Sigma - class corvette The " Sigma " class corvette is a corvette or frigate with ocean capabilities . Modular design . 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 meters long and 13 meters wide , same is with the SIGMA 10513 , 105 meters in length and 13 meters wide . The design was derived from the earlier High Speed Displacement hull form by MARIN Teknikk AS in the 1970s . Indonesian variants . SIGMA 9113 The Indonesian variant is based on the Sigma 9113 design . Work on the first of the class , KRI " Diponegoro " , began with the first steel cutting conducted in October 2004 . The ship was christened on September 16 , 2006 and commissioned on July 2 , 2007 by Admiral Slamet Soebijanto , Indonesian Navy Chief of Staff . Options for 2 other units were exercised on January 2006 with the first steel cut commenced on 3 April 2006 in Damen ' s Schelde Naval Shipbuilding yard , Vlissingen - Oost yard and not in Surabaya stated earlier . In 28 August 2007 , Jane ' s Missiles and Rockets reported 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 missile s as alternatives . However , the ships have already been delivered with the Exocet missiles . SIGMA 10514 On the 16 August 2010 , Indonesia Defense Department , signed a deal with PT PAL Indonesia and Damen Schelde to build a 105 meters frigate in Indonesia based on Damen Schelde Sigma 10514 design . The frigate will be equipped with 76mm Main Canon , 12 MICA vertical launch air defence missile , MM - 40 Exocet block II , Torpedo , phalanx and SMART - S MK2 radar system . Though the Indonesian Navy announced that it will build four " 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 , also the 76mm 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 February 1 , 2013 it was announced that a second unit will be build by Damen Schelde Naval Shipbuilding and PT PAL Surabaya , the second contract includes torpedo tubes , combat control room and a couple of surface weapons . 25 Moroccan variants . On February 6 , 2008 , 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 on the April 1 , 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 , began sea trials on 6 May 2011 and was delivered on 12 September 2011 . The second ship was launched on 2 February 2011 , with sea trials planned for late in the year . The third ship was planned to be launched in September 2011 . Ships of class . TNI - AL / Sigma 9113 design TNI - AL / Sigma 10514 design Moroccan Navy / Sigma 9813 & 10513 design Note : 613 now shows on AIS as Sultan Moulay Ismail . Sigma versions . Simplified comparisons between the different Sigma models . References . 17 . http : / / dl . dropbox . com / u / 36193122 / Sigma % 20Frigate % 20series % 202012 . pdf