Almirante Karam (S43)[1] —previously known as Angostura— is the fourth unit of the s built for the Brazilian Navy by ICN in Itaguaí, and DCNS, a modified design of the original French
The Brazilian boats are larger in length, tonnage and cargo capacity compared to the original French project. The Brazilian version are and 1,900 tons, compared to the original Scorpènes that are and 1,565 tons.[2]
In 2008, Brazil purchased four enlarged Scorpènes for USD 10 billion with a total technology transfer agreement and a second agreement to develop the first Brazilian nuclear-powered submarine, . The hull of Riachuelo was laid down at Cherbourg, France on 27 May 2010 and it was jumboized at the Brazilian Navy Shipyard in Itaguaí in late 2012.
The first submarine Riachuelo was launched on 14 December 2018,[3] the Humaitá was launched on 11 December 2020, and the Tonelero on 27 March 2024.[4]
Almirante Karam was named after the former Admiral Alfredo Karam.[1]