ホヴァルツヴェルケ＝ドイツ造船
"Project Sigma" was given the hull number 970 (she was the 970th build by Blohm + Voss), it was decided that construction would take place at Howaldtswerke-Deutsche Werft (HDW), a sister yard in Kiel also owned by B+V's parent, ThyssenKrupp Marine Systems.