Sigma-class design

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Sigma 9113-class corvette (KRI Diponegoro 365)
Class overview
  • 9113 (Indonesian corvette variant)
  • 9813 (Moroccan heavy corvette variant)
  • 10513 (Moroccan light frigate variant)
  • 10514 (Indonesian frigate variant)
  • 10514 LROPV (POLA) (Mexican LR OPV Variant)
Built: 2005–present
In commission: 2007–present
Planned: 18
Building: 0
Completed: 10
Cancelled: 1
Active: 9
Laid up: 1
General characteristics
Type: Corvette & frigate
Displacement: 1,692 tons
Length: 90.71 m (297 ft 7 in)
Beam: 13.02 m (42 ft 9 in)
Draft: 3.60 m (11 ft 10 in)
  • 2 × SEMT Pielstick 20PA6B STC rated at 8910 kW each driving a lightweight Geislinger coupling combination BE 72/20/125N + BF 110/50/2H (steel – composite coupling combination)
  • 4 × Caterpillar 3406C TA generator rated at 350 kW each
  • 1 × Caterpillar 3304B emergency generator rated at 105 kW
  • 2 × shaft with Rolls Royce Kamewa 5 bladed CP propeller
  • 2 × Renk ASL94 single step reduction gear[1] with passive roll stabilization
  • Maximum: 28 knots (52 km/h; 32 mph)
  • Cruising: 18 knots (33 km/h; 21 mph)
  • Economy: 14 knots (26 km/h; 16 mph)
  • At cruising speed of 18 kn (33 km/h; 21 mph): 3,600 nmi (6,700 km; 4,100 mi)
  • At economy speed of 14 kn (26 km/h; 16 mph): 4,800 nmi (8,900 km; 5,500 mi)
Complement: 20, up to 80
Sensors and
processing systems:
  • Combat System: Thales Group TACTICOS[2] with 4 x Multifunction Operator Console Mk 3 2H
  • Search radar: MW08 3D multibeam surveillance radar
  • IFF: Thales TSB 2525 Mk XA (integrated with MW08)
  • Navigation radar: Sperry Marine BridgeMasterE ARPA radar
  • Fire control radar: LIROD Mk 2 tracking radar
  • Data Link: LINK Y Mk 2 datalink system
  • Sonar: Thales UMS 4132 Kingklip medium frequency active/passive ASW hull mounted sonar
  • Internal Communications: Thales Communication's Fibre Optical COmmunications Network (FOCON) or EID's ICCS where on-board users have access to internal and/or external communication channels and integrated remote control of communications equipment
  • Satellite Comms: Nera F series
  • Navigation System: Raytheon Anschutz integrated navigation
  • Integrated Platform Management System: Imtech UniMACs 3000 Integrated Bridge System[3]
Electronic warfare
& decoys:
  • ESM: Thales DR3000
  • ECM: Racal Scorpion 2L
  • Decoy: TERMA SKWS, DLT-12T 130mm decoy launchers, port, starboard
Aviation facilities: Landing pad, optional hangar

The Sigma class is a Dutch-built family of modular naval vessels, of either corvette or frigate size, designed by Damen Group.

Modular design[edit]

The basic design of the Sigma Patrol Series can vary as the hull segments are designed as components. Ships can vary in the number of hull segments and in the order in which they are placed. Sigma stands for Ship Integrated Geometrical Modularity Approach. The ship's main dimensions are named in the types itself, SIGMA 9113 stands for 91 metres (298 ft 7 in) long and with a beam of 13 metres (42 ft 8 in). Likewise, the SIGMA 10513, is 105 metres (344 ft 6 in) in length with a beam of 13 meters.

The design was derived from the earlier High Speed Displacement hull form by MARIN Teknikk AS in the 1970s.


  • Indonesia (TNI-AL) has four SIGMA 9113 Diponegoro-class corvettes in active service from 2009. In August 2010, Indonesia signed a deal to build Martadinata-class frigates based on the SIGMA 10514 in PT PAL Shipyard at Surabaya, Indonesia. A second contract was signed in February 2013. Eventually six ships will be built; the first ship, KRI Raden Eddy Martadinata (331), was commissioned on 7 April 2017 at Tanjung Priok.[4] The second ship, KRI I Gusti Ngurah Rai (332), was commissioned on 10 January 2018.[5]
  • Morocco has ordered two 9813 class heavy corvettes (with VLS) and a light 10513 class frigate based on a modified design.

