Silent hunter 5 knights cross

[fly2002]

Hi guys. Long time lurker here. Thanks for all of the great mods and everything the community does!!

Question. What threshold do I have to pass to obtain the knights cross? I have 4 iron cross second class and like 5 iron cross first class. Stay out on patrol longer so that the game sees more tonnage when I end patrol? Also when does the type 7c/41 come about?

Thanks guys!!

Eric