T40 Whizbang

The Rocket Launcher T40/M17 (Whizbang) (sometimes spelled WhizBang) was a tank-mounted multiple rocket launcher used by the United States Army during World War II. The launcher was placed atop the Medium Tank M4, and fired a barrage of 7.2 in (180 mm) T37 HE or T21 Chemical rockets from 20 launch tubes. It was developed and used in the late stages of World War II; it saw limited combat in 1944-45. A short variant of the T40 was also developed, but saw little usage.

Design
The T40/M17 rocket launcher held 20 7.2 inch rockets in a box-like frame, which was elevated hydraulically from the 75 mm gun controls. The entire mount could be jettisoned if required, and the rockets could be fired one-by-one or in salvoes. This "limited procurement" weapon was classified as "limited standard".

Service History
This vehicle saw some use in Western Europe in 1944–1945. It served through the Battle of Arracourt, the Battle of the Bulge, and the Invasion of Germany from the West.

T40 (short version)
The T40 (short version) was an experimental model of the T40 WhizBang with shorter rocket tubes and the 75 mm gun was removed, which was r placed by an elevation mechanism for the launcher. The access door for the crew added in the side of the vehicle, which was an M4A2 Sherman tank.