Under construction[edit]

  • Mexico has ordered 1 Sigma 10514 LROPV[6] based upon the Indonesian variant with different weapon systems and different role. The Mexican navy will use its Sigma frigate as a long range patrol vessel; the keel was laid on 17 August 2017, and was launched on 23 November 2018 and service to begin in 2020. The ship will be built in six modules, with two of these modules built by Damen Schelde Naval Shipbuilding in Vlissingen in the Netherlands, and the remaining four by the Mexican Navy shipyard in Salina Cruz under the supervision of Damen Schelde Naval Shipbuilding; the Sigma will replace the four Allende class (ex-USN Knox class), and two Bravo class (ex-USN Bronstein class) of frigates.[citation needed]

Potential operators[edit]

  • Poland - Damen Schelde submitted[7] its SIGMA PL 10514 in two variants for the competition to supply the Polish Navy with options for their Miecznik & Czapla programmes. Miecznik will be a coastal defense ship and Czapla a patrol ship.
  • Peru - The Peruvian Navy plans to acquire between three and six ships, with a displacement of 3,000 to 4,000 tons. During the 6th International Exhibition of Technology in Defense and Prevention of Natural Disasters (Sitdef 2017) Damen Group offered the Sigma-class design to the Peruvian Navy, it believes that the variety of models of frigates offered by the Sigma series allows to fit without difficulty to the requirements of the Peruvian Navy.[8]
  • Colombia - The Colombian Navy wants to buy new ships, which will replace the Almirante Padilla class. Damen is one of the potential candidates to build the ships for the Colombian Navy.[9][10]
  • Romania is planning to purchase four corvettes in the upcoming seven years, which have to be built and equipped in a Romanian building yard.[11][12] Previously, in December 2016, the Romanian government decided that Damen Group would build four Sigma light frigates for a total of 1.6 billion euro at the Damen Galați Shipyard.[13] However, the new Romanian government is repealing this decision and will re-open the procurement again.[14] Nonetheless, Damen Group is a top contender for the job, since it has the only shipyard in Romania that has recent experience with building new naval ships reasonably fast and at a competitive price.[15]

Failed bids[edit]

Indonesian Navy variants[edit]

SIGMA 9113[edit]

The Indonesian variant is based on the Sigma 9113 design.[18] Work on the first of the class, KRI Diponegoro, began with the first steel cutting conducted in October 2004; the ship was christened on 16 September 2006 and commissioned on 2 July 2007 by Admiral Slamet Soebijanto, Indonesian Navy Chief of Staff.[19]

Options for two other units were exercised in January 2006 with the first steel cut commenced on 3 April 2006[20] in Damen's Schelde Naval Shipbuilding yard, Vlissingen-Oost yard and not in Surabaya stated earlier.

On 28 August 2007, Jane's Missiles and Rockets reported[21] that Indonesia was having problems securing the export license for the MM-40 Exocet block II and are considering Chinese made C-802 anti-ship missiles as alternatives. However, the ships have already been delivered with the Exocet missiles.

The SIGMA 10514-class frigate KRI Raden Eddy Martadinata

SIGMA 10514[edit]

On the 16 August 2010, Indonesia Defense Department, signed a deal[22][23] with PT PAL Indonesia and Damen Schelde to build a 105-meter frigate in Indonesia based on Damen Schelde Sigma 10514 design. For the first ship, five modules for the ship will be built in Indonesia and the Dutch manufacturer Damen Schelde will build 2 modules while for the second ship the Indonesians will build six modules and Damen Schelde will build one module; the first hull will only be equipped with guns (without major weapons) and the second hull is complete with major weapons such as 76 mm main cannon, 12 MICA vertical launch air defence missile, MM-40 Exocet block III, Torpedo, and SMART-S MK2 radar system.[24] The Indonesian Navy announced that it will build two destroyer escorts referring to the SIGMA 10514. On the Indo Defence 2012 exposition a model was revealed showing the phalanx and ASW mortar replaced by a single 35 mm Oerlikon Millennium Gun system,[25] also the 76 mm had a stealth cupola; some reported that the VLS missiles will be Aster-15 instead of MICA, due to these changes the ships role also changed from ASW to AAW.

