The Dutch Schelde shipyard in Vlissingen, Netherlands will build four Sigma corvettes for the Vietnamese Navy. The first two ships will be built in Vlissingen, and the last two will be built in Vietnam, under Dutch supervision.
Sigma class corvettes are built to sizes ranging from 50 to 150m in length and 9 to 15m width, addressing the whole spectrum from Offshore Patrol Vessel (OPV), via corvette to frigate size vessels meeting a wide range of customer demands. In fact, the class name Sigma stands for Ship Integrated Geometrical Modularity Approach. The lead ship of the SIGMA class was KRI Diponegoro, launched in 2004 for the Indonesian Navy.
Indonesia was the first customer for the new design, ordering four 9113 class 91 meter corvettes. In 2010 Indonesia has ordered four larger vessels, the 105m’ Type 10514. The Moroccan Navy became the second customer for this class, ordering three frigate sized multi-mission vessels in two classes – SIGMA Type 9813 (98m’) and the 105m’ SIGMA 10145. The first Moroccan Sigma frigate, Tarik ben Ziyad was transferred to the Royal Moroccan Navy on 10 September 2011. With the conclusion of the Vietnam, Schelde will win its third international customer for this class.