T27 Xylophone

The T27 Xylophone was an early Rocket Battery used by the United States army during the latter part of World War II. In Flames of War, it is mounted on a truck for mobility, but in reality it was more often assembled and then fired from a stationary position.

IRL

The Xylophone was introduced in 1944 to offer an American version of more common rocket artillery that was entering the theater along with the M4A3 calliope. The Xylophone was typical of rocket artillery of the period: potentially deadly, noisy, terrifying, and slow as hell to reload. It only saw service in Europe, and was phased out of service after the end of the war. In spite of this, the Xylophone was used in some units as late as the Vietnam war, ehich isn't bad for a 20 year old design.