Sometimes all you need to do is read the freaking english language wikipedia article on the H41...
"The loss of Bismarck in May 1941 also influenced the design; two large skegs were added to the outboard shafts to protect them and increase support for the stern while in drydock. The rudder system was also designed with an explosive charge to detach the rudders in the event they became jammed."
Garzke & Dulin are cited as source. Wish I had their book on axis battleships.
Still don't quite know how to represent this oddity on my drawing.