The Bundesarchiv/Militäraarchiv listened to my prayers and made available the plans for a German fleet submarine project I was looking after since I bought Eberhardt Rössler`s "Geschichte des Deutschen Ubootbaus", in the early1990`s. All we had was a cross section and the general specifications (along with Gröner`s). Here are two drawings from Freiburg. Specs do not match, though (e.g. Gröner states 8 torpedo tubes), and it`s not the first time we see russian handwriting in a German (captured) document.