Complex sentence: The new class was not universally welcomed in the Kriegsmarine, their abnormally light protection gaining the class the derogatory nickname "Ohne Panzer Quatsch" (without armour nonsense) within certain circles of the Navy.
Split into simpler sentences: The new class was not universally welcomed in the Kriegsmarine. Their abnormally-light protection gained it the derogatory nickname "Ohne Panzer Quatsch" (without armour nonsense) within certain circles of the Navy.