The Sturmtiger or Panzermoerser or Sturmpanzer VI was a German Self Propelled Gun developed and manufactured during the last part of World War II. In the beginning, a rocket deep charge was developed by Rheinmetall. This weapon was born to engage enemy submarines off the coast. The rocket was mounted on a self-propelled chassis. The Army asked for its own development with the maximum range increased from 3,000 meters to 5,000 meters. The new rocket was designed as 38cm Raketen-Werfer 61 (or RW 61).