On 1 February 2013 it was announced that a second unit will be built by Damen Schelde Naval Shipbuilding and PT PAL Surabaya, the second contract includes torpedo tubes, combat control room and a couple of surface weapons; as of December 2015, the first ship, KRI Raden Eddy Martadinata (331), was 85% complete and the ship was launched on 18 January 2016.[26][27][28][29][30][31][32][33] On 7 April 2017 the first ship, KRI Raden Eddy Martadinata (331), was commissioned at Tanjung Priok;[4] the second ship, KRI I Gusti Ngurah Rai (332), was commissioned on 10 January 2018.[5]

Moroccan Navy variants[edit]

On 6 February 2008,[34] Morocco signed a USD$1.2 billion contract with Schelde Naval Shipbuilding for two light frigate SIGMA 9813 and one light frigate SIGMA 10145, which are modified versions of the existing Sigma-class design.

A subsequent contract was signed[35] on 1 April 2008 with Thales Nederland for the supply and installation of the command and control and sensor package for the ships; the package included TACTICOS combat management system, SMART-S Mk2 surveillance radar, LIROD Mk2 tracking radar, Thales KINGKLIP sonar system, IFF system, Integrated communication system comprising external communication system and FOCON internal communication system, two Target Designation Sights, VIGILE ESM system, SCORPION ECM system, and the integrated navigation system.

The first frigate for Morocco, Tarik ben Ziyad, was launched in July 2010,[36] began sea trials on 6 May 2011[37] and was delivered on 12 September 2011;[38] the second ship was launched on 2 February 2011,[36] with sea trials planned for late in the year.[37] The third ship was planned to be launched in September 2011.[37]

Romanian Navy variant[edit]

In November 2016 the Romanian Navy indicated that Damen Shipyard's Sigma-class design had been selected to supply four vessels, to be locally constructed at the Damen Shipyard in Galati. Romania will order four multi-role corvettes for a total of 1.6 billion euros including training, spare parts and ammunition. The first ship is planned to be delivered within 2.5 years after contract signing.[11][12]

The Romanian Navy has studied the SIGMA 9813 and SIGMA 10514 with the 10514 meeting most of the requirements. No official confirmation has been given on what variant of SIGMA will be ordered.

In July 2019, the Romanian authorities announced the selection of Naval Group and its partner Santierul Naval Constanta (SNC) for the programme to build four new Gowind multi-mission corvettes.

Mexican Navy variant[edit]

Mexican Long Range OPV "POLA".

On 18 August 2017, Damen announced the keel laying for one SIGMA 10514 Long Range Ocean Patrol Vessel (SIGMA 10514 LROPV/ SIGMA 10514 POLA) at Damen Schelde Naval Shipyard in Vlissingen for the Mexican Navy; the vessel was constructed modularly in six modules, two modules were constructed in Vlissingen and the other four modules in Mexico. According to the Defense Security Cooperation Agency Major Arms Sale notification on 5 January 2018, the primary weapon systems for the Sigma class will include RGM-84L Harpoon Block II, RIM-162 ESSM[39] with eight cell MK56 VLS launcher, MK 54 Mod 0 lightweight torpedoes with two (2) MK 32 Surface Vessel Torpedo Tubes (SVTT) triple tube launchers, Block II Rolling Airframe Missile (RAM) missiles and Bofors 57 mm gun. [40] In April 2018 Damen Group contracted Spanish defense technology company Indra to equip the Mexican Navy's new long-range offshore patrol vessel (POLA) with its RIGEL electronic defense system.[41]

Ships of class[edit]

Indonesian Navy / Sigma 9113 design

Name Pennant Laid down Launched Commissioned Notes
KRI Diponegoro 365 24 March 2005 16 September 2006 5 July 2007 Diponegoro, a National Hero from Central Java
KRI Sultan Hasanuddin 366 24 March 2005 16 September 2006 24 November 2007 Sultan Hasanuddin, a National Hero from South Sulawesi
KRI Sultan Iskandar Muda 367 8 May 2006 24 November 2007 18 October 2008 Iskandar Muda, a National Hero from Aceh
KRI Frans Kaisiepo 368 8 May 2006 28 June 2008 7 March 2009 Frans Kaisiepo, a National Hero from Papua and the fourth Governor of Papua

