Sherman Calliope

The Sherman Calliope was one of the most unusual design concepts of its time: an MLRS turret mounted on an M4A1 or M4A3 tank. It adopted its name from a musical instrument resembling an organ and the Greek muse of epic poetry. It consisted of 60 tubes, with a group of 36 tubes on the top, and two jettisonable groups of 12 tubes (a total of 24) on the bottom.

The main design feature of the Sherman Calliope was that – although it had all of the characteristics of an MLRS – its tank functions were fully retained, and it was the only system that could operate directly on the battlefield and only retreat to the rear when it needed to reload. Its only drawback was that it could not fire from the tank turret when an MLRS salvo was being fired, but this was corrected in later models.