▁Norway ▁during ▁Hart mut ▁was ▁une vent ful . ▁ ▁U - 3 4 ▁- ▁a ▁Type ▁VII A , ▁which ▁tor ped o ed ▁the ▁sc utt led ▁Norwegian ▁min el ayer ▁H No MS ▁Fr ø ya ▁on ▁ 1 3 ▁April . ▁ ▁U - Bo at ▁Group ▁Three ▁Pat rol ▁Area : ▁Ber gen , ▁A ales und , ▁Sh et land ▁Islands ▁ ▁U - 9 ▁- ▁a ▁Type ▁II B ▁commanded ▁by ▁Wolfgang ▁Lü th . ▁While ▁U - 9 ▁had ▁a ▁relatively ▁successful ▁career , ▁she ▁s ank ▁no ▁ships ▁during ▁Hart mut . ▁ ▁U - 1 5 ▁- ▁a ▁Type ▁II B ▁successfully ▁commanded ▁by ▁Herbert ▁W ohl far th , ▁but ▁which ▁failed ▁to ▁sink ▁any ▁ships ▁during ▁Hart mut . ▁ ▁U - 5 6 ▁- ▁a ▁Type ▁II C ▁with ▁an ▁une vent ful ▁pat rol . ▁ ▁U - 6 0 ▁- ▁a ▁Type ▁II C ▁with ▁an ▁une vent ful ▁pat rol . ▁ ▁U - 6 2 ▁- ▁a ▁Type ▁II C ▁with ▁an ▁une vent ful ▁pat rol . ▁ ▁U - Bo at ▁Group ▁Four ▁Pat rol ▁Area : ▁St av anger ▁ ▁U - 1 ▁- ▁a ▁Type ▁II A ▁brought ▁into ▁front line ▁service . ▁The ▁sub marine ▁was ▁s unk ▁by ▁mines , ▁probably ▁on ▁ 6 ▁April . ▁ ▁U - 4 ▁- ▁a ▁Type ▁II A ▁brought ▁into ▁front line ▁status ▁before ▁returning ▁to ▁her ▁role ▁as ▁a ▁training ▁boat .