Indonesian Navy / Sigma 10514 design

Name Pennant Laid down Launched Commissioned Notes
KRI Raden Eddy Martadinata 331 16 April 2014 18 January 2016 7 April 2017 Raden Eddy Martadinata, a National Hero from Bandung and one of the founders Of Indonesian Navy
KRI I Gusti Ngurah Rai 332 18 January 2016 29 September 2016 10 January 2018 I Gusti Ngurah Rai, a National Hero from Bali Island and leader of Puputan War against Dutch Colonialist Government

Moroccan Navy / Sigma 9813 & 10513 design

Name Pennant Laid down Launched Commissioned
RMNS Tarik Ben Ziyad 613 15 April 2009 12 July 2010[42] 10 September 2011[43]
RMNS Sultan Moulay Ismail 614 March 2009 4 February 2011[44] 10 March 2012[45]
RMNS Allal Ben Abdellah 615 September 2009 October 2011 8 September 2012[46]

Note: 613 now shows on AIS as Sultan Moulay Ismail.

Mexican Navy / Sigma 10514 LRP design

Name Pennant Laid down Launched Commissioned
ARM Reformador 101 17 August 2017[47] 23 November 2018[48] 23 November 2018[48]

Sigma versions[edit]

There are three types of Sigma combatants

  • Sigma frigate
  • Sigma corvette
  • Sigma fast attack corvette

Simplified comparisons between the different Sigma models.

Specifications Compact Sigma 5910[49] Compact Sigma 7310 [50] Sigma 9113[51] Sigma 9813[52] Sigma 9814[53][54] Sigma 10513[55] Sigma PKR 10514[56] Sigma 10514 LROPV
Ordered by  Indonesian Navy  Royal Moroccan Navy  Vietnam People's Navy (cancelled[57])  Royal Moroccan Navy  Indonesian Navy  Mexican Navy
Type Fast Attack Corvette Fast Attack Corvette Corvette Frigate Frigate Frigate Frigate Long Range Offshore Patrol Vessel (POLA)
Length 58.6 meters 74.2 meters 90.01 meters 97.91 meters 99.91 meters 105.11 meters 105.11 meters 107.5 meters
Beam 10.00 meters 10.00 meters 13.02 meters 13.02 meters 14.02 meters 13.02 meters 14.02 meters 14.02 meters
Draft 3.10 meters 3.10 meters 3.60 meters 3.75 meters 3.75 meters 3.75 meters 3.75 meters 3.75 meters
Displacement 750 tons 900 tons 1,692 tons 2,075 tons 2,150 tons 2,335 tons 2,365 tons 2,575 tons
Main machinery 3 x – 4x 3900  kW 2 x 8910 kW 2 x 8910 kW tbd 2 x 8910 kW 2 x 10.000kW 2 x 13410 kW
Speed (cruising) 18 knots 18 knots 18 knots 18 knots tbd 18 knots 18 knots 18 knots
Speed (maximum) 32 knots 34 knots 28 knots 28 knots tbd 28 knots 28 knots 28 knots
Endurance 2,000  nm 2,000  nm 3,600 nm 4,000 nm tbd 4,000 nm 5,000 nm 5,000 nm+
Primary sensors Thales Smart-S MK2 Thales NS-100 Thales MW08 Thales SMART-S MK2 Thales SMART-S MK2 Thales SMART-S MK2 Thales SMART-S MK2 Thales SMART-S MK2
Complement 37 50 80 91 103 110 122 122
Helicopter none none deck only deck and hangar (9 ton) deck and hangar deck and hangar (9 ton) deck and hangar (10 ton) deck and hangar (10 ton)
Status In Service In Service Cancelled In Service In Service

There are multiple new Sigma designs released in early 2015 of which little is known, these are the:

Sigma 8313 / Sigma 8011 / Sigma 7613 / Sigma 6610

They are likely to be part of the Compact SIGMA series, a new series small sized combatants with shorter range and up to 2 weeks mission endurance with the same combat systems as the larger Sigmas.[58]

See also[edit]


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External links[edit]