Sigma class Corvette
The SIGMA ship class is a design of Damen Schelde Naval Shipbuilding to built a Frigate or Corvette. This design is special for the export. SIGMA stands for Ship Intergrated Geometrical Modularity Approach. This design is special to be built in modules and easy to built by the wishes of the client. So by a easy way to different variants of the propulsion, sensors and armament. The hull design is a combined effort between Marin and Damen Schelde Naval Shipbuilding. This resulted in a hull that can be built in modules between 52 and 98 meter and from 400 to 1930 tons.
Damen has three basic models, 6910, 8313 and 9113 model. The design nomenclature indicates the beam of the ship in meters [the basic models having a beam of 10 meters and 13 meters, while the initial numbers indicate the ship's lenght, 69, 83 and 91 meters]. Orders for lengthened ships based on this design are also possible. A systematic hull form series has been set up, which has extensively been model tested on hydrodynamic performance. This has resulted in an optimal hull form series, ranging from 50 to 150m in length and 9 to 15m width. With this range, the whole spectrum from Offshore Patrol Vessel, via corvette to frigate is being covered. The vessels have been built up in a standardised modular way, using off the shelf equipment where possible. This approach allows the client to compose its own vessel of standard blocks. Of course every vessel can be further customised, based on specific client requirements like amount of equipment, type and make.
Two clients were initially found for the SIGMA type, Morocco and Indonesia. Indonesia bought 4 ships of the 9113 type, the last one delivered in 2009. These ships armament is, 1 76mm gun, Exocet surface to surface missiles and Mistral surface to air misiles. Morocco ordered two 9813 type and one larger type 10513 [that is, 98 and 105 meters long, with a beam of 13 meters].
For the client this SIGMA Design Philosophy offers the following advantages;
- Flexibility in establishing the optimum arrangement of the clients current operational requirements, whilst maintaining the possibility to implement the changing needs of tomorrow.
- Easy implementation of modifications or upgrades in the future, avoid premature obsolescence of the vessel.
- Affordability by making use of standard equipment where possible. For every vessel the basis is being formed by a repetitive design, allowing for lower engineering cost. Due to the modular set up of the vessel, standardized production methods are being applied.
- Wide selection of hull dimensions and different combat suites, all making use of proven product compositions.
- Short lead time for engineering and construction, achieved by the modular set-up and standardization.
Morocco’s order for three Sigma multimission frigates from Schelde Naval Shipbuilding confirmed the value of the ships’ modular-hull design. The Royal Moroccan Navy signed the contract with Schelde on 06 February 2008 for approximately €510 million ($816 million). The pact calls for the design, build and delivery by 2012 of three surface combatants that the Moroccans are designating multimission frigates. Four missile corvettes built with the Sigma design had been sold to Indonesia, but some observers had dismissed the deal as a case of an old colonial power selling military equipment to a former possession.
The Morocco contract called for one 2,300-ton ship (designated Sigma 10513) that will be 105 meters long, with a beam of 13 meters. The other two ships will have a displacement of 2,100 tons (Sigma 9813s) and a length of 98 meters. The stretched version will have additional facilities for command and control, and accommodations for 110 personnel. The other two ships will have a crew of 91.
During Vietship 2014 Nava Exhibition in Vietnam, Dutch shipyard Damen unveiled for the first time the design of the Sigma 9814 Corvette ordered by Vietnam. It was announced in October 2011 that Damen shipyard in Vlissingen, Netherlands will build four Sigma corvettes for the Vietnamese Navy. The first two ships will be built in Vlissingen (Netherlands), and the last two (options) will be built in Vietnam, under Dutch supervision. The new Sigma 9814 differs combared to existing Sigma designs (9813, 10513 or 10514) especially around the bridge area, and the bow appears to be more angled to possibly provide more stealth. Besides Indonesia and Morocco (which bought three larger frigates from the same class in 2008), the Vietnamese navy is the third export destination for this warship class. With no future order foreseen from the Dutch navy - DSNS' vested customer - the shipyard has become fully dependent of the export market.