During the second world was the United States Army used a tank-mounted multiple rocket launcher the Rocket Launcher T34 (Calliope).
Placed on top of an M4 Sherman tank, it could fire 4.5 inch M8 rockets from 60 launch tubes.
The Sherman was designed in 1940 and entered production the following year. The version that was the most common was armed with a 75 mm M3 L/40 gun and supported by a .50 cal Browning machine gun, accompanied with two more .30 cal machine guns, one in the turret and one in the hull.
This firepower was mainly used to support infantry attacks in combined actions. The tank’s armor was 93 mm (3.7 in), or 118 mm (4.6 in) in an improved version which utilized the 76 mm gun.
There were 3 variants of the Calliope:
Rocket Launcher T34
60 4.5 inch rockets were carried in this version, arranged in a group of 36 tubes which were carried on top, a two 12 tubes groups were carried on the bottom which could be jettisoned.
Rocket Launcher T34E1
Basically the same as the T34 launcher but the groups of 12 jettisonable tubes were replaced by groups of 14 tubes.
It has proved very difficult to find pictures for this variant.
Rocket Launcher T34E2
The caliber of the rockets was increased from 4.5 inch to 7.2 inch, the number of tubes remains at 60. It saw combat in 1944-1945.
In 1945, there were British Shermans fitted with two rails, one either side of the turret, which could carry two 60 lb headed rockets. Tanks of the 1st Coldstream Guards used them at the crossing of the Rhine. The tanks were called “Sherman Tulips”.