While greatly improved compared to the earlier models, by this time infantry anti-tank weapons were improving dramatically, and the Wehrmacht still saw a need for a similar, but more heavily armoured and armed vehicle. Therefore, a decision was made to create a new vehicle based on the Tiger tank and arm it with a 210 mm howitzer. However, this weapon turned out not to be available at the time and was therefore replaced by a 380 mm rocket launcher, which was adapted from a "Kriegsmarine" depth charge launcher.