and commissioned on 28.1.1958. KRI Kapitan Pattimura was national hero from Maluku who fell while fighting against the VOC on December 16, 1817. She started operating in the Indonesian Navy, notably the new Siliwangi (Skoryy) class destroyers (1959) but political situation did not favored a stable tactical or strategic definition of exercises for these ships or the Bondjol class frigates. From 1959, more ships from the Soviet Union and East Europe arrived. The abortive 1965 coup saw a rapid decline in influence of the Navy, choosing the wrong side against the armed forces. The marine corps in particular was suspected of the coup. Lack of maintenance caused series of non-operational status. This crippled the two corvettes. Both were “modernized” in 1976-77 completely put to Soviet standards, with two 85mm/52 90K main guns fore and aft, two twin 25mm/80 2M-3M replacing the Breda-Bofors and two twin 14.5mm/95 DhSk HMG mounts. KRI Pattimura was eventually stricken in 1985.

KRI Sultan Hasanudin (253)

KRI Sultan Hasanudin was ordered under the pennant 253 as hull N°275 at Ansaldo, laid down the same day as her sister on 8 January 1956, launched on 24 March 1957 and commissioned on 8 March 1958. She went through the same issues as her sister Pattimura. Shee too, was “modernized” with soviet artillery. Like her sister, the lack of maintenance was crippling. If the modernization of Sultan Hasanudin was acted, the lack of maintenance was crippling. She was eventually decommissioned just two years later in 1979 if some sources are to be believed. Sultan Hasanuddin (Sultan Hasanuddin Tumenanga Ri Balla Pangkana; (12 January 1631 – 12 June 1670) was the 16th Ruler of The Sultanate of Gowa as Sombaya Ri Gowa XVI from 1653 to 1669. He was proclaimed as Indonesian National Hero on 6 November 1973. The Dutch called Sultan Hasanuddin “the Rooster of the East” as he was described as aggressive in battle.

During their service with the Indonesian Navy (ALRI), these two Pattimura-class corvettes participated in several military operations. One such instance was the preparation for Operation Trikora, aimed at reclaiming West Irian from the Netherlands in the early 1960s; the vessels served as escorts within the Navy’s combat groups at the time. During the New Order era, both ships were deployed to East Timor to support Operation Seroja in 1975. Additionally, Pattimura-class vessels were frequently utilized as command ships to quell various regional uprisings between the late 1950s and the early 1970s. Despite being relatively small corvettes, the Pattimura class was regarded as robust and highly capable at sea. In fact, in their country of origin, these ships remained in service until the 1990s. In Indonesia, they served until the late 1970s; the second ship, KRI Hasanuddin, was retired and scuttled in 1979, followed by the class’s lead ship, KRI Pattimura, in 1980.