T34 Calliope
Mounted on a M4 Sherman the T34 rocket launcher had 60 tubes that fired a 4.5 inch rocket to a maximum effective range of 3900 yards.
A problem with the T34 was tube life, the tubes started to break up after only four salvoes and tube life was only 15 to 20 salvoes. The rockets could be fired singly or in salvo, ALL 60 ROCKETS could be fired in 30 SECONDS, and each round impacted with the equivalency of a 105mm round.
The Calliope's elevation worked off the elevation of the main gun and the main gun could not be fired as long as the Calliope was attached. The T34 could be jettisoned hydraulically in a matter of seconds however.
EDIT:didnt have AA rockets