USA T27E1 4.5-inch Multiple Rocket Launcher.

The T27 was designed during the Second World War. In October 1944, tactical uses for this weapon were developed by the 18th Field Artillery Battalion, First U.S. Army. It was discovered that the rocket launcher’s concentrated firepower initially had a great demoralizing effect on the enemy. However, it had limited range and was time consuming to reload. This created an erratic firing pattern. The tests also revealed that the T27 was difficult to position for ground firing, so the T27E1 with a modified mount was developed.