Converted from 18 battle damaged Tiger I Es, the Sturmmörserwagen 606/4is the concept of the Sturmpanzer IV "Stupa" carried to the extreme. Possessing a similar layout as the "Stupa", this vehicle mounted a 380mm rocket launcher that fired a 761 lb spin-stabilized missile up to 6,000 yards. There were two types of ammunition, high explosive and a shaped charge for use against concrete. A counter-balanced crane was mounted on the left rear of the superstructure to load the missiles into the launcher via a hatch in the superstructure roof.
The Sturmmörser 606/4 was obsolete when it appeared in 1944. It was designed to assault fortified positions, by the time it was ready for combat the Germans were on the defensive and its battlefield role had vanished.
The idea for a heavy infantry support vehicle capable of demolishing heavily defended buildings or fortified areas with a single shot came out of the experiences of the heavy urban fighting in the Stalingrad in 1942.
At the time, the SIG 33B was available for destroying buildings and roadblocks. Twelve of them were lost when Stalingrad surrendered. The Sturmpanzer IV, the direct successor to the SIG 33B, started production in March of 1943. Despite having another vehicle suited for this task, the Wehrmacht saw a need for a larger, heavier armed and armored vehicle.
The decision was made to create a new vehicle based on the Tiger tank and arm it with a 210 mm howitzer. 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.
In September 1943 plans were made to fabricate new Tiger I armored hulls for the Sturmmörser. The original plan was for the first Sturmmörsers to roll off the assembly line late February 1944. Due to delays, production was not authorized until mid-April 1944.
The first three production series Sturmmörsers were completed by Alkett in August 1944. Ten more were produced in September, along with an additional five in December 1944.
The total production was 18 combat units and one prototype.
Three new Panzer companies were raised to operate the vehicles. Panzer Sturmmörser Kompanien (PzStuMrKp) 1000, 1001 and 1002. These originally were supposed to be equipped with fourteen vehicles, but this figure was later reduced to four each, divided into two platoons.
PzStuMrKp 1000 was raised on 13 August 1944 and fought during the Warsaw Uprising with two vehicles, as did the prototype in a separate action. This may have been the only time the Sturmmörser 606/4 was used in its intended role.
PzStuMrKp 1001 (Hauptmann von Gottberg) was raised in September 1944. PzStuMrKp 1002 (Leutnant Zippel) was raised in October 1944.
Both PzStuMrKp 1000 and 1001 served during the Ardennes Offensive, with a total of seven Sturmmörser 606/4s.
After the Ardennes, the Sturmmörsers were used in the defense of Germany proper, mainly on the Western front.