7.2-Inch Demolition Rocket

The 7.2-Inch Demolition Rocket was developed by Section L of the National Defense Research Committee, located at Caltech,[2] in late 1943 as a modification of the existing "mousetrap" (7.2-Inch ASW Rocket) rocket for use against heavily fortified ground targets. Assigned to the United States Navy for development and production in July 1944,[3] two versions of the rocket were produced; the T37 HE Demolition Rocket and the T21 Chemical Warfare Rocket.[4] An additional high-explosive rocket, the T24, was planned, but was dropped in favor of the T37.[5] The rockets utilized a standard 2.25-inch (57 mm) rocket motor, fitted with a larger-diameter warhead; a longer-ranged version utilizing a 3.5-inch (89 mm) motor was also produced.[6]

The T37 saw its first operational use during Operation Dragoon, the invasion of southern France, in August 1944,[7] fired from 120-round "Woofus" launchers mounted aboard Landing Craft Rocket vessels offshore.[8]

The rocket was also intended to be fired from tanks for the clearing of bunkers and anti-tank obstacles. The initial launcher, dubbed "Cowcatcher", was mounted on the front of M4 Sherman tanks;[9] it was quickly found unsatisfactory, and was replaced by 20-round (T40 "Whiz Bang")[10] and 24-round ("Grand Slam") launchers mounted atop the tank's turret.[7][9] The 20-round launcher could fire its entire loadout of rockets in approximately 10 seconds;[11] however the tank installation was unpopular with crews, as the launcher prevented the tank's turret hatches from being opened.[9]